Em Wed, Sep 26, 2018 at 03:52:05PM +0200, Milian Wolff escreveu:
> Fixes a crash when the report encounters an address that
> could not be associated with an mmaped region:
Milian, can you spot which cset introduced this problem? So that we can
add a "Fixes: sha" tag in this (and the others, if needed) to help the
stable kernel maintainers to find which kernels this has to be
backported to?
Thanks for working on this!
- Arnaldo
> #0 0x00005555557bdc4a in callchain_srcline (ip=<error reading variable:
> Cannot access memory at address 0x38>, sym=0x0, map=0x0) at
> util/machine.c:2329
> #1 unwind_entry (entry=entry@entry=0x7fffffff9180,
> arg=arg@entry=0x7ffff5642498) at util/machine.c:2329
> #2 0x00005555558370af in entry (arg=0x7ffff5642498, cb=0x5555557bdb50
> <unwind_entry>, thread=<optimized out>, ip=18446744073709551615) at
> util/unwind-libunwind-local.c:586
> #3 get_entries (ui=ui@entry=0x7fffffff9620, cb=0x5555557bdb50
> <unwind_entry>, arg=0x7ffff5642498, max_stack=<optimized out>) at
> util/unwind-libunwind-local.c:703
> #4 0x0000555555837192 in _unwind__get_entries (cb=<optimized out>,
> arg=<optimized out>, thread=<optimized out>, data=<optimized out>,
> max_stack=<optimized out>) at util/unwind-libunwind-local.c:725
> #5 0x00005555557c310f in thread__resolve_callchain_unwind (max_stack=127,
> sample=0x7fffffff9830, evsel=0x555555c7b3b0, cursor=0x7ffff5642498,
> thread=0x555555c7f6f0) at util/machine.c:2351
> #6 thread__resolve_callchain (thread=0x555555c7f6f0, cursor=0x7ffff5642498,
> evsel=0x555555c7b3b0, sample=0x7fffffff9830, parent=0x7fffffff97b8,
> root_al=0x7fffffff9750, max_stack=127) at util/machine.c:2378
> #7 0x00005555557ba4ee in sample__resolve_callchain (sample=<optimized out>,
> cursor=<optimized out>, parent=parent@entry=0x7fffffff97b8, evsel=<optimized
> out>, al=al@entry=0x7fffffff9750,
> max_stack=<optimized out>) at util/callchain.c:1085
>
> Signed-off-by: Milian Wolff <milian.wo...@kdab.com>
> Cc: Sandipan Das <sandi...@linux.ibm.com>
> Cc: Arnaldo Carvalho de Melo <a...@kernel.org>
> ---
> tools/perf/util/machine.c | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
> index c4acd2001db0..0cb4f8bf3ca7 100644
> --- a/tools/perf/util/machine.c
> +++ b/tools/perf/util/machine.c
> @@ -2312,7 +2312,7 @@ static int unwind_entry(struct unwind_entry *entry,
> void *arg)
> {
> struct callchain_cursor *cursor = arg;
> const char *srcline = NULL;
> - u64 addr;
> + u64 addr = entry->ip;
>
> if (symbol_conf.hide_unresolved && entry->sym == NULL)
> return 0;
> @@ -2324,7 +2324,8 @@ static int unwind_entry(struct unwind_entry *entry,
> void *arg)
> * Convert entry->ip from a virtual address to an offset in
> * its corresponding binary.
> */
> - addr = map__map_ip(entry->map, entry->ip);
> + if (entry->map)
> + addr = map__map_ip(entry->map, entry->ip);
>
> srcline = callchain_srcline(entry->map, entry->sym, addr);
> return callchain_cursor_append(cursor, entry->ip,
> --
> 2.19.0
