[PATCH] fgraph: Make sure fregs is non-null when accessing

[sunliming]

From: sunliming <sunliming@xxxxxxxxxx>

Fix below smatch warnings:
kernel/trace/fgraph.c:834 __ftrace_return_to_handler() error: we previously
assumed 'fregs' could be null (see line 830)

Reported-by: kernel test robot <lkp@xxxxxxxxx>
Reported-by: Dan Carpenter <error27@xxxxxxxxx>
Closes: https://lore.kernel.org/r/202512131657.JQUt5fXQ-lkp@xxxxxxxxx/
Signed-off-by: sunliming <sunliming@xxxxxxxxxx>
---
 kernel/trace/fgraph.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/kernel/trace/fgraph.c b/kernel/trace/fgraph.c
index cc48d16be43e..0f50a55032c5 100644
--- a/kernel/trace/fgraph.c
+++ b/kernel/trace/fgraph.c
@@ -837,7 +837,8 @@ __ftrace_return_to_handler(struct ftrace_regs *fregs, unsigned long frame_pointe
 		goto out;
 
 #ifdef CONFIG_FUNCTION_GRAPH_RETVAL
-	trace.retval = ftrace_regs_get_return_value(fregs);
+	if (fregs)
+		trace.retval = ftrace_regs_get_return_value(fregs);
 #endif
 
 	bitmap = get_bitmap_bits(current, offset);
-- 
2.25.1