From patchwork Sun Mar 2 14:55:52 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ryan Roberts X-Patchwork-Id: 13997840 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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8AAEAC282C6 for ; Sun, 2 Mar 2025 14:56:17 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 237F56B0083; Sun, 2 Mar 2025 09:56:17 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 1EA3C6B0085; Sun, 2 Mar 2025 09:56:17 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 03AFD6B0089; Sun, 2 Mar 2025 09:56:16 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id CC8FF6B0083 for ; Sun, 2 Mar 2025 09:56:16 -0500 (EST) Received: from smtpin22.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id 5B7E4160185 for ; Sun, 2 Mar 2025 14:56:16 +0000 (UTC) X-FDA: 83176911552.22.68C8761 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by imf25.hostedemail.com (Postfix) with ESMTP id C04C1A0014 for ; Sun, 2 Mar 2025 14:56:14 +0000 (UTC) Authentication-Results: imf25.hostedemail.com; dkim=none; dmarc=pass (policy=none) header.from=arm.com; spf=pass (imf25.hostedemail.com: domain of ryan.roberts@arm.com designates 217.140.110.172 as permitted sender) smtp.mailfrom=ryan.roberts@arm.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1740927374; a=rsa-sha256; cv=none; b=Si4VasGQ6PcMMypZHttE8mOPw9vOeMSjc8EUtbFjoM4pCrhn+tP4eOsSW1ZXqoPYrLf//K xykicwor99qB9+zDPEa7mzrEWbxzNmglJRw+aGPxGKtmd9x8xW3IwxuRyklHSt81EQSA+T Ze3lvEPgtFXYR42gKLAX2TJYiH2Z4Lk= ARC-Authentication-Results: i=1; imf25.hostedemail.com; dkim=none; dmarc=pass (policy=none) header.from=arm.com; spf=pass (imf25.hostedemail.com: domain of ryan.roberts@arm.com designates 217.140.110.172 as permitted sender) smtp.mailfrom=ryan.roberts@arm.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1740927374; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=74hnGihyX9jEup2KRN3+iLUKBxGL+YGeX9Qs83VnFo4=; b=ji3kXOXKa9/V9FFLb41nxE8X6sLoLUC/jfU5AtwM6nrMXU9KfUgC4yu33+k4747z7LTusi RD9VHJEAsvTB8LtuE9ULF/yuSF9tVczH29Ro+BeV/K7Hz9MguEEEyABsT2EXjvTRIh2fSk E7S3/WTRJRvixAJMj8ummIdTAzHe8kU= Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 4A5BE13D5; Sun, 2 Mar 2025 06:56:28 -0800 (PST) Received: from e125769.cambridge.arm.com (e125769.cambridge.arm.com [10.1.196.27]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 7B5213F5A1; Sun, 2 Mar 2025 06:56:11 -0800 (PST) From: Ryan Roberts To: Andrew Morton , "David S. Miller" , Andreas Larsson , Juergen Gross , Boris Ostrovsky , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , "H. Peter Anvin" , "Matthew Wilcox (Oracle)" , Catalin Marinas Cc: Ryan Roberts , linux-mm@kvack.org, sparclinux@vger.kernel.org, xen-devel@lists.xenproject.org, linux-kernel@vger.kernel.org Subject: [PATCH v1 2/4] sparc/mm: Disable preemption in lazy mmu mode Date: Sun, 2 Mar 2025 14:55:52 +0000 Message-ID: <20250302145555.3236789-3-ryan.roberts@arm.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20250302145555.3236789-1-ryan.roberts@arm.com> References: <20250302145555.3236789-1-ryan.roberts@arm.com> MIME-Version: 1.0 X-Rspam-User: X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: C04C1A0014 X-Stat-Signature: yf11hfusrd53ff1rf4w7ap9k8u6pcp5s X-HE-Tag: 1740927374-723232 X-HE-Meta: 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 hDYPGVLO YEGXDdRxtW3qgXKqa2Oxd0Wvn6cHy0+r+6TiQ2uU1vf6AGRnY6xgeo/jH2u6QaWRl96Jhddgz1NCKVI+FXhJQZwEPXCudJ0BAich0vt7RtrqRRqLoGIe6984XifZ424BGpuQYZz3/DEpGJbO3yaNi2ZTi8Q== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: Since commit 38e0edb15bd0 ("mm/apply_to_range: call pte function with lazy updates") it's been possible for arch_[enter|leave]_lazy_mmu_mode() to be called without holding a page table lock (for the kernel mappings case), and therefore it is possible that preemption may occur while in the lazy mmu mode. The Sparc lazy mmu implementation is not robust to preemption since it stores the lazy mode state in a per-cpu structure and does not attempt to manage that state on task switch. Powerpc had the same issue and fixed it by explicitly disabling preemption in arch_enter_lazy_mmu_mode() and re-enabling in arch_leave_lazy_mmu_mode(). See commit b9ef323ea168 ("powerpc/64s: Disable preemption in hash lazy mmu mode"). Given Sparc's lazy mmu mode is based on powerpc's, let's fix it in the same way here. Fixes: 38e0edb15bd0 ("mm/apply_to_range: call pte function with lazy updates") Signed-off-by: Ryan Roberts Acked-by: David Hildenbrand Acked-by: Andreas Larsson --- arch/sparc/mm/tlb.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/arch/sparc/mm/tlb.c b/arch/sparc/mm/tlb.c index 8648a50afe88..a35ddcca5e76 100644 --- a/arch/sparc/mm/tlb.c +++ b/arch/sparc/mm/tlb.c @@ -52,8 +52,10 @@ void flush_tlb_pending(void) void arch_enter_lazy_mmu_mode(void) { - struct tlb_batch *tb = this_cpu_ptr(&tlb_batch); + struct tlb_batch *tb; + preempt_disable(); + tb = this_cpu_ptr(&tlb_batch); tb->active = 1; } @@ -64,6 +66,7 @@ void arch_leave_lazy_mmu_mode(void) if (tb->tlb_nr) flush_tlb_pending(); tb->active = 0; + preempt_enable(); } static void tlb_batch_add_one(struct mm_struct *mm, unsigned long vaddr,