Show binary offsets for userspace addr with map in perf script output
with callchain.
In commit 19610184693c("perf script: Show virtual addresses instead of
offsets"), the addr shown in perf script output with callchain is changed
from binary offsets to virtual address to fix the incorrectness when
displaying symbol offset.
This is inconvenient in scenario that the binary is stripped and
symbol cannot be resolved. If someone wants to further resolve symbols for
specific binaries later, he would need an extra step to translate virtual
address to binary offset with mapping information recorded in perf.data,
which can be difficult for people not familiar with perf.
This patch modifies function sample__fprintf_callchain to print binary
offset for userspace addr with dsos, and virtual address otherwise. It
does not affect symbol offset calculation so symoff remains correct.
Before applying this patch:
test 1512 78.711307: 533129 cycles:
aaaae0da07f4 [unknown] (/tmp/test)
aaaae0da0704 [unknown] (/tmp/test)
ffffbe9f7ef4 __libc_start_main+0xe4 (/lib64/libc-2.31.so)
After this patch:
test 1519 111.330127: 406953 cycles:
7f4 [unknown] (/tmp/test)
704 [unknown] (/tmp/test)
20ef4 __libc_start_main+0xe4 (/lib64/libc-2.31.so)
Fixes: 19610184693c("perf script: Show virtual addresses instead of offsets")
Signed-off-by: Lexi Shao <[email protected]>
---
tools/perf/util/evsel_fprintf.c | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)
diff --git a/tools/perf/util/evsel_fprintf.c b/tools/perf/util/evsel_fprintf.c
index bfedd7b23521..8c2ea8001329 100644
--- a/tools/perf/util/evsel_fprintf.c
+++ b/tools/perf/util/evsel_fprintf.c
@@ -11,6 +11,7 @@
#include "strlist.h"
#include "symbol.h"
#include "srcline.h"
+#include "dso.h"
static int comma_fprintf(FILE *fp, bool *first, const char *fmt, ...)
{
@@ -144,12 +145,17 @@ int sample__fprintf_callchain(struct perf_sample *sample, int left_alignment,
if (print_arrow && !first)
printed += fprintf(fp, " <-");
- if (print_ip)
- printed += fprintf(fp, "%c%16" PRIx64, s, node->ip);
-
if (map)
addr = map->map_ip(map, node->ip);
+ if (print_ip) {
+ /* Show binary offset for userspace addr */
+ if (map && !map->dso->kernel)
+ printed += fprintf(fp, "%c%16" PRIx64, s, addr);
+ else
+ printed += fprintf(fp, "%c%16" PRIx64, s, node->ip);
+ }
+
if (print_sym) {
printed += fprintf(fp, " ");
node_al.addr = addr;
--
2.12.3
On Tue, Oct 19, 2021 at 03:24:17PM +0800, Lexi Shao wrote:
> Show binary offsets for userspace addr with map in perf script output
> with callchain.
>
> In commit 19610184693c("perf script: Show virtual addresses instead of
> offsets"), the addr shown in perf script output with callchain is changed
> from binary offsets to virtual address to fix the incorrectness when
> displaying symbol offset.
>
> This is inconvenient in scenario that the binary is stripped and
> symbol cannot be resolved. If someone wants to further resolve symbols for
> specific binaries later, he would need an extra step to translate virtual
> address to binary offset with mapping information recorded in perf.data,
> which can be difficult for people not familiar with perf.
>
> This patch modifies function sample__fprintf_callchain to print binary
> offset for userspace addr with dsos, and virtual address otherwise. It
> does not affect symbol offset calculation so symoff remains correct.
>
> Before applying this patch:
> test 1512 78.711307: 533129 cycles:
> aaaae0da07f4 [unknown] (/tmp/test)
> aaaae0da0704 [unknown] (/tmp/test)
> ffffbe9f7ef4 __libc_start_main+0xe4 (/lib64/libc-2.31.so)
>
> After this patch:
> test 1519 111.330127: 406953 cycles:
> 7f4 [unknown] (/tmp/test)
> 704 [unknown] (/tmp/test)
> 20ef4 __libc_start_main+0xe4 (/lib64/libc-2.31.so)
>
> Fixes: 19610184693c("perf script: Show virtual addresses instead of offsets")
>
> Signed-off-by: Lexi Shao <[email protected]>
makes sense to me
Acked-/Tested-by Jiri Olsa <[email protected]>
should we have a way to display these callchain detail in perf report output as well?
thanks,
jirka
> ---
> tools/perf/util/evsel_fprintf.c | 12 +++++++++---
> 1 file changed, 9 insertions(+), 3 deletions(-)
>
> diff --git a/tools/perf/util/evsel_fprintf.c b/tools/perf/util/evsel_fprintf.c
> index bfedd7b23521..8c2ea8001329 100644
> --- a/tools/perf/util/evsel_fprintf.c
> +++ b/tools/perf/util/evsel_fprintf.c
> @@ -11,6 +11,7 @@
> #include "strlist.h"
> #include "symbol.h"
> #include "srcline.h"
> +#include "dso.h"
>
> static int comma_fprintf(FILE *fp, bool *first, const char *fmt, ...)
> {
> @@ -144,12 +145,17 @@ int sample__fprintf_callchain(struct perf_sample *sample, int left_alignment,
> if (print_arrow && !first)
> printed += fprintf(fp, " <-");
>
> - if (print_ip)
> - printed += fprintf(fp, "%c%16" PRIx64, s, node->ip);
> -
> if (map)
> addr = map->map_ip(map, node->ip);
>
> + if (print_ip) {
> + /* Show binary offset for userspace addr */
> + if (map && !map->dso->kernel)
> + printed += fprintf(fp, "%c%16" PRIx64, s, addr);
> + else
> + printed += fprintf(fp, "%c%16" PRIx64, s, node->ip);
> + }
> +
> if (print_sym) {
> printed += fprintf(fp, " ");
> node_al.addr = addr;
> --
> 2.12.3
>
Em Wed, Oct 20, 2021 at 03:24:19PM +0200, Jiri Olsa escreveu:
> On Tue, Oct 19, 2021 at 03:24:17PM +0800, Lexi Shao wrote:
> > Show binary offsets for userspace addr with map in perf script output
> > with callchain.
> >
> > In commit 19610184693c("perf script: Show virtual addresses instead of
> > offsets"), the addr shown in perf script output with callchain is changed
> > from binary offsets to virtual address to fix the incorrectness when
> > displaying symbol offset.
> >
> > This is inconvenient in scenario that the binary is stripped and
> > symbol cannot be resolved. If someone wants to further resolve symbols for
> > specific binaries later, he would need an extra step to translate virtual
> > address to binary offset with mapping information recorded in perf.data,
> > which can be difficult for people not familiar with perf.
> >
> > This patch modifies function sample__fprintf_callchain to print binary
> > offset for userspace addr with dsos, and virtual address otherwise. It
> > does not affect symbol offset calculation so symoff remains correct.
> >
> > Before applying this patch:
> > test 1512 78.711307: 533129 cycles:
> > aaaae0da07f4 [unknown] (/tmp/test)
> > aaaae0da0704 [unknown] (/tmp/test)
> > ffffbe9f7ef4 __libc_start_main+0xe4 (/lib64/libc-2.31.so)
> >
> > After this patch:
> > test 1519 111.330127: 406953 cycles:
> > 7f4 [unknown] (/tmp/test)
> > 704 [unknown] (/tmp/test)
> > 20ef4 __libc_start_main+0xe4 (/lib64/libc-2.31.so)
> >
> > Fixes: 19610184693c("perf script: Show virtual addresses instead of offsets")
> >
> > Signed-off-by: Lexi Shao <[email protected]>
>
> makes sense to me
>
> Acked-/Tested-by Jiri Olsa <[email protected]>
Thanks, applied.
- Arnaldo
> should we have a way to display these callchain detail in perf report output as well?
>
> thanks,
> jirka
>
> > ---
> > tools/perf/util/evsel_fprintf.c | 12 +++++++++---
> > 1 file changed, 9 insertions(+), 3 deletions(-)
> >
> > diff --git a/tools/perf/util/evsel_fprintf.c b/tools/perf/util/evsel_fprintf.c
> > index bfedd7b23521..8c2ea8001329 100644
> > --- a/tools/perf/util/evsel_fprintf.c
> > +++ b/tools/perf/util/evsel_fprintf.c
> > @@ -11,6 +11,7 @@
> > #include "strlist.h"
> > #include "symbol.h"
> > #include "srcline.h"
> > +#include "dso.h"
> >
> > static int comma_fprintf(FILE *fp, bool *first, const char *fmt, ...)
> > {
> > @@ -144,12 +145,17 @@ int sample__fprintf_callchain(struct perf_sample *sample, int left_alignment,
> > if (print_arrow && !first)
> > printed += fprintf(fp, " <-");
> >
> > - if (print_ip)
> > - printed += fprintf(fp, "%c%16" PRIx64, s, node->ip);
> > -
> > if (map)
> > addr = map->map_ip(map, node->ip);
> >
> > + if (print_ip) {
> > + /* Show binary offset for userspace addr */
> > + if (map && !map->dso->kernel)
> > + printed += fprintf(fp, "%c%16" PRIx64, s, addr);
> > + else
> > + printed += fprintf(fp, "%c%16" PRIx64, s, node->ip);
> > + }
> > +
> > if (print_sym) {
> > printed += fprintf(fp, " ");
> > node_al.addr = addr;
> > --
> > 2.12.3
> >
--
- Arnaldo