[for-next][PATCH 08/11] tracing/perf: Use strndup_user instead of kzalloc/strncpy_from_user

Steven Rostedt
2022-11-24T14:51:42Z

From: Chuang Wang <nashuiliang@gmail.com>

This patch uses strndup_user instead of kzalloc + strncpy_from_user,
which makes the code more concise.

Link: https://lkml.kernel.org/r/20221121080831.707409-1-nashuiliang@gmail.com

Signed-off-by: Chuang Wang <nashuiliang@gmail.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---
kernel/trace/trace_event_perf.c | 16 ++++++----------
1 file changed, 6 insertions(+), 10 deletions(-)

diff --git a/kernel/trace/trace_event_perf.c b/kernel/trace/trace_event_perf.c
index 61e3a2620fa3..05e791241812 100644
--- a/kernel/trace/trace_event_perf.c
+++ b/kernel/trace/trace_event_perf.c
@@ -251,16 +251,12 @@ int perf_kprobe_init(struct perf_event *p_event, bool is_retprobe)
struct trace_event_call *tp_event;

if (p_event->attr.kprobe_func) {
- func = kzalloc(KSYM_NAME_LEN, GFP_KERNEL);
- if (!func)
- return -ENOMEM;
- ret = strncpy_from_user(
- func, u64_to_user_ptr(p_event->attr.kprobe_func),
- KSYM_NAME_LEN);
- if (ret == KSYM_NAME_LEN)
- ret = -E2BIG;
- if (ret < 0)
- goto out;
+ func = strndup_user(u64_to_user_ptr(p_event->attr.kprobe_func),
+ KSYM_NAME_LEN);
+ if (IS_ERR(func)) {
+ ret = PTR_ERR(func);
+ return (ret == -EINVAL) ? -E2BIG : ret;
+ }

if (func[0] == '\0') {
kfree(func);
--
2.35.1