lkml.org 
[lkml]   [2015]   [Mar]   [12]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCHv2 8/8] perf probe powerpc: Fixup function entry if using kallsyms lookup
Em Mon, Dec 15, 2014 at 08:20:38PM +0530, Naveen N. Rao escreveu:
> On powerpc ABIv2, if no debug-info is found and we use kallsyms, we need
> to fixup the function entry to point to the local entry point. Use
> offset of 8 since current toolchains always generate 2 instructions (8
> bytes).


So perhaps we should rename ARCH_SYMBOL_HANDLING to ARCH_ABI_SYMBOL_FIXUPS?

> Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
> ---
> Changes:
> Generalize and introduce helper to post-process trace point.
>
> tools/perf/arch/powerpc/util/sym-handling.c | 17 +++++++++++++++++
> tools/perf/util/probe-event.c | 1 +
> tools/perf/util/probe-event.h | 10 ++++++++++
> 3 files changed, 28 insertions(+)
>
> diff --git a/tools/perf/arch/powerpc/util/sym-handling.c b/tools/perf/arch/powerpc/util/sym-handling.c
> index 22fc2e6..30c8797 100644
> --- a/tools/perf/arch/powerpc/util/sym-handling.c
> +++ b/tools/perf/arch/powerpc/util/sym-handling.c
> @@ -45,3 +45,20 @@ inline bool prefer_symtab(void)
> return false;
> #endif
> }
> +
> +void arch_fix_tev_from_maps(struct perf_probe_event *pev __maybe_unused,
> + struct probe_trace_event *tev __maybe_unused,
> + struct map *map __maybe_unused)
> +{
> +#if defined(_CALL_ELF) && _CALL_ELF == 2
> + /*
> + * If we used kallsyms, we should fixup the function entry address here.
> + * ppc64 ABIv2 local entry point is currently always 2 instructions (8 bytes)
> + * after the global entry point. Fix this if it ever changes.
> + */
> + if (!pev->uprobes && map->dso->symtab_type == DSO_BINARY_TYPE__KALLSYMS) {
> + tev->point.address += 8;
> + tev->point.offset += 8;
> + }
> +#endif
> +}
> diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
> index dfc3151..85f37a4 100644
> --- a/tools/perf/util/probe-event.c
> +++ b/tools/perf/util/probe-event.c
> @@ -2340,6 +2340,7 @@ static int find_probe_trace_events_from_map(struct perf_probe_event *pev,
> strdup_or_goto(pev->args[i].type,
> nomem_out);
> }
> + arch_fix_tev_from_maps(pev, tev, map);
> }
>
> out:
> diff --git a/tools/perf/util/probe-event.h b/tools/perf/util/probe-event.h
> index 5f92906..335a6a4 100644
> --- a/tools/perf/util/probe-event.h
> +++ b/tools/perf/util/probe-event.h
> @@ -147,6 +147,16 @@ extern bool prefer_symtab(void);
> static inline bool prefer_symtab(void) { return false; };
> #endif
>
> +#ifdef HAVE_ARCH_SYMBOL_HANDLING
> +extern void arch_fix_tev_from_maps(struct perf_probe_event *pev __maybe_unused,
> + struct probe_trace_event *tev __maybe_unused,
> + struct map *map __maybe_unused);
> +#else
> +static inline void arch_fix_tev_from_maps(struct perf_probe_event *pev __maybe_unused,
> + struct probe_trace_event *tev __maybe_unused,
> + struct map *map __maybe_unused) { }
> +#endif
> +
> /* Maximum index number of event-name postfix */
> #define MAX_EVENT_INDEX 1024
>
> --
> 2.1.3


\
 
 \ /
  Last update: 2015-03-12 21:41    [W:2.821 / U:0.060 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site