From nobody Mon May 11 00:45:31 2026 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 B21C2C433EF for ; Tue, 19 Apr 2022 19:35:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1354642AbiDSThu (ORCPT ); Tue, 19 Apr 2022 15:37:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51310 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1354562AbiDSThc (ORCPT ); Tue, 19 Apr 2022 15:37:32 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7042BE47; Tue, 19 Apr 2022 12:34:48 -0700 (PDT) Date: Tue, 19 Apr 2022 19:34:44 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1650396886; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=4By39Zx+Sp4N6rN9AxawR4v/Be2Kj3yLRJ69iBAZCYg=; b=OB6acdsfvUcuBKKsuojRPfuofwc3eMOqCsbvhEnc/ba1UqGFRMhsS7DNKtXHoY5n2ys8Si GbOw0Jf1KujAtwntxI7pZ99AhungFHcbRcsr5uBNQTCtmGbt82qwW71C/vtG4nagDCFtjk +ifJc29Ti74VbsaZ1VoecSAJv8LTK+pnInfemzx0cr/+frMG2rVv5y6GH7Xsnu82rYxoW0 Rb1feqnYF8nL1lbTmIHIgCwHQ+ybutGg5MxvGzQgVXdsRjsrq4SMX6kSyeYyvCjN0nLlD4 Z8gAJrZ+LX0U+XYnyqT6dTZ8hG6yAvPg04oJbBH8EWpsGSRhkPOrDkx1TJSMLA== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1650396886; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=4By39Zx+Sp4N6rN9AxawR4v/Be2Kj3yLRJ69iBAZCYg=; b=oI+zT5pCDBRYf9vsmz9NPEXcA01wTSwl3FPZdkpmJAATPu8pGFV+bPzoDseyaBu8raUkMV aBDV/pPbrkJUsNAg== From: "tip-bot2 for Zhipeng Xie" Sender: tip-bot2@linutronix.de Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: perf/urgent] perf/core: Fix perf_mmap fail when CONFIG_PERF_USE_VMALLOC enabled Cc: Zhipeng Xie , "Peter Zijlstra (Intel)" , x86@kernel.org, linux-kernel@vger.kernel.org In-Reply-To: <20220209145417.6495-1-xiezhipeng1@huawei.com> References: <20220209145417.6495-1-xiezhipeng1@huawei.com> MIME-Version: 1.0 Message-ID: <165039688484.4207.14509998247013429471.tip-bot2@tip-bot2> Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The following commit has been merged into the perf/urgent branch of tip: Commit-ID: 60490e7966659b26d74bf1fa4aa8693d9a94ca88 Gitweb: https://git.kernel.org/tip/60490e7966659b26d74bf1fa4aa8693d9= a94ca88 Author: Zhipeng Xie AuthorDate: Wed, 09 Feb 2022 09:54:17 -05:00 Committer: Peter Zijlstra CommitterDate: Tue, 19 Apr 2022 21:15:42 +02:00 perf/core: Fix perf_mmap fail when CONFIG_PERF_USE_VMALLOC enabled 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 !=3D nr_pages in perf_mmap is true when CONFIG_PERF_USE_VMALLOC is enabled where event->rb->nr_pages =3D 1 and nr_pages =3D 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 --- 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 23bb197..7858baf 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -6247,7 +6247,7 @@ static int perf_mmap(struct file *file, struct vm_are= a_struct *vma) again: mutex_lock(&event->mmap_mutex); if (event->rb) { - if (event->rb->nr_pages !=3D nr_pages) { + if (data_page_nr(event->rb) !=3D nr_pages) { ret =3D -EINVAL; goto unlock; } diff --git a/kernel/events/internal.h b/kernel/events/internal.h index 0828327..5150d5f 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 =20 +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 5286871..fb35b92 100644 --- a/kernel/events/ring_buffer.c +++ b/kernel/events/ring_buffer.c @@ -859,11 +859,6 @@ void rb_free(struct perf_buffer *rb) } =20 #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) {