123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100 |
- From 903a79a1efff18fc7cc50db09a3fe5d768adc9a8 Mon 19 Mar 2018 09:58:06 +0100
- From: Lars T Hansen <lhansen@mozilla.com>
- Date: Fri, 23 Mar 2018 22:01:33 +0000
- Subject: [PATCH] save x28 before clobbering it in the regex compiler
- Fixes: https://bugzilla.mozilla.org/show_bug.cgi?id=1445907
- Upsream-status: Applied
- See: https://hg.mozilla.org/mozilla-central/rev/903a79a1efff
- Signed-off-by: Lars T Hansen <lhansen@mozilla.com>
- Signed-off-by: Adam Duskett <aduskett@gmail.com>
- ---
- diff --git a/js/src/irregexp/NativeRegExpMacroAssembler.cpp b/js/src/irregexp/NativeRegExpMacroAssembler.cpp
- --- a/js/src/irregexp/NativeRegExpMacroAssembler.cpp
- +++ b/js/src/irregexp/NativeRegExpMacroAssembler.cpp
- @@ -118,17 +118,25 @@ NativeRegExpMacroAssembler::GenerateCode
- Label return_temp0;
- // Finalize code - write the entry point code now we know how many
- // registers we need.
- 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
- // Push non-volatile registers which might be modified by jitcode.
- size_t pushedNonVolatileRegisters = 0;
- for (GeneralRegisterForwardIterator iter(savedNonVolatileRegisters); iter.more(); ++iter) {
- masm.Push(*iter);
- pushedNonVolatileRegisters++;
- @@ -416,17 +424,32 @@ NativeRegExpMacroAssembler::GenerateCode
- masm.pop(temp0);
- masm.movePtr(temp0, StackPointer);
- #endif
- // Restore non-volatile registers which were saved on entry.
- 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()) {
- masm.bind(&backtrack_label_);
- Backtrack();
- }
- // Backtrack stack overflow code.
- diff --git a/js/src/jit-test/tests/regexp/bug1445907.js b/js/src/jit-test/tests/regexp/bug1445907.js
- new file mode 100644
- --- /dev/null
- +++ b/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()");
- --
- 2.23.0
|