linux-kernel - [PATCH v2 05/24] perf: Simplify perf_event_release

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20250205102448.789958355@infradead.org>
Date: Wed, 05 Feb 2025 11:21:25 +0100
From: Peter Zijlstra <peterz@...radead.org>
To: mingo@...nel.org,
 ravi.bangoria@....com,
 lucas.demarchi@...el.com
Cc: linux-kernel@...r.kernel.org,
 peterz@...radead.org,
 willy@...radead.org,
 acme@...nel.org,
 namhyung@...nel.org,
 mark.rutland@....com,
 alexander.shishkin@...ux.intel.com,
 jolsa@...nel.org,
 irogers@...gle.com,
 adrian.hunter@...el.com,
 kan.liang@...ux.intel.com
Subject: [PATCH v2 05/24] perf: Simplify perf_event_release_kernel()

Get rid of the free_list...

Signed-off-by: Peter Zijlstra (Intel) <peterz@...radead.org>
---
 kernel/events/core.c |   12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)

--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -5462,7 +5462,6 @@ int perf_event_release_kernel(struct per
 {
 	struct perf_event_context *ctx = event->ctx;
 	struct perf_event *child, *tmp;
-	LIST_HEAD(free_list);
 
 	/*
 	 * If we got here through err_alloc: free_event(event); we will not
@@ -5531,27 +5530,26 @@ int perf_event_release_kernel(struct per
 					       struct perf_event, child_list);
 		if (tmp == child) {
 			perf_remove_from_context(child, DETACH_GROUP | DETACH_CHILD);
-			list_add(&child->child_list, &free_list);
 			/*
 			 * This matches the refcount bump in inherit_event();
 			 * this can't be the last reference.
 			 */
 			put_event(event);
+		} else {
+			child = NULL;
 		}
 
 		mutex_unlock(&event->child_mutex);
 		mutex_unlock(&ctx->mutex);
+
+		if (child)
+			free_event(child);
 		put_ctx(ctx);
 
 		goto again;
 	}
 	mutex_unlock(&event->child_mutex);
 
-	list_for_each_entry_safe(child, tmp, &free_list, child_list) {
-		list_del(&child->child_list);
-		free_event(child);
-	}
-
 no_ctx:
 	put_event(event); /* Must be the 'last' reference */
 	return 0;