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 8B240C77B7E for ; Sun, 28 May 2023 19:23:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229994AbjE1TXY (ORCPT ); Sun, 28 May 2023 15:23:24 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40882 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229993AbjE1TXY (ORCPT ); Sun, 28 May 2023 15:23:24 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 29DE9A0 for ; Sun, 28 May 2023 12:23:23 -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 BC1B660EE0 for ; Sun, 28 May 2023 19:23:22 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id DA0EDC433EF; Sun, 28 May 2023 19:23:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1685301802; bh=LGa5rmrsNWZw33RZf0cWsonH+rv2VN+FUrGrm2H+D4U=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=rFZZTdCY6L2pKwm4/SLXwib3mAnM+yVtveaet7u4YCi2Yk56ZPf5m99q4QBj/zBqD o3Dir2lwjCnW1OZ7tyt7gmLsEHo184+EkB/GB1yZzAVLfMb1npo6gPkqaTDItNyKNE 9GifQGoV9LjZGB/hUKStjUvm9R0/qMwHKXEYJSCc= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Roy Novich , Aya Levin , Saeed Mahameed , Tariq Toukan , Leon Romanovsky , Michal Kubiak , Paolo Abeni , Sasha Levin Subject: [PATCH 5.4 004/161] linux/dim: Do nothing if no time delta between samples Date: Sun, 28 May 2023 20:08:48 +0100 Message-Id: <20230528190837.226129476@linuxfoundation.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230528190837.051205996@linuxfoundation.org> References: <20230528190837.051205996@linuxfoundation.org> User-Agent: quilt/0.67 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: Roy Novich [ Upstream commit 162bd18eb55adf464a0fa2b4144b8d61c75ff7c2 ] Add return value for dim_calc_stats. This is an indication for the caller if curr_stats was assigned by the function. Avoid using curr_stats uninitialized over {rdma/net}_dim, when no time delta between samples. Coverity reported this potential use of an uninitialized variable. Fixes: 4c4dbb4a7363 ("net/mlx5e: Move dynamic interrupt coalescing code to include/linux") Fixes: cb3c7fd4f839 ("net/mlx5e: Support adaptive RX coalescing") Signed-off-by: Roy Novich Reviewed-by: Aya Levin Reviewed-by: Saeed Mahameed Signed-off-by: Tariq Toukan Reviewed-by: Leon Romanovsky Reviewed-by: Michal Kubiak Link: https://lore.kernel.org/r/20230507135743.138993-1-tariqt@nvidia.com Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin --- include/linux/dim.h | 3 ++- lib/dim/dim.c | 5 +++-- lib/dim/net_dim.c | 3 ++- lib/dim/rdma_dim.c | 3 ++- 4 files changed, 9 insertions(+), 5 deletions(-) diff --git a/include/linux/dim.h b/include/linux/dim.h index 2571da63877c5..ad5f219ce2ff2 100644 --- a/include/linux/dim.h +++ b/include/linux/dim.h @@ -233,8 +233,9 @@ void dim_park_tired(struct dim *dim); * * Calculate the delta between two samples (in data rates). * Takes into consideration counter wrap-around. + * Returned boolean indicates whether curr_stats are reliable. */ -void dim_calc_stats(struct dim_sample *start, struct dim_sample *end, +bool dim_calc_stats(struct dim_sample *start, struct dim_sample *end, struct dim_stats *curr_stats); /** diff --git a/lib/dim/dim.c b/lib/dim/dim.c index 38045d6d05381..e89aaf07bde50 100644 --- a/lib/dim/dim.c +++ b/lib/dim/dim.c @@ -54,7 +54,7 @@ void dim_park_tired(struct dim *dim) } EXPORT_SYMBOL(dim_park_tired); -void dim_calc_stats(struct dim_sample *start, struct dim_sample *end, +bool dim_calc_stats(struct dim_sample *start, struct dim_sample *end, struct dim_stats *curr_stats) { /* u32 holds up to 71 minutes, should be enough */ @@ -66,7 +66,7 @@ void dim_calc_stats(struct dim_sample *start, struct dim_sample *end, start->comp_ctr); if (!delta_us) - return; + return false; curr_stats->ppms = DIV_ROUND_UP(npkts * USEC_PER_MSEC, delta_us); curr_stats->bpms = DIV_ROUND_UP(nbytes * USEC_PER_MSEC, delta_us); @@ -79,5 +79,6 @@ void dim_calc_stats(struct dim_sample *start, struct dim_sample *end, else curr_stats->cpe_ratio = 0; + return true; } EXPORT_SYMBOL(dim_calc_stats); diff --git a/lib/dim/net_dim.c b/lib/dim/net_dim.c index dae3b51ac3d9b..0e4f3a686f1de 100644 --- a/lib/dim/net_dim.c +++ b/lib/dim/net_dim.c @@ -227,7 +227,8 @@ void net_dim(struct dim *dim, struct dim_sample end_sample) dim->start_sample.event_ctr); if (nevents < DIM_NEVENTS) break; - dim_calc_stats(&dim->start_sample, &end_sample, &curr_stats); + if (!dim_calc_stats(&dim->start_sample, &end_sample, &curr_stats)) + break; if (net_dim_decision(&curr_stats, dim)) { dim->state = DIM_APPLY_NEW_PROFILE; schedule_work(&dim->work); diff --git a/lib/dim/rdma_dim.c b/lib/dim/rdma_dim.c index f7e26c7b4749f..d32c8b105adc9 100644 --- a/lib/dim/rdma_dim.c +++ b/lib/dim/rdma_dim.c @@ -88,7 +88,8 @@ void rdma_dim(struct dim *dim, u64 completions) nevents = curr_sample->event_ctr - dim->start_sample.event_ctr; if (nevents < DIM_NEVENTS) break; - dim_calc_stats(&dim->start_sample, curr_sample, &curr_stats); + if (!dim_calc_stats(&dim->start_sample, curr_sample, &curr_stats)) + break; if (rdma_dim_decision(&curr_stats, dim)) { dim->state = DIM_APPLY_NEW_PROFILE; schedule_work(&dim->work); -- 2.39.2