From patchwork Mon Mar 6 21:03:09 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vernon Yang X-Patchwork-Id: 659662 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 194B6C64EC4 for ; Mon, 6 Mar 2023 21:03:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229975AbjCFVDw (ORCPT ); Mon, 6 Mar 2023 16:03:52 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52036 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229524AbjCFVDo (ORCPT ); Mon, 6 Mar 2023 16:03:44 -0500 Received: from mail-pf1-x431.google.com (mail-pf1-x431.google.com [IPv6:2607:f8b0:4864:20::431]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3834E37579; Mon, 6 Mar 2023 13:03:43 -0800 (PST) Received: by mail-pf1-x431.google.com with SMTP id n5so6736686pfv.11; Mon, 06 Mar 2023 13:03:43 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; t=1678136622; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=ohhBlm5/EvdaRANIY+/17hlHt7n4eAlMQRKCzUzJefs=; b=jddwh84zwUpSQuatvj4c7Dpgl/B68lIc/yasenGO6pdLPdPi5mYHxG8eXh62Yz++wr 64vwB8kutOmKeAyu9i2kM3ICs828b7TCLH1GK0jUbMwkeQbvl0Ii8ptdMYZhXHMuzIPL V+3uMHRGAOPTgIkB94ykDqXF8VeLLXqH/ZMXQi8Ve4saIO0PImMGq3bxlmzsZFS15pQG NoIWQlxj3IqaCV7yHbxIrQ0fa/vPWBV4XKjFE5PjiYzL8MaaZyakd/MKhl/WaZ1C7mch 4IobHwykjv/5tIFUOenW8tcEBFDD+ZAL/zwr9gNMnLbPmDRDzCnw+cfg89CxNO266/// ye2g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1678136622; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=ohhBlm5/EvdaRANIY+/17hlHt7n4eAlMQRKCzUzJefs=; b=5xJOZXxGTqRNiTItWUbWSyA+Rg+ivxenKGFFToOnYeije+/pRjR1jCtopC7w08g8WW fJpnms4CNnI9NWfobQFwrtC7z/vJ7MjxZhNOcT2tsNF8gGDOk4gpkbCTOujE3qZ+1jl3 FLmDR80YljX8nkyrxf4mp/H6aL74sJbTW4lua6usu6e54hb1lCkIoel8hblhMuW3mUFA Y3hSV+oUjUII/mrI43t/5YKZTiVHsXEIYotgiUI95+IJaZBHeaTrGH7fr4lV1R4l+fLs wwBwopvLDRMgb0nJebp3x0xiNmS7WCDU45xIwst2JOM8oDLj28vWFGA/Kn5WriDUITJ9 Hpkw== X-Gm-Message-State: AO0yUKWv8toMaT8r+Lb/SNSE0Ml5Ry1nui/vVdEr2/ItZfOiCHxd84Vf HCUgtdZnHQGvQtdZBNxGwBU= X-Google-Smtp-Source: AK7set9C+GX1uA5tZkGP2zTQMIs94EYIBwyVaiOu7iZSR8QoXhcin7YC0GzM7XQYnpJ1bW1BZLgToQ== X-Received: by 2002:a62:5105:0:b0:593:ed9c:9f07 with SMTP id f5-20020a625105000000b00593ed9c9f07mr11960629pfb.27.1678136622631; Mon, 06 Mar 2023 13:03:42 -0800 (PST) Received: from vernon-pc.. ([49.67.2.142]) by smtp.gmail.com with ESMTPSA id 3-20020aa79143000000b005810c4286d6sm6706760pfi.0.2023.03.06.13.03.37 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 06 Mar 2023 13:03:42 -0800 (PST) From: Vernon Yang To: torvalds@linux-foundation.org, tytso@mit.edu, Jason@zx2c4.com, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, jejb@linux.ibm.com, martin.petersen@oracle.com, yury.norov@gmail.com, andriy.shevchenko@linux.intel.com, linux@rasmusvillemoes.dk, james.smart@broadcom.com, dick.kennedy@broadcom.com Cc: linux-kernel@vger.kernel.org, wireguard@lists.zx2c4.com, netdev@vger.kernel.org, linux-scsi@vger.kernel.org, Vernon Yang Subject: [PATCH v2 1/4] random: fix try_to_generate_entropy() if no further cpus set Date: Tue, 7 Mar 2023 05:03:09 +0800 Message-Id: <20230306210312.2614988-2-vernon2gm@gmail.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230306210312.2614988-1-vernon2gm@gmail.com> References: <20230306210312.2614988-1-vernon2gm@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org When cpumask_next() the return value is greater than or equal to nr_cpu_ids, it indicates invalid. Before commit 596ff4a09b89 ("cpumask: re-introduce constant-sized cpumask optimizations"), when cpumask_next() returned an invalid cpu, the driver used the judgment equal to nr_cpu_ids to indicate the invalid cpu, so it happened to work normally, but this is the wrong approach. After commit 596ff4a09b89 ("cpumask: re-introduce constant-sized cpumask optimizations"), these incorrect practices actively buggy, so fix it to correctly. Signed-off-by: Vernon Yang --- drivers/char/random.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/char/random.c b/drivers/char/random.c index ce3ccd172cc8..253f2ddb8913 100644 --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -1311,7 +1311,7 @@ static void __cold try_to_generate_entropy(void) /* Basic CPU round-robin, which avoids the current CPU. */ do { cpu = cpumask_next(cpu, &timer_cpus); - if (cpu == nr_cpumask_bits) + if (cpu >= nr_cpu_ids) cpu = cpumask_first(&timer_cpus); } while (cpu == smp_processor_id() && num_cpus > 1);