Commit 7cf0b79e authored by Masami Hiramatsu's avatar Masami Hiramatsu Committed by Arnaldo Carvalho de Melo

perf probe: Fix error message if get_real_path() failed

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@hitachi.com>
Cc: Chase Douglas <chase.douglas@canonical.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Acked-by: default avatarChase Douglas <chase.douglas@canonical.com>
Signed-off-by: default avatarMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 0dd9ac63
......@@ -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)
......
......@@ -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 @@ int find_perf_probe_point(int fd, unsigned long addr,
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;
......
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