[PATCH 6/6] perf-probe: handle gracefully some stupid and buggy line syntaxes

From: Franck Bui-Huu
Date: Mon Dec 20 2010 - 09:18:36 EST


From: Franck Bui-Huu <fbuihuu@xxxxxxxxx>

Currently perf-probe doesn't handle those incorrect syntaxes

$ perf probe -L sched.c:++13
$ perf probe -L sched.c:-+13
$ perf probe -L sched.c:10000000000000000000000000000+13

This patches rewrites parse_line_range_desc() to handle them.

As a bonus side, it reports more usefull error messages instead of:
"Tailing with invalid character...".

Signed-off-by: Franck Bui-Huu <fbuihuu@xxxxxxxxx>
---
tools/perf/util/probe-event.c | 92 ++++++++++++++++++++++++++--------------
1 files changed, 60 insertions(+), 32 deletions(-)

diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
index 1e81936..469ad35 100644
--- a/tools/perf/util/probe-event.c
+++ b/tools/perf/util/probe-event.c
@@ -539,6 +539,19 @@ int show_available_vars(struct perf_probe_event *pevs __unused,
}
#endif

+static int parse_line_num(char **ptr, int *val, const char *what)
+{
+ const char *start = *ptr;
+
+ errno = 0;
+ *val = strtol(*ptr, ptr, 0);
+ if (errno || *ptr == start) {
+ semantic_error("'%s' is not a valid number.\n", what);
+ return -EINVAL;
+ }
+ return 0;
+}
+
/*
* Stuff 'lr' according to the line range described by 'arg'.
* The line range syntax is described by:
@@ -548,50 +561,65 @@ int show_available_vars(struct perf_probe_event *pevs __unused,
*/
int parse_line_range_desc(const char *arg, struct line_range *lr)
{
- const char *ptr;
- char *tmp;
+ char *range, *name = strdup(arg);
+ int err;
+
+ if (!name)
+ return -ENOMEM;
+
+ lr->start = 0;
+ lr->end = INT_MAX;
+
+ range = strchr(name, ':');
+ if (range) {
+ *range++ = '\0';
+
+ err = parse_line_num(&range, &lr->start, "start line");
+ if (err)
+ goto err;
+
+ if (*range == '+' || *range == '-') {
+ const char c = *range++;
+
+ err = parse_line_num(&range, &lr->end, "end line");
+ if (err)
+ goto err;
+
+ if (c == '+') {
+ lr->end += lr->start;
+ /*
+ * Adjust the number of lines here.
+ * If the number of lines == 1, the
+ * the end of line should be equal to
+ * the start of line.
+ */
+ lr->end--;
+ }
+ }

- ptr = strchr(arg, ':');
- if (ptr) {
- lr->start = (int)strtoul(ptr + 1, &tmp, 0);
- if (*tmp == '+') {
- lr->end = lr->start + (int)strtoul(tmp + 1, &tmp, 0);
- lr->end--; /*
- * Adjust the number of lines here.
- * If the number of lines == 1, the
- * the end of line should be equal to
- * the start of line.
- */
- } else if (*tmp == '-')
- lr->end = (int)strtoul(tmp + 1, &tmp, 0);
- else
- lr->end = INT_MAX;
pr_debug("Line range is %d to %d\n", lr->start, lr->end);
+
+ err = -EINVAL;
if (lr->start > lr->end) {
semantic_error("Start line must be smaller"
" than end line.\n");
- return -EINVAL;
+ goto err;
}
- if (*tmp != '\0') {
- semantic_error("Tailing with invalid character '%d'.\n",
- *tmp);
- return -EINVAL;
+ if (*range != '\0') {
+ semantic_error("Tailing with invalid str '%s'.\n", range);
+ goto err;
}
- tmp = strndup(arg, (ptr - arg));
- } else {
- tmp = strdup(arg);
- lr->end = INT_MAX;
}

- if (tmp == NULL)
- return -ENOMEM;
-
- if (strchr(tmp, '.'))
- lr->file = tmp;
+ if (strchr(name, '.'))
+ lr->file = name;
else
- lr->function = tmp;
+ lr->function = name;

return 0;
+err:
+ free(name);
+ return err;
}

/* Check the name is good for event/group */
--
1.7.3.2

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