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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 DC326C433E2 for ; Tue, 30 Mar 2021 15:36:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AE568619D7 for ; Tue, 30 Mar 2021 15:36:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232514AbhC3Pfg (ORCPT ); Tue, 30 Mar 2021 11:35:36 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59848 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232319AbhC3PfY (ORCPT ); Tue, 30 Mar 2021 11:35:24 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 77783C061764 for ; Tue, 30 Mar 2021 08:35:18 -0700 (PDT) From: John Ogness DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1617118516; 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=OwQDSIFoC6niL2q+iQikUcrCHMhBQ+TPKnmxalLmhps=; b=3MZdTxc07gPLoLG1Y05bTp4za31m59TfFkDh03a4fN2YeHv6KYFwCoPPs035TtzGOR2IVM 6ZHxhCxmSBgHFUPEWbVgOmREvQ4Fb5KYKwgId2vrUEvU+i0Is7KO7bSr9kgVff6fu/fLka z+9hQu7WZKQFZSw+UtbRYEo0whw5QBI9rjJznLcJiYdHl8HyGoUMz1OU59He8JCflnh2/R WF76aAQ7lsotxltgUhAD5Z/SIR4TQ/abukl8s5JpOWfN+MA5KscM/XERr3okF+iQ9Xg3U7 cgsitmN17S8YmOwptvbOSnSyujmtO4vDgnAczznO4M3W260HLsekSu/YFqvO0A== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1617118516; 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=OwQDSIFoC6niL2q+iQikUcrCHMhBQ+TPKnmxalLmhps=; b=mJrR1Dwat/8IblWUcdzjdoqaqEWo3jNv5KZO79ZDrEMeJ/RbsBBGQ+jDQzL1WiliL8QtHC 4b15j6gy2C83BXCg== To: Petr Mladek Cc: Sergey Senozhatsky , Sergey Senozhatsky , Steven Rostedt , Thomas Gleixner , linux-kernel@vger.kernel.org, Russell King , Michael Ellerman , Benjamin Herrenschmidt , Paul Mackerras , Ingo Molnar , Marc Zyngier , Valentin Schneider , Andrew Morton , Mike Rapoport , Geert Uytterhoeven , Anshuman Khandual , Leonardo Bras , Peter Zijlstra , Andy Lutomirski , Will Deacon , Frederic Weisbecker , "Paul E. McKenney" , Masahiro Yamada , Nathan Chancellor , Alexei Starovoitov , Kees Cook , Nick Terrell , David Howells , Johannes Weiner , linux-arm-kernel@lists.infradead.org, linuxppc-dev@lists.ozlabs.org Subject: [PATCH printk v2 3/5] printk: remove NMI tracking Date: Tue, 30 Mar 2021 17:35:10 +0200 Message-Id: <20210330153512.1182-4-john.ogness@linutronix.de> In-Reply-To: <20210330153512.1182-1-john.ogness@linutronix.de> References: <20210330153512.1182-1-john.ogness@linutronix.de> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org All NMI contexts are handled the same as the safe context: store the message and defer printing. There is no need to have special NMI context tracking for this. Using in_nmi() is enough. Signed-off-by: John Ogness --- arch/arm/kernel/smp.c | 2 -- arch/powerpc/kexec/crash.c | 3 --- include/linux/hardirq.h | 2 -- include/linux/printk.h | 12 ------------ init/Kconfig | 5 ----- kernel/printk/internal.h | 6 ------ kernel/printk/printk_safe.c | 37 +------------------------------------ kernel/trace/trace.c | 2 -- 8 files changed, 1 insertion(+), 68 deletions(-) diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c index 5c48eb4fd0e5..77a720c1f402 100644 --- a/arch/arm/kernel/smp.c +++ b/arch/arm/kernel/smp.c @@ -671,9 +671,7 @@ static void do_handle_IPI(int ipinr) break; case IPI_CPU_BACKTRACE: - printk_nmi_enter(); nmi_cpu_backtrace(get_irq_regs()); - printk_nmi_exit(); break; default: diff --git a/arch/powerpc/kexec/crash.c b/arch/powerpc/kexec/crash.c index c9a889880214..d488311efab1 100644 --- a/arch/powerpc/kexec/crash.c +++ b/arch/powerpc/kexec/crash.c @@ -311,9 +311,6 @@ void default_machine_crash_shutdown(struct pt_regs *regs) unsigned int i; int (*old_handler)(struct pt_regs *regs); - /* Avoid hardlocking with irresponsive CPU holding logbuf_lock */ - printk_nmi_enter(); - /* * This function is only called after the system * has panicked or is otherwise in a critical state. diff --git a/include/linux/hardirq.h b/include/linux/hardirq.h index 7c9d6a2d7e90..0926e9ca4d85 100644 --- a/include/linux/hardirq.h +++ b/include/linux/hardirq.h @@ -115,7 +115,6 @@ extern void rcu_nmi_exit(void); do { \ lockdep_off(); \ arch_nmi_enter(); \ - printk_nmi_enter(); \ BUG_ON(in_nmi() == NMI_MASK); \ __preempt_count_add(NMI_OFFSET + HARDIRQ_OFFSET); \ } while (0) @@ -134,7 +133,6 @@ extern void rcu_nmi_exit(void); do { \ BUG_ON(!in_nmi()); \ __preempt_count_sub(NMI_OFFSET + HARDIRQ_OFFSET); \ - printk_nmi_exit(); \ arch_nmi_exit(); \ lockdep_on(); \ } while (0) diff --git a/include/linux/printk.h b/include/linux/printk.h index 2476796c1150..77f66625706e 100644 --- a/include/linux/printk.h +++ b/include/linux/printk.h @@ -149,18 +149,6 @@ static inline __printf(1, 2) __cold void early_printk(const char *s, ...) { } #endif -#ifdef CONFIG_PRINTK_NMI -extern void printk_nmi_enter(void); -extern void printk_nmi_exit(void); -extern void printk_nmi_direct_enter(void); -extern void printk_nmi_direct_exit(void); -#else -static inline void printk_nmi_enter(void) { } -static inline void printk_nmi_exit(void) { } -static inline void printk_nmi_direct_enter(void) { } -static inline void printk_nmi_direct_exit(void) { } -#endif /* PRINTK_NMI */ - struct dev_printk_info; #ifdef CONFIG_PRINTK diff --git a/init/Kconfig b/init/Kconfig index 096e1af5c586..ea58c0d30a97 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -1482,11 +1482,6 @@ config PRINTK very difficult to diagnose system problems, saying N here is strongly discouraged. -config PRINTK_NMI - def_bool y - depends on PRINTK - depends on HAVE_NMI - config BUG bool "BUG() support" if EXPERT default y diff --git a/kernel/printk/internal.h b/kernel/printk/internal.h index 6cc35c5de890..ff890ae3ee6a 100644 --- a/kernel/printk/internal.h +++ b/kernel/printk/internal.h @@ -6,12 +6,6 @@ #ifdef CONFIG_PRINTK -#define PRINTK_SAFE_CONTEXT_MASK 0x007ffffff -#define PRINTK_NMI_DIRECT_CONTEXT_MASK 0x008000000 -#define PRINTK_NMI_CONTEXT_MASK 0xff0000000 - -#define PRINTK_NMI_CONTEXT_OFFSET 0x010000000 - __printf(4, 0) int vprintk_store(int facility, int level, const struct dev_printk_info *dev_info, diff --git a/kernel/printk/printk_safe.c b/kernel/printk/printk_safe.c index 4b5df5c27334..4da1ab3332d6 100644 --- a/kernel/printk/printk_safe.c +++ b/kernel/printk/printk_safe.c @@ -4,12 +4,9 @@ */ #include -#include -#include #include #include #include -#include #include #include @@ -17,35 +14,6 @@ static DEFINE_PER_CPU(int, printk_context); -#ifdef CONFIG_PRINTK_NMI -void noinstr printk_nmi_enter(void) -{ - this_cpu_add(printk_context, PRINTK_NMI_CONTEXT_OFFSET); -} - -void noinstr printk_nmi_exit(void) -{ - this_cpu_sub(printk_context, PRINTK_NMI_CONTEXT_OFFSET); -} - -/* - * Marks a code that might produce many messages in NMI context - * and the risk of losing them is more critical than eventual - * reordering. - */ -void printk_nmi_direct_enter(void) -{ - if (this_cpu_read(printk_context) & PRINTK_NMI_CONTEXT_MASK) - this_cpu_or(printk_context, PRINTK_NMI_DIRECT_CONTEXT_MASK); -} - -void printk_nmi_direct_exit(void) -{ - this_cpu_and(printk_context, ~PRINTK_NMI_DIRECT_CONTEXT_MASK); -} - -#endif /* CONFIG_PRINTK_NMI */ - /* Can be preempted by NMI. */ void __printk_safe_enter(void) { @@ -70,10 +38,7 @@ asmlinkage int vprintk(const char *fmt, va_list args) * Use the main logbuf even in NMI. But avoid calling console * drivers that might have their own locks. */ - if (this_cpu_read(printk_context) & - (PRINTK_NMI_DIRECT_CONTEXT_MASK | - PRINTK_NMI_CONTEXT_MASK | - PRINTK_SAFE_CONTEXT_MASK)) { + if (this_cpu_read(printk_context) || in_nmi()) { unsigned long flags; int len; diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index b5815a022ecc..83a3663d1dc0 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -9344,7 +9344,6 @@ void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) tracing_off(); local_irq_save(flags); - printk_nmi_direct_enter(); /* Simulate the iterator */ trace_init_global_iter(&iter); @@ -9424,7 +9423,6 @@ void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) atomic_dec(&per_cpu_ptr(iter.array_buffer->data, cpu)->disabled); } atomic_dec(&dump_running); - printk_nmi_direct_exit(); local_irq_restore(flags); } EXPORT_SYMBOL_GPL(ftrace_dump); -- 2.20.1 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=-13.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 96D16C433C1 for ; Tue, 30 Mar 2021 15:35:52 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id B5221619C5 for ; Tue, 30 Mar 2021 15:35:51 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B5221619C5 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linutronix.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4F8tnf1Fd1z3c6W for ; Wed, 31 Mar 2021 02:35:50 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; secure) header.d=linutronix.de header.i=@linutronix.de header.a=rsa-sha256 header.s=2020 header.b=3MZdTxc0; dkim=fail reason="signature verification failed" header.d=linutronix.de header.i=@linutronix.de header.a=ed25519-sha256 header.s=2020e header.b=mJrR1Dwa; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=linutronix.de (client-ip=2a0a:51c0:0:12e:550::1; helo=galois.linutronix.de; envelope-from=john.ogness@linutronix.de; receiver=) Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; secure) header.d=linutronix.de header.i=@linutronix.de header.a=rsa-sha256 header.s=2020 header.b=3MZdTxc0; dkim=pass header.d=linutronix.de header.i=@linutronix.de header.a=ed25519-sha256 header.s=2020e header.b=mJrR1Dwa; dkim-atps=neutral Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4F8tn84Hbwz3bpR for ; Wed, 31 Mar 2021 02:35:23 +1100 (AEDT) From: John Ogness DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1617118516; 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=OwQDSIFoC6niL2q+iQikUcrCHMhBQ+TPKnmxalLmhps=; b=3MZdTxc07gPLoLG1Y05bTp4za31m59TfFkDh03a4fN2YeHv6KYFwCoPPs035TtzGOR2IVM 6ZHxhCxmSBgHFUPEWbVgOmREvQ4Fb5KYKwgId2vrUEvU+i0Is7KO7bSr9kgVff6fu/fLka z+9hQu7WZKQFZSw+UtbRYEo0whw5QBI9rjJznLcJiYdHl8HyGoUMz1OU59He8JCflnh2/R WF76aAQ7lsotxltgUhAD5Z/SIR4TQ/abukl8s5JpOWfN+MA5KscM/XERr3okF+iQ9Xg3U7 cgsitmN17S8YmOwptvbOSnSyujmtO4vDgnAczznO4M3W260HLsekSu/YFqvO0A== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1617118516; 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=OwQDSIFoC6niL2q+iQikUcrCHMhBQ+TPKnmxalLmhps=; b=mJrR1Dwat/8IblWUcdzjdoqaqEWo3jNv5KZO79ZDrEMeJ/RbsBBGQ+jDQzL1WiliL8QtHC 4b15j6gy2C83BXCg== To: Petr Mladek Subject: [PATCH printk v2 3/5] printk: remove NMI tracking Date: Tue, 30 Mar 2021 17:35:10 +0200 Message-Id: <20210330153512.1182-4-john.ogness@linutronix.de> In-Reply-To: <20210330153512.1182-1-john.ogness@linutronix.de> References: <20210330153512.1182-1-john.ogness@linutronix.de> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Sergey Senozhatsky , Peter Zijlstra , Alexei Starovoitov , David Howells , Paul Mackerras , Will Deacon , Leonardo Bras , Marc Zyngier , Masahiro Yamada , Russell King , Ingo Molnar , Geert Uytterhoeven , Valentin Schneider , Kees Cook , "Paul E. McKenney" , Anshuman Khandual , Frederic Weisbecker , Johannes Weiner , Steven Rostedt , Nathan Chancellor , Nick Terrell , Andy Lutomirski , Thomas Gleixner , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Sergey Senozhatsky , Andrew Morton , linuxppc-dev@lists.ozlabs.org, Mike Rapoport Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" All NMI contexts are handled the same as the safe context: store the message and defer printing. There is no need to have special NMI context tracking for this. Using in_nmi() is enough. Signed-off-by: John Ogness --- arch/arm/kernel/smp.c | 2 -- arch/powerpc/kexec/crash.c | 3 --- include/linux/hardirq.h | 2 -- include/linux/printk.h | 12 ------------ init/Kconfig | 5 ----- kernel/printk/internal.h | 6 ------ kernel/printk/printk_safe.c | 37 +------------------------------------ kernel/trace/trace.c | 2 -- 8 files changed, 1 insertion(+), 68 deletions(-) diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c index 5c48eb4fd0e5..77a720c1f402 100644 --- a/arch/arm/kernel/smp.c +++ b/arch/arm/kernel/smp.c @@ -671,9 +671,7 @@ static void do_handle_IPI(int ipinr) break; case IPI_CPU_BACKTRACE: - printk_nmi_enter(); nmi_cpu_backtrace(get_irq_regs()); - printk_nmi_exit(); break; default: diff --git a/arch/powerpc/kexec/crash.c b/arch/powerpc/kexec/crash.c index c9a889880214..d488311efab1 100644 --- a/arch/powerpc/kexec/crash.c +++ b/arch/powerpc/kexec/crash.c @@ -311,9 +311,6 @@ void default_machine_crash_shutdown(struct pt_regs *regs) unsigned int i; int (*old_handler)(struct pt_regs *regs); - /* Avoid hardlocking with irresponsive CPU holding logbuf_lock */ - printk_nmi_enter(); - /* * This function is only called after the system * has panicked or is otherwise in a critical state. diff --git a/include/linux/hardirq.h b/include/linux/hardirq.h index 7c9d6a2d7e90..0926e9ca4d85 100644 --- a/include/linux/hardirq.h +++ b/include/linux/hardirq.h @@ -115,7 +115,6 @@ extern void rcu_nmi_exit(void); do { \ lockdep_off(); \ arch_nmi_enter(); \ - printk_nmi_enter(); \ BUG_ON(in_nmi() == NMI_MASK); \ __preempt_count_add(NMI_OFFSET + HARDIRQ_OFFSET); \ } while (0) @@ -134,7 +133,6 @@ extern void rcu_nmi_exit(void); do { \ BUG_ON(!in_nmi()); \ __preempt_count_sub(NMI_OFFSET + HARDIRQ_OFFSET); \ - printk_nmi_exit(); \ arch_nmi_exit(); \ lockdep_on(); \ } while (0) diff --git a/include/linux/printk.h b/include/linux/printk.h index 2476796c1150..77f66625706e 100644 --- a/include/linux/printk.h +++ b/include/linux/printk.h @@ -149,18 +149,6 @@ static inline __printf(1, 2) __cold void early_printk(const char *s, ...) { } #endif -#ifdef CONFIG_PRINTK_NMI -extern void printk_nmi_enter(void); -extern void printk_nmi_exit(void); -extern void printk_nmi_direct_enter(void); -extern void printk_nmi_direct_exit(void); -#else -static inline void printk_nmi_enter(void) { } -static inline void printk_nmi_exit(void) { } -static inline void printk_nmi_direct_enter(void) { } -static inline void printk_nmi_direct_exit(void) { } -#endif /* PRINTK_NMI */ - struct dev_printk_info; #ifdef CONFIG_PRINTK diff --git a/init/Kconfig b/init/Kconfig index 096e1af5c586..ea58c0d30a97 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -1482,11 +1482,6 @@ config PRINTK very difficult to diagnose system problems, saying N here is strongly discouraged. -config PRINTK_NMI - def_bool y - depends on PRINTK - depends on HAVE_NMI - config BUG bool "BUG() support" if EXPERT default y diff --git a/kernel/printk/internal.h b/kernel/printk/internal.h index 6cc35c5de890..ff890ae3ee6a 100644 --- a/kernel/printk/internal.h +++ b/kernel/printk/internal.h @@ -6,12 +6,6 @@ #ifdef CONFIG_PRINTK -#define PRINTK_SAFE_CONTEXT_MASK 0x007ffffff -#define PRINTK_NMI_DIRECT_CONTEXT_MASK 0x008000000 -#define PRINTK_NMI_CONTEXT_MASK 0xff0000000 - -#define PRINTK_NMI_CONTEXT_OFFSET 0x010000000 - __printf(4, 0) int vprintk_store(int facility, int level, const struct dev_printk_info *dev_info, diff --git a/kernel/printk/printk_safe.c b/kernel/printk/printk_safe.c index 4b5df5c27334..4da1ab3332d6 100644 --- a/kernel/printk/printk_safe.c +++ b/kernel/printk/printk_safe.c @@ -4,12 +4,9 @@ */ #include -#include -#include #include #include #include -#include #include #include @@ -17,35 +14,6 @@ static DEFINE_PER_CPU(int, printk_context); -#ifdef CONFIG_PRINTK_NMI -void noinstr printk_nmi_enter(void) -{ - this_cpu_add(printk_context, PRINTK_NMI_CONTEXT_OFFSET); -} - -void noinstr printk_nmi_exit(void) -{ - this_cpu_sub(printk_context, PRINTK_NMI_CONTEXT_OFFSET); -} - -/* - * Marks a code that might produce many messages in NMI context - * and the risk of losing them is more critical than eventual - * reordering. - */ -void printk_nmi_direct_enter(void) -{ - if (this_cpu_read(printk_context) & PRINTK_NMI_CONTEXT_MASK) - this_cpu_or(printk_context, PRINTK_NMI_DIRECT_CONTEXT_MASK); -} - -void printk_nmi_direct_exit(void) -{ - this_cpu_and(printk_context, ~PRINTK_NMI_DIRECT_CONTEXT_MASK); -} - -#endif /* CONFIG_PRINTK_NMI */ - /* Can be preempted by NMI. */ void __printk_safe_enter(void) { @@ -70,10 +38,7 @@ asmlinkage int vprintk(const char *fmt, va_list args) * Use the main logbuf even in NMI. But avoid calling console * drivers that might have their own locks. */ - if (this_cpu_read(printk_context) & - (PRINTK_NMI_DIRECT_CONTEXT_MASK | - PRINTK_NMI_CONTEXT_MASK | - PRINTK_SAFE_CONTEXT_MASK)) { + if (this_cpu_read(printk_context) || in_nmi()) { unsigned long flags; int len; diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index b5815a022ecc..83a3663d1dc0 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -9344,7 +9344,6 @@ void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) tracing_off(); local_irq_save(flags); - printk_nmi_direct_enter(); /* Simulate the iterator */ trace_init_global_iter(&iter); @@ -9424,7 +9423,6 @@ void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) atomic_dec(&per_cpu_ptr(iter.array_buffer->data, cpu)->disabled); } atomic_dec(&dump_running); - printk_nmi_direct_exit(); local_irq_restore(flags); } EXPORT_SYMBOL_GPL(ftrace_dump); -- 2.20.1 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=-13.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 07F2EC433C1 for ; Tue, 30 Mar 2021 15:37:27 +0000 (UTC) Received: from desiato.infradead.org (desiato.infradead.org [90.155.92.199]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 9EEA3619BC for ; Tue, 30 Mar 2021 15:37:26 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9EEA3619BC Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linutronix.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=desiato.20200630; h=Sender:Content-Transfer-Encoding :Content-Type:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To:Message-Id:Date: Subject:Cc:To:From:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=jmZXUXJGlreBM9+ellhbZbupCFXGVqQQ/PTENo0IBlk=; b=mS54MX9DUMRqndWnl3NuuL3Lw y5UkbOLXxHTnuWjok9zS6+kz1+ywd7WAUyvsb5BNOire6EwgCIwDXIau1+2NmZg5LGQ3hRK4xVLm7 HQbKJIqeGJiKBemwDUM7nuygNJt2PK11UizeRS2TuuANSsk0/6MmFaVUqy18uGYnqDltAw3Q7QVo5 yOv0X+bieh/wlsUCiF8mhnorPmv9TGs/6KqsZwuXpQ5Nv8IYYtZITQJotHeIenx3gY/Lb3ApK225V CEJTzj+jyz4eK0VEVJgZTN6qkK3GAMQXvMnGa9GveSBCRz1U89EIhiEFoIa1ih5jyTjl9CY/0N2qw C8OZV/iew==; Received: from localhost ([::1] helo=desiato.infradead.org) by desiato.infradead.org with esmtp (Exim 4.94 #2 (Red Hat Linux)) id 1lRGP9-004DPr-A9; Tue, 30 Mar 2021 15:35:43 +0000 Received: from galois.linutronix.de ([2a0a:51c0:0:12e:550::1]) by desiato.infradead.org with esmtps (Exim 4.94 #2 (Red Hat Linux)) id 1lRGOi-004DJo-W9 for linux-arm-kernel@lists.infradead.org; Tue, 30 Mar 2021 15:35:19 +0000 From: John Ogness DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1617118516; 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=OwQDSIFoC6niL2q+iQikUcrCHMhBQ+TPKnmxalLmhps=; b=3MZdTxc07gPLoLG1Y05bTp4za31m59TfFkDh03a4fN2YeHv6KYFwCoPPs035TtzGOR2IVM 6ZHxhCxmSBgHFUPEWbVgOmREvQ4Fb5KYKwgId2vrUEvU+i0Is7KO7bSr9kgVff6fu/fLka z+9hQu7WZKQFZSw+UtbRYEo0whw5QBI9rjJznLcJiYdHl8HyGoUMz1OU59He8JCflnh2/R WF76aAQ7lsotxltgUhAD5Z/SIR4TQ/abukl8s5JpOWfN+MA5KscM/XERr3okF+iQ9Xg3U7 cgsitmN17S8YmOwptvbOSnSyujmtO4vDgnAczznO4M3W260HLsekSu/YFqvO0A== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1617118516; 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=OwQDSIFoC6niL2q+iQikUcrCHMhBQ+TPKnmxalLmhps=; b=mJrR1Dwat/8IblWUcdzjdoqaqEWo3jNv5KZO79ZDrEMeJ/RbsBBGQ+jDQzL1WiliL8QtHC 4b15j6gy2C83BXCg== To: Petr Mladek Cc: Sergey Senozhatsky , Sergey Senozhatsky , Steven Rostedt , Thomas Gleixner , linux-kernel@vger.kernel.org, Russell King , Michael Ellerman , Benjamin Herrenschmidt , Paul Mackerras , Ingo Molnar , Marc Zyngier , Valentin Schneider , Andrew Morton , Mike Rapoport , Geert Uytterhoeven , Anshuman Khandual , Leonardo Bras , Peter Zijlstra , Andy Lutomirski , Will Deacon , Frederic Weisbecker , "Paul E. McKenney" , Masahiro Yamada , Nathan Chancellor , Alexei Starovoitov , Kees Cook , Nick Terrell , David Howells , Johannes Weiner , linux-arm-kernel@lists.infradead.org, linuxppc-dev@lists.ozlabs.org Subject: [PATCH printk v2 3/5] printk: remove NMI tracking Date: Tue, 30 Mar 2021 17:35:10 +0200 Message-Id: <20210330153512.1182-4-john.ogness@linutronix.de> In-Reply-To: <20210330153512.1182-1-john.ogness@linutronix.de> References: <20210330153512.1182-1-john.ogness@linutronix.de> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210330_163517_627452_0832FFB2 X-CRM114-Status: GOOD ( 17.72 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org All NMI contexts are handled the same as the safe context: store the message and defer printing. There is no need to have special NMI context tracking for this. Using in_nmi() is enough. Signed-off-by: John Ogness --- arch/arm/kernel/smp.c | 2 -- arch/powerpc/kexec/crash.c | 3 --- include/linux/hardirq.h | 2 -- include/linux/printk.h | 12 ------------ init/Kconfig | 5 ----- kernel/printk/internal.h | 6 ------ kernel/printk/printk_safe.c | 37 +------------------------------------ kernel/trace/trace.c | 2 -- 8 files changed, 1 insertion(+), 68 deletions(-) diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c index 5c48eb4fd0e5..77a720c1f402 100644 --- a/arch/arm/kernel/smp.c +++ b/arch/arm/kernel/smp.c @@ -671,9 +671,7 @@ static void do_handle_IPI(int ipinr) break; case IPI_CPU_BACKTRACE: - printk_nmi_enter(); nmi_cpu_backtrace(get_irq_regs()); - printk_nmi_exit(); break; default: diff --git a/arch/powerpc/kexec/crash.c b/arch/powerpc/kexec/crash.c index c9a889880214..d488311efab1 100644 --- a/arch/powerpc/kexec/crash.c +++ b/arch/powerpc/kexec/crash.c @@ -311,9 +311,6 @@ void default_machine_crash_shutdown(struct pt_regs *regs) unsigned int i; int (*old_handler)(struct pt_regs *regs); - /* Avoid hardlocking with irresponsive CPU holding logbuf_lock */ - printk_nmi_enter(); - /* * This function is only called after the system * has panicked or is otherwise in a critical state. diff --git a/include/linux/hardirq.h b/include/linux/hardirq.h index 7c9d6a2d7e90..0926e9ca4d85 100644 --- a/include/linux/hardirq.h +++ b/include/linux/hardirq.h @@ -115,7 +115,6 @@ extern void rcu_nmi_exit(void); do { \ lockdep_off(); \ arch_nmi_enter(); \ - printk_nmi_enter(); \ BUG_ON(in_nmi() == NMI_MASK); \ __preempt_count_add(NMI_OFFSET + HARDIRQ_OFFSET); \ } while (0) @@ -134,7 +133,6 @@ extern void rcu_nmi_exit(void); do { \ BUG_ON(!in_nmi()); \ __preempt_count_sub(NMI_OFFSET + HARDIRQ_OFFSET); \ - printk_nmi_exit(); \ arch_nmi_exit(); \ lockdep_on(); \ } while (0) diff --git a/include/linux/printk.h b/include/linux/printk.h index 2476796c1150..77f66625706e 100644 --- a/include/linux/printk.h +++ b/include/linux/printk.h @@ -149,18 +149,6 @@ static inline __printf(1, 2) __cold void early_printk(const char *s, ...) { } #endif -#ifdef CONFIG_PRINTK_NMI -extern void printk_nmi_enter(void); -extern void printk_nmi_exit(void); -extern void printk_nmi_direct_enter(void); -extern void printk_nmi_direct_exit(void); -#else -static inline void printk_nmi_enter(void) { } -static inline void printk_nmi_exit(void) { } -static inline void printk_nmi_direct_enter(void) { } -static inline void printk_nmi_direct_exit(void) { } -#endif /* PRINTK_NMI */ - struct dev_printk_info; #ifdef CONFIG_PRINTK diff --git a/init/Kconfig b/init/Kconfig index 096e1af5c586..ea58c0d30a97 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -1482,11 +1482,6 @@ config PRINTK very difficult to diagnose system problems, saying N here is strongly discouraged. -config PRINTK_NMI - def_bool y - depends on PRINTK - depends on HAVE_NMI - config BUG bool "BUG() support" if EXPERT default y diff --git a/kernel/printk/internal.h b/kernel/printk/internal.h index 6cc35c5de890..ff890ae3ee6a 100644 --- a/kernel/printk/internal.h +++ b/kernel/printk/internal.h @@ -6,12 +6,6 @@ #ifdef CONFIG_PRINTK -#define PRINTK_SAFE_CONTEXT_MASK 0x007ffffff -#define PRINTK_NMI_DIRECT_CONTEXT_MASK 0x008000000 -#define PRINTK_NMI_CONTEXT_MASK 0xff0000000 - -#define PRINTK_NMI_CONTEXT_OFFSET 0x010000000 - __printf(4, 0) int vprintk_store(int facility, int level, const struct dev_printk_info *dev_info, diff --git a/kernel/printk/printk_safe.c b/kernel/printk/printk_safe.c index 4b5df5c27334..4da1ab3332d6 100644 --- a/kernel/printk/printk_safe.c +++ b/kernel/printk/printk_safe.c @@ -4,12 +4,9 @@ */ #include -#include -#include #include #include #include -#include #include #include @@ -17,35 +14,6 @@ static DEFINE_PER_CPU(int, printk_context); -#ifdef CONFIG_PRINTK_NMI -void noinstr printk_nmi_enter(void) -{ - this_cpu_add(printk_context, PRINTK_NMI_CONTEXT_OFFSET); -} - -void noinstr printk_nmi_exit(void) -{ - this_cpu_sub(printk_context, PRINTK_NMI_CONTEXT_OFFSET); -} - -/* - * Marks a code that might produce many messages in NMI context - * and the risk of losing them is more critical than eventual - * reordering. - */ -void printk_nmi_direct_enter(void) -{ - if (this_cpu_read(printk_context) & PRINTK_NMI_CONTEXT_MASK) - this_cpu_or(printk_context, PRINTK_NMI_DIRECT_CONTEXT_MASK); -} - -void printk_nmi_direct_exit(void) -{ - this_cpu_and(printk_context, ~PRINTK_NMI_DIRECT_CONTEXT_MASK); -} - -#endif /* CONFIG_PRINTK_NMI */ - /* Can be preempted by NMI. */ void __printk_safe_enter(void) { @@ -70,10 +38,7 @@ asmlinkage int vprintk(const char *fmt, va_list args) * Use the main logbuf even in NMI. But avoid calling console * drivers that might have their own locks. */ - if (this_cpu_read(printk_context) & - (PRINTK_NMI_DIRECT_CONTEXT_MASK | - PRINTK_NMI_CONTEXT_MASK | - PRINTK_SAFE_CONTEXT_MASK)) { + if (this_cpu_read(printk_context) || in_nmi()) { unsigned long flags; int len; diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index b5815a022ecc..83a3663d1dc0 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -9344,7 +9344,6 @@ void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) tracing_off(); local_irq_save(flags); - printk_nmi_direct_enter(); /* Simulate the iterator */ trace_init_global_iter(&iter); @@ -9424,7 +9423,6 @@ void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) atomic_dec(&per_cpu_ptr(iter.array_buffer->data, cpu)->disabled); } atomic_dec(&dump_running); - printk_nmi_direct_exit(); local_irq_restore(flags); } EXPORT_SYMBOL_GPL(ftrace_dump); -- 2.20.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel