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author | Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> | 2010-07-09 09:29:11 (GMT) |
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committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2010-07-16 14:48:09 (GMT) |
commit | 6a330a3c8a648916b3c6bda79a78c38ac093af17 (patch) | |
tree | 76322d562a438cb47ebf95311d898394efceca8e /tools | |
parent | 7cf0b79e6ffd04bba5d4e625a0fe2e30a5b383e5 (diff) | |
download | linux-6a330a3c8a648916b3c6bda79a78c38ac093af17.tar.xz |
perf probe: Support comp_dir to find an absolute source path
Gcc generates DW_AT_comp_dir and stores relative source path if building kernel
without O= option. In that case, perf probe --line sometimes doesn't work
without --source option, because it tries to access relative source path.
This adds DW_AT_comp_dir support to perf probe for finding an absolute source
path when no --source option.
LKML-Reference: <4C36EBE7.3060802@hitachi.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools')
-rw-r--r-- | tools/perf/util/probe-event.c | 34 | ||||
-rw-r--r-- | tools/perf/util/probe-event.h | 1 | ||||
-rw-r--r-- | tools/perf/util/probe-finder.c | 21 |
3 files changed, 44 insertions, 12 deletions
diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c index 8d08e75..4445a1e 100644 --- a/tools/perf/util/probe-event.c +++ b/tools/perf/util/probe-event.c @@ -201,28 +201,38 @@ static int try_to_find_kprobe_trace_events(struct perf_probe_event *pev, * a newly allocated path on success. * Return 0 if file was found and readable, -errno otherwise. */ -static int get_real_path(const char *raw_path, char **new_path) +static int get_real_path(const char *raw_path, const char *comp_dir, + char **new_path) { - if (!symbol_conf.source_prefix) { - if (access(raw_path, R_OK) == 0) { - *new_path = strdup(raw_path); - return 0; - } else - return -errno; + const char *prefix = symbol_conf.source_prefix; + + if (!prefix) { + if (raw_path[0] != '/' && comp_dir) + /* If not an absolute path, try to use comp_dir */ + prefix = comp_dir; + else { + if (access(raw_path, R_OK) == 0) { + *new_path = strdup(raw_path); + return 0; + } else + return -errno; + } } - *new_path = malloc((strlen(symbol_conf.source_prefix) + - strlen(raw_path) + 2)); + *new_path = malloc((strlen(prefix) + strlen(raw_path) + 2)); if (!*new_path) return -ENOMEM; for (;;) { - sprintf(*new_path, "%s/%s", symbol_conf.source_prefix, - raw_path); + sprintf(*new_path, "%s/%s", prefix, raw_path); if (access(*new_path, R_OK) == 0) return 0; + if (!symbol_conf.source_prefix) + /* In case of searching comp_dir, don't retry */ + return -errno; + switch (errno) { case ENAMETOOLONG: case ENOENT: @@ -318,7 +328,7 @@ int show_line_range(struct line_range *lr) /* Convert source file path */ tmp = lr->path; - ret = get_real_path(tmp, &lr->path); + ret = get_real_path(tmp, lr->comp_dir, &lr->path); free(tmp); /* Free old path */ if (ret < 0) { pr_warning("Failed to find source file. (%d)\n", ret); diff --git a/tools/perf/util/probe-event.h b/tools/perf/util/probe-event.h index bc06d3e..ed362ac 100644 --- a/tools/perf/util/probe-event.h +++ b/tools/perf/util/probe-event.h @@ -86,6 +86,7 @@ struct line_range { int end; /* End line number */ int offset; /* Start line offset */ char *path; /* Real path name */ + char *comp_dir; /* Compile directory */ struct list_head line_list; /* Visible lines */ }; diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c index a934a36..37dcdb6 100644 --- a/tools/perf/util/probe-finder.c +++ b/tools/perf/util/probe-finder.c @@ -144,6 +144,15 @@ static const char *cu_find_realpath(Dwarf_Die *cu_die, const char *fname) return src; } +/* Get DW_AT_comp_dir (should be NULL with older gcc) */ +static const char *cu_get_comp_dir(Dwarf_Die *cu_die) +{ + Dwarf_Attribute attr; + if (dwarf_attr(cu_die, DW_AT_comp_dir, &attr) == NULL) + return NULL; + return dwarf_formstring(&attr); +} + /* Compare diename and tname */ static bool die_compare_name(Dwarf_Die *dw_die, const char *tname) { @@ -1374,6 +1383,7 @@ int find_line_range(int fd, struct line_range *lr) size_t cuhl; Dwarf_Die *diep; Dwarf *dbg; + const char *comp_dir; dbg = dwarf_begin(fd, DWARF_C_READ); if (!dbg) { @@ -1409,6 +1419,17 @@ int find_line_range(int fd, struct line_range *lr) } off = noff; } + + /* Store comp_dir */ + if (lf.found) { + comp_dir = cu_get_comp_dir(&lf.cu_die); + if (comp_dir) { + lr->comp_dir = strdup(comp_dir); + if (!lr->comp_dir) + ret = -ENOMEM; + } + } + pr_debug("path: %s\n", lr->path); dwarf_end(dbg); |