On Thu, 2013-03-07 at 09:42 +0100, Jan Kratochvil wrote: > On Wed, 06 Mar 2013 16:13:47 +0100, Mark Wielaard wrote: > > On Wed, 2013-03-06 at 14:38 +0000, Richard W.M. Jones wrote: > [...] > > > ==11843== 56 bytes in 1 blocks are definitely lost in loss record 6 of 6 > > > ==11843== at 0x4A06409: malloc (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so) > > > ==11843== by 0x38EAC861F9: strdup (strdup.c:42) > > > ==11843== by 0x38EC8097C9: setprocattrcon_raw.constprop.3 (procattr.c:241) > > > ==11843== by 0x38EC8099B7: setprocattrcon.constprop.2 (procattr.c:274) > > > ==11843== by 0x400955: main (in /tmp/test) > [...] > > It looks like you will have to use the setprocattrcon[.constprop] > > function name in your suppression file. I am not exactly sure how the > > linker ends up pointing directly to that one for setsockcreatecon (), > > but it apparently is. And so valgrind will only know it by that name. > > Symbol table '.symtab' contains 770 entries: > Num: Value Size Type Bind Vis Ndx Name > 70: 0000000000009990 62 FUNC LOCAL DEFAULT 11 setprocattrcon.constprop.2 > > Contents of the .debug_info section: > <1><62c6>: Abbrev Number: 58 (DW_TAG_subprogram) > <62c7> DW_AT_name : (indirect string, offset: 0x3eb4): setprocattrcon > <62d2> DW_AT_inline : 1 (inlined) > <1><6791>: Abbrev Number: 40 (DW_TAG_subprogram) > <6792> DW_AT_abstract_origin: <0x62c6> > <6794> DW_AT_low_pc : 0x9990 > <679c> DW_AT_high_pc : 62 > > Valgrind apparently used the ELF symbol name. But in DWARF there is the real > function name (and it is even marked as 'inlined' - although it is a standalone > function). > > GDB also knows the real name from DWARF: > > (gdb) disas 'setprocattrcon.constprop.2' > Dump of assembler code for function setprocattrcon: > 0x0000000000009990 <+0>: push %rbx > [...] > 0x00000000000099cd <+61>: retq > End of assembler dump. > > So it is possible to fix it in Valgrind. Aha, thanks. Yes using DWARF might help getting more user friendly/recognizable names. Though note that the name we were really looking for was setsockcreatecon, since that is what was called from main. I think that one is doing a tail-call to setprocattrcon.constprop.2 so might not easily be available in the backtrace. If you compile and run Richard's reproducer from https://bugzilla.redhat.com/show_bug.cgi?id=918572 and break at the strdup call, can you get a backtrace from gdb with setsockcreatecon in it? Also using DWARF .debug_info will only work if it is available. By default valgrind doesn't require DWARF, it uses only the symbol table. I can look in extending valgrind to use the DWARF info when available for matching suppressions, but that might mean a suppression only works when the debuginfo is installed (and it might make valgrind even slower). Cheers, Mark -- devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxxx https://admin.fedoraproject.org/mailman/listinfo/devel
