[compiler-rt] 679c076 - [sanitizer_common] Remove hacks for __builtin_return_address abuse on SPARC

[Rainer Orth via llvm-commits]

Author: Rainer Orth
Date: 2023-08-03T16:06:59+02:00
New Revision: 679c076ae446af81eba81ce9b94203a273d4b88a

URL: https://github.com/llvm/llvm-project/commit/679c076ae446af81eba81ce9b94203a273d4b88a
DIFF: https://github.com/llvm/llvm-project/commit/679c076ae446af81eba81ce9b94203a273d4b88a.diff

LOG: [sanitizer_common] Remove hacks for __builtin_return_address abuse on SPARC

As detailed in Issue #57624, the introduction of
`__builtin_extract_return_address` to `GET_CALLER_PC` in
4248f32b9ebe87c7af8ee53911efd47c2652f488
<https://reviews.llvm.org/rG4248f32b9ebe87c7af8ee53911efd47c2652f488> broke
`TestCases/Misc/missing_return.cpp` on Solaris/SPARC.  Unlike most other
targets, the builtin isn't a no-op on SPARC and thus has always been
necessary. Its lack had previously been worked around by calls to
`GetNextInstructionPc` in `sanitizer_stacktrace_sparc.cpp`
(`BufferedStackTrace::UnwindFast`) and `sanitizer_unwind_linux_libcdep.cpp`
(`BufferedStackTrace::UnwindSlow`).  However, those calls are superfluous
now and actually harmful.

This patch removes those hacks, fixing the failure.

Tested on `sparcv9-sun-solaris2.11` and on `sparc-sun-solaris2.11` in the
GCC tree.  On the latter, several more testcase failures had been caused by
this issue since ASan actually works with `gcc` on SPARC, unlike `clang`.

Differential Revision: https://reviews.llvm.org/D156504

Added: 
    

Modified: 
    compiler-rt/lib/sanitizer_common/sanitizer_stacktrace_sparc.cpp
    compiler-rt/lib/sanitizer_common/sanitizer_unwind_linux_libcdep.cpp

Removed: 
    


################################################################################
diff  --git a/compiler-rt/lib/sanitizer_common/sanitizer_stacktrace_sparc.cpp b/compiler-rt/lib/sanitizer_common/sanitizer_stacktrace_sparc.cpp
index 1e635a66978f36..a2000798a3907d 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_stacktrace_sparc.cpp
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_stacktrace_sparc.cpp
@@ -30,13 +30,7 @@ void BufferedStackTrace::UnwindFast(uptr pc, uptr bp, uptr stack_top,
   // TODO(yln): add arg sanity check for stack_top/stack_bottom
   CHECK_GE(max_depth, 2);
   const uptr kPageSize = GetPageSizeCached();
-#if defined(__GNUC__)
-  // __builtin_return_address returns the address of the call instruction
-  // on the SPARC and not the return address, so we need to compensate.
-  trace_buffer[0] = GetNextInstructionPc(pc);
-#else
   trace_buffer[0] = pc;
-#endif
   size = 1;
   if (stack_top < 4096) return;  // Sanity check for stack top.
   // Flush register windows to memory

diff  --git a/compiler-rt/lib/sanitizer_common/sanitizer_unwind_linux_libcdep.cpp b/compiler-rt/lib/sanitizer_common/sanitizer_unwind_linux_libcdep.cpp
index 72f025a7d307ad..6a8e82e2e213c0 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_unwind_linux_libcdep.cpp
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_unwind_linux_libcdep.cpp
@@ -139,13 +139,7 @@ void BufferedStackTrace::UnwindSlow(uptr pc, u32 max_depth) {
   if (to_pop == 0 && size > 1)
     to_pop = 1;
   PopStackFrames(to_pop);
-#if defined(__GNUC__) && defined(__sparc__)
-  // __builtin_return_address returns the address of the call instruction
-  // on the SPARC and not the return address, so we need to compensate.
-  trace_buffer[0] = GetNextInstructionPc(pc);
-#else
   trace_buffer[0] = pc;
-#endif
 }
 
 void BufferedStackTrace::UnwindSlow(uptr pc, void *context, u32 max_depth) {