[PATCH] tracing: Initialize ret in syscall_enter_define_fields()

[PATCH] tracing: Initialize ret in syscall_enter_define_fields()

[Steven Rostedt]

From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>

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.

Link: https://lore.kernel.org/r/0FA8C6E3-D9F5-416D-A1B0-5E4CD583A101@lca.pw
Fixes: 04ae87a52074e ("ftrace: Rework event_create_dir()")
Reported-by: Qian Cai <cai@lca.pw>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
 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 73140d80dd46..2978c29d87d4 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],
-- 
2.20.1

Re: [PATCH] tracing: Initialize ret in syscall_enter_define_fields()

[Peter Zijlstra]

On Wed, Jan 08, 2020 at 08:57:55AM -0500, Steven Rostedt wrote:
> 
> From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
> 
> 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.
> 
> Link: https://lore.kernel.org/r/0FA8C6E3-D9F5-416D-A1B0-5E4CD583A101@lca.pw
> Fixes: 04ae87a52074e ("ftrace: Rework event_create_dir()")
> Reported-by: Qian Cai <cai@lca.pw>
> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

Thanks Steve!