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=-10.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_2 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 9DDC0C0650E for ; Wed, 3 Jul 2019 14:55:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7ABE321882 for ; Wed, 3 Jul 2019 14:55:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726841AbfGCOzP (ORCPT ); Wed, 3 Jul 2019 10:55:15 -0400 Received: from mail.kernel.org ([198.145.29.99]:47208 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725944AbfGCOzO (ORCPT ); Wed, 3 Jul 2019 10:55:14 -0400 Received: from gandalf.local.home (cpe-66-24-58-225.stny.res.rr.com [66.24.58.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 2ED3121882; Wed, 3 Jul 2019 14:55:13 +0000 (UTC) Date: Wed, 3 Jul 2019 10:55:11 -0400 From: Steven Rostedt To: Linus Torvalds Cc: LKML , Ingo Molnar , Andrew Morton Subject: [GIT PULL] tracing: A few fixes for this rc release Message-ID: <20190703105511.263ffd56@gandalf.local.home> X-Mailer: Claws Mail 3.17.3 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Linus, This includes three fixes: - Fixes a deadlock from a previous fix to keep module loading and function tracing text modifications from stepping on each other. (this has a few patches to help document the issue in comments) - Fix a crash when the snapshot buffer gets out of sync with the main ring buffer. - Fix a memory leak when reading the memory logs Please pull the latest trace-v5.2-rc5 tree, which can be found at: git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace.git trace-v5.2-rc5 Tag SHA1: e2d01e8f26e849e0e45742a46727ba0da8af7c55 Head SHA1: 074376ac0e1d1fcd4fafebca86ee6158e7c20680 Eiichi Tsukata (1): tracing/snapshot: Resize spare buffer if size changed Jiri Kosina (1): ftrace/x86: Anotate text_mutex split between ftrace_arch_code_modify_post_process() and ftrace_arch_code_modify_prepare() Petr Mladek (1): ftrace/x86: Remove possible deadlock between register_kprobe() and ftrace_run_update_code() Steven Rostedt (VMware) (1): ftrace/x86: Add a comment to why we take text_mutex in ftrace_arch_code_modify_prepare() Takeshi Misawa (1): tracing: Fix memory leak in tracing_err_log_open() ---- arch/x86/kernel/ftrace.c | 10 ++++++++++ kernel/trace/ftrace.c | 10 +--------- kernel/trace/trace.c | 24 +++++++++++++++++++----- 3 files changed, 30 insertions(+), 14 deletions(-) --------------------------- diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c index 0927bb158ffc..76228525acd0 100644 --- a/arch/x86/kernel/ftrace.c +++ b/arch/x86/kernel/ftrace.c @@ -22,6 +22,7 @@ #include #include #include +#include #include @@ -34,16 +35,25 @@ #ifdef CONFIG_DYNAMIC_FTRACE int ftrace_arch_code_modify_prepare(void) + __acquires(&text_mutex) { + /* + * Need to grab text_mutex to prevent a race from module loading + * and live kernel patching from changing the text permissions while + * ftrace has it set to "read/write". + */ + mutex_lock(&text_mutex); set_kernel_text_rw(); set_all_modules_text_rw(); return 0; } int ftrace_arch_code_modify_post_process(void) + __releases(&text_mutex) { set_all_modules_text_ro(); set_kernel_text_ro(); + mutex_unlock(&text_mutex); return 0; } diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 38277af44f5c..576c41644e77 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -34,7 +34,6 @@ #include #include #include -#include #include @@ -2611,12 +2610,10 @@ static void ftrace_run_update_code(int command) { int ret; - mutex_lock(&text_mutex); - ret = ftrace_arch_code_modify_prepare(); FTRACE_WARN_ON(ret); if (ret) - goto out_unlock; + return; /* * By default we use stop_machine() to modify the code. @@ -2628,9 +2625,6 @@ static void ftrace_run_update_code(int command) ret = ftrace_arch_code_modify_post_process(); FTRACE_WARN_ON(ret); - -out_unlock: - mutex_unlock(&text_mutex); } static void ftrace_run_modify_code(struct ftrace_ops *ops, int command, @@ -5784,7 +5778,6 @@ void ftrace_module_enable(struct module *mod) struct ftrace_page *pg; mutex_lock(&ftrace_lock); - mutex_lock(&text_mutex); if (ftrace_disabled) goto out_unlock; @@ -5846,7 +5839,6 @@ void ftrace_module_enable(struct module *mod) ftrace_arch_code_modify_post_process(); out_unlock: - mutex_unlock(&text_mutex); mutex_unlock(&ftrace_lock); process_cached_mods(mod->name); diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 83e08b78dbee..c3aabb576fe5 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -6719,11 +6719,13 @@ tracing_snapshot_write(struct file *filp, const char __user *ubuf, size_t cnt, break; } #endif - if (!tr->allocated_snapshot) { + if (tr->allocated_snapshot) + ret = resize_buffer_duplicate_size(&tr->max_buffer, + &tr->trace_buffer, iter->cpu_file); + else ret = tracing_alloc_snapshot_instance(tr); - if (ret < 0) - break; - } + if (ret < 0) + break; local_irq_disable(); /* Now, we're going to swap */ if (iter->cpu_file == RING_BUFFER_ALL_CPUS) @@ -7126,12 +7128,24 @@ static ssize_t tracing_err_log_write(struct file *file, return count; } +static int tracing_err_log_release(struct inode *inode, struct file *file) +{ + struct trace_array *tr = inode->i_private; + + trace_array_put(tr); + + if (file->f_mode & FMODE_READ) + seq_release(inode, file); + + return 0; +} + static const struct file_operations tracing_err_log_fops = { .open = tracing_err_log_open, .write = tracing_err_log_write, .read = seq_read, .llseek = seq_lseek, - .release = tracing_release_generic_tr, + .release = tracing_err_log_release, }; static int tracing_buffers_open(struct inode *inode, struct file *filp)