Re: [PATCH 6/6] perf-probe: handle gracefully some stupid and buggyline syntaxes

From: Masami Hiramatsu
Date: Tue Dec 21 2010 - 08:11:12 EST


(2010/12/20 23:18), Franck Bui-Huu wrote:
> 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.

OK, without this patch, perf probe accepted that as "0+13".
With this, perf probe rejects it as an invalid input.

Thank you!

>
> As a bonus side, it reports more usefull error messages instead of:
> "Tailing with invalid character...".
>
> Signed-off-by: Franck Bui-Huu <fbuihuu@xxxxxxxxx>

Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@xxxxxxxxxxx>

> ---
> 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 */


--
Masami HIRAMATSU
2nd Dept. Linux Technology Center
Hitachi, Ltd., Systems Development Laboratory
E-mail: masami.hiramatsu.pt@xxxxxxxxxxx
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/