Re: [PATCHv2 8/8] perf probe powerpc: Fixup function entry if using kallsyms lookup
From: Arnaldo Carvalho de Melo <acme@kernel.org>
Date: 2015-03-12 20:37:16
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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?
quoted hunk ↗ jump to hunk
Signed-off-by: Naveen N. Rao <redacted> --- 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