1 files changed, 75 insertions, 0 deletions
diff --git a/mail/thunderbird/files/patch-bug1445907 b/mail/thunderbird/files/patch-bug1445907
new file mode 100644
index 000000000000..924ac0aa7cd7
--- /dev/null
+++ b/mail/thunderbird/files/patch-bug1445907
@@ -0,0 +1,75 @@
+commit 0c6dd4a750db
+Author: Lars T Hansen <lhansen@mozilla.com>
+Date:   Mon Mar 19 09:58:06 2018 +0100
+
+    Bug 1445907 - Save x28 before clobbering it in the regex compiler. r=sstangl
+---
+ js/src/irregexp/NativeRegExpMacroAssembler.cpp | 25 ++++++++++++++++++++++++-
+ js/src/jit-test/tests/regexp/bug1445907.js     | 15 +++++++++++++++
+ 2 files changed, 39 insertions(+), 1 deletion(-)
+
+diff --git js/src/irregexp/NativeRegExpMacroAssembler.cpp js/src/irregexp/NativeRegExpMacroAssembler.cpp
+index 28a4c35e75bfe..c08b005cf856b 100644
+--- js/src/irregexp/NativeRegExpMacroAssembler.cpp
++++ js/src/irregexp/NativeRegExpMacroAssembler.cpp
+@@ -123,7 +123,15 @@ NativeRegExpMacroAssembler::GenerateCode(JSContext* cx, bool match_only)
+     masm.bind(&entry_label_);
+ 
+ #ifdef JS_CODEGEN_ARM64
+-    // ARM64 communicates stack address via sp, but uses a pseudo-sp for addressing.
++    // ARM64 communicates stack address via SP, but uses a pseudo-sp (PSP) for
++    // addressing.  The register we use for PSP may however also be used by
++    // calling code, and it is nonvolatile, so save it.  Do this as a special
++    // case first because the generic save/restore code needs the PSP to be
++    // initialized already.
++    MOZ_ASSERT(PseudoStackPointer64.Is(masm.GetStackPointer64()));
++    masm.Str(PseudoStackPointer64, vixl::MemOperand(sp, -16, vixl::PreIndex));
++
++    // Initialize the PSP from the SP.
+     masm.initStackPtr();
+ #endif
+ 
+@@ -421,7 +429,22 @@ NativeRegExpMacroAssembler::GenerateCode(JSContext* cx, bool match_only)
+     for (GeneralRegisterBackwardIterator iter(savedNonVolatileRegisters); iter.more(); ++iter)
+         masm.Pop(*iter);
+ 
++#ifdef JS_CODEGEN_ARM64
++    // Now restore the value that was in the PSP register on entry, and return.
++
++    // Obtain the correct SP from the PSP.
++    masm.Mov(sp, PseudoStackPointer64);
++
++    // Restore the saved value of the PSP register, this value is whatever the
++    // caller had saved in it, not any actual SP value, and it must not be
++    // overwritten subsequently.
++    masm.Ldr(PseudoStackPointer64, vixl::MemOperand(sp, 16, vixl::PostIndex));
++
++    // Perform a plain Ret(), as abiret() will move SP <- PSP and that is wrong.
++    masm.Ret(vixl::lr);
++#else
+     masm.abiret();
++#endif
+ 
+     // Backtrack code (branch target for conditional backtracks).
+     if (backtrack_label_.used()) {
+diff --git js/src/jit-test/tests/regexp/bug1445907.js js/src/jit-test/tests/regexp/bug1445907.js
+new file mode 100644
+index 0000000000000..75b23753eaf93
+--- /dev/null
++++ js/src/jit-test/tests/regexp/bug1445907.js
+@@ -0,0 +1,15 @@
++// On ARM64, we failed to save x28 properly when generating code for the regexp
++// matcher.
++//
++// There's wasm and Debugger code here because the combination forces the use of
++// x28 and exposes the bug when running on the simulator.
++
++if (!wasmIsSupported())
++    quit();
++
++var g = newGlobal('');
++var dbg = new Debugger(g);
++g.eval(`var m = new WebAssembly.Instance(new WebAssembly.Module(wasmTextToBinary('(module (func (export "test")))')))`);
++var re = /./;
++dbg.onEnterFrame = function(frame) { re.exec("x") };
++result = g.eval("m.exports.test()");