[tip: core/kprobes] tracing: Initialize ret in syscall_enter_define_fields()

[tip-bot2 for Steven Rostedt (VMware)]

The following commit has been merged into the core/kprobes branch of tip:

Commit-ID:     31537cf8f3f95d45360b995ad8be2c870edc5b02
Gitweb:        https://git.kernel.org/tip/31537cf8f3f95d45360b995ad8be2c870edc5b02
Author:        Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
AuthorDate:    Wed, 08 Jan 2020 08:57:55 -05:00
Committer:     Peter Zijlstra <peterz@xxxxxxxxxxxxx>
CommitterDate: Fri, 17 Jan 2020 10:19:18 +01:00

tracing: Initialize ret in syscall_enter_define_fields()

If syscall_enter_define_fields() is called on a system call with no
arguments, the return code variable "ret" will never get initialized.
Initialize it to zero.

Fixes: 04ae87a52074e ("ftrace: Rework event_create_dir()")
Reported-by: Qian Cai <cai@xxxxxx>
Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/0FA8C6E3-D9F5-416D-A1B0-5E4CD583A101@xxxxxx
---
 kernel/trace/trace_syscalls.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c
index 73140d8..2978c29 100644
--- a/kernel/trace/trace_syscalls.c
+++ b/kernel/trace/trace_syscalls.c
@@ -274,7 +274,8 @@ static int __init syscall_enter_define_fields(struct trace_event_call *call)
 	struct syscall_trace_enter trace;
 	struct syscall_metadata *meta = call->data;
 	int offset = offsetof(typeof(trace), args);
-	int ret, i;
+	int ret = 0;
+	int i;
 
 	for (i = 0; i < meta->nb_args; i++) {
 		ret = trace_define_field(call, meta->types[i],