From ea13613572db918380b21c34a755abc3531a39a4 Mon Sep 17 00:00:00 2001 From: George Karpenkov Date: Wed, 10 Oct 2018 00:57:24 +0000 Subject: [PATCH] [sancov] Generalize the code to get the previous instruction to multiple architectures sancov subtracts one from the address to get the previous instruction, which makes sense on x86_64, but not on other platforms. This change ensures that the offset is correct for different platforms. The logic for computing the offset is copied from sanitizer_common. Differential Revision: https://reviews.llvm.org/D53039 llvm-svn: 344103 --- llvm/tools/sancov/sancov.cpp | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) diff --git a/llvm/tools/sancov/sancov.cpp b/llvm/tools/sancov/sancov.cpp index 0bddd35..e8935d1 100644 --- a/llvm/tools/sancov/sancov.cpp +++ b/llvm/tools/sancov/sancov.cpp @@ -766,6 +766,19 @@ findSanitizerCovFunctions(const object::ObjectFile &O) { return Result; } +static uint64_t getPreviousInstructionPc(uint64_t PC, + Triple TheTriple) { + if (TheTriple.isARM()) { + return (PC - 3) & (~1); + } else if (TheTriple.isAArch64()) { + return PC - 4; + } else if (TheTriple.isMIPS()) { + return PC - 8; + } else { + return PC - 1; + } +} + // Locate addresses of all coverage points in a file. Coverage point // is defined as the 'address of instruction following __sanitizer_cov // call - 1'. @@ -832,7 +845,7 @@ static void getObjectCoveragePoints(const object::ObjectFile &O, } uint64_t Addr = Index + SectionAddr; // Sanitizer coverage uses the address of the next instruction - 1. - uint64_t CovPoint = Addr + Size - 1; + uint64_t CovPoint = getPreviousInstructionPc(Addr + Size, TheTriple); uint64_t Target; if (MIA->isCall(Inst) && MIA->evaluateBranch(Inst, SectionAddr + Index, Size, Target) && -- 2.7.4