linux-kernel - [tip: perf/core] unwind: Simplify unwind_user

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Message-ID: <176173057456.2601451.3608458082589938407.tip-bot2@tip-bot2>
Date: Wed, 29 Oct 2025 09:36:14 -0000
From: "tip-bot2 for Peter Zijlstra" <tip-bot2@...utronix.de>
To: linux-tip-commits@...r.kernel.org
Cc: "Peter Zijlstra (Intel)" <peterz@...radead.org>, x86@...nel.org,
 linux-kernel@...r.kernel.org
Subject: [tip: perf/core] unwind: Simplify unwind_user_faultable()

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

Commit-ID:     42b9138f81fc22c36128f9524bb21bc9eabfb1b8
Gitweb:        https://git.kernel.org/tip/42b9138f81fc22c36128f9524bb21bc9eabfb1b8
Author:        Peter Zijlstra <peterz@...radead.org>
AuthorDate:    Mon, 22 Sep 2025 15:49:14 +02:00
Committer:     Peter Zijlstra <peterz@...radead.org>
CommitterDate: Wed, 29 Oct 2025 10:29:56 +01:00

unwind: Simplify unwind_user_faultable()

Signed-off-by: Peter Zijlstra (Intel) <peterz@...radead.org>
Link: https://patch.msgid.link/20250924080119.271671514@infradead.org
---
 kernel/unwind/deferred.c | 15 ++++++---------
 1 file changed, 6 insertions(+), 9 deletions(-)

diff --git a/kernel/unwind/deferred.c b/kernel/unwind/deferred.c
index 6395192..09617d8 100644
--- a/kernel/unwind/deferred.c
+++ b/kernel/unwind/deferred.c
@@ -128,17 +128,14 @@ int unwind_user_faultable(struct unwind_stacktrace *trace)
 
 	cache = info->cache;
 	trace->entries = cache->entries;
-
-	if (cache->nr_entries) {
-		/*
-		 * The user stack has already been previously unwound in this
-		 * entry context.  Skip the unwind and use the cache.
-		 */
-		trace->nr = cache->nr_entries;
+	trace->nr = cache->nr_entries;
+	/*
+	 * The user stack has already been previously unwound in this
+	 * entry context.  Skip the unwind and use the cache.
+	 */
+	if (trace->nr)
 		return 0;
-	}
 
-	trace->nr = 0;
 	unwind_user(trace, UNWIND_MAX_ENTRIES);
 
 	cache->nr_entries = trace->nr;