APAR status
Closed as program error.
Error description
After a call to pthread_exit in an application compiled with the stack protect -fstack-protector-strong option, the program encounters a segmentation fault during the thread stack frame unwinding process. The GDB stack trace may look similar to: #0 0x00003fffb7d3b4cc in ?? () from /lib/powerpc64le-linux-gnu/libgcc_s.so.1 #1 0x00003fffb7d3b968 in ?? () from /lib/powerpc64le-linux-gnu/libgcc_s.so.1 #2 0x00003fffb7d3bce0 in ?? () from /lib/powerpc64le-linux-gnu/libgcc_s.so.1 #3 0x00003fffb7d3c378 in _Unwind_ForcedUnwind () from /lib/powerpc64le-linux-gnu/libgcc_s.so.1 #4 0x00003fffb7f4762c in _Unwind_ForcedUnwind (exc=<optimized out>, stop=<optimized out>, stop_argument=<optimized out>) at ../sysdeps/nptl/unwind-forcedunwind.c:134 #5 0x00003fffb7f443ec in __GI___pthread_unwind (buf=<optimized out>) at unwind.c:121 #6 0x00003fffb7f39424 in __do_cancel () at pthreadP.h:283 #7 __pthread_exit (value=<optimized out>) at pthread_exit.c:28
Local fix
Do no use -fstack-protector-strong
Problem summary
PROBLEM DESCRIPTION: The ehframe saved on the stack was corrupted by the store of the stack guard canary value. When unwinding happens, a crash occurs. USERS AFFECTED: Users of -fstack-protector-strong and pthreads.
Problem conclusion
The store of the canary word was corrected and the generated frame is now safe for unwinding.
Temporary fix
Comments
APAR Information
APAR number
LI80715
Reported component name
XL C/C++ LINUX
Reported component ID
5725C7310
Reported release
G11
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt / Xsystem
Submitted date
2019-04-16
Closed date
2019-06-21
Last modified date
2019-06-21
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
Fix information
Fixed component name
XL C/C++ LINUX
Fixed component ID
5725C7310
Applicable component levels
[{"Business Unit":{"code":"BU058","label":"IBM Infrastructure w\/TPS"},"Product":{"code":"SSXVZZ","label":"XL C\/C++ for Linux"},"Component":"","ARM Category":[],"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"G11","Edition":"","Line of Business":{"code":"LOB57","label":"Power"}}]
Document Information
Modified date:
21 June 2019