[RFC PATCH v2 1/7] tracing/probe: Check maxactive error cases

Masami Hiramatsu
2019-03-14T04:30:30Z

Check maxactive on kprobe error case, because maxactive
is only for kretprobe, not for kprobe. Also, maxactive
should not be 0, it should be at least 1.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
---
kernel/trace/trace_kprobe.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index d5fb09ebba8b..d47e12596f12 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -624,7 +624,11 @@ static int trace_kprobe_create(int argc, const char *argv[])
if (event)
event++;

- if (is_return && isdigit(argv[0][1])) {
+ if (isdigit(argv[0][1])) {
+ if (!is_return) {
+ pr_info("Maxactive is not for kprobe");
+ return -EINVAL;
+ }
if (event)
len = event - &argv[0][1] - 1;
else
@@ -634,8 +638,8 @@ static int trace_kprobe_create(int argc, const char *argv[])
memcpy(buf, &argv[0][1], len);
buf[len] = '\0';
ret = kstrtouint(buf, 0, &maxactive);
- if (ret) {
- pr_info("Failed to parse maxactive.\n");
+ if (ret || !maxactive) {
+ pr_info("Invalid maxactive number\n");
return ret;
}
/* kretprobes instances are iterated over via a list. The