From patchwork Thu Oct 6 14:04:11 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nicholas Piggin X-Patchwork-Id: 1686917 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=lists.ozlabs.org (client-ip=2404:9400:2:0:216:3eff:fee1:b9f1; helo=lists.ozlabs.org; envelope-from=linuxppc-dev-bounces+incoming=patchwork.ozlabs.org@lists.ozlabs.org; receiver=) Authentication-Results: legolas.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20210112 header.b=XlsSVomq; dkim-atps=neutral Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2404:9400:2:0:216:3eff:fee1:b9f1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-384)) (No client certificate requested) by legolas.ozlabs.org (Postfix) with ESMTPS id 4MjtXZ43wdz1yqk for ; Fri, 7 Oct 2022 01:06:38 +1100 (AEDT) Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4MjtXZ1VrRz3dsl for ; Fri, 7 Oct 2022 01:06:38 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20210112 header.b=XlsSVomq; dkim-atps=neutral X-Original-To: linuxppc-dev@lists.ozlabs.org Delivered-To: linuxppc-dev@lists.ozlabs.org Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=gmail.com (client-ip=2607:f8b0:4864:20::1035; helo=mail-pj1-x1035.google.com; envelope-from=npiggin@gmail.com; receiver=) Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20210112 header.b=XlsSVomq; dkim-atps=neutral Received: from mail-pj1-x1035.google.com (mail-pj1-x1035.google.com [IPv6:2607:f8b0:4864:20::1035]) (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 4MjtVC5xC4z3bnH for ; Fri, 7 Oct 2022 01:04:35 +1100 (AEDT) Received: by mail-pj1-x1035.google.com with SMTP id b15so1855877pje.1 for ; Thu, 06 Oct 2022 07:04:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date; bh=8LvpQvcpcFN1tsqIY/Uy4lSuvckbcO6NzLuJ8RGjMpM=; b=XlsSVomq9W6BTm6R/QCGnHRuHONO8cvh5v7k5LyTjPCrQlzaUmsK6trNUVMqNuV0G5 moRpIeyoI4EnE7g5V0uF5txGG7YuL8zGCd1MM/StAgEp6X4Bbv1UgNV39TDznf4UL9F/ kywcHOTo3MAlrpPyTD8gSR01NdIF9e1k2/ZUSbnTQFjE8XeLBe3sZaxcI20StpsVpQlc wOReFHu1+/w+Vp7mNrUlwD9dG47G5/5c+oY+Vat7bbNAuwMbTU5Dh08M6Up7f6CvnbZM Sx71ttpZsLiQVb5wkobNQAvFOx+E/gMQCFRHrDWRPwNApQxJ1Dl1YWVD1YOmgM84z9JQ TySA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date; bh=8LvpQvcpcFN1tsqIY/Uy4lSuvckbcO6NzLuJ8RGjMpM=; b=wj5/aTeduc+J/WSUpXToCzBjrUWCGEO6fWoVheZzyFH9smzFXkG19e2pgmwSv6IJ9s lnCHryZYbOCTb51TI1HyGXzFfgv1AKKBZDY+4A3WW4RmRdqMC+ZC9eGR3xr1aF4Iy7xo yLR6s6flkk9kGYMMwo32tGoHZyUZW/8M4MJn6uMvRpxCwT9oaTkrLD+QePKUnEftai+8 7itcUq51evxbm5CdbGoGrynib9wordpEZmEqs+1caf2EaWhm+HsN6Kk9rCZxpmmZephP hTazaiXE4El0jiHXAZYQeB8Yd61lkR9Vt99MEuVu1FOv7EGue7fN3yruH68bflQuHKtU i/eQ== X-Gm-Message-State: ACrzQf1NPj58VaJFfp00IyZxE2dWVBfGuNM57ky9oMuF5NQB9tedg/Qb 4yi1fyIJdRqFulHijl7IWJyQjGz5JLc= X-Google-Smtp-Source: AMsMyM7C1iW42JwTbXdxWWsMY+TDYC7smbCN2Zb72RntKS5kfjakhRxKiTLmd7GezQA/k4DQP+JowQ== X-Received: by 2002:a17:902:b942:b0:178:be25:203f with SMTP id h2-20020a170902b94200b00178be25203fmr77182pls.101.1665065073059; Thu, 06 Oct 2022 07:04:33 -0700 (PDT) Received: from bobo.ibm.com ([118.208.156.99]) by smtp.gmail.com with ESMTPSA id m1-20020a170902bb8100b0017bf6061ee4sm4602901pls.117.2022.10.06.07.04.30 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 06 Oct 2022 07:04:32 -0700 (PDT) From: Nicholas Piggin To: linuxppc-dev@lists.ozlabs.org Subject: [PATCH 2/4] powerpc/64s/interrupt: Perf NMI should not take normal exit path Date: Fri, 7 Oct 2022 00:04:11 +1000 Message-Id: <20221006140413.126443-3-npiggin@gmail.com> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20221006140413.126443-1-npiggin@gmail.com> References: <20221006140413.126443-1-npiggin@gmail.com> MIME-Version: 1.0 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: Nicholas Piggin Errors-To: linuxppc-dev-bounces+incoming=patchwork.ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" NMI interrupts should exit with EXCEPTION_RESTORE_REGS not with interrupt_return_srr, which is what the perf NMI handler currently does. This breaks if a PMI hits after interrupt_exit_user_prepare_main() has switched the context tracking to user mode, then the CT_WARN_ON() in interrupt_exit_kernel_prepare() fires because it returns to kernel with context set to user. This could possibly be solved by soft-disabling PMIs in the exit path, but that reduces our ability to profile that code. The warning could be removed, but it's potentially useful. All other NMIs and soft-NMIs return using EXCEPTION_RESTORE_REGS, so this makes perf interrupts consistent with that and seems like the best fix. Signed-off-by: Nicholas Piggin --- arch/powerpc/kernel/exceptions-64s.S | 14 +++++++++++++- arch/powerpc/kernel/traps.c | 2 -- 2 files changed, 13 insertions(+), 3 deletions(-) diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S index 5381a43e50fe..651c36b056bd 100644 --- a/arch/powerpc/kernel/exceptions-64s.S +++ b/arch/powerpc/kernel/exceptions-64s.S @@ -2357,9 +2357,21 @@ EXC_VIRT_END(performance_monitor, 0x4f00, 0x20) EXC_COMMON_BEGIN(performance_monitor_common) GEN_COMMON performance_monitor addi r3,r1,STACK_FRAME_OVERHEAD - bl performance_monitor_exception + lbz r4,PACAIRQSOFTMASK(r13) + cmpdi r4,IRQS_ENABLED + bne 1f + bl performance_monitor_exception_async b interrupt_return_srr +1: + bl performance_monitor_exception_nmi + /* Clear MSR_RI before setting SRR0 and SRR1. */ + li r9,0 + mtmsrd r9,1 + kuap_kernel_restore r9, r10 + + EXCEPTION_RESTORE_REGS hsrr=0 + RFI_TO_KERNEL /** * Interrupt 0xf20 - Vector Unavailable Interrupt. diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c index 9bdd79aa51cf..6138ee22d06c 100644 --- a/arch/powerpc/kernel/traps.c +++ b/arch/powerpc/kernel/traps.c @@ -1899,7 +1899,6 @@ DEFINE_INTERRUPT_HANDLER(vsx_unavailable_tm) #endif /* CONFIG_PPC_TRANSACTIONAL_MEM */ #ifdef CONFIG_PPC64 -DECLARE_INTERRUPT_HANDLER_NMI(performance_monitor_exception_nmi); DEFINE_INTERRUPT_HANDLER_NMI(performance_monitor_exception_nmi) { __this_cpu_inc(irq_stat.pmu_irqs); @@ -1910,7 +1909,6 @@ DEFINE_INTERRUPT_HANDLER_NMI(performance_monitor_exception_nmi) } #endif -DECLARE_INTERRUPT_HANDLER_ASYNC(performance_monitor_exception_async); DEFINE_INTERRUPT_HANDLER_ASYNC(performance_monitor_exception_async) { __this_cpu_inc(irq_stat.pmu_irqs);