On Wed, 29 Mar 2017 00:23:35 +0900
Masami Hiramatsu <mhira...@kernel.org> wrote:
> > @@ -598,8 +601,10 @@ static int create_trace_kprobe(int argc, char **argv)
> > {
> > /*
> > * Argument syntax:
> > - * - Add kprobe: p[:[GRP/]EVENT] [MOD:]KSYM[+OFFS]|KADDR [FETCHARGS]
> > - * - Add kretprobe: r[:[GRP/]EVENT] [MOD:]KSYM[+0] [FETCHARGS]
> > + * - Add kprobe:
> > + * p[:[GRP/]EVENT] [MOD:]KSYM[+OFFS]|KADDR [FETCHARGS]
> > + * - Add kretprobe:
> > + * r[MAXACTIVE][:[GRP/]EVENT] [MOD:]KSYM[+0] [FETCHARGS]
> > * Fetch args:
> > * $retval : fetch return value
> > * $stack : fetch stack address
> > @@ -619,6 +624,7 @@ static int create_trace_kprobe(int argc, char **argv)
> > int i, ret = 0;
> > bool is_return = false, is_delete = false;
> > char *symbol = NULL, *event = NULL, *group = NULL;
> > + int maxactive = 0;
> > char *arg;
> > unsigned long offset = 0;
> > void *addr = NULL;
> > @@ -637,8 +643,26 @@ static int create_trace_kprobe(int argc, char **argv)
> > return -EINVAL;
> > }
> >
> > - if (argv[0][1] == ':') {
> > + if (is_return && isdigit(argv[0][1]) && strchr(&argv[0][1], ':')) {
>
> This only supports r[MAXACTIVE:[GRP/]EVENT]. e.g "r100" without event name.
You mean it doesn't support adding MAXACTIVE without the ':event'.
>
> Thank you,
>
> > + event = strchr(&argv[0][1], ':') + 1;
> > + event[-1] = '\0';
> > + ret = kstrtouint(&argv[0][1], 0, &maxactive);
> > + if (ret) {
> > + pr_info("Failed to parse maxactive.\n");
> > + return ret;
> > + }
> > + /* kretprobes instances are iterated over via a list. The
> > + * maximum should stay reasonable.
> > + */
> > + if (maxactive > 1024) {
Also, can we get rid of magic numbers within the code. There should be a
const or macro defined as MAX_MAXACTIVE or something, and use that here.
-- Steve
> > + pr_info("Maxactive is too big.\n");
> > + return -EINVAL;
> > + }
> > + } else if (argv[0][1] == ':') {
> > event = &argv[0][2];
> > + }
> > +
> > + if (event) {
> > if (strchr(event, '/')) {
> > group = event;
> > event = strchr(group, '/') + 1;
> > @@ -718,8 +742,8 @@ static int create_trace_kprobe(int argc, char **argv)
> > is_return ? 'r' : 'p', addr);
> > event = buf;
> > }
> > - tk = alloc_trace_kprobe(group, event, addr, symbol, offset, argc,
> > - is_return);
> > + tk = alloc_trace_kprobe(group, event, addr, symbol, offset, maxactive,
> > + argc, is_return);
> > if (IS_ERR(tk)) {
> > pr_info("Failed to allocate trace_probe.(%d)\n",
> > (int)PTR_ERR(tk));
> > --
> > 2.7.4
> >
>
>
