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 90EA7C369CB for ; Tue, 22 Apr 2025 08:19:06 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 97F1E6B0085; Tue, 22 Apr 2025 04:18:59 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 907B76B0088; Tue, 22 Apr 2025 04:18:59 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 72F986B0089; Tue, 22 Apr 2025 04:18:59 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) by kanga.kvack.org (Postfix) with ESMTP id 5623F6B0085 for ; Tue, 22 Apr 2025 04:18:59 -0400 (EDT) Received: from smtpin08.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay08.hostedemail.com (Postfix) with ESMTP id 841181413CE for ; Tue, 22 Apr 2025 08:19:00 +0000 (UTC) X-FDA: 83360979240.08.1EF8507 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by imf17.hostedemail.com (Postfix) with ESMTP id D484340007 for ; Tue, 22 Apr 2025 08:18:58 +0000 (UTC) Authentication-Results: imf17.hostedemail.com; dkim=none; dmarc=pass (policy=none) header.from=arm.com; spf=pass (imf17.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=1745309939; a=rsa-sha256; cv=none; b=Zy7pqioppoAQngJEifahjN6s9QOwclePuqj0DMFlfrNoY/o/MubdLgvpQ55epyysfuMU2J HeOleKKNHDpMrEDvNFslgmv3dwMAQkO04DNcULLCCr6sz/H5bddZ9bikeQk/3m9w4AApv8 Km2wVcynL4qEg1jI37UZgmLZP2XB2DI= ARC-Authentication-Results: i=1; imf17.hostedemail.com; dkim=none; dmarc=pass (policy=none) header.from=arm.com; spf=pass (imf17.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=1745309939; 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=Tjfl4ziwjfHSxtx/Q53uZF468Ponlql0YZKHd4fmxws=; b=oTx9IlXgokU48Rnku4zMz0H8uhy9tbscLTWqs1rqC/z63kSuQGFyeHSr6ia2rz1kxKJyK9 bXS8SXmkxb6+N3rrZ/0Hv6loy+CshcvNf4V/dL8eJYMJ38iuHqA5i3SJoQ7G48b1GvLVWc YXIKmFQYrPMnHXbD43B28uOz2bIFBow= 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 E5AD319F0; Tue, 22 Apr 2025 01:18:53 -0700 (PDT) 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 3E4B73F66E; Tue, 22 Apr 2025 01:18:56 -0700 (PDT) From: Ryan Roberts To: Catalin Marinas , Will Deacon , Pasha Tatashin , Andrew Morton , Uladzislau Rezki , Christoph Hellwig , David Hildenbrand , "Matthew Wilcox (Oracle)" , Mark Rutland , Anshuman Khandual , Alexandre Ghiti , Kevin Brodsky Cc: Ryan Roberts , linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [PATCH v4 08/11] mm/vmalloc: Gracefully unmap huge ptes Date: Tue, 22 Apr 2025 09:18:16 +0100 Message-ID: <20250422081822.1836315-9-ryan.roberts@arm.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20250422081822.1836315-1-ryan.roberts@arm.com> References: <20250422081822.1836315-1-ryan.roberts@arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Rspam-User: X-Rspamd-Queue-Id: D484340007 X-Rspamd-Server: rspam04 X-Stat-Signature: chycwp6s7dz8zzf4qksw3radxfcica6g X-HE-Tag: 1745309938-49056 X-HE-Meta: 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 tKRTgR+E VU9uUUQPdkqpBPEimZv+o0dSnNFUC3ib1wo28hhs5TILKpjNk8xH9DrUbpkMtCnMY4g8s4l3lV9rrQ6ailZrTMtFO6GDG4bLuNR66hiWK3QXG/42+dbCxOKBncxUR3iCvfvxvS0B9U7onX7E7tmO/GIyZl3VI4sJ3P2I29yaD9ss3Bomg20AhD6u/eg== 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: Commit f7ee1f13d606 ("mm/vmalloc: enable mapping of huge pages at pte level in vmap") added its support by reusing the set_huge_pte_at() API, which is otherwise only used for user mappings. But when unmapping those huge ptes, it continued to call ptep_get_and_clear(), which is a layering violation. To date, the only arch to implement this support is powerpc and it all happens to work ok for it. But arm64's implementation of ptep_get_and_clear() can not be safely used to clear a previous set_huge_pte_at(). So let's introduce a new arch opt-in function, arch_vmap_pte_range_unmap_size(), which can provide the size of a (present) pte. Then we can call huge_ptep_get_and_clear() to tear it down properly. Note that if vunmap_range() is called with a range that starts in the middle of a huge pte-mapped page, we must unmap the entire huge page so the behaviour is consistent with pmd and pud block mappings. In this case emit a warning just like we do for pmd/pud mappings. Reviewed-by: Anshuman Khandual Reviewed-by: Uladzislau Rezki (Sony) Reviewed-by: Catalin Marinas Signed-off-by: Ryan Roberts --- include/linux/vmalloc.h | 8 ++++++++ mm/vmalloc.c | 18 ++++++++++++++++-- 2 files changed, 24 insertions(+), 2 deletions(-) diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h index 31e9ffd936e3..16dd4cba64f2 100644 --- a/include/linux/vmalloc.h +++ b/include/linux/vmalloc.h @@ -113,6 +113,14 @@ static inline unsigned long arch_vmap_pte_range_map_size(unsigned long addr, uns } #endif +#ifndef arch_vmap_pte_range_unmap_size +static inline unsigned long arch_vmap_pte_range_unmap_size(unsigned long addr, + pte_t *ptep) +{ + return PAGE_SIZE; +} +#endif + #ifndef arch_vmap_pte_supported_shift static inline int arch_vmap_pte_supported_shift(unsigned long size) { diff --git a/mm/vmalloc.c b/mm/vmalloc.c index d60d3a29d149..fe2e2cc8da94 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -350,12 +350,26 @@ static void vunmap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end, pgtbl_mod_mask *mask) { pte_t *pte; + pte_t ptent; + unsigned long size = PAGE_SIZE; pte = pte_offset_kernel(pmd, addr); do { - pte_t ptent = ptep_get_and_clear(&init_mm, addr, pte); +#ifdef CONFIG_HUGETLB_PAGE + size = arch_vmap_pte_range_unmap_size(addr, pte); + if (size != PAGE_SIZE) { + if (WARN_ON(!IS_ALIGNED(addr, size))) { + addr = ALIGN_DOWN(addr, size); + pte = PTR_ALIGN_DOWN(pte, sizeof(*pte) * (size >> PAGE_SHIFT)); + } + ptent = huge_ptep_get_and_clear(&init_mm, addr, pte, size); + if (WARN_ON(end - addr < size)) + size = end - addr; + } else +#endif + ptent = ptep_get_and_clear(&init_mm, addr, pte); WARN_ON(!pte_none(ptent) && !pte_present(ptent)); - } while (pte++, addr += PAGE_SIZE, addr != end); + } while (pte += (size >> PAGE_SHIFT), addr += size, addr != end); *mask |= PGTBL_PTE_MODIFIED; } -- 2.43.0