From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 457B0C433EF for ; Tue, 5 Jul 2022 12:15:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235502AbiGEMPd (ORCPT ); Tue, 5 Jul 2022 08:15:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54392 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232512AbiGEMOC (ORCPT ); Tue, 5 Jul 2022 08:14:02 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E114818E25; Tue, 5 Jul 2022 05:11:18 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 7DCF4619BF; Tue, 5 Jul 2022 12:11:18 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 89265C341C7; Tue, 5 Jul 2022 12:11:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1657023077; bh=dy7bOytgF344lIFWXNRmT21pW2lZa+vQbXwQxR7s3v4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=QcJJ38o9hiIogKceuO0WxPs2lvmnO+tjVKmIBlw/K0fJQoZ8c3GQLBMzDmxuE1a0H /Wwmf3y2R8aKcRz4qhEAlpgMC75xyTeC2xWObtkAmqEfKt7/Iumjdiyl30JFuPNiXF hT5RFgsepo6kCDxweB9hWqfUKCoyy9poP2vSHmpI= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Tao Liu , Max Gurtovoy , Leon Romanovsky , Jason Gunthorpe Subject: [PATCH 5.15 29/98] linux/dim: Fix divide by 0 in RDMA DIM Date: Tue, 5 Jul 2022 13:57:47 +0200 Message-Id: <20220705115618.419776878@linuxfoundation.org> X-Mailer: git-send-email 2.37.0 In-Reply-To: <20220705115617.568350164@linuxfoundation.org> References: <20220705115617.568350164@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Tao Liu commit 0fe3dbbefb74a8575f61d7801b08dbc50523d60d upstream. Fix a divide 0 error in rdma_dim_stats_compare() when prev->cpe_ratio == 0. CallTrace: Hardware name: H3C R4900 G3/RS33M2C9S, BIOS 2.00.37P21 03/12/2020 task: ffff880194b78000 task.stack: ffffc90006714000 RIP: 0010:backport_rdma_dim+0x10e/0x240 [mlx_compat] RSP: 0018:ffff880c10e83ec0 EFLAGS: 00010202 RAX: 0000000000002710 RBX: ffff88096cd7f780 RCX: 0000000000000064 RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000001 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 000000001d7c6c09 R13: ffff88096cd7f780 R14: ffff880b174fe800 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff880c10e80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000a0965b00 CR3: 000000000200a003 CR4: 00000000007606e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: ib_poll_handler+0x43/0x80 [ib_core] irq_poll_softirq+0xae/0x110 __do_softirq+0xd1/0x28c irq_exit+0xde/0xf0 do_IRQ+0x54/0xe0 common_interrupt+0x8f/0x8f ? cpuidle_enter_state+0xd9/0x2a0 ? cpuidle_enter_state+0xc7/0x2a0 ? do_idle+0x170/0x1d0 ? cpu_startup_entry+0x6f/0x80 ? start_secondary+0x1b9/0x210 ? secondary_startup_64+0xa5/0xb0 Code: 0f 87 e1 00 00 00 8b 4c 24 14 44 8b 43 14 89 c8 4d 63 c8 44 29 c0 99 31 d0 29 d0 31 d2 48 98 48 8d 04 80 48 8d 04 80 48 c1 e0 02 <49> f7 f1 48 83 f8 0a 0f 86 c1 00 00 00 44 39 c1 7f 10 48 89 df RIP: backport_rdma_dim+0x10e/0x240 [mlx_compat] RSP: ffff880c10e83ec0 Fixes: f4915455dcf0 ("linux/dim: Implement RDMA adaptive moderation (DIM)") Link: https://lore.kernel.org/r/20220627140004.3099-1-thomas.liu@ucloud.cn Signed-off-by: Tao Liu Reviewed-by: Max Gurtovoy Acked-by: Leon Romanovsky Signed-off-by: Jason Gunthorpe Signed-off-by: Greg Kroah-Hartman --- include/linux/dim.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/include/linux/dim.h +++ b/include/linux/dim.h @@ -21,7 +21,7 @@ * We consider 10% difference as significant. */ #define IS_SIGNIFICANT_DIFF(val, ref) \ - (((100UL * abs((val) - (ref))) / (ref)) > 10) + ((ref) && (((100UL * abs((val) - (ref))) / (ref)) > 10)) /* * Calculate the gap between two values.