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author | David Ahern <dsahern@gmail.com> | 2012-04-16 04:54:15 +0200 |
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committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2012-04-16 16:18:22 +0200 |
commit | 9e755756e4a22784abfb001688357745ea8ca97c (patch) | |
tree | f1b23c22aae655695872fb7f325018b2a566876a | |
parent | Merge tag 'perf-urgent-for-mingo' of git://git.kernel.org/pub/scm/linux/kerne... (diff) | |
download | linux-9e755756e4a22784abfb001688357745ea8ca97c.tar.xz linux-9e755756e4a22784abfb001688357745ea8ca97c.zip |
perf report: Fix crash showing warning related to kernel maps
While testing https://lkml.org/lkml/2012/4/10/123 I hit this crash:
(gdb) bt
0 0x000000000042000f in __cmd_report (rep=0x7fff80cec580) at builtin-report.c:380
1 cmd_report (argc=0, argv=<optimized out>, prefix=<optimized out>) at builtin-report.c:759
2 0x0000000000414513 in run_builtin (p=0x7724a8, argc=3, argv=0x7fff80ceca70) at perf.c:273
3 0x0000000000413d41 in handle_internal_command (argv=0x7fff80ceca70, argc=3) at perf.c:345
4 run_argv (argv=0x7fff80cec880, argcp=0x7fff80cec88c) at perf.c:389
5 main (argc=3, argv=0x7fff80ceca70) at perf.c:487
kernel_map can be NULL, so need to handle it while dumping a warning
to user.
v2:
- fixed RB_EMPTY_ROOT check -- desc takes the altnerative output when RB_EMPTY_ROOT is false.
Signed-off-by: David Ahern <dsahern@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Namhyung Kim <namhyung.kim@lge.com>
Link: http://lkml.kernel.org/r/1334544855-55021-1-git-send-email-dsahern@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
-rw-r--r-- | tools/perf/builtin-report.c | 17 |
1 files changed, 12 insertions, 5 deletions
diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c index 2e317438980b..cdae9b2db1cc 100644 --- a/tools/perf/builtin-report.c +++ b/tools/perf/builtin-report.c @@ -374,16 +374,23 @@ static int __cmd_report(struct perf_report *rep) (kernel_map->dso->hit && (kernel_kmap->ref_reloc_sym == NULL || kernel_kmap->ref_reloc_sym->addr == 0))) { - const struct dso *kdso = kernel_map->dso; + const char *desc = + "As no suitable kallsyms nor vmlinux was found, kernel samples\n" + "can't be resolved."; + + if (kernel_map) { + const struct dso *kdso = kernel_map->dso; + if (!RB_EMPTY_ROOT(&kdso->symbols[MAP__FUNCTION])) { + desc = "If some relocation was applied (e.g. " + "kexec) symbols may be misresolved."; + } + } ui__warning( "Kernel address maps (/proc/{kallsyms,modules}) were restricted.\n\n" "Check /proc/sys/kernel/kptr_restrict before running 'perf record'.\n\n%s\n\n" "Samples in kernel modules can't be resolved as well.\n\n", - RB_EMPTY_ROOT(&kdso->symbols[MAP__FUNCTION]) ? -"As no suitable kallsyms nor vmlinux was found, kernel samples\n" -"can't be resolved." : -"If some relocation was applied (e.g. kexec) symbols may be misresolved."); + desc); } if (dump_trace) { |