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=-3.5 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED autolearn=no 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 2DD13C433DF for ; Wed, 27 May 2020 15:53:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EDF5C20899 for ; Wed, 27 May 2020 15:53:56 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="ZnDpCFqK" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390490AbgE0Px4 (ORCPT ); Wed, 27 May 2020 11:53:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57322 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390393AbgE0PwG (ORCPT ); Wed, 27 May 2020 11:52:06 -0400 Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:e::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 69F48C05BD1E for ; Wed, 27 May 2020 08:52:06 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=Content-Type:MIME-Version:References: Subject:Cc:To:From:Date:Message-ID:Sender:Reply-To:Content-Transfer-Encoding: Content-ID:Content-Description:In-Reply-To; bh=UOj/pEVWrVPLn+XP9VNIoLrTqQL4onfm76HyQA1XrC4=; b=ZnDpCFqKhu0+zQ4ikUVEBeV51j 9EvRPZIjWBxTm2HZ3Y/O+GwmgjQtrgzi2ho9G3eWx7y4hCO0A1BLQyvbwVYdkDlUo4+Ul9MDpGgca gcPNRY0CAuJwvUHVAVfPCGhvMI0h/2R6i+BCkTs/tFoTK0KkPTYnPzlA5ihUPN26hmdze/+OEWpkY nDKFiB1yAKszCoYwzQSTTBhZMLj2kw+k/seaKPYd8XEz435nr3pi3QwlMuGGfJdFKb/B3ejKKTmUg Ytac34gGMfIbzdV4OmzHpHs9D/38RW5DFDgsDxLF2Ifm8JkjnpXteKs+FQkH1pHS+Xkhq/vVOP+/1 PYdTijpA==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by bombadil.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1jdyLS-0001wG-Pq; Wed, 27 May 2020 15:51:55 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 112073079B9; Wed, 27 May 2020 17:51:50 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 0) id C2C722015DDF9; Wed, 27 May 2020 17:51:49 +0200 (CEST) Message-ID: <20200527155003.485332738@infradead.org> User-Agent: quilt/0.66 Date: Wed, 27 May 2020 17:45:33 +0200 From: Peter Zijlstra To: mingo@kernel.org, will@kernel.org, tglx@linutronix.de Cc: x86@kernel.org, linux-kernel@vger.kernel.org, a.darwish@linutronix.de, rostedt@goodmis.org, bigeasy@linutronix.de, peterz@infradead.org Subject: [PATCH 6/6] x86/entry: Fix NMI vs IRQ state tracking References: <20200527154527.233385756@infradead.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 While the nmi_enter() users did trace_hardirqs_{off_prepare,on_finish}() there was no matching lockdep_hardirqs_*() calls to complete the picture. Introduce idtentry_{enter,exit}_nmi() to enable proper IRQ state tracking across the NMIs. Signed-off-by: Peter Zijlstra (Intel) --- arch/x86/entry/common.c | 32 ++++++++++++++++++++++++++++---- arch/x86/include/asm/idtentry.h | 3 +++ arch/x86/kernel/nmi.c | 7 ++----- arch/x86/kernel/traps.c | 21 ++++++--------------- include/linux/hardirq.h | 22 ++++++++++++++++------ 5 files changed, 55 insertions(+), 30 deletions(-) --- a/arch/x86/entry/common.c +++ b/arch/x86/entry/common.c @@ -550,7 +550,7 @@ SYSCALL_DEFINE0(ni_syscall) * The return value must be fed into the rcu_exit argument of * idtentry_exit_cond_rcu(). */ -bool noinstr idtentry_enter_cond_rcu(struct pt_regs *regs) +noinstr bool idtentry_enter_cond_rcu(struct pt_regs *regs) { if (user_mode(regs)) { enter_from_user_mode(); @@ -619,7 +619,7 @@ static void idtentry_exit_cond_resched(s * Counterpart to idtentry_enter_cond_rcu(). The return value of the entry * function must be fed into the @rcu_exit argument. */ -void noinstr idtentry_exit_cond_rcu(struct pt_regs *regs, bool rcu_exit) +noinstr void idtentry_exit_cond_rcu(struct pt_regs *regs, bool rcu_exit) { lockdep_assert_irqs_disabled(); @@ -663,7 +663,7 @@ void noinstr idtentry_exit_cond_rcu(stru * Invokes enter_from_user_mode() to establish the proper context for * NOHZ_FULL. Otherwise scheduling on exit would not be possible. */ -void noinstr idtentry_enter_user(struct pt_regs *regs) +noinstr void idtentry_enter_user(struct pt_regs *regs) { enter_from_user_mode(); } @@ -680,13 +680,37 @@ void noinstr idtentry_enter_user(struct * * Counterpart to idtentry_enter_user(). */ -void noinstr idtentry_exit_user(struct pt_regs *regs) +noinstr void idtentry_exit_user(struct pt_regs *regs) { lockdep_assert_irqs_disabled(); prepare_exit_to_usermode(regs); } +noinstr void idtentry_enter_nmi(struct pt_regs *regs) +{ + lockdep_hardirqs_off(CALLER_ADDR0); + __nmi_enter(); + instrumentation_begin(); + trace_hardirqs_off_finish(); + instrumentation_end(); + lockdep_hardirq_enter(); +} + +noinstr void idtentry_exit_nmi(struct pt_regs *regs) +{ + lockdep_hardirq_exit(); + if (regs->flags & X86_EFLAGS_IF) { + instrumentation_begin(); + trace_hardirqs_on_prepare(); + lockdep_hardirqs_on_prepare(CALLER_ADDR0); + instrumentation_end(); + } + __nmi_exit(); + if (regs->flags & X86_EFLAGS_IF) + lockdep_hardirqs_on(CALLER_ADDR0); +} + #ifdef CONFIG_XEN_PV #ifndef CONFIG_PREEMPTION /* --- a/arch/x86/include/asm/idtentry.h +++ b/arch/x86/include/asm/idtentry.h @@ -16,6 +16,9 @@ void idtentry_exit_user(struct pt_regs * bool idtentry_enter_cond_rcu(struct pt_regs *regs); void idtentry_exit_cond_rcu(struct pt_regs *regs, bool rcu_exit); +void idtentry_enter_nmi(struct pt_regs *regs); +void idtentry_exit_nmi(struct pt_regs *regs); + /** * DECLARE_IDTENTRY - Declare functions for simple IDT entry points * No error code pushed by hardware --- a/arch/x86/kernel/nmi.c +++ b/arch/x86/kernel/nmi.c @@ -330,7 +330,6 @@ static noinstr void default_do_nmi(struc __this_cpu_write(last_nmi_rip, regs->ip); instrumentation_begin(); - trace_hardirqs_off_finish(); handled = nmi_handle(NMI_LOCAL, regs); __this_cpu_add(nmi_stats.normal, handled); @@ -417,8 +416,6 @@ static noinstr void default_do_nmi(struc unknown_nmi_error(reason, regs); out: - if (regs->flags & X86_EFLAGS_IF) - trace_hardirqs_on_prepare(); instrumentation_end(); } @@ -535,14 +532,14 @@ DEFINE_IDTENTRY_NMI(exc_nmi) } #endif - nmi_enter(); + idtentry_enter_nmi(regs); inc_irq_stat(__nmi_count); if (!ignore_nmis) default_do_nmi(regs); - nmi_exit(); + idtentry_exit_nmi(regs); #ifdef CONFIG_X86_64 if (unlikely(this_cpu_read(update_debug_stack))) { --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -387,7 +387,8 @@ DEFINE_IDTENTRY_DF(exc_double_fault) } #endif - nmi_enter(); + + idtentry_enter_nmi(regs); instrumentation_begin(); notify_die(DIE_TRAP, str, regs, error_code, X86_TRAP_DF, SIGSEGV); @@ -632,15 +633,12 @@ DEFINE_IDTENTRY_RAW(exc_int3) instrumentation_end(); idtentry_exit_user(regs); } else { - nmi_enter(); + idtentry_enter_nmi(regs); instrumentation_begin(); - trace_hardirqs_off_finish(); if (!do_int3(regs)) die("int3", regs, 0); - if (regs->flags & X86_EFLAGS_IF) - trace_hardirqs_on_prepare(); instrumentation_end(); - nmi_exit(); + idtentry_exit_nmi(regs); } } @@ -852,10 +850,7 @@ static void noinstr handle_debug(struct static __always_inline void exc_debug_kernel(struct pt_regs *regs, unsigned long dr6) { - nmi_enter(); - instrumentation_begin(); - trace_hardirqs_off_finish(); - instrumentation_end(); + idtentry_enter_nmi(regs); /* * The SDM says "The processor clears the BTF flag when it @@ -878,11 +873,7 @@ static __always_inline void exc_debug_ke if (dr6) handle_debug(regs, dr6, false); - instrumentation_begin(); - if (regs->flags & X86_EFLAGS_IF) - trace_hardirqs_on_prepare(); - instrumentation_end(); - nmi_exit(); + idtentry_exit_nmi(regs); } static __always_inline void exc_debug_user(struct pt_regs *regs, --- a/include/linux/hardirq.h +++ b/include/linux/hardirq.h @@ -111,32 +111,42 @@ extern void rcu_nmi_exit(void); /* * nmi_enter() can nest up to 15 times; see NMI_BITS. */ -#define nmi_enter() \ +#define __nmi_enter() \ do { \ + lockdep_off(); \ arch_nmi_enter(); \ printk_nmi_enter(); \ - lockdep_off(); \ BUG_ON(in_nmi() == NMI_MASK); \ __preempt_count_add(NMI_OFFSET + HARDIRQ_OFFSET); \ rcu_nmi_enter(); \ - lockdep_hardirq_enter(); \ instrumentation_begin(); \ ftrace_nmi_enter(); \ instrumentation_end(); \ } while (0) -#define nmi_exit() \ +#define nmi_enter() \ + do { \ + lockdep_hardirq_enter(); \ + __nmi_enter(); \ + } while (0) + +#define __nmi_exit() \ do { \ instrumentation_begin(); \ ftrace_nmi_exit(); \ instrumentation_end(); \ - lockdep_hardirq_exit(); \ rcu_nmi_exit(); \ BUG_ON(!in_nmi()); \ __preempt_count_sub(NMI_OFFSET + HARDIRQ_OFFSET); \ - lockdep_on(); \ printk_nmi_exit(); \ arch_nmi_exit(); \ + lockdep_on(); \ + } while (0) + +#define nmi_exit() \ + do { \ + __nmi_exit(); \ + lockdep_hardirq_exit(); \ } while (0) #endif /* LINUX_HARDIRQ_H */