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Commit 29b596b5 authored by Adrian Hunter's avatar Adrian Hunter Committed by Arnaldo Carvalho de Melo
Browse files

perf tools: Add kallsyms__get_function_start() 



Separate out the logic used to find the start address of the reference
symbol used to track kernel relocation.  kallsyms__get_function_start()
is used in subsequent patches.

Signed-off-by: default avatarAdrian Hunter <adrian.hunter@intel.com>
Tested-by: default avatarJiri Olsa <jolsa@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1391004884-10334-3-git-send-email-adrian.hunter@intel.com


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 9176753d

tools/perf/util/event.c

+15 −3
Original line number Diff line number Diff line
@@ -470,6 +470,17 @@ static int find_symbol_cb(void *arg, const char *name, char type, 
	return 1;

}



u64 kallsyms__get_function_start(const char *kallsyms_filename,

				 const char *symbol_name)

{

	struct process_symbol_args args = { .name = symbol_name, };



	if (kallsyms__parse(kallsyms_filename, &args, find_symbol_cb) <= 0)

		return 0;



	return args.start;

}



int perf_event__synthesize_kernel_mmap(struct perf_tool *tool,

				       perf_event__handler_t process,

				       struct machine *machine,
@@ -480,13 +491,13 @@ int perf_event__synthesize_kernel_mmap(struct perf_tool *tool, 
	char path[PATH_MAX];

	char name_buff[PATH_MAX];

	struct map *map;

	u64 start;

	int err;

	/*

	 * We should get this from /sys/kernel/sections/.text, but till that is

	 * available use this, and after it is use this as a fallback for older

	 * kernels.

	 */

	struct process_symbol_args args = { .name = symbol_name, };

	union perf_event *event = zalloc((sizeof(event->mmap) +

					  machine->id_hdr_size));

	if (event == NULL) {
@@ -513,7 +524,8 @@ int perf_event__synthesize_kernel_mmap(struct perf_tool *tool, 
		}

	}



	if (kallsyms__parse(filename, &args, find_symbol_cb) <= 0) {

	start = kallsyms__get_function_start(filename, symbol_name);

	if (!start) {

		free(event);

		return -ENOENT;

	}
@@ -525,7 +537,7 @@ int perf_event__synthesize_kernel_mmap(struct perf_tool *tool, 
	event->mmap.header.type = PERF_RECORD_MMAP;

	event->mmap.header.size = (sizeof(event->mmap) -

			(sizeof(event->mmap.filename) - size) + machine->id_hdr_size);

	event->mmap.pgoff = args.start;

	event->mmap.pgoff = start;

	event->mmap.start = map->start;

	event->mmap.len   = map->end - event->mmap.start;

	event->mmap.pid   = machine->pid;

tools/perf/util/event.h

+3 −0
Original line number Diff line number Diff line
@@ -279,4 +279,7 @@ size_t perf_event__fprintf_mmap2(union perf_event *event, FILE *fp); 
size_t perf_event__fprintf_task(union perf_event *event, FILE *fp);

size_t perf_event__fprintf(union perf_event *event, FILE *fp);



u64 kallsyms__get_function_start(const char *kallsyms_filename,

				 const char *symbol_name);



#endif /* __PERF_RECORD_H */