From 29b596b57426831fce92cd0ebb01c77627616fdf Mon Sep 17 00:00:00 2001 From: Adrian Hunter Date: Wed, 29 Jan 2014 16:14:37 +0200 Subject: 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: Adrian Hunter Tested-by: Jiri Olsa Cc: David Ahern Cc: Frederic Weisbecker Cc: Ingo Molnar Cc: Jiri Olsa Cc: Mike Galbraith Cc: Namhyung Kim Cc: Paul Mackerras Cc: Peter Zijlstra Cc: Stephane Eranian Link: http://lkml.kernel.org/r/1391004884-10334-3-git-send-email-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/event.c | 18 +++++++++++++++--- tools/perf/util/event.h | 3 +++ 2 files changed, 18 insertions(+), 3 deletions(-) (limited to 'tools') diff --git a/tools/perf/util/event.c b/tools/perf/util/event.c index 1fc1c2f04772..17476df5c7b2 100644 --- a/tools/perf/util/event.c +++ b/tools/perf/util/event.c @@ -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; diff --git a/tools/perf/util/event.h b/tools/perf/util/event.h index faf6e219be21..66a0c0392863 100644 --- a/tools/perf/util/event.h +++ b/tools/perf/util/event.h @@ -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 */ -- cgit v1.2.3-70-g09d2