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[Bug libc/9689] New: using profiling C library (-lc_p) segfaults early
- From: "vapier at gentoo dot org" <sourceware-bugzilla at sourceware dot org>
- To: glibc-bugs at sources dot redhat dot com
- Date: 27 Dec 2008 22:02:15 -0000
- Subject: [Bug libc/9689] New: using profiling C library (-lc_p) segfaults early
- Reply-to: sourceware-bugzilla at sourceware dot org
building up glibc with --enable-profile and then trying to use the resulting
library like so:
$ cat test.c
main(){}
$ gcc test.c -static -pg -lc_p -g
results in a crash:
$ gdb ./a.out
(gdb) r
Starting program: /home/vapier/test
Program received signal SIGSEGV, Segmentation fault.
0x000000000042fecb in __mcount_internal ()
(gdb) bt
#0 0x000000000042fecb in __mcount_internal ()
#1 0x000000000040dc04 in mcount ()
#2 0x0000000000000000 in ?? ()
(gdb)
the crash seems to be because gmon/mcount.c uses atomic code which relies on the
TLS descriptors being setup, but that doesnt happen until __libc_start_main. but
since __libc_start_main itself (and other functions early on) calls mcount, we
crash.
crash is easily reproducible with current git and x86_64 or x86. it's been this
way since at least glibc-2.6.1.
--
Summary: using profiling C library (-lc_p) segfaults early
Product: glibc
Version: unspecified
Status: NEW
Severity: normal
Priority: P2
Component: libc
AssignedTo: drepper at redhat dot com
ReportedBy: vapier at gentoo dot org
CC: glibc-bugs at sources dot redhat dot com,toolchain at
gentoo dot org
GCC host triplet: x86_64-linux-gnu
http://sourceware.org/bugzilla/show_bug.cgi?id=9689
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