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 X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 26B82C7618B for ; Thu, 25 Jul 2019 14:39:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E370D218EA for ; Thu, 25 Jul 2019 14:39:03 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lca.pw header.i=@lca.pw header.b="TzOLZZSV" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729149AbfGYOjC (ORCPT ); Thu, 25 Jul 2019 10:39:02 -0400 Received: from mail-qk1-f193.google.com ([209.85.222.193]:47081 "EHLO mail-qk1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726736AbfGYOjC (ORCPT ); Thu, 25 Jul 2019 10:39:02 -0400 Received: by mail-qk1-f193.google.com with SMTP id r4so36509188qkm.13 for ; Thu, 25 Jul 2019 07:39:01 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=lca.pw; s=google; h=from:to:cc:subject:date:message-id; bh=xoSQWHPuY8p2jMXFibHmTvGdIgXKgADFPKfleeYedKc=; b=TzOLZZSVdD98/bsYWrEMVRMiB7YL1jkX/aTLpQQQtcwfOb/qvsneJBe4ac8EsSFTTG 25/V0MPGaTCyIpTLaOnzxFOyZ+gYsrUCNjhfXhZUSJg8dm1t31mafVWEHNv5JoDnoom6 E2P8lvJqW1Vue20LcRbEobmcdJ6POxMdXCXfwCmH3edcF4f+nQajPgBn3JT4kuJXudac zE9teWow4RjihX6O/KhNJlEo4SXIICJ3ol2Ld2ryW4ZJ0+Cok3BRCgnYpi3eXnwR2PCo 8nxB/76FOl+0+oplA6XmD1H2jVANH4fq0kaoJuEsoxOj/NjYJdaZyfaA9Bxd42DWqlAe 19+Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=xoSQWHPuY8p2jMXFibHmTvGdIgXKgADFPKfleeYedKc=; b=UOHf/Kp7dCHeefjENu/K/TIML93J4Gd7YCwleXgQE4xm1hOaS5yh5fACdnVNLUQ9rL y20nFGUU5nVlEH3owLFY50VvvGuP1L6z+Qe+COwJQj/48CqcpdIAC6J3Ytmg9ojdfSiC QxeaUaahALy76ddT4Ha5jQlrqFETKOz3pfMILgurNkV7hI4oQ+xKwuw/Z5o44OLwLW0S yjtcH4SrQhG48gqn5xzOr4BDdluL4LrpZGlftWJa4VIcMr5rbE6b+xhAEml8gGPYqxtV nKFm5E4IJexfNkv7Tu9sprzacpxV4j+QhLB7ZfXYzSLa+TpOIrqxN9m0UBffVGpRfRyQ aNqA== X-Gm-Message-State: APjAAAXeOzXGWZR7uz+IwMHtd3HGdyvD83+PAzW7JtfvTTdO1Ve3rQ7n o6ZP5ysmejqjLXkxnFfCVpbwyQ== X-Google-Smtp-Source: APXvYqwYdHITXRbJ6ij5XUgOpu0S6BImw+97Pi1ktV41V8Wq/G73zQvo8GFdTk+JgKe/q/9DxQvXnw== X-Received: by 2002:a37:4d82:: with SMTP id a124mr57121919qkb.72.1564065540575; Thu, 25 Jul 2019 07:39:00 -0700 (PDT) Received: from qcai.nay.com (nat-pool-bos-t.redhat.com. [66.187.233.206]) by smtp.gmail.com with ESMTPSA id q17sm17821291qtl.13.2019.07.25.07.38.59 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 25 Jul 2019 07:38:59 -0700 (PDT) From: Qian Cai To: akpm@linux-foundation.org Cc: tobin@kernel.org, rostedt@goodmis.org, mingo@redhat.com, tj@kernel.org, dchinner@redhat.com, fengguang.wu@intel.com, jack@suse.cz, axboe@kernel.dk, linux-kernel@vger.kernel.org, Qian Cai Subject: [PATCH v2] writeback: fix -Wstringop-truncation warnings Date: Thu, 25 Jul 2019 10:38:31 -0400 Message-Id: <1564065511-13206-1-git-send-email-cai@lca.pw> X-Mailer: git-send-email 1.8.3.1 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org There are many of those warnings. In file included from ./arch/powerpc/include/asm/paca.h:15, from ./arch/powerpc/include/asm/current.h:13, from ./include/linux/thread_info.h:21, from ./include/asm-generic/preempt.h:5, from ./arch/powerpc/include/generated/asm/preempt.h:1, from ./include/linux/preempt.h:78, from ./include/linux/spinlock.h:51, from fs/fs-writeback.c:19: In function 'strncpy', inlined from 'perf_trace_writeback_page_template' at ./include/trace/events/writeback.h:56:1: ./include/linux/string.h:260:9: warning: '__builtin_strncpy' specified bound 32 equals destination size [-Wstringop-truncation] return __builtin_strncpy(p, q, size); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Fix it by using the new strscpy_pad() which was introduced in the commit 458a3bf82df4 ("lib/string: Add strscpy_pad() function") and will always be NUL-terminated instead of strncpy(). Also, changes strlcpy() to use strscpy_pad() in this file for consistency. Fixes: 455b2864686d ("writeback: Initial tracing support") Fixes: 028c2dd184c0 ("writeback: Add tracing to balance_dirty_pages") Fixes: e84d0a4f8e39 ("writeback: trace event writeback_queue_io") Fixes: b48c104d2211 ("writeback: trace event bdi_dirty_ratelimit") Fixes: cc1676d917f3 ("writeback: Move requeueing when I_SYNC set to writeback_sb_inodes()") Fixes: 9fb0a7da0c52 ("writeback: add more tracepoints") Signed-off-by: Qian Cai --- v2: Use strscpy_pad() to address the possible data leaking concern from Steve [1]. Replace strlcpy() as well for consistency. [1] https://lore.kernel.org/lkml/20190716170339.1c44719d@gandalf.local.home/ include/trace/events/writeback.h | 39 +++++++++++++++++++++------------------ 1 file changed, 21 insertions(+), 18 deletions(-) diff --git a/include/trace/events/writeback.h b/include/trace/events/writeback.h index aa7f3aeac740..41092d63a8de 100644 --- a/include/trace/events/writeback.h +++ b/include/trace/events/writeback.h @@ -66,8 +66,10 @@ ), TP_fast_assign( - strncpy(__entry->name, - mapping ? dev_name(inode_to_bdi(mapping->host)->dev) : "(unknown)", 32); + strscpy_pad(__entry->name, + mapping ? + dev_name(inode_to_bdi(mapping->host)->dev) : + "(unknown)", 32); __entry->ino = mapping ? mapping->host->i_ino : 0; __entry->index = page->index; ), @@ -110,8 +112,8 @@ struct backing_dev_info *bdi = inode_to_bdi(inode); /* may be called for files on pseudo FSes w/ unregistered bdi */ - strncpy(__entry->name, - bdi->dev ? dev_name(bdi->dev) : "(unknown)", 32); + strscpy_pad(__entry->name, + bdi->dev ? dev_name(bdi->dev) : "(unknown)", 32); __entry->ino = inode->i_ino; __entry->state = inode->i_state; __entry->flags = flags; @@ -190,8 +192,8 @@ static inline unsigned int __trace_wbc_assign_cgroup(struct writeback_control *w ), TP_fast_assign( - strncpy(__entry->name, - dev_name(inode_to_bdi(inode)->dev), 32); + strscpy_pad(__entry->name, + dev_name(inode_to_bdi(inode)->dev), 32); __entry->ino = inode->i_ino; __entry->sync_mode = wbc->sync_mode; __entry->cgroup_ino = __trace_wbc_assign_cgroup(wbc); @@ -234,8 +236,9 @@ static inline unsigned int __trace_wbc_assign_cgroup(struct writeback_control *w __field(unsigned int, cgroup_ino) ), TP_fast_assign( - strncpy(__entry->name, - wb->bdi->dev ? dev_name(wb->bdi->dev) : "(unknown)", 32); + strscpy_pad(__entry->name, + wb->bdi->dev ? dev_name(wb->bdi->dev) : + "(unknown)", 32); __entry->nr_pages = work->nr_pages; __entry->sb_dev = work->sb ? work->sb->s_dev : 0; __entry->sync_mode = work->sync_mode; @@ -288,7 +291,7 @@ static inline unsigned int __trace_wbc_assign_cgroup(struct writeback_control *w __field(unsigned int, cgroup_ino) ), TP_fast_assign( - strncpy(__entry->name, dev_name(wb->bdi->dev), 32); + strscpy_pad(__entry->name, dev_name(wb->bdi->dev), 32); __entry->cgroup_ino = __trace_wb_assign_cgroup(wb); ), TP_printk("bdi %s: cgroup_ino=%u", @@ -310,7 +313,7 @@ static inline unsigned int __trace_wbc_assign_cgroup(struct writeback_control *w __array(char, name, 32) ), TP_fast_assign( - strncpy(__entry->name, dev_name(bdi->dev), 32); + strscpy_pad(__entry->name, dev_name(bdi->dev), 32); ), TP_printk("bdi %s", __entry->name @@ -335,7 +338,7 @@ static inline unsigned int __trace_wbc_assign_cgroup(struct writeback_control *w ), TP_fast_assign( - strncpy(__entry->name, dev_name(bdi->dev), 32); + strscpy_pad(__entry->name, dev_name(bdi->dev), 32); __entry->nr_to_write = wbc->nr_to_write; __entry->pages_skipped = wbc->pages_skipped; __entry->sync_mode = wbc->sync_mode; @@ -386,7 +389,7 @@ static inline unsigned int __trace_wbc_assign_cgroup(struct writeback_control *w ), TP_fast_assign( unsigned long *older_than_this = work->older_than_this; - strncpy(__entry->name, dev_name(wb->bdi->dev), 32); + strscpy_pad(__entry->name, dev_name(wb->bdi->dev), 32); __entry->older = older_than_this ? *older_than_this : 0; __entry->age = older_than_this ? (jiffies - *older_than_this) * 1000 / HZ : -1; @@ -472,7 +475,7 @@ static inline unsigned int __trace_wbc_assign_cgroup(struct writeback_control *w ), TP_fast_assign( - strlcpy(__entry->bdi, dev_name(wb->bdi->dev), 32); + strscpy_pad(__entry->bdi, dev_name(wb->bdi->dev), 32); __entry->write_bw = KBps(wb->write_bandwidth); __entry->avg_write_bw = KBps(wb->avg_write_bandwidth); __entry->dirty_rate = KBps(dirty_rate); @@ -537,7 +540,7 @@ static inline unsigned int __trace_wbc_assign_cgroup(struct writeback_control *w TP_fast_assign( unsigned long freerun = (thresh + bg_thresh) / 2; - strlcpy(__entry->bdi, dev_name(wb->bdi->dev), 32); + strscpy_pad(__entry->bdi, dev_name(wb->bdi->dev), 32); __entry->limit = global_wb_domain.dirty_limit; __entry->setpoint = (global_wb_domain.dirty_limit + @@ -597,8 +600,8 @@ static inline unsigned int __trace_wbc_assign_cgroup(struct writeback_control *w ), TP_fast_assign( - strncpy(__entry->name, - dev_name(inode_to_bdi(inode)->dev), 32); + strscpy_pad(__entry->name, + dev_name(inode_to_bdi(inode)->dev), 32); __entry->ino = inode->i_ino; __entry->state = inode->i_state; __entry->dirtied_when = inode->dirtied_when; @@ -671,8 +674,8 @@ static inline unsigned int __trace_wbc_assign_cgroup(struct writeback_control *w ), TP_fast_assign( - strncpy(__entry->name, - dev_name(inode_to_bdi(inode)->dev), 32); + strscpy_pad(__entry->name, + dev_name(inode_to_bdi(inode)->dev), 32); __entry->ino = inode->i_ino; __entry->state = inode->i_state; __entry->dirtied_when = inode->dirtied_when; -- 1.8.3.1