From 1422855a403391ab2896f774871c5f3748f415dc Mon Sep 17 00:00:00 2001 From: Segher Boessenkool Date: Wed, 14 Mar 2018 14:46:03 +0100 Subject: [PATCH] rs6000: Fix sanitizer frame unwind on 32-bit ABIs This fixes more than half of our testcase failures on BE. libsanitizer/ * sanitizer_common/sanitizer_stacktrace.cc (BufferedStackTrace::FastUnwindStack): Use the correct frame offset for PowerPC SYSV ABI. From-SVN: r258525 --- libsanitizer/ChangeLog | 6 ++++++ .../sanitizer_common/sanitizer_stacktrace.cc | 13 ++++++++++--- 2 files changed, 16 insertions(+), 3 deletions(-) diff --git a/libsanitizer/ChangeLog b/libsanitizer/ChangeLog index b6250839281..f98188a1c60 100644 --- a/libsanitizer/ChangeLog +++ b/libsanitizer/ChangeLog @@ -1,3 +1,9 @@ +2018-03-14 Segher Boessenkool + + * sanitizer_common/sanitizer_stacktrace.cc + (BufferedStackTrace::FastUnwindStack): Use the correct frame offset + for PowerPC SYSV ABI. + 2018-02-14 Igor Tsimbalist PR target/84148 diff --git a/libsanitizer/sanitizer_common/sanitizer_stacktrace.cc b/libsanitizer/sanitizer_common/sanitizer_stacktrace.cc index 83309d6ee38..2de585c3298 100644 --- a/libsanitizer/sanitizer_common/sanitizer_stacktrace.cc +++ b/libsanitizer/sanitizer_common/sanitizer_stacktrace.cc @@ -78,14 +78,21 @@ void BufferedStackTrace::FastUnwindStack(uptr pc, uptr bp, uptr stack_top, IsAligned((uptr)frame, sizeof(*frame)) && size < max_depth) { #ifdef __powerpc__ - // PowerPC ABIs specify that the return address is saved at offset - // 16 of the *caller's* stack frame. Thus we must dereference the - // back chain to find the caller frame before extracting it. + // PowerPC ABIs specify that the return address is saved on the + // *caller's* stack frame. Thus we must dereference the back chain + // to find the caller frame before extracting it. uhwptr *caller_frame = (uhwptr*)frame[0]; if (!IsValidFrame((uptr)caller_frame, stack_top, bottom) || !IsAligned((uptr)caller_frame, sizeof(uhwptr))) break; + // For most ABIs the offset where the return address is saved is two + // register sizes. The exception is the SVR4 ABI, which uses an + // offset of only one register size. +#ifdef _CALL_SYSV + uhwptr pc1 = caller_frame[1]; +#else uhwptr pc1 = caller_frame[2]; +#endif #elif defined(__s390__) uhwptr pc1 = frame[14]; #else -- 2.30.2