[v4,33/39] perf: Simplify get_perf_callchain() user logic

Commit Message

Josh Poimboeuf Jan. 22, 2025, 2:31 a.m. UTC

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

Acked-by: Namhyung Kim <[e-mail]>
Signed-off-by: Josh Poimboeuf <[e-mail]>
---
 kernel/events/callchain.c | 20 +++++++++-----------
 1 file changed, 9 insertions(+), 11 deletions(-)

Patch

diff --git a/kernel/events/callchain.c b/kernel/events/callchain.c
index 655fb25a725b..2278402b7ac9 100644
--- a/kernel/events/callchain.c
+++ b/kernel/events/callchain.c
@@ -241,22 +241,20 @@  get_perf_callchain(struct pt_regs *regs, bool kernel, bool user,
 
 	if (user) {
 		if (!user_mode(regs)) {
-			if  (current->mm)
-				regs = task_pt_regs(current);
-			else
-				regs = NULL;
+			if (!current->mm)
+				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;