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From: Arnaldo Carvalho de Melo on 16 Jul 2010 14:10
From: Masami Hiramatsu <masami.hiramatsu.pt(a)hitachi.com>

Perf probe -L shows incorrect error message (Dwarf error) if it fails to find
source file. This can confuse users.

# ./perf probe -s /nowhere -L vfs_read
Debuginfo analysis failed. (-2)
Error: Failed to show lines. (-2)

With this patch, it shows correct message.

# ./perf probe -s /nowhere -L vfs_read
Failed to find source file. (-2)
Error: Failed to show lines. (-2)

LKML-Reference: <4C36EBDB.4020308(a)hitachi.com>
Cc: Chase Douglas <chase.douglas(a)canonical.com>
Cc: Arnaldo Carvalho de Melo <acme(a)redhat.com>
Cc: Ingo Molnar <mingo(a)elte.hu>
Acked-by: Chase Douglas <chase.douglas(a)canonical.com>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt(a)hitachi.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme(a)redhat.com>
---
tools/perf/util/probe-event.c | 59 ++++++++++++++++++++++++++++++++++++++
tools/perf/util/probe-finder.c | 61 +++------------------------------------
2 files changed, 64 insertions(+), 56 deletions(-)

diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
index 09cf546..8d08e75 100644
--- a/tools/perf/util/probe-event.c
+++ b/tools/perf/util/probe-event.c
@@ -195,6 +195,55 @@ static int try_to_find_kprobe_trace_events(struct perf_probe_event *pev,
return ntevs;
}

+/*
+ * Find a src file from a DWARF tag path. Prepend optional source path prefix
+ * and chop off leading directories that do not exist. Result is passed back as
+ * 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)
+{
+ if (!symbol_conf.source_prefix) {
+ 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));
+ if (!*new_path)
+ return -ENOMEM;
+
+ for (;;) {
+ sprintf(*new_path, "%s/%s", symbol_conf.source_prefix,
+ raw_path);
+
+ if (access(*new_path, R_OK) == 0)
+ return 0;
+
+ switch (errno) {
+ case ENAMETOOLONG:
+ case ENOENT:
+ case EROFS:
+ case EFAULT:
+ raw_path = strchr(++raw_path, '/');
+ if (!raw_path) {
+ free(*new_path);
+ *new_path = NULL;
+ return -ENOENT;
+ }
+ continue;
+
+ default:
+ free(*new_path);
+ *new_path = NULL;
+ return -errno;
+ }
+ }
+}
+
#define LINEBUF_SIZE 256
#define NR_ADDITIONAL_LINES 2

@@ -244,6 +293,7 @@ int show_line_range(struct line_range *lr)
struct line_node *ln;
FILE *fp;
int fd, ret;
+ char *tmp;

/* Search a line range */
ret = init_vmlinux();
@@ -266,6 +316,15 @@ int show_line_range(struct line_range *lr)
return ret;
}

+ /* Convert source file path */
+ tmp = lr->path;
+ ret = get_real_path(tmp, &lr->path);
+ free(tmp); /* Free old path */
+ if (ret < 0) {
+ pr_warning("Failed to find source file. (%d)\n", ret);
+ return ret;
+ }
+
setup_pager();

if (lr->function)
diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c
index 3e64e1f..a934a36 100644
--- a/tools/perf/util/probe-finder.c
+++ b/tools/perf/util/probe-finder.c
@@ -58,55 +58,6 @@ static int strtailcmp(const char *s1, const char *s2)
return 0;
}

-/*
- * Find a src file from a DWARF tag path. Prepend optional source path prefix
- * and chop off leading directories that do not exist. Result is passed back as
- * 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)
-{
- if (!symbol_conf.source_prefix) {
- 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));
- if (!*new_path)
- return -ENOMEM;
-
- for (;;) {
- sprintf(*new_path, "%s/%s", symbol_conf.source_prefix,
- raw_path);
-
- if (access(*new_path, R_OK) == 0)
- return 0;
-
- switch (errno) {
- case ENAMETOOLONG:
- case ENOENT:
- case EROFS:
- case EFAULT:
- raw_path = strchr(++raw_path, '/');
- if (!raw_path) {
- free(*new_path);
- *new_path = NULL;
- return -ENOENT;
- }
- continue;
-
- default:
- free(*new_path);
- *new_path = NULL;
- return -errno;
- }
- }
-}
-
/* Line number list operations */

/* Add a line to line number list */
@@ -1256,13 +1207,11 @@ end:
static int line_range_add_line(const char *src, unsigned int lineno,
struct line_range *lr)
{
- int ret;
-
- /* Copy real path */
+ /* Copy source path */
if (!lr->path) {
- ret = get_real_path(src, &lr->path);
- if (ret != 0)
- return ret;
+ lr->path = strdup(src);
+ if (lr->path == NULL)
+ return -ENOMEM;
}
return line_list__add_line(&lr->line_list, lineno);
}
@@ -1460,7 +1409,7 @@ int find_line_range(int fd, struct line_range *lr)
}
off = noff;
}
- pr_debug("path: %lx\n", (unsigned long)lr->path);
+ pr_debug("path: %s\n", lr->path);
dwarf_end(dbg);

return (ret < 0) ? ret : lf.found;
--
1.6.2.5

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Prev: pci/mrst: Detect loops when reading fixed BAR cap.
Next: [GIT PULL 0/1] perf/urgent fixes