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Commit 7b6ff0bd authored by Naveen N. Rao's avatar Naveen N. Rao Committed by Arnaldo Carvalho de Melo
Browse files

perf probe ppc64le: Fixup function entry if using kallsyms lookup 



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).

Signed-off-by: default avatarNaveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Reviewed-by: default avatarSrikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Cc: linuxppc-dev@lists.ozlabs.org
Link: http://lkml.kernel.org/r/92253021e77a104b23b615c8c23bf9501dfe60bf.1430217967.git.naveen.n.rao@linux.vnet.ibm.com


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent d5c2e2c1

tools/perf/arch/powerpc/util/sym-handling.c

+15 −0
Original line number Diff line number Diff line
@@ -64,4 +64,19 @@ bool arch__prefers_symtab(void) 
{

	return true;

}



#define PPC64LE_LEP_OFFSET	8



void arch__fix_tev_from_maps(struct perf_probe_event *pev,

			     struct probe_trace_event *tev, struct map *map)

{

	/*

	 * ppc64 ABIv2 local entry point is currently always 2 instructions

	 * (8 bytes) after the global entry point.

	 */

	if (!pev->uprobes && map->dso->symtab_type == DSO_BINARY_TYPE__KALLSYMS) {

		tev->point.address += PPC64LE_LEP_OFFSET;

		tev->point.offset += PPC64LE_LEP_OFFSET;

	}

}

#endif

tools/perf/util/probe-event.c

+5 −0
Original line number Diff line number Diff line
@@ -2447,6 +2447,10 @@ static int find_probe_functions(struct map *map, char *name) 
#define strdup_or_goto(str, label)	\

	({ char *__p = strdup(str); if (!__p) goto label; __p; })



void __weak arch__fix_tev_from_maps(struct perf_probe_event *pev __maybe_unused,

				struct probe_trace_event *tev __maybe_unused,

				struct map *map __maybe_unused) { }



/*

 * Find probe function addresses from map.

 * Return an error or the number of found probe_trace_event
@@ -2553,6 +2557,7 @@ 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:

tools/perf/util/probe-event.h

+2 −0
Original line number Diff line number Diff line
@@ -136,6 +136,8 @@ extern int show_available_vars(struct perf_probe_event *pevs, int npevs, 
extern int show_available_funcs(const char *module, struct strfilter *filter,

				bool user);

bool arch__prefers_symtab(void);

void arch__fix_tev_from_maps(struct perf_probe_event *pev,

			     struct probe_trace_event *tev, struct map *map);



/* Maximum index number of event-name postfix */

#define MAX_EVENT_INDEX	1024