[PATCH 6.12.y 1/2] perf: Simplify get_perf_callchain() user logic

[Sasha Levin <sashal@kernel.org>]

From: Josh Poimboeuf <jpoimboe@kernel.org>

[ Upstream commit d77e3319e31098a6cb97b7ce4e71ba676e327fd7 ]

Simplify the get_perf_callchain() user logic a bit.  task_pt_regs()
should never be NULL.

Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20250820180428.760066227@kernel.org
Stable-dep-of: 76ed27608f7d ("perf: sched: Fix perf crash with new is_user_task() helper")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 kernel/events/callchain.c | 18 ++++++++----------
 1 file changed, 8 insertions(+), 10 deletions(-)

diff --git a/kernel/events/callchain.c b/kernel/events/callchain.c
index 677901f456a94..012a2c9a9babe 100644
--- a/kernel/events/callchain.c
+++ b/kernel/events/callchain.c
@@ -246,21 +246,19 @@ get_perf_callchain(struct pt_regs *regs, bool kernel, bool user,
 	if (user && !crosstask) {
 		if (!user_mode(regs)) {
 			if (current->flags & (PF_KTHREAD | PF_USER_WORKER))
-				regs = NULL;
-			else
-				regs = task_pt_regs(current);
+				goto exit_put;
+			regs = task_pt_regs(current);
 		}
 
-		if (regs) {
-			if (add_mark)
-				perf_callchain_store_context(&ctx, PERF_CONTEXT_USER);
+		if (add_mark)
+			perf_callchain_store_context(&ctx, PERF_CONTEXT_USER);
 
-			start_entry_idx = entry->nr;
-			perf_callchain_user(&ctx, regs);
-			fixup_uretprobe_trampoline_entries(entry, start_entry_idx);
-		}
+		start_entry_idx = entry->nr;
+		perf_callchain_user(&ctx, regs);
+		fixup_uretprobe_trampoline_entries(entry, start_entry_idx);
 	}
 
+exit_put:
 	put_callchain_entry(rctx);
 
 	return entry;
-- 
2.51.0