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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C3E8CC4332F for ; Tue, 5 Apr 2022 23:25:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1574772AbiDEXBG (ORCPT ); Tue, 5 Apr 2022 19:01:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50238 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238546AbiDEKfQ (ORCPT ); Tue, 5 Apr 2022 06:35:16 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 477E73D4BC; Tue, 5 Apr 2022 03:20:47 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id D8D3D616D7; Tue, 5 Apr 2022 10:20:46 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id F08E3C385A1; Tue, 5 Apr 2022 10:20:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1649154046; bh=tz5dKMKdWhwlPogvpzcTJlJIFOcl7X9ZbyiFjU7lt1E=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=06NHh+Vn1kbk2oxjCxuEssMdYZfkpb0TMGB1zra1sToQVeIi1MhYwGWyKJdfQQPYi Fmf/9klvIBr1+VkHniMHtcetoFV/nYm16J+n8SP4TcEGt4yMcJxHhXzPbl3T0ThL7q wp++7KXDHk05vvgqIK10oBLE+NSOBWl5n2CqIbew= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, =?UTF-8?q?Marek=20Marczykowski-G=C3=B3recki?= , Juergen Gross , Boris Ostrovsky , Sasha Levin Subject: [PATCH 5.10 437/599] xen: fix is_xen_pmu() Date: Tue, 5 Apr 2022 09:32:11 +0200 Message-Id: <20220405070311.836925618@linuxfoundation.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220405070258.802373272@linuxfoundation.org> References: <20220405070258.802373272@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Juergen Gross [ Upstream commit de2ae403b4c0e79a3410e63bc448542fbb9f9bfc ] is_xen_pmu() is taking the cpu number as parameter, but it is not using it. Instead it just tests whether the Xen PMU initialization on the current cpu did succeed. As this test is done by checking a percpu pointer, preemption needs to be disabled in order to avoid switching the cpu while doing the test. While resuming from suspend() this seems not to be the case: [ 88.082751] ACPI: PM: Low-level resume complete [ 88.087933] ACPI: EC: EC started [ 88.091464] ACPI: PM: Restoring platform NVS memory [ 88.097166] xen_acpi_processor: Uploading Xen processor PM info [ 88.103850] Enabling non-boot CPUs ... [ 88.108128] installing Xen timer for CPU 1 [ 88.112763] BUG: using smp_processor_id() in preemptible [00000000] code: systemd-sleep/7138 [ 88.122256] caller is is_xen_pmu+0x12/0x30 [ 88.126937] CPU: 0 PID: 7138 Comm: systemd-sleep Tainted: G W 5.16.13-2.fc32.qubes.x86_64 #1 [ 88.137939] Hardware name: Star Labs StarBook/StarBook, BIOS 7.97 03/21/2022 [ 88.145930] Call Trace: [ 88.148757] [ 88.151193] dump_stack_lvl+0x48/0x5e [ 88.155381] check_preemption_disabled+0xde/0xe0 [ 88.160641] is_xen_pmu+0x12/0x30 [ 88.164441] xen_smp_intr_init_pv+0x75/0x100 Fix that by replacing is_xen_pmu() by a simple boolean variable which reflects the Xen PMU initialization state on cpu 0. Modify xen_pmu_init() to return early in case it is being called for a cpu other than cpu 0 and the boolean variable not being set. Fixes: bf6dfb154d93 ("xen/PMU: PMU emulation code") Reported-by: Marek Marczykowski-Górecki Signed-off-by: Juergen Gross Reviewed-by: Boris Ostrovsky Link: https://lore.kernel.org/r/20220325142002.31789-1-jgross@suse.com Signed-off-by: Boris Ostrovsky Signed-off-by: Sasha Levin --- arch/x86/xen/pmu.c | 10 ++++------ arch/x86/xen/pmu.h | 3 ++- arch/x86/xen/smp_pv.c | 2 +- 3 files changed, 7 insertions(+), 8 deletions(-) diff --git a/arch/x86/xen/pmu.c b/arch/x86/xen/pmu.c index e13b0b49fcdf..d7249f4c90f1 100644 --- a/arch/x86/xen/pmu.c +++ b/arch/x86/xen/pmu.c @@ -512,10 +512,7 @@ irqreturn_t xen_pmu_irq_handler(int irq, void *dev_id) return ret; } -bool is_xen_pmu(int cpu) -{ - return (get_xenpmu_data() != NULL); -} +bool is_xen_pmu; void xen_pmu_init(int cpu) { @@ -526,7 +523,7 @@ void xen_pmu_init(int cpu) BUILD_BUG_ON(sizeof(struct xen_pmu_data) > PAGE_SIZE); - if (xen_hvm_domain()) + if (xen_hvm_domain() || (cpu != 0 && !is_xen_pmu)) return; xenpmu_data = (struct xen_pmu_data *)get_zeroed_page(GFP_KERNEL); @@ -547,7 +544,8 @@ void xen_pmu_init(int cpu) per_cpu(xenpmu_shared, cpu).xenpmu_data = xenpmu_data; per_cpu(xenpmu_shared, cpu).flags = 0; - if (cpu == 0) { + if (!is_xen_pmu) { + is_xen_pmu = true; perf_register_guest_info_callbacks(&xen_guest_cbs); xen_pmu_arch_init(); } diff --git a/arch/x86/xen/pmu.h b/arch/x86/xen/pmu.h index 0e83a160589b..65c58894fc79 100644 --- a/arch/x86/xen/pmu.h +++ b/arch/x86/xen/pmu.h @@ -4,6 +4,8 @@ #include +extern bool is_xen_pmu; + irqreturn_t xen_pmu_irq_handler(int irq, void *dev_id); #ifdef CONFIG_XEN_HAVE_VPMU void xen_pmu_init(int cpu); @@ -12,7 +14,6 @@ void xen_pmu_finish(int cpu); static inline void xen_pmu_init(int cpu) {} static inline void xen_pmu_finish(int cpu) {} #endif -bool is_xen_pmu(int cpu); bool pmu_msr_read(unsigned int msr, uint64_t *val, int *err); bool pmu_msr_write(unsigned int msr, uint32_t low, uint32_t high, int *err); int pmu_apic_update(uint32_t reg); diff --git a/arch/x86/xen/smp_pv.c b/arch/x86/xen/smp_pv.c index 8f9e7e2407c8..35b6d15d874d 100644 --- a/arch/x86/xen/smp_pv.c +++ b/arch/x86/xen/smp_pv.c @@ -130,7 +130,7 @@ int xen_smp_intr_init_pv(unsigned int cpu) per_cpu(xen_irq_work, cpu).irq = rc; per_cpu(xen_irq_work, cpu).name = callfunc_name; - if (is_xen_pmu(cpu)) { + if (is_xen_pmu) { pmu_name = kasprintf(GFP_KERNEL, "pmu%d", cpu); rc = bind_virq_to_irqhandler(VIRQ_XENPMU, cpu, xen_pmu_irq_handler, -- 2.34.1