From nobody Thu Dec 18 08:30:37 2025 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C5B81266572; Mon, 24 Feb 2025 18:36:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=193.142.43.55 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740422203; cv=none; b=cnTj4hMiw/2P5ykqDu8JjGK1bZ9H1Dsb0mvBJef6gLA6fFZeBfUesBkUnWk3ig241FJ/0F+wRUbggwH9Zv3vvO8C5Q0I553PmgdScq9GS0WwwAeza72MckCq8L2DUftSbTBcQkVmyWuVjeObfChEbj6WnzD3Ka5n1gvKNklBoH4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740422203; c=relaxed/simple; bh=0OOQOk1ZnJvAAWZOrlMhlnGqbC5S/BxglUYn7c+m+7Y=; h=Date:From:To:Subject:Cc:In-Reply-To:References:MIME-Version: Message-ID:Content-Type; b=lxbDxFU8SETGxi6GuAb/H+bMNtSt+2DdIDIVRLBf/EgoHZHepqDaOcsJlcI2YcZzV8VquOQw9PJuiVb+XlYxmp2T6HnzKR0TOpBgpUWTEZlFF+M4Xj6OlFoy+Z19GKPEGxlC0pLIOCxThNSDzfSxv9J+cNgDSxM28V+WWX+3YRQ= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de; spf=pass smtp.mailfrom=linutronix.de; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=mUc4jY4r; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=Sltbqph7; arc=none smtp.client-ip=193.142.43.55 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linutronix.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="mUc4jY4r"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="Sltbqph7" Date: Mon, 24 Feb 2025 18:36:38 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1740422199; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=3YdY6dX/V8XAG25x3F3g6c2bm9h3Ih0E7bzan2RKkkM=; b=mUc4jY4rZlEve/sGKYtuYEhibivr3XdOykuoMj05jRIRK3wkBARqJ3CPRc3HEobFCakiYn luyU8js7FzbbI95WSeOqt3xgNINA3r+b5vVi4qCU97S6NT94fhjpHmpqtxb/6MxzS35LNJ rJkWRcOliZxAgni1rKqE+gYK1oXMm+TIW+5xJJakU8IdrSbpR0YSKaFzkXZ9VcsUmVqCI6 lAkUiBkWv+KAmElAYbfIVXrdajonsBEzWo+UjUVvP0g8FzFQXJO25FoFo11pTdLhgl/MAs cqVIZhIzjTO1DLMvjobZWjfjFa4/nhaYnU3mWWi2QtVvmSYsUwvtu1RZlOakbA== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1740422199; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=3YdY6dX/V8XAG25x3F3g6c2bm9h3Ih0E7bzan2RKkkM=; b=Sltbqph7mWmNONlnPt6QCI6u6ZVmesTz+yVNmKLcLKlX8hJOnxXpctVMgFYkUkM6JeQswS kwnLxgmJFJ56k4Cg== From: "tip-bot2 for Breno Leitao" Sender: tip-bot2@linutronix.de Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: perf/urgent] perf/core: Add RCU read lock protection to perf_iterate_ctx() Cc: Breno Leitao , Ingo Molnar , "Peter Zijlstra (Intel)" , stable@vger.kernel.org, x86@kernel.org, linux-kernel@vger.kernel.org In-Reply-To: <20250117-fix_perf_rcu-v1-1-13cb9210fc6a@debian.org> References: <20250117-fix_perf_rcu-v1-1-13cb9210fc6a@debian.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-ID: <174042219873.10177.3901726341080483847.tip-bot2@tip-bot2> Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Precedence: bulk Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable The following commit has been merged into the perf/urgent branch of tip: Commit-ID: 0fe8813baf4b2e865d3b2c735ce1a15b86002c74 Gitweb: https://git.kernel.org/tip/0fe8813baf4b2e865d3b2c735ce1a15b8= 6002c74 Author: Breno Leitao AuthorDate: Fri, 17 Jan 2025 06:41:07 -08:00 Committer: Ingo Molnar CommitterDate: Mon, 24 Feb 2025 19:17:04 +01:00 perf/core: Add RCU read lock protection to perf_iterate_ctx() The perf_iterate_ctx() function performs RCU list traversal but currently lacks RCU read lock protection. This causes lockdep warnings when running perf probe with unshare(1) under CONFIG_PROVE_RCU_LIST=3Dy: WARNING: suspicious RCU usage kernel/events/core.c:8168 RCU-list traversed in non-reader section!! Call Trace: lockdep_rcu_suspicious ? perf_event_addr_filters_apply perf_iterate_ctx perf_event_exec begin_new_exec ? load_elf_phdrs load_elf_binary ? lock_acquire ? find_held_lock ? bprm_execve bprm_execve do_execveat_common.isra.0 __x64_sys_execve do_syscall_64 entry_SYSCALL_64_after_hwframe This protection was previously present but was removed in commit bd2756811766 ("perf: Rewrite core context handling"). Add back the necessary rcu_read_lock()/rcu_read_unlock() pair around perf_iterate_ctx() call in perf_event_exec(). [ mingo: Use scoped_guard() as suggested by Peter ] Fixes: bd2756811766 ("perf: Rewrite core context handling") Signed-off-by: Breno Leitao Signed-off-by: Ingo Molnar Acked-by: Peter Zijlstra (Intel) Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20250117-fix_perf_rcu-v1-1-13cb9210fc6a@deb= ian.org --- kernel/events/core.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/kernel/events/core.c b/kernel/events/core.c index bcb09e0..7dabbca 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -8321,7 +8321,8 @@ void perf_event_exec(void) =20 perf_event_enable_on_exec(ctx); perf_event_remove_on_exec(ctx); - perf_iterate_ctx(ctx, perf_event_addr_filters_exec, NULL, true); + scoped_guard(rcu) + perf_iterate_ctx(ctx, perf_event_addr_filters_exec, NULL, true); =20 perf_unpin_context(ctx); put_ctx(ctx);