(2013/09/03 16:37), Hemant Kumar wrote:
> This patch enables perf to probe on the marker name specified on the command
> line.
At least you must show how this works, and how to use in the comment.
Thank you,
> ---
> tools/perf/builtin-probe.c | 7 +++
> tools/perf/util/probe-event.c | 11 ++++
> tools/perf/util/symbol-elf.c | 112
> +++++++++++++++++++++++++++++++++++++++++
> tools/perf/util/symbol.h | 5 ++
> 4 files changed, 135 insertions(+)
>
> diff --git a/tools/perf/builtin-probe.c b/tools/perf/builtin-probe.c
> index 3d8dcdf..8382853 100644
> --- a/tools/perf/builtin-probe.c
> +++ b/tools/perf/builtin-probe.c
> @@ -378,6 +378,13 @@ int cmd_probe(int argc, const char **argv, const char
> *prefix __maybe_unused)
> " (%d)\n", ret);
> return ret;
> }
> + params.uprobes = true;
> + ret = probe_marker(params.target,
> + params.events[0].point.function);
> + if (ret < 0)
> + pr_err("Could not probe at %s marker\n",
> + params.events[0].point.function);
> + return ret;
> }
>
> if (params.list_events) {
> diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
> index 7f846f9..014d642 100644
> --- a/tools/perf/util/probe-event.c
> +++ b/tools/perf/util/probe-event.c
> @@ -2378,3 +2378,14 @@ int show_available_markers(const char *target)
> setup_pager();
> return list_markers(target);
> }
> +
> +int probe_marker(const char *name, char *mark)
> +{
> + int fd;
> +
> + fd = open_uprobe_events(true);
> + if (fd == -1)
> + return fd;
> + else
> + return probe__marker(name, mark, fd);
> +}
> diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c
> index f3630f2..60938a5 100644
> --- a/tools/perf/util/symbol-elf.c
> +++ b/tools/perf/util/symbol-elf.c
> @@ -1040,6 +1040,118 @@ out_ret:
> return ret;
> }
>
> +static void extract_first_name(const char *target, char *fname)
> +{
> + int i, len;
> + char *file;
> +
> + file = strrchr(target, DIR_SEP);
> + file++;
> + len = strlen(file);
> + for (i = 0; i <= len; i++) {
> + if (!isalpha(file[i]))
> + break;
> + fname[i] = file[i];
> + }
> + fname[i] = '\0';
> +}
> +
> +static int probe_at_note(struct sdt_note *r_note, const char *target, bool
> exec,
> + int fd)
> +{
> + char buf[MAX_CMDLEN];
> + int len, err = -1;
> + Elf64_Addr offset;
> + char *fname = NULL;
> +
> + if (exec)
> + offset = r_note->addr.a64[0] - TEXT_SCN;
> + else
> + offset = r_note->addr.a64[0];
> +
> + fname = (char *)zalloc(sizeof(char) * strlen(target));
> + if (fname == NULL) {
> + pr_err("Error in allocating memory to fname\n");
> + goto out_ret;
> + }
> +
> + extract_first_name(target, fname);
> + len = snprintf(buf, MAX_CMDLEN, "%c:%s%s/%s %s:0x%x", 'p', "probe_",
> + fname, r_note->name, target, (unsigned)offset);
> +
> + len = write(fd, buf, MAX_CMDLEN);
> + if (len < 0) {
> + pr_err("Couldn't write into uprobe_events!\n");
> + goto out_close;
> + } else {
> + printf("Added new event :\n");
> + printf("event = %s \t (on 0x%x)\n\n", r_note->name,
> + (unsigned)offset);
> + printf("You can now use it on all perf tools such as :\n\n");
> + printf("\t perf record -e %s%s:%s -aR sleep 1\n\n", "probe_",
> fname, r_note->name);
> + err = 0;
> + }
> +
> +out_close:
> + close(fd);
> + free(fname);
> +out_ret:
> + return err;
> +}
> +
> +static int search_and_probe_at_note(char *key, struct sdt_note **start,
> + const char *target, bool exec, int fd)
> +{
> + int ret = -1;
> + struct sdt_note *req;
> +
> + for (req = (*start); req != NULL; req = req->next) {
> + if (!strcmp(key, req->name))
> + break;
> + }
> + if (!req) {
> + pr_err("Could not find marker %s\n", key);
> + return ret;
> + }
> +
> + ret = probe_at_note(req, target, exec, fd);
> + return ret;
> +}
> +
> +int probe__marker(const char *name, char *mark, int evfd)
> +{
> + int ret = -1, fd;
> + Elf *elf;
> + bool exec = false;
> + struct sdt_note *head = NULL;
> +
> + fd = open(name, O_RDONLY);
> + if (fd < 0) {
> + pr_err("Failed to open the file\n");
> + goto out_ret;
> + }
> +
> + symbol__elf_init();
> + elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
> + if (elf == NULL) {
> + pr_debug("%s: cannot read %s ELF file.\n", __func__, name);
> + goto out_close;
> + }
> +
> + head = get_elf_markers(elf, &exec, true);
> + if (head) {
> + ret = search_and_probe_at_note(mark, &head, name, exec, evfd);
> + cleanup_notes(head);
> + }
> +
> + elf_end(elf);
> +
> +out_close:
> + close(fd);
> +out_ret:
> + return ret;
> +}
> +
> void cleanup_notes(struct sdt_note *start)
> {
> struct sdt_note *tmp;
> diff --git a/tools/perf/util/symbol.h b/tools/perf/util/symbol.h
> index f2d17b7..95289fd 100644
> --- a/tools/perf/util/symbol.h
> +++ b/tools/perf/util/symbol.h
> @@ -262,8 +262,13 @@ void __map_groups__fixup_end(struct map_groups *mg, enum
> map_type type);
> int show_available_markers(const char *module);
> int list_markers(const char *name);
> void cleanup_notes(struct sdt_note *start);
> +int probe_marker(const char *name, char *mark);
> +int probe__marker(const char *name, char *mark, int fd);
>
> #define SDT_NOTE_TYPE 3
> #define NOTE_SCN ".note.stapsdt"
> +#define TEXT_SCN 0x400000
> +#define DIR_SEP '/'
> +#define MAX_CMDLEN 256
>
> #endif /* __PERF_SYMBOL */
>
> --
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>
--
Masami HIRAMATSU
IT Management Research Dept. Linux Technology Center
Hitachi, Ltd., Yokohama Research Laboratory
E-mail: [email protected]
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