maxjhandsome
/
llvm-project
forked from OSchip/llvm-project
1
0
Fork 0
Code Issues Pull Requests Packages Releases Wiki Activity

Always inlining PrintCurrentStackSlow of tsan library to fix tail-call issue 

The real problem is that sanitizer_print_stack_trace obtains current PC and
expects the PC to be in the stack trace after function calls. We don't
prevent tail calls in sanitizer runtimes, so this assumption does not
necessary hold.

We add "always inline" attribute on PrintCurrentStackSlow to address this
issue, however this solution is not reliable enough, but unfortunately, we
don't see any simple, reliable solution.

Reviewers: samsonov hfinkel kbarton tjablin dvyukov kcc

http://reviews.llvm.org/D19148

Thanks Hal, dvyukov, and kcc for invaluable discussion, I have even borrowed
part of dvyukov's summary as my commit message!

llvm-svn: 266869
This commit is contained in:
Chuang-Yu Cheng 2016-04-20 10:28:41 +00:00
parent 71630b9ea7
commit e480455fd6
1 changed files with 8 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
compiler-rt/lib/tsan/rtl/tsan_rtl_report.cc
View File

@ -680,6 +680,14 @@ void PrintCurrentStack(ThreadState *thr, uptr pc) {
PrintStack(SymbolizeStack(trace));
}
// Always inlining PrintCurrentStackSlow, because LocatePcInTrace assumes
// __sanitizer_print_stack_trace exists in the actual unwinded stack, but
// tail-call to PrintCurrentStackSlow breaks this assumption because
// __sanitizer_print_stack_trace disappears after tail-call.
// However, this solution is not reliable enough, please see dvyukov's comment
// http://reviews.llvm.org/D19148#406208
// Also see PR27280 comment 2 and 3 for breaking examples and analysis.
ALWAYS_INLINE
void PrintCurrentStackSlow(uptr pc) {
#ifndef SANITIZER_GO
BufferedStackTrace *ptrace =