From b64d3273a331e40bfbd9c76b7d40e45b92ea3217 Mon Sep 17 00:00:00 2001 From: Saleem Abdulrasool Date: Sat, 21 Jan 2017 16:22:59 +0000 Subject: [PATCH] X86: swap EBP, ESP on !APPLE Restore the `libunwind.h` enumeration values back to the inverted values. This diverges from the DWARF definition of the register values. However, this allows our header to be compatible with other unwind implementations (e.g. HP, GNU Savannah, GCC). The register IDs are only swapped in the header and need to be unswapped when accessing the unwind register file. The flipped EBP and ESP only applies on non-Apple x86 targets. When optimizations were enabled, EBP and ESP would no longer be equivalent. As a result, the incorrect access on Linux would manifest as a failure to unwind the stack. We can now unwind the stack with and without FPO on Linux x86. Resolves PR30879! llvm-svn: 292723 --- libunwind/include/libunwind.h | 5 ----- libunwind/src/Registers.hpp | 16 ++++++++++++++++ 2 files changed, 16 insertions(+), 5 deletions(-) diff --git a/libunwind/include/libunwind.h b/libunwind/include/libunwind.h index 9d72d48..fef72bf 100644 --- a/libunwind/include/libunwind.h +++ b/libunwind/include/libunwind.h @@ -165,13 +165,8 @@ enum { UNW_X86_ECX = 1, UNW_X86_EDX = 2, UNW_X86_EBX = 3, -#if defined(__CloudABI__) || defined(__FreeBSD__) - UNW_X86_ESP = 4, - UNW_X86_EBP = 5, -#else UNW_X86_EBP = 4, UNW_X86_ESP = 5, -#endif UNW_X86_ESI = 6, UNW_X86_EDI = 7 }; diff --git a/libunwind/src/Registers.hpp b/libunwind/src/Registers.hpp index 8066b80..ff57c60 100644 --- a/libunwind/src/Registers.hpp +++ b/libunwind/src/Registers.hpp @@ -122,9 +122,17 @@ inline uint32_t Registers_x86::getRegister(int regNum) const { return _registers.__edx; case UNW_X86_EBX: return _registers.__ebx; +#if !defined(__APPLE__) + case UNW_X86_ESP: +#else case UNW_X86_EBP: +#endif return _registers.__ebp; +#if !defined(__APPLE__) + case UNW_X86_EBP: +#else case UNW_X86_ESP: +#endif return _registers.__esp; case UNW_X86_ESI: return _registers.__esi; @@ -154,10 +162,18 @@ inline void Registers_x86::setRegister(int regNum, uint32_t value) { case UNW_X86_EBX: _registers.__ebx = value; return; +#if !defined(__APPLE__) + case UNW_X86_ESP: +#else case UNW_X86_EBP: +#endif _registers.__ebp = value; return; +#if !defined(__APPLE__) + case UNW_X86_EBP: +#else case UNW_X86_ESP: +#endif _registers.__esp = value; return; case UNW_X86_ESI: -- 2.7.4