Re: [PATCH] trace-cmd: Leave out absolute addresses to fix bogus symbol resolutions

From: Jan Kiszka
Date: Tue Sep 15 2015 - 12:30:31 EST


On 2015-07-31 16:04, Jan Kiszka wrote:
> On x86, page_fault_* tracepoints report userspace address via kernel
> symbols because all the per-cpu variable offsets are in kallsyms,
> occupying the lower address space. Fix this by skipping over absolute
> addresses while processing kallsyms.
>
> Signed-off-by: Jan Kiszka <jan.kiszka@xxxxxxxxxxx>
> ---
> trace-util.c | 8 ++++++--
> 1 file changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/trace-util.c b/trace-util.c
> index 8a81dd0..da20e4c 100644
> --- a/trace-util.c
> +++ b/trace-util.c
> @@ -434,8 +434,12 @@ void parse_proc_kallsyms(struct pevent *pevent,
> if (mod)
> mod[strlen(mod) - 1] = 0;
>
> - /* Hack for arm arch that adds a lot of bogus '$a' functions */
> - if (func[0] != '$')
> + /*
> + * Hacks for
> + * - arm arch that adds a lot of bogus '$a' functions
> + * - x86-64 that reports per-cpu variable offsets as absolute
> + */
> + if (func[0] != '$' && ch != 'A')
> pevent_register_function(pevent, func, addr, mod);
> free(func);
> free(mod);
>

Ping.

Jan

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Siemens AG, Corporate Technology, CT RTC ITP SES-DE
Corporate Competence Center Embedded Linux
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