diff options
Diffstat (limited to 'source/l/mozjs60/patches/Save-and-restore-non-volatile-x28-on-ARM64-for-generated-unboxed-object-constructor.patch')
| -rw-r--r-- | source/l/mozjs60/patches/Save-and-restore-non-volatile-x28-on-ARM64-for-generated-unboxed-object-constructor.patch | 64 |
1 files changed, 64 insertions, 0 deletions
diff --git a/source/l/mozjs60/patches/Save-and-restore-non-volatile-x28-on-ARM64-for-generated-unboxed-object-constructor.patch b/source/l/mozjs60/patches/Save-and-restore-non-volatile-x28-on-ARM64-for-generated-unboxed-object-constructor.patch new file mode 100644 index 00000000..46d280d0 --- /dev/null +++ b/source/l/mozjs60/patches/Save-and-restore-non-volatile-x28-on-ARM64-for-generated-unboxed-object-constructor.patch @@ -0,0 +1,64 @@ +# HG changeset patch +# User Lars T Hansen <lhansen@mozilla.com> +# Date 1519822672 -3600 +# Node ID 800abe66894d6b07b24bccecbf6a65e2261076f6 +# Parent 223c97459e96183eb616aed39147207bdb953ba8 +Bug 1375074 - Save and restore non-volatile x28 on ARM64 for generated unboxed object constructor. r=sstangl + +Origin: upstream +Applied-upstream: 61, commit: https://hg.mozilla.org/mozilla-central/rev/800abe66894d +--- + js/src/vm/UnboxedObject.cpp | 30 ++++++++++++++++++++++++++---- + 1 file changed, 26 insertions(+), 4 deletions(-) + +diff --git a/js/src/vm/UnboxedObject.cpp b/js/src/vm/UnboxedObject.cpp +index 35ca20d7405f..1c20a1093d13 100644 +--- a/js/src/vm/UnboxedObject.cpp ++++ b/js/src/vm/UnboxedObject.cpp +@@ -86,9 +86,16 @@ static const uintptr_t CLEAR_CONSTRUCTOR_CODE_TOKEN = 0x1; + #endif + + #ifdef JS_CODEGEN_ARM64 +- // ARM64 communicates stack address via sp, but uses a pseudo-sp for +- // addressing. +- masm.initStackPtr(); ++ // 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 + + MOZ_ASSERT(propertiesReg.volatile_()); +@@ -239,7 +246,22 @@ static const uintptr_t CLEAR_CONSTRUCTOR_CODE_TOKEN = 0x1; + if (ScratchDoubleReg.volatile_()) masm.pop(ScratchDoubleReg); + masm.PopRegsInMask(savedNonVolatileRegisters); + +- masm.abiret(); ++#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 + + masm.bind(&failureStoreOther); + +-- +2.21.0 + |