* [PATCH] perf report: fix crash showing warning related to kernel maps
@ 2012-04-10 16:15 David Ahern
2012-04-15 20:59 ` David Ahern
0 siblings, 1 reply; 3+ messages in thread
From: David Ahern @ 2012-04-10 16:15 UTC (permalink / raw)
To: acme, linux-kernel; +Cc: mingo, peterz, eranian, namhyung.kim, David Ahern
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.
Signed-off-by: David Ahern <dsahern@gmail.com>
---
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 2e31743..002c644 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) {
--
1.7.5.4
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] perf report: fix crash showing warning related to kernel maps
2012-04-10 16:15 [PATCH] perf report: fix crash showing warning related to kernel maps David Ahern
@ 2012-04-15 20:59 ` David Ahern
0 siblings, 0 replies; 3+ messages in thread
From: David Ahern @ 2012-04-15 20:59 UTC (permalink / raw)
To: acme; +Cc: linux-kernel, mingo, peterz, eranian, namhyung.kim
Hi Arnaldo:
Haven't seen this one come through your urgent queue.
On 4/10/12 10:15 AM, David Ahern wrote:
> 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.
>
> Signed-off-by: David Ahern<dsahern@gmail.com>
> ---
> 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 2e31743..002c644 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) {
^ permalink raw reply [flat|nested] 3+ messages in thread
* [PATCH] perf report: fix crash showing warning related to kernel maps
@ 2012-04-16 2:54 David Ahern
0 siblings, 0 replies; 3+ messages in thread
From: David Ahern @ 2012-04-16 2:54 UTC (permalink / raw)
To: acme, linux-kernel; +Cc: mingo, peterz, eranian, namhyung.kim, David Ahern
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>
---
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 2e31743..42c06db4 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) {
--
1.7.5.4
^ permalink raw reply related [flat|nested] 3+ messages in thread
end of thread, other threads:[~2012-04-16 2:54 UTC | newest]
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2012-04-10 16:15 [PATCH] perf report: fix crash showing warning related to kernel maps David Ahern
2012-04-15 20:59 ` David Ahern
2012-04-16 2:54 David Ahern
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