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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id B74FBC19F2C for ; Mon, 1 Aug 2022 19:03:00 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 346106B0074; Mon, 1 Aug 2022 15:03:00 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 2F5E78E0002; Mon, 1 Aug 2022 15:03:00 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 197598E0001; Mon, 1 Aug 2022 15:03:00 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id 0AD596B0074 for ; Mon, 1 Aug 2022 15:03:00 -0400 (EDT) Received: from smtpin26.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id D2788160AD7 for ; Mon, 1 Aug 2022 19:02:59 +0000 (UTC) X-FDA: 79751946078.26.FA7C3AA Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by imf22.hostedemail.com (Postfix) with ESMTP id 43854C0009 for ; Mon, 1 Aug 2022 19:02:59 +0000 (UTC) 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 ams.source.kernel.org (Postfix) with ESMTPS id 512B3B81640; Mon, 1 Aug 2022 19:02:57 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id F1189C433D6; Mon, 1 Aug 2022 19:02:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1659380576; bh=lr/O/Sqo9jAT0CJINbDmGwYZqdTIDsZBeQx+pXa7b6s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=pEc/zYFZ+0OyuN0Dw0JgK43GWwzgQi6I1cRcFwsZi5OQoAKSwE5NxCQRgKR30bTc6 /KfFB30bC4egSQtJIvy1W4RL5hUtqMZM2lcfn/DTsSeoblZUWWCOMT8x7vlcR79IjG oQ6MIKsEJ2jDKBzVdTcFI5JznfNAQCQSWdSYwqlS2HF50mpJrZRyDfjpbHN3BLU/JT Qg8z9gnLvmj1kjhvQqcEynB1+Uk7NLymumziQm02Ler1bSDwme34iBOO1K+YXDk0r1 PjQ3d/FICtmT70jeJbCGSz7FeWHBjnbQu41MJG9pvpkO3QuWAfNz+dSGIW2IOviw/t Gy5fgNlUnrXAw== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Peter Zijlstra , Will Deacon , Linus Torvalds , Sasha Levin , aneesh.kumar@linux.ibm.com, npiggin@gmail.com, linux-arch@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH AUTOSEL 5.15 6/8] mmu_gather: Force tlb-flush VM_PFNMAP vmas Date: Mon, 1 Aug 2022 15:02:41 -0400 Message-Id: <20220801190243.3818811-6-sashal@kernel.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220801190243.3818811-1-sashal@kernel.org> References: <20220801190243.3818811-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit ARC-Authentication-Results: i=1; imf22.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b="pEc/zYFZ"; spf=pass (imf22.hostedemail.com: domain of sashal@kernel.org designates 145.40.68.75 as permitted sender) smtp.mailfrom=sashal@kernel.org; dmarc=pass (policy=none) header.from=kernel.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1659380579; a=rsa-sha256; cv=none; b=djyFdgZxWvQAHCgO6Lc0pcK6ZI0pbaNYUC5CCRP5K4YYZo37ynq4I2L/9L7CdioPRxwG0J TvI/IviXE8t1k+6Xmqs1Qpm48JIWpCToUQuC96x6G2/MBwQA3pZBAYpowR8DHd6UaFLSdl drDSM37BeOVHc237AWN71cMCEApNops= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1659380579; 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:dkim-signature; bh=rG9XyW89JUXrd9p8VlD24iDiSierPiVUFsLZzGEpdt4=; b=VQIOrT/iTg7DxriT2Nki1sMzbbepx8lCX2focWutsOdx1LQsowFGqHIH2ng1Mf0QG6B1kX j5uFoKDDP3pfHfY86xNJtKz7+B14w63h0Cm2nk9RaxkT7dX4VJ3mHWRd2lJy/W30POeD0I g+5eYUZdsHuVYle+A8R5ScSFs1mR7bA= X-Stat-Signature: xgxbg7ddt1rgu446s8d5ik4deuoauyzr X-Rspamd-Queue-Id: 43854C0009 X-Rspam-User: Authentication-Results: imf22.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b="pEc/zYFZ"; spf=pass (imf22.hostedemail.com: domain of sashal@kernel.org designates 145.40.68.75 as permitted sender) smtp.mailfrom=sashal@kernel.org; dmarc=pass (policy=none) header.from=kernel.org X-Rspamd-Server: rspam04 X-HE-Tag: 1659380579-605710 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: From: Peter Zijlstra [ Upstream commit b67fbebd4cf980aecbcc750e1462128bffe8ae15 ] Jann reported a race between munmap() and unmap_mapping_range(), where unmap_mapping_range() will no-op once unmap_vmas() has unlinked the VMA; however munmap() will not yet have invalidated the TLBs. Therefore unmap_mapping_range() will complete while there are still (stale) TLB entries for the specified range. Mitigate this by force flushing TLBs for VM_PFNMAP ranges. Signed-off-by: Peter Zijlstra (Intel) Acked-by: Will Deacon Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin --- include/asm-generic/tlb.h | 31 ++++++++++++++++--------------- 1 file changed, 16 insertions(+), 15 deletions(-) diff --git a/include/asm-generic/tlb.h b/include/asm-generic/tlb.h index 17815e9d38b7..afe6d5915270 100644 --- a/include/asm-generic/tlb.h +++ b/include/asm-generic/tlb.h @@ -288,6 +288,7 @@ struct mmu_gather { */ unsigned int vma_exec : 1; unsigned int vma_huge : 1; + unsigned int vma_pfn : 1; unsigned int batch_count; @@ -358,7 +359,6 @@ tlb_update_vma_flags(struct mmu_gather *tlb, struct vm_area_struct *vma) { } #else /* CONFIG_MMU_GATHER_NO_RANGE */ #ifndef tlb_flush - /* * When an architecture does not provide its own tlb_flush() implementation * but does have a reasonably efficient flush_vma_range() implementation @@ -378,6 +378,9 @@ static inline void tlb_flush(struct mmu_gather *tlb) flush_tlb_range(&vma, tlb->start, tlb->end); } } +#endif + +#endif /* CONFIG_MMU_GATHER_NO_RANGE */ static inline void tlb_update_vma_flags(struct mmu_gather *tlb, struct vm_area_struct *vma) @@ -395,17 +398,9 @@ tlb_update_vma_flags(struct mmu_gather *tlb, struct vm_area_struct *vma) */ tlb->vma_huge = is_vm_hugetlb_page(vma); tlb->vma_exec = !!(vma->vm_flags & VM_EXEC); + tlb->vma_pfn = !!(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP)); } -#else - -static inline void -tlb_update_vma_flags(struct mmu_gather *tlb, struct vm_area_struct *vma) { } - -#endif - -#endif /* CONFIG_MMU_GATHER_NO_RANGE */ - static inline void tlb_flush_mmu_tlbonly(struct mmu_gather *tlb) { /* @@ -494,12 +489,18 @@ static inline void tlb_end_vma(struct mmu_gather *tlb, struct vm_area_struct *vm return; /* - * Do a TLB flush and reset the range at VMA boundaries; this avoids - * the ranges growing with the unused space between consecutive VMAs, - * but also the mmu_gather::vma_* flags from tlb_start_vma() rely on - * this. + * VM_PFNMAP is more fragile because the core mm will not track the + * page mapcount -- there might not be page-frames for these PFNs after + * all. Force flush TLBs for such ranges to avoid munmap() vs + * unmap_mapping_range() races. */ - tlb_flush_mmu_tlbonly(tlb); + if (tlb->vma_pfn || !IS_ENABLED(CONFIG_MMU_GATHER_MERGE_VMAS)) { + /* + * Do a TLB flush and reset the range at VMA boundaries; this avoids + * the ranges growing with the unused space between consecutive VMAs. + */ + tlb_flush_mmu_tlbonly(tlb); + } } /* -- 2.35.1