From patchwork Sun Apr 9 08:15:25 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Rong Tao X-Patchwork-Id: 13205910 X-Patchwork-Delegate: bpf@iogearbox.net 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 C6ECFC77B61 for ; Sun, 9 Apr 2023 08:21:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229564AbjDIIVq (ORCPT ); Sun, 9 Apr 2023 04:21:46 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51578 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229557AbjDIIVo (ORCPT ); Sun, 9 Apr 2023 04:21:44 -0400 Received: from out203-205-221-191.mail.qq.com (out203-205-221-191.mail.qq.com [203.205.221.191]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5E62D618A for ; Sun, 9 Apr 2023 01:21:43 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=foxmail.com; s=s201512; t=1681028501; bh=1BlGx1afgSOPlmGiINyQ3UClfYQu3kEy3LXJFKQ8+FY=; h=From:To:Cc:Subject:Date; b=nSrz1K/IBvtzLTlOv40KNAvXjGKkERmbzm60Wwt715e9/uW89FrnBKD/dlQsLNRst gTJi4TgiMQ08yn4HIKmRACROSAiPm+Il141ish/6wKzROLo0rK1fO7fsJn1sWgodsr OKtvVW4buS1wUeFEduE0VxdG7OhoOj7e4HzyNIXM= Received: from rtoax.. ([111.199.190.121]) by newxmesmtplogicsvrszb9-0.qq.com (NewEsmtp) with SMTP id 3DB170ED; Sun, 09 Apr 2023 16:15:27 +0800 X-QQ-mid: xmsmtpt1681028127ta0a5h3cn Message-ID: X-QQ-XMAILINFO: Mi0NhBPPe/4R2b23CkWNOcjl6/zGeo8g7OI8JOhvvNufzVBxQ0jK6neRCgu1m5 aBnJqPQx16B8w2KUDIsUycPw/kqP+Zm8ZL4x6kXtwmon0hzTcQ1RI2oAEc0bJ5KdwFRRu+0dlkEo txb/5ZSo7AWb7j9O3jgNMMUHK22+83SvlRZ0djb05mP2txPDS/YcGvlr/8aLHEaljN25aUtdBM7t ltlZVinkp4vcedUcCPsRfk1aSgYoJtLinSQmLB09/0RKM3ZJYXpuY1XJiXu4DKbtuIYQrqvceal/ D6MCY8Ir3GLHImrbvdZnzNXtUoQQOpyxlmJM91me/zteJVt8uYnhSsEvYlB8snxXWEZyX1Ijcwbi B2EQPW+GWob2hme/A5+2HYyHVXVCrXaFD4thxhY+k/eSUXER5TlLgdKRgaye0ZIoTylhQGho9HRw cftPcqzFQRpiM3OBt7trUa5sEnfo5Z/ufymc+uzcyrQgERSY3VOH4E6dSA5cJAMcsQX4M9nUN7Dg XOYp6x3evulsK3uhcc1r1zBRyFi/TJjCVENFY6wU3ZCpBWJ3rmCn6erq2IK64FVrrrf7vldwv/r2 P68uCwlEQGLc/so809fCD3GSh37P0kWIus5dPAIdDMBkVf3UazfwwdotVd2YY5iL5vOFtBxUTfj5 q4DPpluLl5acQ67ZcG/TahwibDVyiQAKKLb64GDt6iu/JpcBwcmCi7oh5yFOlqlEr8lzz0+ovyhH EpHWM7hkewFeoZAeHCc19Vhi47Vm8chNOd43rIz8WBMktSjVG2X62i1Aek8BLnKRtXkUNG1CaANH vydtQ5HnxMdHeMFcmD/Q0Cfeuz2FEthh7sB4naa5n3j5TgpKVY5pjuGl2hBQLl1pAGhW38FhAXx5 vRc5voteBdRR/ZHv3cY7cKi5RQThSTojAOQRFcNJEedX5pwSOK9S/kvWaeMv19hhuElGhyth8+ld yZAG19VhsFpNqeYNwc+LzKwzW3szYEmCm8goERRJ2C6UI++iXBQA== From: Rong Tao To: ast@kernel.org Cc: rongtao@cestc.cn, Daniel Borkmann , Andrii Nakryiko , Martin KaFai Lau , Song Liu , Yonghong Song , John Fastabend , KP Singh , Stanislav Fomichev , Hao Luo , Jiri Olsa , Mykola Lysenko , Shuah Khan , Nick Terrell , bpf@vger.kernel.org (open list:BPF [GENERAL] (Safe Dynamic Programs and Tools)), linux-kselftest@vger.kernel.org (open list:KERNEL SELFTEST FRAMEWORK), linux-kernel@vger.kernel.org (open list) Subject: [PATCH bpf-next] selftests/bpf: trace_helpers.c: Fix segfault Date: Sun, 9 Apr 2023 16:15:25 +0800 X-OQ-MSGID: <20230409081525.182264-1-rtoax@foxmail.com> X-Mailer: git-send-email 2.39.2 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net From: Rong Tao When the number of symbols is greater than MAX_SYMS (300000), the access array struct ksym syms[MAX_SYMS] goes out of bounds, which will result in a segfault. Resolve this issue by judging the maximum number and exiting the loop, and increasing the default size appropriately. (6.2.9 = 329839 below) $ cat /proc/kallsyms | wc -l 329839 GDB debugging: $ cd linux/samples/bpf $ sudo gdb ./sampleip ... (gdb) r ... Program received signal SIGSEGV, Segmentation fault. 0x00007ffff7e2debf in malloc () from /lib64/libc.so.6 Missing separate debuginfos, use: dnf debuginfo-install elfutils-libelf-0.189-1.fc37.x86_64 glibc-2.36-9.fc37.x86_64 libzstd-1.5.4-1.fc37.x86_64 zlib-1.2.12-5.fc37.x86_64 (gdb) bt #0 0x00007ffff7e2debf in malloc () from /lib64/libc.so.6 #1 0x00007ffff7e33f8e in strdup () from /lib64/libc.so.6 #2 0x0000000000403fb0 in load_kallsyms_refresh() from trace_helpers.c #3 0x00000000004038b2 in main () Signed-off-by: Rong Tao Acked-by: Jiri Olsa --- tools/testing/selftests/bpf/trace_helpers.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/tools/testing/selftests/bpf/trace_helpers.c b/tools/testing/selftests/bpf/trace_helpers.c index 09a16a77bae4..a9d589c560d2 100644 --- a/tools/testing/selftests/bpf/trace_helpers.c +++ b/tools/testing/selftests/bpf/trace_helpers.c @@ -14,7 +14,7 @@ #define DEBUGFS "/sys/kernel/debug/tracing/" -#define MAX_SYMS 300000 +#define MAX_SYMS 400000 static struct ksym syms[MAX_SYMS]; static int sym_cnt; @@ -44,7 +44,8 @@ int load_kallsyms_refresh(void) continue; syms[i].addr = (long) addr; syms[i].name = strdup(func); - i++; + if (++i >= MAX_SYMS) + break; } fclose(f); sym_cnt = i;