From nobody Fri Dec 19 00:55:23 2025 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2A03518132D for ; Thu, 2 May 2024 21:38:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=193.142.43.55 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714685928; cv=none; b=gdlDkKh/jmWcX2PEOGwiH3mFqrnaNetNriQiSqb1Cw8q0O7tAX9G99KHu2U3Clk/HssKv1mDtheV59qPJ97gN2Br9/98+AkLaDnbS7owVK78dwax1eoS0IMrP5BsY3fE1MjVTxt51W6VrJBD5RSE3mMF+Lcyz0HEl6J08A9lxMI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714685928; c=relaxed/simple; bh=NbX9KqSu+VKC9sOzIh/s7S68iv2vejeD4ejGhNdGI1Q=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=XXGa/37Jjtmypn5BKtF3/dpksK0AvJIGezqwokHPVsQxCidsQ7jbLHnrTSRHcJ71PNnotX+W2mc2OWwrAnjgHVHt3gtkaW6kWW3CVg6MWOVF4w+Qoao1+xJlklA/HZXVSBGeJ/HFsRhePyV1v4O/iXA/vbS4eEmshFnFe0bnLfM= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de; spf=pass smtp.mailfrom=linutronix.de; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=mHVEbyNa; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=tdV4BBLA; arc=none smtp.client-ip=193.142.43.55 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linutronix.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="mHVEbyNa"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="tdV4BBLA" From: John Ogness DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1714685925; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=iGNvVJcsNgc3jll4nDoPF6g4hs94SRVjeR/SV60Zi28=; b=mHVEbyNadP/y1Aos7cR+kyTwG2WXBYdr8zim+Ij95yqUPwx6QXNQxyleYFc2zrkmmGhdVW vOmnUG0r/5prUSrKhwh3UIfggbBnjvJtw7vRaYUuaDKRonp+K/a6bFHyRk6O0YfOcFrDkL 59VqfLSWbH9DIb/62uQ9s+PGFiSgU7avdjgtVQxgJ0ILBCehAPCBgEWI0rAS2ycnjLY0Q6 tEB1j/WqhJ81rPRc1e+aAYmjP/7aTCQRKLrZLwKheHQdluicbuEQpF7IakMWUU6G4ji4TR Sphs4L3GeGiL33C8Eso/uXs5xPjF9wsasW8pZ4F8+b6VlDu856phRvMto2O40w== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1714685925; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=iGNvVJcsNgc3jll4nDoPF6g4hs94SRVjeR/SV60Zi28=; b=tdV4BBLA7zeb6GnBsc/iksSNwSqxn2/A5A0Hj8cJEN8Qlx3pEaJZejdQjtpdTBvFTCfMLr s4uskHnUNj9VDQCw== To: Petr Mladek Cc: Sergey Senozhatsky , Steven Rostedt , Thomas Gleixner , linux-kernel@vger.kernel.org, Sebastian Andrzej Siewior Subject: [PATCH printk v5 04/30] printk: Check printk_deferred_enter()/_exit() usage Date: Thu, 2 May 2024 23:44:13 +0206 Message-Id: <20240502213839.376636-5-john.ogness@linutronix.de> In-Reply-To: <20240502213839.376636-1-john.ogness@linutronix.de> References: <20240502213839.376636-1-john.ogness@linutronix.de> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Sebastian Andrzej Siewior Add validation that printk_deferred_enter()/_exit() are called in non-migration contexts. Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: John Ogness Reviewed-by: Petr Mladek --- include/linux/printk.h | 9 +++++---- kernel/printk/internal.h | 3 +++ kernel/printk/printk_safe.c | 12 ++++++++++++ 3 files changed, 20 insertions(+), 4 deletions(-) diff --git a/include/linux/printk.h b/include/linux/printk.h index 2fde40cc9677..d8b3f51d9e98 100644 --- a/include/linux/printk.h +++ b/include/linux/printk.h @@ -157,15 +157,16 @@ int _printk(const char *fmt, ...); */ __printf(1, 2) __cold int _printk_deferred(const char *fmt, ...); =20 -extern void __printk_safe_enter(void); -extern void __printk_safe_exit(void); +extern void __printk_deferred_enter(void); +extern void __printk_deferred_exit(void); + /* * The printk_deferred_enter/exit macros are available only as a hack for * some code paths that need to defer all printk console printing. Interru= pts * must be disabled for the deferred duration. */ -#define printk_deferred_enter __printk_safe_enter -#define printk_deferred_exit __printk_safe_exit +#define printk_deferred_enter() __printk_deferred_enter() +#define printk_deferred_exit() __printk_deferred_exit() =20 /* * Please don't use printk_ratelimit(), because it shares ratelimiting sta= te diff --git a/kernel/printk/internal.h b/kernel/printk/internal.h index 739b82adc383..831f95f26d48 100644 --- a/kernel/printk/internal.h +++ b/kernel/printk/internal.h @@ -53,6 +53,9 @@ int vprintk_store(int facility, int level, __printf(1, 0) int vprintk_default(const char *fmt, va_list args); __printf(1, 0) int vprintk_deferred(const char *fmt, va_list args); =20 +void __printk_safe_enter(void); +void __printk_safe_exit(void); + bool printk_percpu_data_ready(void); =20 #define printk_safe_enter_irqsave(flags) \ diff --git a/kernel/printk/printk_safe.c b/kernel/printk/printk_safe.c index 6d10927a07d8..4421ccac3113 100644 --- a/kernel/printk/printk_safe.c +++ b/kernel/printk/printk_safe.c @@ -26,6 +26,18 @@ void __printk_safe_exit(void) this_cpu_dec(printk_context); } =20 +void __printk_deferred_enter(void) +{ + cant_migrate(); + __printk_safe_enter(); +} + +void __printk_deferred_exit(void) +{ + cant_migrate(); + __printk_safe_exit(); +} + asmlinkage int vprintk(const char *fmt, va_list args) { #ifdef CONFIG_KGDB_KDB --=20 2.39.2