From patchwork Tue Nov 15 20:28:41 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thomas Gleixner X-Patchwork-Id: 624933 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 388ADC4332F for ; Tue, 15 Nov 2022 20:29:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232370AbiKOU3I (ORCPT ); Tue, 15 Nov 2022 15:29:08 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37614 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231915AbiKOU2r (ORCPT ); Tue, 15 Nov 2022 15:28:47 -0500 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AB6EA1056C; Tue, 15 Nov 2022 12:28:43 -0800 (PST) Message-ID: <20221115202117.267934419@linutronix.de> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1668544122; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: references:references; bh=+c6hXmXMFU+cA9M4ph7NzjesG8KGkczgV8QouyLFMhg=; b=Rk3f/zGx/ynmX6PJI0+Y/8yGMsMSaGsqFNzAwtnfnWpoXMm7qOFmlpjwCtkNjf5gUM6F0O hvFKvBn3aZALHNCWW5BaBsHJ+vPYoxgwYXQUo1fO6w8B5pfWWL/sF3We+OFujgCprXMzdU Xuf+cRNzeaS3oR9T88JsS4oYQsQ1mljxlgP5q9yp+ON9vtuI4k4rB23sK/8oYnqG1f9bqt N469PmNJNlhLPSehiztNG2eBzCddF3LcPNlRuM6AkAoSAJPP9DWJJ7Yl8wKZqbetE3BJQS 6MDJicVS0Kg0JIC9gdLzrKqrV1GCoQQqrkon5xTvhWY8tSFhdAOk6WWlaKvluA== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1668544122; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: references:references; bh=+c6hXmXMFU+cA9M4ph7NzjesG8KGkczgV8QouyLFMhg=; b=vHzcFij6caEAmwrBaTi6i/5ROuLhTfBF0oiSGsA/MCF+cI6pPQ9eZaxtUgGzlevwFMT4Gt G3EpvNkyAxD+vGBQ== From: Thomas Gleixner To: LKML Cc: Linus Torvalds , Steven Rostedt , Anna-Maria Behnsen , Peter Zijlstra , Stephen Boyd , Guenter Roeck , Andrew Morton , Julia Lawall , Arnd Bergmann , Viresh Kumar , Marc Zyngier , Marcel Holtmann , Johan Hedberg , Luiz Augusto von Dentz , linux-bluetooth@vger.kernel.org, "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , netdev@vger.kernel.org Subject: [patch 05/15] timers: Replace BUG_ON()s References: <20221115195802.415956561@linutronix.de> MIME-Version: 1.0 Date: Tue, 15 Nov 2022 21:28:41 +0100 (CET) Precedence: bulk List-ID: X-Mailing-List: linux-bluetooth@vger.kernel.org The timer code still has a few BUG_ON()s left which are crashing the kernel in situations where it still can recover or simply refuse to take an action. Remove the one in the hotplug callback which checks for the CPU being offline. If that happens then the whole hotplug machinery will explode in colourful ways. Replace the rest with WARN_ON_ONCE() and conditional returns where appropriate. Signed-off-by: Thomas Gleixner Reviewed-by: Steven Rostedt (Google) --- kernel/time/timer.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) --- a/kernel/time/timer.c +++ b/kernel/time/timer.c @@ -1193,7 +1193,8 @@ EXPORT_SYMBOL(timer_reduce); */ void add_timer(struct timer_list *timer) { - BUG_ON(timer_pending(timer)); + if (WARN_ON_ONCE(timer_pending(timer))) + return; __mod_timer(timer, timer->expires, MOD_TIMER_NOTPENDING); } EXPORT_SYMBOL(add_timer); @@ -1210,7 +1211,8 @@ void add_timer_on(struct timer_list *tim struct timer_base *new_base, *base; unsigned long flags; - BUG_ON(timer_pending(timer) || !timer->function); + if (WARN_ON_ONCE(timer_pending(timer) || !timer->function)) + return; new_base = get_timer_cpu_base(timer->flags, cpu); @@ -2017,8 +2019,6 @@ int timers_dead_cpu(unsigned int cpu) struct timer_base *new_base; int b, i; - BUG_ON(cpu_online(cpu)); - for (b = 0; b < NR_BASES; b++) { old_base = per_cpu_ptr(&timer_bases[b], cpu); new_base = get_cpu_ptr(&timer_bases[b]); @@ -2035,7 +2035,8 @@ int timers_dead_cpu(unsigned int cpu) */ forward_timer_base(new_base); - BUG_ON(old_base->running_timer); + WARN_ON_ONCE(old_base->running_timer); + old_base->running_timer = NULL; for (i = 0; i < WHEEL_SIZE; i++) migrate_timer_list(new_base, old_base->vectors + i);