[RESEND PATCH 6/6] perf: powerpc: choose local entry point with kretprobes
From: Naveen N. Rao <hidden>
Date: 2017-03-07 10:50:02
Also in:
lkml
Subsystem:
performance events subsystem, the rest · Maintainers:
Peter Zijlstra, Ingo Molnar, Arnaldo Carvalho de Melo, Namhyung Kim, Linus Torvalds
perf now uses an offset from _text/_stext for kretprobes if the kernel supports it, rather than the actual function name. As such, let's choose the LEP for powerpc ABIv2 so as to ensure the probe gets hit. Do it only if the kernel supports specifying offsets with kretprobes. Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Naveen N. Rao <redacted> --- tools/perf/arch/powerpc/util/sym-handling.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/tools/perf/arch/powerpc/util/sym-handling.c b/tools/perf/arch/powerpc/util/sym-handling.c
index 1030a6e504bb..e93b3db25012 100644
--- a/tools/perf/arch/powerpc/util/sym-handling.c
+++ b/tools/perf/arch/powerpc/util/sym-handling.c@@ -10,6 +10,7 @@ #include "symbol.h" #include "map.h" #include "probe-event.h" +#include "trace-event.h" #ifdef HAVE_LIBELF_SUPPORT bool elf__needs_adjust_symbols(GElf_Ehdr ehdr)
@@ -79,11 +80,12 @@ void arch__fix_tev_from_maps(struct perf_probe_event *pev, * However, if the user specifies an offset, we fall back to using the * GEP since all userspace applications (objdump/readelf) show function * disassembly with offsets from the GEP. - * - * In addition, we shouldn't specify an offset for kretprobes. */ - if (pev->point.offset || (!pev->uprobes && pev->point.retprobe) || - !map || !sym) + if (pev->point.offset || !map || !sym) + return; + + /* For kretprobes, add an offset only if the kernel supports it */ + if (!pev->uprobes && pev->point.retprobe && !kretprobe_offset_is_supported()) return; lep_offset = PPC64_LOCAL_ENTRY_OFFSET(sym->arch_sym);
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2.11.1