| Summary: | Valgrind doesn't handle GCC's __sync_fetch_and_add (unhandled instruction) | ||
|---|---|---|---|
| Product: | [Developer tools] valgrind | Reporter: | j+kdebugs |
| Component: | general | Assignee: | Julian Seward <jseward> |
| Status: | RESOLVED DUPLICATE | ||
| Severity: | major | CC: | mark, tom |
| Priority: | NOR | ||
| Version: | 3.8.0 | ||
| Target Milestone: | --- | ||
| Platform: | Arch Linux | ||
| OS: | Linux | ||
| Latest Commit: | Version Fixed In: | ||
| Sentry Crash Report: | |||
Nice testcase. This is a duplicate of https://bugs.kde.org/show_bug.cgi?id=307106 *** This bug has been marked as a duplicate of bug 307106 *** |
The following code compiled with GCC 4.7.1 on amd64 (I haven't tested x86) crashes Valgrind 3.8.1: int main() { unsigned char value; unsigned char result = __sync_fetch_and_add( &value, 1 ); return 0; } Result: ==24468== Memcheck, a memory error detector ==24468== Copyright (C) 2002-2012, and GNU GPL'd, by Julian Seward et al. ==24468== Using Valgrind-3.8.1 and LibVEX; rerun with -h for copyright info ==24468== Command: ./a.out ==24468== vex amd64->IR: unhandled instruction bytes: 0xF0 0xF 0xC0 0x45 0xFE 0x88 0x45 0xFF vex amd64->IR: REX=0 REX.W=0 REX.R=0 REX.X=0 REX.B=0 vex amd64->IR: VEX=0 VEX.L=0 VEX.nVVVV=0x0 ESC=0F vex amd64->IR: PFX.66=0 PFX.F2=0 PFX.F3=0 ==24468== valgrind: Unrecognised instruction at address 0x4004b5. ==24468== at 0x4004B5: main (in /tmp/a.out) (...) Reproducible: Always Steps to Reproduce: 1. Save the code as test.c 2. Run: gcc test.c && valgrind ./a.out