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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham 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 E3F7EC43603 for ; Tue, 10 Dec 2019 21:13:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B61252077B for ; Tue, 10 Dec 2019 21:13:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1576012384; bh=W4y7qxt9zncxLFVbblXwIze/qP8OdDiCDJPyJRUsryA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=yaz6PHmxVMP4ObKWe6QmjVVMjFai/lkhBnCUOh/dDkjQ8PQRkjpY3dilMhnttMRvW v/eOIgACq3fCOlO7rAGc6idlh9WHHuH4XXIpvVkfkwVTwFo4ShxVGTBfUXHjRgO5s0 Ypcw3C7synMLR3zuwSZQ6XxkpXVo55tMK84y3kh8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728532AbfLJVND (ORCPT ); Tue, 10 Dec 2019 16:13:03 -0500 Received: from mail.kernel.org ([198.145.29.99]:38698 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728617AbfLJVND (ORCPT ); Tue, 10 Dec 2019 16:13:03 -0500 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id C60832465B; Tue, 10 Dec 2019 21:13:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1576012382; bh=W4y7qxt9zncxLFVbblXwIze/qP8OdDiCDJPyJRUsryA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Y+Srg/kam+97uMeVdyrOa77SUXunhtAKtWaAdmiOdiU14ooLKckT28aVq2bGe7P1j lHHmgWe13L/tq9b7VHgcJ2QyMl8WezjGhiCczQgVL3shVevVtLZ0yf+zZis38Tvn1W NfEnCztCTqpFRdSg2bqARl23vVwIUFLXjaDWabcI= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Alexander Shishkin , Thomas Richter , Peter Zijlstra , Arnaldo Carvalho de Melo , Jiri Olsa , Linus Torvalds , Mark Rutland , Namhyung Kim , Stephane Eranian , Thomas Gleixner , Vince Weaver , Ingo Molnar , Sasha Levin Subject: [PATCH AUTOSEL 5.4 305/350] perf/core: Fix the mlock accounting, again Date: Tue, 10 Dec 2019 16:06:50 -0500 Message-Id: <20191210210735.9077-266-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20191210210735.9077-1-sashal@kernel.org> References: <20191210210735.9077-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Alexander Shishkin [ Upstream commit 36b3db03b4741b8935b68fffc7e69951d8d70a89 ] Commit: 5e6c3c7b1ec2 ("perf/aux: Fix tracking of auxiliary trace buffer allocation") tried to guess the correct combination of arithmetic operations that would undo the AUX buffer's mlock accounting, and failed, leaking the bottom part when an allocation needs to be charged partially to both user->locked_vm and mm->pinned_vm, eventually leaving the user with no locked bonus: $ perf record -e intel_pt//u -m1,128 uname [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.061 MB perf.data ] $ perf record -e intel_pt//u -m1,128 uname Permission error mapping pages. Consider increasing /proc/sys/kernel/perf_event_mlock_kb, or try again with a smaller value of -m/--mmap_pages. (current value: 1,128) Fix this by subtracting both locked and pinned counts when AUX buffer is unmapped. Reported-by: Thomas Richter Tested-by: Thomas Richter Signed-off-by: Alexander Shishkin Acked-by: Peter Zijlstra Cc: Arnaldo Carvalho de Melo Cc: Jiri Olsa Cc: Linus Torvalds Cc: Mark Rutland Cc: Namhyung Kim Cc: Stephane Eranian Cc: Thomas Gleixner Cc: Vince Weaver Signed-off-by: Ingo Molnar Signed-off-by: Sasha Levin --- kernel/events/core.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/kernel/events/core.c b/kernel/events/core.c index 00a014670ed02..8f66a4833dedd 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -5607,10 +5607,8 @@ static void perf_mmap_close(struct vm_area_struct *vma) perf_pmu_output_stop(event); /* now it's safe to free the pages */ - if (!rb->aux_mmap_locked) - atomic_long_sub(rb->aux_nr_pages, &mmap_user->locked_vm); - else - atomic64_sub(rb->aux_mmap_locked, &vma->vm_mm->pinned_vm); + atomic_long_sub(rb->aux_nr_pages - rb->aux_mmap_locked, &mmap_user->locked_vm); + atomic64_sub(rb->aux_mmap_locked, &vma->vm_mm->pinned_vm); /* this has to be the last one */ rb_free_aux(rb); -- 2.20.1