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=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS 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 DF0AAC2D0DB for ; Sun, 26 Jan 2020 19:20:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BBEE321741 for ; Sun, 26 Jan 2020 19:20:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729213AbgAZTUe (ORCPT ); Sun, 26 Jan 2020 14:20:34 -0500 Received: from mail.kernel.org ([198.145.29.99]:53732 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726382AbgAZTUX (ORCPT ); Sun, 26 Jan 2020 14:20:23 -0500 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 82F7E2075D; Sun, 26 Jan 2020 19:20:22 +0000 (UTC) Received: from rostedt by gandalf.local.home with local (Exim 4.93) (envelope-from ) id 1ivnSH-000zt0-Ey; Sun, 26 Jan 2020 14:20:21 -0500 Message-Id: <20200126192021.350763989@goodmis.org> User-Agent: quilt/0.65 Date: Sun, 26 Jan 2020 14:19:39 -0500 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Ingo Molnar , Andrew Morton , Dmitry Vyukov Subject: [for-next][PATCH 7/7] tracing: Use pr_err() instead of WARN() for memory failures References: <20200126191932.984391723@goodmis.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: "Steven Rostedt (VMware)" As warnings can trigger panics, especially when "panic_on_warn" is set, memory failure warnings can cause panics and fail fuzz testers that are stressing memory. Create a MEM_FAIL() macro to use instead of WARN() in the tracing code (perhaps this should be a kernel wide macro?), and use that for memory failure issues. This should stop failing fuzz tests due to warnings. Link: https://lore.kernel.org/r/CACT4Y+ZP-7np20GVRu3p+eZys9GPtbu+JpfV+HtsufAzvTgJrg@mail.gmail.com Suggested-by: Dmitry Vyukov Signed-off-by: Steven Rostedt (VMware) --- kernel/trace/ftrace.c | 4 ++-- kernel/trace/trace.c | 18 +++++++++--------- kernel/trace/trace.h | 12 ++++++++++++ 3 files changed, 23 insertions(+), 11 deletions(-) diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 5c701765da5b..fdb1a9532420 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -5459,7 +5459,7 @@ static void __init set_ftrace_early_graph(char *buf, int enable) struct ftrace_hash *hash; hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS); - if (WARN_ON(!hash)) + if (MEM_FAIL(!hash, "Failed to allocate hash\n")) return; while (buf) { @@ -6591,7 +6591,7 @@ static void add_to_clear_hash_list(struct list_head *clear_list, func = kmalloc(sizeof(*func), GFP_KERNEL); if (!func) { - WARN_ONCE(1, "alloc failure, ftrace filter could be stale\n"); + MEM_FAIL(1, "alloc failure, ftrace filter could be stale\n"); return; } diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 0a5569b1cace..6a28b1b9bf42 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -3126,7 +3126,7 @@ static int alloc_percpu_trace_buffer(void) struct trace_buffer_struct *buffers; buffers = alloc_percpu(struct trace_buffer_struct); - if (WARN(!buffers, "Could not allocate percpu trace_printk buffer")) + if (MEM_FAIL(!buffers, "Could not allocate percpu trace_printk buffer")) return -ENOMEM; trace_percpu_buffer = buffers; @@ -7932,7 +7932,7 @@ static struct dentry *tracing_dentry_percpu(struct trace_array *tr, int cpu) tr->percpu_dir = tracefs_create_dir("per_cpu", d_tracer); - WARN_ONCE(!tr->percpu_dir, + MEM_FAIL(!tr->percpu_dir, "Could not create tracefs directory 'per_cpu/%d'\n", cpu); return tr->percpu_dir; @@ -8253,7 +8253,7 @@ create_trace_option_files(struct trace_array *tr, struct tracer *tracer) for (cnt = 0; opts[cnt].name; cnt++) { create_trace_option_file(tr, &topts[cnt], flags, &opts[cnt]); - WARN_ONCE(topts[cnt].entry == NULL, + MEM_FAIL(topts[cnt].entry == NULL, "Failed to create trace option: %s", opts[cnt].name); } @@ -8437,7 +8437,7 @@ static int allocate_trace_buffers(struct trace_array *tr, int size) #ifdef CONFIG_TRACER_MAX_TRACE ret = allocate_trace_buffer(tr, &tr->max_buffer, allocate_snapshot ? size : 1); - if (WARN_ON(ret)) { + if (MEM_FAIL(ret, "Failed to allocate trace buffer\n")) { ring_buffer_free(tr->array_buffer.buffer); tr->array_buffer.buffer = NULL; free_percpu(tr->array_buffer.data); @@ -8726,7 +8726,7 @@ static __init void create_trace_instances(struct dentry *d_tracer) trace_instance_dir = tracefs_create_instance_dir("instances", d_tracer, instance_mkdir, instance_rmdir); - if (WARN_ON(!trace_instance_dir)) + if (MEM_FAIL(!trace_instance_dir, "Failed to create instances directory\n")) return; } @@ -8796,7 +8796,7 @@ init_tracer_tracefs(struct trace_array *tr, struct dentry *d_tracer) #endif if (ftrace_create_function_files(tr, d_tracer)) - WARN(1, "Could not allocate function filter files"); + MEM_FAIL(1, "Could not allocate function filter files"); #ifdef CONFIG_TRACER_SNAPSHOT trace_create_file("snapshot", 0644, d_tracer, @@ -9348,8 +9348,7 @@ __init static int tracer_alloc_buffers(void) /* TODO: make the number of buffers hot pluggable with CPUS */ if (allocate_trace_buffers(&global_trace, ring_buf_size) < 0) { - printk(KERN_ERR "tracer: failed to allocate ring buffer!\n"); - WARN_ON(1); + MEM_FAIL(1, "tracer: failed to allocate ring buffer!\n"); goto out_free_savedcmd; } @@ -9422,7 +9421,8 @@ void __init early_trace_init(void) if (tracepoint_printk) { tracepoint_print_iter = kmalloc(sizeof(*tracepoint_print_iter), GFP_KERNEL); - if (WARN_ON(!tracepoint_print_iter)) + if (MEM_FAIL(!tracepoint_print_iter, + "Failed to allocate trace iterator\n")) tracepoint_printk = 0; else static_key_enable(&tracepoint_printk_key.key); diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 4812a36affac..6bb64d89c321 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -94,6 +94,18 @@ enum trace_type { #include "trace_entries.h" +/* Use this for memory failure errors */ +#define MEM_FAIL(condition, fmt, ...) ({ \ + static bool __section(.data.once) __warned; \ + int __ret_warn_once = !!(condition); \ + \ + if (unlikely(__ret_warn_once && !__warned)) { \ + __warned = true; \ + pr_err("ERROR: " fmt, ##__VA_ARGS__); \ + } \ + unlikely(__ret_warn_once); \ +}) + /* * syscalls are special, and need special handling, this is why * they are not included in trace_entries.h -- 2.24.1