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 046AFC433FE for ; Tue, 26 Apr 2022 09:37:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1348135AbiDZJjF (ORCPT ); Tue, 26 Apr 2022 05:39:05 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38456 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1346502AbiDZJIX (ORCPT ); Tue, 26 Apr 2022 05:08:23 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3D2ED13FB8; Tue, 26 Apr 2022 01:49:14 -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 ams.source.kernel.org (Postfix) with ESMTPS id E1A65B81D09; Tue, 26 Apr 2022 08:49:12 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 42404C385BE; Tue, 26 Apr 2022 08:49:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1650962951; bh=3cOjFrytvu+eMwtQ4tbOjqFmZep/na2RTLi1ivZ+4d4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=o5TEQ/jU720560Mnex5Ld1dO38H7ynSa0WZijPU6b4tnGV1cfbBxpAR9spWMqHBHP qSsklAV1mAcfRziBZ7tjO3LJqUrZrQQzNxjj+xZXds0/PVsWlU+BFl25CyfuZFlrcn oEfJVVI64NNAWcmXC6XozZM/blEME0cPUKSfQNYU= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Zhipeng Xie , "Peter Zijlstra (Intel)" , Sasha Levin Subject: [PATCH 5.17 103/146] perf/core: Fix perf_mmap fail when CONFIG_PERF_USE_VMALLOC enabled Date: Tue, 26 Apr 2022 10:21:38 +0200 Message-Id: <20220426081752.954011534@linuxfoundation.org> X-Mailer: git-send-email 2.36.0 In-Reply-To: <20220426081750.051179617@linuxfoundation.org> References: <20220426081750.051179617@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: linux-kernel@vger.kernel.org From: Zhipeng Xie [ Upstream commit 60490e7966659b26d74bf1fa4aa8693d9a94ca88 ] This problem can be reproduced with CONFIG_PERF_USE_VMALLOC enabled on both x86_64 and aarch64 arch when using sysdig -B(using ebpf)[1]. sysdig -B works fine after rebuilding the kernel with CONFIG_PERF_USE_VMALLOC disabled. I tracked it down to the if condition event->rb->nr_pages != nr_pages in perf_mmap is true when CONFIG_PERF_USE_VMALLOC is enabled where event->rb->nr_pages = 1 and nr_pages = 2048 resulting perf_mmap to return -EINVAL. This is because when CONFIG_PERF_USE_VMALLOC is enabled, rb->nr_pages is always equal to 1. Arch with CONFIG_PERF_USE_VMALLOC enabled by default: arc/arm/csky/mips/sh/sparc/xtensa Arch with CONFIG_PERF_USE_VMALLOC disabled by default: x86_64/aarch64/... Fix this problem by using data_page_nr() [1] https://github.com/draios/sysdig Fixes: 906010b2134e ("perf_event: Provide vmalloc() based mmap() backing") Signed-off-by: Zhipeng Xie Signed-off-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/20220209145417.6495-1-xiezhipeng1@huawei.com Signed-off-by: Sasha Levin --- kernel/events/core.c | 2 +- kernel/events/internal.h | 5 +++++ kernel/events/ring_buffer.c | 5 ----- 3 files changed, 6 insertions(+), 6 deletions(-) diff --git a/kernel/events/core.c b/kernel/events/core.c index 0ee9ffceb976..baa0fe350246 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -6352,7 +6352,7 @@ static int perf_mmap(struct file *file, struct vm_area_struct *vma) again: mutex_lock(&event->mmap_mutex); if (event->rb) { - if (event->rb->nr_pages != nr_pages) { + if (data_page_nr(event->rb) != nr_pages) { ret = -EINVAL; goto unlock; } diff --git a/kernel/events/internal.h b/kernel/events/internal.h index 082832738c8f..5150d5f84c03 100644 --- a/kernel/events/internal.h +++ b/kernel/events/internal.h @@ -116,6 +116,11 @@ static inline int page_order(struct perf_buffer *rb) } #endif +static inline int data_page_nr(struct perf_buffer *rb) +{ + return rb->nr_pages << page_order(rb); +} + static inline unsigned long perf_data_size(struct perf_buffer *rb) { return rb->nr_pages << (PAGE_SHIFT + page_order(rb)); diff --git a/kernel/events/ring_buffer.c b/kernel/events/ring_buffer.c index 52868716ec35..fb35b926024c 100644 --- a/kernel/events/ring_buffer.c +++ b/kernel/events/ring_buffer.c @@ -859,11 +859,6 @@ void rb_free(struct perf_buffer *rb) } #else -static int data_page_nr(struct perf_buffer *rb) -{ - return rb->nr_pages << page_order(rb); -} - static struct page * __perf_mmap_to_page(struct perf_buffer *rb, unsigned long pgoff) { -- 2.35.1