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 B985E1A6192; Tue, 30 Jul 2024 16:35:27 +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=1722357327; cv=none; b=S9/kw/1LMDlBPUszTH9rf/uInsm6teJAVB28J+c90huOEsqF9TrhLSTiEIXTZ3oEFPk/BuyUd0OsmVxNrRs/bSGBl/jsLhX4GBxDRJFTCcv2hHcqrp3wRCLisqpgL0niUDiRZw/R2H7mKiGRKYwQvvDOhN9g/vY+1I8l7AHmbmk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722357327; c=relaxed/simple; bh=Oz6QvzP7/8lzR4vErGJj/RVN8Itur8Y1YAu6NMObZJM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=YDITHrwWfVAreFTQGOd0F2YZCrIs1Apk/C7Kt4R51XnzefSifXoj5fZrMwqlj6M9FHFQruQ7TaPnbTA2lqphazl5rLdHjjOUibv95gTqDbuUmoU31ngJEVubg2DyZsshInpYeEHtAKwLUUNNwCa464I+Ab4jpAK/ujXneakfP+w= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=ISaWNAnV; 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="ISaWNAnV" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3ED1FC4AF10; Tue, 30 Jul 2024 16:35:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1722357327; bh=Oz6QvzP7/8lzR4vErGJj/RVN8Itur8Y1YAu6NMObZJM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ISaWNAnVj4nAvUBRYQMWXSk9WcL7fiS8H2cBd8mNYw9HKKtvLtniypoDMA4rD2l4q 4qOkpX7yxezWV4Jl8U6KSoNOTQZ583CHFpdH0u4mvW2HHAWSpHGpOP4T1FGNknjwsl ybnUDZV5kBDHs7kCkC5Cxpr7NyIqow6FZ2CrnrsU= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Adrian Hunter , "Peter Zijlstra (Intel)" , Sasha Levin Subject: [PATCH 6.10 225/809] perf: Fix default aux_watermark calculation Date: Tue, 30 Jul 2024 17:41:41 +0200 Message-ID: <20240730151733.494906361@linuxfoundation.org> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20240730151724.637682316@linuxfoundation.org> References: <20240730151724.637682316@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 6.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Adrian Hunter [ Upstream commit 43deb76b19663a96ec2189d8f4eb9a9dc2d7623f ] The default aux_watermark is half the AUX area buffer size. In general, on a 64-bit architecture, the AUX area buffer size could be a bigger than fits in a 32-bit type, but the calculation does not allow for that possibility. However the aux_watermark value is recorded in a u32, so should not be more than U32_MAX either. Fix by doing the calculation in a correctly sized type, and limiting the result to U32_MAX. Fixes: d68e6799a5c8 ("perf: Cap allocation order at aux_watermark") Signed-off-by: Adrian Hunter Signed-off-by: Peter Zijlstra (Intel) Link: https://lore.kernel.org/r/20240624201101.60186-7-adrian.hunter@intel.com Signed-off-by: Sasha Levin --- kernel/events/ring_buffer.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/kernel/events/ring_buffer.c b/kernel/events/ring_buffer.c index 4013408ce0123..485cf0a66631b 100644 --- a/kernel/events/ring_buffer.c +++ b/kernel/events/ring_buffer.c @@ -688,7 +688,9 @@ int rb_alloc_aux(struct perf_buffer *rb, struct perf_event *event, * max_order, to aid PMU drivers in double buffering. */ if (!watermark) - watermark = nr_pages << (PAGE_SHIFT - 1); + watermark = min_t(unsigned long, + U32_MAX, + (unsigned long)nr_pages << (PAGE_SHIFT - 1)); /* * Use aux_watermark as the basis for chunking to -- 2.43.0