When parsing lines from objdump a line containing source code starting
with a numeric label is mistaken for a line of disassembly starting with
a memory address.
Current validation fails to recognise that the "memory address" is out
of range and calculates an invalid offset which later causes this
segfault:
Program received signal SIGSEGV, Segmentation fault.
0x0000000000457315 in disasm__calc_percent (notes=0xc98970, evidx=0, offset=143705, end=2127526177, path=0x7fffffffbf50)
at util/annotate.c:631
631 hits += h->addr[offset++];
(gdb) bt
#0 0x0000000000457315 in disasm__calc_percent (notes=0xc98970, evidx=0, offset=143705, end=2127526177, path=0x7fffffffbf50)
at util/annotate.c:631
#1 0x00000000004d65e3 in annotate_browser__calc_percent (browser=0x7fffffffd130, evsel=0xa01da0) at ui/browsers/annotate.c:364
#2 0x00000000004d7433 in annotate_browser__run (browser=0x7fffffffd130, evsel=0xa01da0, hbt=0x0) at ui/browsers/annotate.c:672
#3 0x00000000004d80c9 in symbol__tui_annotate (sym=0xc989a0, map=0xa02660, evsel=0xa01da0, hbt=0x0) at ui/browsers/annotate.c:962
#4 0x00000000004d7aa0 in hist_entry__tui_annotate (he=0xdf73f0, evsel=0xa01da0, hbt=0x0) at ui/browsers/annotate.c:823
#5 0x00000000004dd648 in perf_evsel__hists_browse (evsel=0xa01da0, nr_events=1, helpline=
0x58b768 "For a higher level overview, try: perf report --sort comm,dso", ev_name=0xa02cd0 "cycles", left_exits=false, hbt=
0x0, min_pcnt=0, env=0xa011e0) at ui/browsers/hists.c:1659
#6 0x00000000004de372 in perf_evlist__tui_browse_hists (evlist=0xa01520, help=
0x58b768 "For a higher level overview, try: perf report --sort comm,dso", hbt=0x0, min_pcnt=0, env=0xa011e0)
at ui/browsers/hists.c:1950
#7 0x000000000042cf6b in __cmd_report (rep=0x7fffffffd6c0) at builtin-report.c:581
#8 0x000000000042e25d in cmd_report (argc=0, argv=0x7fffffffe4b0, prefix=0x0) at builtin-report.c:965
#9 0x000000000041a0e1 in run_builtin (p=0x801548, argc=1, argv=0x7fffffffe4b0) at perf.c:319
#10 0x000000000041a319 in handle_internal_command (argc=1, argv=0x7fffffffe4b0) at perf.c:376
#11 0x000000000041a465 in run_argv (argcp=0x7fffffffe38c, argv=0x7fffffffe380) at perf.c:420
#12 0x000000000041a707 in main (argc=1, argv=0x7fffffffe4b0) at perf.c:521
After the fix is applied the symbol can be annotated showing the
problematic line "1: rep"
copy_user_generic_string /usr/lib/debug/lib/modules/3.9.10-100.fc17.x86_64/vmlinux
*/
ENTRY(copy_user_generic_string)
CFI_STARTPROC
ASM_STAC
andl %edx,%edx
and %edx,%edx
jz 4f
je 37
cmpl $8,%edx
cmp $0x8,%edx
jb 2f /* less than 8 bytes, go to byte copy loop */
jb 33
ALIGN_DESTINATION
mov %edi,%ecx
and $0x7,%ecx
je 28
sub $0x8,%ecx
neg %ecx
sub %ecx,%edx
1a: mov (%rsi),%al
mov %al,(%rdi)
inc %rsi
inc %rdi
dec %ecx
jne 1a
movl %edx,%ecx
28: mov %edx,%ecx
shrl $3,%ecx
shr $0x3,%ecx
andl $7,%edx
and $0x7,%edx
1: rep
100.00 rep movsq %ds:(%rsi),%es:(%rdi)
movsq
2: movl %edx,%ecx
33: mov %edx,%ecx
3: rep
rep movsb %ds:(%rsi),%es:(%rdi)
movsb
4: xorl %eax,%eax
37: xor %eax,%eax
data32 xchg %ax,%ax
ASM_CLAC
ret
retq
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1379009721-27667-1-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
886b37baa6