From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 E16661774B; Thu, 18 Jan 2024 10:55:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705575305; cv=none; b=DB9p4YvMqgwyq96RlHRDJk9Zg1NfbhZjjnCOIrbSVhMD57OZiOnRZ6KnWThmAvMVaI+XL7yRgvRZn8Cr0igiDrXeycM1TbtqUXAJ42WTOiIluqBBKMfDIb7WOeeWkAHRlRlWgiwGt3yEzoZ7nF/n+LRW55mz+49OBcl/Ymw7+Ic= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705575305; c=relaxed/simple; bh=sQy3sHiCI3SeWNqRE/Dl6j1vBNJ50JW21KoA1BvWmZU=; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID: X-Mailer:In-Reply-To:References:User-Agent:X-stable: X-Patchwork-Hint:MIME-Version:Content-Transfer-Encoding; b=clVLDq/CWadJFMjXfJHLc+orwAEuYzuVQBsVCY/0ZcSJWEnnE8gWT7Np5IutAn+8/d1kirqIppwgVdajs5cpPMX26ckQ5nU/tlPRtmVLthvAmTAfl7rPzZ09loiSbrfI6SIG6i5fj16clIAIt4KbCShZ2hGP3MTC43vOUhqUBeI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=aq0dZ049; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="aq0dZ049" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 668CAC433C7; Thu, 18 Jan 2024 10:55:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1705575304; bh=sQy3sHiCI3SeWNqRE/Dl6j1vBNJ50JW21KoA1BvWmZU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=aq0dZ049Sn7xSmPKikBFHG2Z9fqWYFq0w5xmgOikfx+2oIilZqOQZftk35HqCzxHR oemyl+rjjva46iJJU/W1VkzTcfCiTnV9MHO779Ytr1xnH+RcymLKilL8DsMMKUBUPZ kcAqENrpLAurjK0QnL3XFnKBtDSKSEErWA4Kx2g8= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Masami Hiramatsu , Mark Rutland , Mathieu Desnoyers , "Steven Rostedt (Google)" , Sasha Levin Subject: [PATCH 6.6 084/150] ring-buffer: Do not record in NMI if the arch does not support cmpxchg in NMI Date: Thu, 18 Jan 2024 11:48:26 +0100 Message-ID: <20240118104323.856578567@linuxfoundation.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240118104320.029537060@linuxfoundation.org> References: <20240118104320.029537060@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Steven Rostedt (Google) [ Upstream commit 712292308af2265cd9b126aedfa987f10f452a33 ] As the ring buffer recording requires cmpxchg() to work, if the architecture does not support cmpxchg in NMI, then do not do any recording within an NMI. Link: https://lore.kernel.org/linux-trace-kernel/20231213175403.6fc18540@gandalf.local.home Cc: Masami Hiramatsu Cc: Mark Rutland Cc: Mathieu Desnoyers Signed-off-by: Steven Rostedt (Google) Signed-off-by: Sasha Levin --- kernel/trace/ring_buffer.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 901a140e30fa..f232cf56fa05 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -3649,6 +3649,12 @@ rb_reserve_next_event(struct trace_buffer *buffer, int nr_loops = 0; int add_ts_default; + /* ring buffer does cmpxchg, make sure it is safe in NMI context */ + if (!IS_ENABLED(CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG) && + (unlikely(in_nmi()))) { + return NULL; + } + rb_start_commit(cpu_buffer); /* The commit page can not change after this */ -- 2.43.0