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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0E010C433F5 for ; Wed, 13 Oct 2021 10:24:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DFCE360E09 for ; Wed, 13 Oct 2021 10:24:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239337AbhJMK0D (ORCPT ); Wed, 13 Oct 2021 06:26:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48850 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239282AbhJMK0A (ORCPT ); Wed, 13 Oct 2021 06:26:00 -0400 Received: from mail-pj1-x1033.google.com (mail-pj1-x1033.google.com [IPv6:2607:f8b0:4864:20::1033]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4C4C5C061570 for ; Wed, 13 Oct 2021 03:23:57 -0700 (PDT) Received: by mail-pj1-x1033.google.com with SMTP id kk10so1853342pjb.1 for ; Wed, 13 Oct 2021 03:23:57 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=cXGU1FgivtpbQOCuG+kADAWoAeGXN23a0S+JAEkjpg4=; b=cJZZYtf+ukMuwUhDeGIfx/8qAtStq8C9IyUqSfnwgxntj2iivjIM/0IbPolL0KaJ6A 5dEL96Kc8/XXqRCrk2AGfxH66cNsvSVvc0cxSr9JCXr9LTnrh3TZmaT+XB/m/OyDSzwm /cDYmEJRehL1Fj4YFvLYYD1UL0fnS9Y3+B6lyvGG+kc4jZGrbNzab61AtchgQc775uP5 Kuvrz02m8YVxHa391dv1LNthjcF3QXJHJY0GMlBLNIqbGJxSRUzlkM81CZcQypTQDP1/ eua+QUDkc0aomkEGl17WyIPUpiYujUWhhB+LM40HkK+Z15wiX9LJcMrEZb0EWVOg0ZT/ uFMg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=cXGU1FgivtpbQOCuG+kADAWoAeGXN23a0S+JAEkjpg4=; b=GBFGnL61NXnKQtEYgsYN3xi+o6DDZnT+Q92SzI9hIskfM/SGJu4vQN4JYuS0+gpXDo rSlMsrjjvvpEZe0D+Xjd1RDbSsRLmW2/CuUpr9qNBFoBdJjZ5oCUfkoL2rFELJQrbSfY HfLMAVvXbm0pLTnY3J1iKNaI1Sa1QARX2W5IXVsfZoyPC6EsZl/MUSqefHrKoxPbJY0Q LzYwGFtGRkP8pvricNF3AK4Ho3RBw0s1MuJbJQtm7FWB8Az51OTTmeeQ/jnN6ihhz6pU DJfG3XQ3GApDozjhaV6QUzIsmFDvKIKjBuu3t/sTic0jr0hMYN6cvA9xzYvVTGjc1ZOL b4Ag== X-Gm-Message-State: AOAM531FkvOFtK+OeWNAyEEg9puTOgFsqOZDVYUqEghgbR/f0dhRu4lV dLLyDPZgMRGF23iFTwk2R1Y= X-Google-Smtp-Source: ABdhPJzGKNspjxR8A8B7b44R+2o7lZ4ENaSPHVk9rrp3R4zCLs93/pe5c56/czCE8+OXMznekQZVYw== X-Received: by 2002:a17:902:b492:b0:13f:4f30:88de with SMTP id y18-20020a170902b49200b0013f4f3088demr9676650plr.35.1634120636892; Wed, 13 Oct 2021 03:23:56 -0700 (PDT) Received: from vultr.guest ([144.202.123.152]) by smtp.gmail.com with ESMTPSA id 184sm13900994pfw.49.2021.10.13.03.23.55 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 13 Oct 2021 03:23:56 -0700 (PDT) From: Yafang Shao To: keescook@chromium.org, rostedt@goodmis.org, peterz@infradead.org, pmladek@suse.com, viro@zeniv.linux.org.uk, akpm@linux-foundation.org, valentin.schneider@arm.com, mathieu.desnoyers@efficios.com, qiang.zhang@windriver.com, robdclark@chromium.org, christian@brauner.io, dietmar.eggemann@arm.com, mingo@redhat.com, juri.lelli@redhat.com, vincent.guittot@linaro.org, bsegall@google.com, mgorman@suse.de, bristot@redhat.com, davem@davemloft.net, kuba@kernel.org Cc: linux-kernel@vger.kernel.org, Yafang Shao , kernel test robot Subject: [PATCH v4 1/5] elfcore: use TASK_COMM_LEN instead of 16 in prpsinfo Date: Wed, 13 Oct 2021 10:23:42 +0000 Message-Id: <20211013102346.179642-2-laoar.shao@gmail.com> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20211013102346.179642-1-laoar.shao@gmail.com> References: <20211013102346.179642-1-laoar.shao@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org kernel test robot reported a -Wstringop-truncation warning after I extend task comm from 16 to 24. Below is the detailed warning: fs/binfmt_elf.c: In function 'fill_psinfo.isra': >> fs/binfmt_elf.c:1575:9: warning: 'strncpy' output may be truncated copying 16 bytes from a string of length 23 [-Wstringop-truncation] 1575 | strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname)); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ This patch can fix this warning. struct elf_prpsinfo was moved from include/uapi/linux/elfcore.h into include/linux/elfcore.h in commit 1e6b57d6421f ("unexport linux/elfcore.h") As it is not UAPI code, we can replace 16 with TASK_COMM_LEN without worrying about breaking userspace things. struct elf_prpsinfo is used to dump the task information in userspace coredump or kernel vmcore. So I verified what will happen to vmcore if I extend the size of TASK_COMM_LEN to 24. The result is that the vmcore still work fine as expected, for example: crash> ps PID PPID CPU TASK ST %MEM VSZ RSS COMM > 0 0 0 ffffffff8501a940 RU 0.0 0 0 [swapper/0] > 0 0 1 ffff996e00f81f80 RU 0.0 0 0 [swapper/1] > 0 0 2 ffff996e00f80000 RU 0.0 0 0 [swapper/2] > 0 0 3 ffff996e00f85e80 RU 0.0 0 0 [swapper/3] > 0 0 4 ffff996e00f83f00 RU 0.0 0 0 [swapper/4] 0 0 5 ffff996e00f8de80 RU 0.0 0 0 [swapper/5] > 0 0 6 ffff996e00f8bf00 RU 0.0 0 0 [swapper/6] > 0 0 7 ffff996e00f89f80 RU 0.0 0 0 [swapper/7] > 0 0 8 ffff996e00f88000 RU 0.0 0 0 [swapper/8] > 0 0 9 ffff996e00f93f00 RU 0.0 0 0 [swapper/9] > 0 0 10 ffff996e00f91f80 RU 0.0 0 0 [swapper/10] > 0 0 11 ffff996e00f90000 RU 0.0 0 0 [swapper/11] > 0 0 12 ffff996e00f95e80 RU 0.0 0 0 [swapper/12] > 0 0 13 ffff996e00f98000 RU 0.0 0 0 [swapper/13] > 0 0 14 ffff996e00f9de80 RU 0.0 0 0 [swapper/14] > 0 0 15 ffff996e00f9bf00 RU 0.0 0 0 [swapper/15] Reported-by: kernel test robot Signed-off-by: Yafang Shao Cc: Peter Zijlstra Cc: Steven Rostedt Cc: Kees Cook Cc: Al Viro Cc: Petr Mladek --- include/linux/elfcore-compat.h | 2 +- include/linux/elfcore.h | 4 ++-- 2 files changed, 3 insertions(+), 3 deletions(-) diff --git a/include/linux/elfcore-compat.h b/include/linux/elfcore-compat.h index e272c3d452ce..8a52a782161d 100644 --- a/include/linux/elfcore-compat.h +++ b/include/linux/elfcore-compat.h @@ -43,7 +43,7 @@ struct compat_elf_prpsinfo __compat_uid_t pr_uid; __compat_gid_t pr_gid; compat_pid_t pr_pid, pr_ppid, pr_pgrp, pr_sid; - char pr_fname[16]; + char pr_fname[TASK_COMM_LEN]; char pr_psargs[ELF_PRARGSZ]; }; diff --git a/include/linux/elfcore.h b/include/linux/elfcore.h index 2aaa15779d50..ff4e4e455160 100644 --- a/include/linux/elfcore.h +++ b/include/linux/elfcore.h @@ -65,8 +65,8 @@ struct elf_prpsinfo __kernel_gid_t pr_gid; pid_t pr_pid, pr_ppid, pr_pgrp, pr_sid; /* Lots missing */ - char pr_fname[16]; /* filename of executable */ - char pr_psargs[ELF_PRARGSZ]; /* initial part of arg list */ + char pr_fname[TASK_COMM_LEN]; /* filename of executable */ + char pr_psargs[ELF_PRARGSZ]; /* initial part of arg list */ }; static inline void elf_core_copy_regs(elf_gregset_t *elfregs, struct pt_regs *regs) -- 2.17.1