Re: [PATCH v2 04/10] perf trace: Add some string arguments' name in syscall_arg_fmt__init_array()

Howard Chu
2024-08-23T04:37:13Z

On Fri, Aug 23, 2024 at 6:14 AM Arnaldo Carvalho de Melo
<acme@kernel.org> wrote:
>
> On Thu, Aug 15, 2024 at 09:36:20AM +0800, Howard Chu wrote:
> > Add them so that we can augment more strings (which is a file path)
> >
> > Signed-off-by: Howard Chu <howardchu95@gmail.com>
> > ---
> > tools/perf/builtin-trace.c | 8 +++++++-
> > 1 file changed, 7 insertions(+), 1 deletion(-)
> >
> > diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c
> > index e7e8c89d9538..84c7398312d8 100644
> > --- a/tools/perf/builtin-trace.c
> > +++ b/tools/perf/builtin-trace.c
> > @@ -1918,7 +1918,13 @@ syscall_arg_fmt__init_array(struct syscall_arg_fmt *arg, struct tep_format_field
> >
> > if (strcmp(field->type, "const char *") == 0 &&
> > ((len >= 4 && strcmp(field->name + len - 4, "name") == 0) ||
> > - strstr(field->name, "path") != NULL))
> > + strstr(field->name, "path") ||
> > + strstr(field->name, "file") ||
> > + strstr(field->name, "root") ||
> > + strstr(field->name, "key") ||
> > + strstr(field->name, "special") ||
> > + strstr(field->name, "type") ||
> > + strstr(field->name, "description")))
> > arg->scnprintf = SCA_FILENAME;
> > else if ((field->flags & TEP_FIELD_IS_POINTER) || strstr(field->name, "addr"))
> > arg->scnprintf = SCA_PTR;
>
> Humm?
>
> root@number:~# for field_name in file root key special type description ; do grep "field:.* $field_name\>" /sys/kernel/tracing/events/syscalls/sys_enter_*/format ; done
>
> /sys/kernel/tracing/events/syscalls/sys_enter_msgget/format: field:key_t key; offset:16; size:8; signed:0;
> /sys/kernel/tracing/events/syscalls/sys_enter_semget/format: field:key_t key; offset:16; size:8; signed:0;
> /sys/kernel/tracing/events/syscalls/sys_enter_shmget/format: field:key_t key; offset:16; size:8; signed:0;
> /sys/kernel/tracing/events/syscalls/sys_enter_quotactl/format: field:const char * special; offset:24; size:8; signed:0;
> /sys/kernel/tracing/events/syscalls/sys_enter_kcmp/format: field:int type; offset:32; size:8; signed:0;
> /sys/kernel/tracing/events/syscalls/sys_enter_mount/format: field:char * type; offset:32; size:8; signed:0;
> /sys/kernel/tracing/events/syscalls/sys_enter_socket/format: field:int type; offset:24; size:8; signed:0;
> /sys/kernel/tracing/events/syscalls/sys_enter_socketpair/format: field:int type; offset:24; size:8; signed:0;
> /sys/kernel/tracing/events/syscalls/sys_enter_syslog/format: field:int type; offset:16; size:8; signed:0;
> root@number:~#
>
> Skipping this one. Please ellaborate, what am I missing?

Hello, just some minor changes on your command, if I do:
```
perf $ for field_name in file root key special type description ; do
grep "field:.*char \* .*$field_name\>"
/sys/kernel/tracing/events/syscalls/sys_enter_*/format ; done
/sys/kernel/tracing/events/syscalls/sys_enter_swapoff/format:
field:const char * specialfile; offset:16; size:8; signed:0;
/sys/kernel/tracing/events/syscalls/sys_enter_swapon/format:
field:const char * specialfile; offset:16; size:8; signed:0;
/sys/kernel/tracing/events/syscalls/sys_enter_pivot_root/format:
field:const char * new_root; offset:16; size:8; signed:0;
/sys/kernel/tracing/events/syscalls/sys_enter_fsconfig/format:
field:const char * _key; offset:32; size:8; signed:0;
/sys/kernel/tracing/events/syscalls/sys_enter_quotactl/format:
field:const char * special; offset:24; size:8; signed:0;
/sys/kernel/tracing/events/syscalls/sys_enter_add_key/format:
field:const char * _type; offset:16; size:8; signed:0;
/sys/kernel/tracing/events/syscalls/sys_enter_mount/format:
field:char * type; offset:32; size:8; signed:0;
/sys/kernel/tracing/events/syscalls/sys_enter_request_key/format:field:const
char * _type; offset:16; size:8; signed:0;
/sys/kernel/tracing/events/syscalls/sys_enter_add_key/format:
field:const char * _description; offset:24; size:8; signed:0;
/sys/kernel/tracing/events/syscalls/sys_enter_request_key/format:field:const
char * _description; offset:24; size:8; signed:0;
```

They pop up.

Because it's strstr(), not strcmp(). Do you think we should use
"strstr(field->name, "description") ||" or "strstr(field->name,
"_description") ||"? Please let me know.

Thanks,
Howard

>
> - Arnaldo