From nobody Fri Dec 19 04:55:38 2025 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 2562AEE14D0 for ; Thu, 7 Sep 2023 00:43:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244891AbjIGAnW (ORCPT ); Wed, 6 Sep 2023 20:43:22 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57550 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241271AbjIGAnV (ORCPT ); Wed, 6 Sep 2023 20:43:21 -0400 Received: from out30-130.freemail.mail.aliyun.com (out30-130.freemail.mail.aliyun.com [115.124.30.130]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B6A5E19A2; Wed, 6 Sep 2023 17:43:16 -0700 (PDT) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R111e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018045176;MF=xueshuai@linux.alibaba.com;NM=1;PH=DS;RN=16;SR=0;TI=SMTPD_---0VrV7Fnx_1694047393; Received: from localhost.localdomain(mailfrom:xueshuai@linux.alibaba.com fp:SMTPD_---0VrV7Fnx_1694047393) by smtp.aliyun-inc.com; Thu, 07 Sep 2023 08:43:14 +0800 From: Shuai Xue To: alexander.shishkin@linux.intel.com, peterz@infradead.org, james.clark@arm.com, leo.yan@linaro.org Cc: mingo@redhat.com, baolin.wang@linux.alibaba.com, acme@kernel.org, mark.rutland@arm.com, jolsa@kernel.org, namhyung@kernel.org, irogers@google.com, adrian.hunter@intel.com, linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org, nathan@kernel.org, bpf@vger.kernel.org Subject: [PATCH v5 1/2] perf/core: Bail out early if the request AUX area is out of bound Date: Thu, 7 Sep 2023 08:43:07 +0800 Message-Id: <20230907004308.25874-2-xueshuai@linux.alibaba.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230907004308.25874-1-xueshuai@linux.alibaba.com> References: <20230907004308.25874-1-xueshuai@linux.alibaba.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" When perf-record with a large AUX area, e.g 4GB, it fails with: #perf record -C 0 -m ,4G -e arm_spe_0// -- sleep 1 failed to mmap with 12 (Cannot allocate memory) and it reveals a WARNING with __alloc_pages(): [ 66.595604] ------------[ cut here ]------------ [ 66.600206] WARNING: CPU: 44 PID: 17573 at mm/page_alloc.c:5568 __alloc_= pages+0x1ec/0x248 [ 66.608375] Modules linked in: ip6table_filter(E) ip6_tables(E) iptable_= filter(E) ebtable_nat(E) ebtables(E) aes_ce_blk(E) vfat(E) fat(E) aes_ce_ci= pher(E) crct10dif_ce(E) ghash_ce(E) sm4_ce_cipher(E) sm4(E) sha2_ce(E) sha2= 56_arm64(E) sha1_ce(E) acpi_ipmi(E) sbsa_gwdt(E) sg(E) ipmi_si(E) ipmi_devi= ntf(E) ipmi_msghandler(E) ip_tables(E) sd_mod(E) ast(E) drm_kms_helper(E) s= yscopyarea(E) sysfillrect(E) nvme(E) sysimgblt(E) i2c_algo_bit(E) nvme_core= (E) drm_shmem_helper(E) ahci(E) t10_pi(E) libahci(E) drm(E) crc64_rocksoft(= E) i40e(E) crc64(E) libata(E) i2c_core(E) [ 66.657719] CPU: 44 PID: 17573 Comm: perf Kdump: loaded Tainted: G = E 6.3.0-rc4+ #58 [ 66.666749] Hardware name: Default Default/Default, BIOS 1.2.M1.AL.P.139= .00 03/22/2023 [ 66.674650] pstate: 23400009 (nzCv daif +PAN -UAO +TCO +DIT -SSBS BTYPE= =3D--) [ 66.681597] pc : __alloc_pages+0x1ec/0x248 [ 66.685680] lr : __kmalloc_large_node+0xc0/0x1f8 [ 66.690285] sp : ffff800020523980 [ 66.693585] pmr_save: 000000e0 [ 66.696624] x29: ffff800020523980 x28: ffff000832975800 x27: 00000000000= 00000 [ 66.703746] x26: 0000000000100000 x25: 0000000000100000 x24: ffff8000083= 615d0 [ 66.710866] x23: 0000000000040dc0 x22: ffff000823d6d140 x21: 00000000000= 0000b [ 66.717987] x20: 000000000000000b x19: 0000000000000000 x18: 00000000000= 00030 [ 66.725108] x17: 0000000000000000 x16: ffff800008f05be8 x15: ffff000823d= 6d6d0 [ 66.732229] x14: 0000000000000000 x13: 343373656761705f x12: 726e202c302= 06574 [ 66.739350] x11: 00000000ffff7fff x10: 00000000ffff7fff x9 : ffff8000083= af570 [ 66.746471] x8 : 00000000000bffe8 x7 : c0000000ffff7fff x6 : 00000000000= 5fff4 [ 66.753592] x5 : 0000000000000000 x4 : ffff000823d6d8d8 x3 : 00000000000= 00000 [ 66.760713] x2 : 0000000000000000 x1 : 0000000000000001 x0 : 00000000000= 40dc0 [ 66.767834] Call trace: [ 66.770267] __alloc_pages+0x1ec/0x248 [ 66.774003] __kmalloc_large_node+0xc0/0x1f8 [ 66.778259] __kmalloc_node+0x134/0x1e8 [ 66.782081] rb_alloc_aux+0xe0/0x298 [ 66.785643] perf_mmap+0x440/0x660 [ 66.789031] mmap_region+0x308/0x8a8 [ 66.792593] do_mmap+0x3c0/0x528 [ 66.795807] vm_mmap_pgoff+0xf4/0x1b8 [ 66.799456] ksys_mmap_pgoff+0x18c/0x218 [ 66.803365] __arm64_sys_mmap+0x38/0x58 [ 66.807187] invoke_syscall+0x50/0x128 [ 66.810922] el0_svc_common.constprop.0+0x58/0x188 [ 66.815698] do_el0_svc+0x34/0x50 [ 66.818999] el0_svc+0x34/0x108 [ 66.822127] el0t_64_sync_handler+0xb8/0xc0 [ 66.826296] el0t_64_sync+0x1a4/0x1a8 [ 66.829946] ---[ end trace 0000000000000000 ]--- 'rb->aux_pages' allocated by kcalloc() is a pointer array which is used to maintains AUX trace pages. The allocated page for this array is physically contiguous (and virtually contiguous) with an order of 0..MAX_ORDER. If the size of pointer array crosses the limitation set by MAX_ORDER, it reveals a WARNING. So bail out early with -ENOMEM if the request AUX area is out of bound, e.g.: #perf record -C 0 -m ,4G -e arm_spe_0// -- sleep 1 failed to mmap with 12 (Cannot allocate memory) Signed-off-by: Shuai Xue --- kernel/events/ring_buffer.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/kernel/events/ring_buffer.c b/kernel/events/ring_buffer.c index fb1e180b5f0a..e8d82c2f07d0 100644 --- a/kernel/events/ring_buffer.c +++ b/kernel/events/ring_buffer.c @@ -700,6 +700,12 @@ int rb_alloc_aux(struct perf_buffer *rb, struct perf_e= vent *event, watermark =3D 0; } =20 + /* + * kcalloc_node() is unable to allocate buffer if the size is larger + * than: PAGE_SIZE << MAX_ORDER; directly bail out in this case. + */ + if (get_order((unsigned long)nr_pages * sizeof(void *)) > MAX_ORDER) + return -ENOMEM; rb->aux_pages =3D kcalloc_node(nr_pages, sizeof(void *), GFP_KERNEL, node); if (!rb->aux_pages) --=20 2.39.3 From nobody Fri Dec 19 04:55:38 2025 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 13E70EE14C3 for ; Thu, 7 Sep 2023 00:43:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S245015AbjIGAnY (ORCPT ); Wed, 6 Sep 2023 20:43:24 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57552 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241271AbjIGAnW (ORCPT ); Wed, 6 Sep 2023 20:43:22 -0400 Received: from out30-119.freemail.mail.aliyun.com (out30-119.freemail.mail.aliyun.com [115.124.30.119]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id ECEAB172E; Wed, 6 Sep 2023 17:43:17 -0700 (PDT) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R131e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018045168;MF=xueshuai@linux.alibaba.com;NM=1;PH=DS;RN=16;SR=0;TI=SMTPD_---0VrV7FoD_1694047394; Received: from localhost.localdomain(mailfrom:xueshuai@linux.alibaba.com fp:SMTPD_---0VrV7FoD_1694047394) by smtp.aliyun-inc.com; Thu, 07 Sep 2023 08:43:15 +0800 From: Shuai Xue To: alexander.shishkin@linux.intel.com, peterz@infradead.org, james.clark@arm.com, leo.yan@linaro.org Cc: mingo@redhat.com, baolin.wang@linux.alibaba.com, acme@kernel.org, mark.rutland@arm.com, jolsa@kernel.org, namhyung@kernel.org, irogers@google.com, adrian.hunter@intel.com, linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org, nathan@kernel.org, bpf@vger.kernel.org Subject: [PATCH v5 2/2] perf record: Update docs regarding the maximum limitation of AUX area Date: Thu, 7 Sep 2023 08:43:08 +0800 Message-Id: <20230907004308.25874-3-xueshuai@linux.alibaba.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230907004308.25874-1-xueshuai@linux.alibaba.com> References: <20230907004308.25874-1-xueshuai@linux.alibaba.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" The maximum AUX area is limited by the page size of the system. Update the documentation to reflect this. Signed-off-by: Shuai Xue --- tools/perf/Documentation/perf-record.txt | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/tools/perf/Documentation/perf-record.txt b/tools/perf/Document= ation/perf-record.txt index 680396c56bd1..dfc322d6f1f1 100644 --- a/tools/perf/Documentation/perf-record.txt +++ b/tools/perf/Documentation/perf-record.txt @@ -292,6 +292,17 @@ OPTIONS Also, by adding a comma, the number of mmap pages for AUX area tracing can be specified. =20 + The maximum AUX area is limited by the maximum physically contiguous + memory allocated from slab/slub. It can be calculated with following + formula: + + PAGE_SIZE << MAX_ORDER + ( ---------------------- ) * PAGE_SIZE + sizeof(page_pointer) + + For example with 4K pages and MAX_ORDER=3D10 configured, the maximum AUX + area is 2GiB. + -g:: Enables call-graph (stack chain/backtrace) recording for both kernel space and user space. --=20 2.39.3