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 X-Spam-Level: X-Spam-Status: No, score=-5.3 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLACK autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8B230C433E2 for ; Tue, 21 Jul 2020 20:49:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 667F72072E for ; Tue, 21 Jul 2020 20:49:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1595364570; bh=sFDPbRrZ8r+/PiGLHBuN4i4zwMJ8TfW2SYocOT0d+RE=; h=Date:From:To:Subject:In-Reply-To:Reply-To:List-ID:From; b=CsOL3huz3U19jczG6Vvo3YLyPmlyVyrdGST7w1p/JNbmTMBd2zvIEGufBp0dAgvtl 78ms4b+Lm1S2iib4Q1s57E/w843RcMYzz2JskFQHLcISOkSnqFsMZCLOAFnuaTfnns aHpmi57+pvCpWUahLj+oRWFRyEOEEM6cTDUS8FmQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728878AbgGUUta (ORCPT ); Tue, 21 Jul 2020 16:49:30 -0400 Received: from mail.kernel.org ([198.145.29.99]:53724 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726029AbgGUUt3 (ORCPT ); Tue, 21 Jul 2020 16:49:29 -0400 Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id B6B8E20717; Tue, 21 Jul 2020 20:49:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1595364568; bh=sFDPbRrZ8r+/PiGLHBuN4i4zwMJ8TfW2SYocOT0d+RE=; h=Date:From:To:Subject:In-Reply-To:From; b=2PqVVB+xfBifSjLmKdKcj2mAwvJ+ZifdX6HPKjgwSUQjU1rkxBsTNRZa9wdaRhIB/ HB9RYO4Y6yUO5uPjKyDGVBAh2BhBtGN8zfaI6PVfU/z9evfilJg4DUN7PPbMKfe8eA cUKuUBdA1bMJcAl1dl+Jlmm1JRx24UzUe39N780Q= Date: Tue, 21 Jul 2020 13:49:28 -0700 From: Andrew Morton To: cai@lca.pw, mm-commits@vger.kernel.org, mpe@ellerman.id.au, peterz@infradead.org, stable@vger.kernel.org Subject: + fork-silence-a-false-postive-warning-in-__mmdrop.patch added to -mm tree Message-ID: <20200721204928.ScSj1rpgM%akpm@linux-foundation.org> In-Reply-To: <20200703151445.b6a0cfee402c7c5c4651f1b1@linux-foundation.org> User-Agent: s-nail v14.8.16 Sender: mm-commits-owner@vger.kernel.org Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org The patch titled Subject: fork: silence a false postive warning in __mmdrop has been added to the -mm tree. Its filename is fork-silence-a-false-postive-warning-in-__mmdrop.patch This patch should soon appear at http://ozlabs.org/~akpm/mmots/broken-out/fork-silence-a-false-postive-warning-in-__mmdrop.patch and later at http://ozlabs.org/~akpm/mmotm/broken-out/fork-silence-a-false-postive-warning-in-__mmdrop.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Qian Cai Subject: fork: silence a false postive warning in __mmdrop commit bf2c59fce407 ("sched/core: Fix illegal RCU from offline CPUs") delayed, idle->active_mm = &init_mm; into finish_cpu() instead of idle_task_exit() which results in a false positive warning that was originally designed in the commit 3eda69c92d47 ("kernel/fork.c: detect early free of a live mm"). WARNING: CPU: 127 PID: 72976 at kernel/fork.c:697 __mmdrop+0x230/0x2c0 do_exit+0x424/0xfa0 Call Trace: do_exit+0x424/0xfa0 do_group_exit+0x64/0xd0 sys_exit_group+0x24/0x30 system_call_exception+0x108/0x1d0 system_call_common+0xf0/0x278 Link: http://lkml.kernel.org/r/20200604150344.1796-1-cai@lca.pw Fixes: bf2c59fce407 ("sched/core: Fix illegal RCU from offline CPUs") Signed-off-by: Qian Cai Cc: Peter Zijlstra (Intel) Cc: Michael Ellerman (powerpc) Cc: Signed-off-by: Andrew Morton --- kernel/fork.c | 1 - 1 file changed, 1 deletion(-) --- a/kernel/fork.c~fork-silence-a-false-postive-warning-in-__mmdrop +++ a/kernel/fork.c @@ -694,7 +694,6 @@ void __mmdrop(struct mm_struct *mm) { BUG_ON(mm == &init_mm); WARN_ON_ONCE(mm == current->mm); - WARN_ON_ONCE(mm == current->active_mm); mm_free_pgd(mm); destroy_context(mm); mmu_notifier_subscriptions_destroy(mm); _ Patches currently in -mm which might be from cai@lca.pw are fork-silence-a-false-postive-warning-in-__mmdrop.patch mm-page_alloc-silence-a-kasan-false-positive.patch mm-kmemleak-silence-kcsan-splats-in-checksum.patch mm-frontswap-mark-various-intentional-data-races.patch mm-page_io-mark-various-intentional-data-races.patch mm-page_io-mark-various-intentional-data-races-v2.patch mm-swap_state-mark-various-intentional-data-races.patch mm-swapfile-fix-and-annotate-various-data-races.patch mm-swapfile-fix-and-annotate-various-data-races-v2.patch mm-page_counter-fix-various-data-races-at-memsw.patch mm-memcontrol-fix-a-data-race-in-scan-count.patch mm-list_lru-fix-a-data-race-in-list_lru_count_one.patch mm-mempool-fix-a-data-race-in-mempool_free.patch mm-rmap-annotate-a-data-race-at-tlb_flush_batched.patch mm-swap-annotate-data-races-for-lru_rotate_pvecs.patch mm-annotate-a-data-race-in-page_zonenum.patch