Messages in this thread | | | Date | Thu, 30 Jan 2014 17:10:18 -0300 | From | Arnaldo Carvalho de Melo <> | Subject | Re: [PATCH V2 1/9] perf tools: Fix symbol annotation for relocated kernel |
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Em Thu, Jan 30, 2014 at 03:15:30PM -0300, Arnaldo Carvalho de Melo escreveu: > Em Thu, Jan 30, 2014 at 03:12:32PM -0300, Arnaldo Carvalho de Melo escreveu: > > Em Thu, Jan 30, 2014 at 03:08:23PM -0300, Arnaldo Carvalho de Melo escreveu: > > > Getting segfaults with: > > > > > [acme@ssdandy linux]$ git log --oneline | head -10 > > > c059c953531f perf tests: vmlinux-kallsyms test does not need to set up ref_reloc_sym > > > be2530836ebe perf symbols: Prevent the use of kcore if the kernel has moved > > > 9b2fd7840cb0 perf record: Get ref_reloc_sym from kernel map
bummer, I got the message with 4/9 delayed and didn't notice it was missing, after applying it in the intended order, the segfault was cured.
thanks to Adrian for bringing this to my attention.
- Arnaldo
> > > bcf5e06a0c75 perf symbols: Add kallsyms__get_function_start() > > > 94591ed0963e perf machine: Add machine__get_kallsyms_filename() > > > 18923cddb839 perf symbols: Fix symbol annotation for relocated kernel > > > > Program received signal SIGSEGV, Segmentation fault. > > perf_event__synthesize_kernel_mmap (tool=0x81fd20 <record>, process=0x42ad51 <process_synthesized_event>, machine=0x916380) at util/event.c:520 > > 520 size = snprintf(event->mmap.filename, sizeof(event->mmap.filename), > > 521 "%s%s", mmap_name, kmap->ref_reloc_sym->name) + 1; > > (gdb) p mmap_name > > $4 = 0x7fffffffabd0 "[kernel.kallsyms]" > > (gdb) p kmap->ref_reloc_sym > > $5 = (struct ref_reloc_sym *) 0x0 > > (gdb) > > This is the buggy one: > > [acme@ssdandy linux]$ perf record usleep 1 > [ perf record: Woken up 1 times to write data ] > [ perf record: Captured and wrote 0.018 MB perf.data (~770 samples) ] > [acme@ssdandy linux]$ git show 9b2fd7840cb0d23068bc97e08db46f57f41021fe > commit 9b2fd7840cb0d23068bc97e08db46f57f41021fe > Author: Adrian Hunter <adrian.hunter@intel.com> > Date: Wed Jan 29 16:14:40 2014 +0200 > > perf record: Get ref_reloc_sym from kernel map > > Now that ref_reloc_sym is set up when the kernel map is created, 'perf > record' does not need to pass the symbol names to > perf_event__synthesize_kernel_mmap() which can read the values needed > from ref_reloc_sym directly.
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