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[2604:1380:4601:e00::3]) by mx.google.com with ESMTPS id a4-20020a1709062b0400b00a3d6cc63d45si532457ejg.135.2024.02.15.02.36.55 for (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 15 Feb 2024 02:36:55 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel+bounces-66643-ouuuleilei=gmail.com@vger.kernel.org designates 2604:1380:4601:e00::3 as permitted sender) client-ip=2604:1380:4601:e00::3; Authentication-Results: mx.google.com; arc=pass (i=1 spf=pass spfdomain=arm.com dmarc=pass fromdomain=arm.com); spf=pass (google.com: domain of linux-kernel+bounces-66643-ouuuleilei=gmail.com@vger.kernel.org designates 2604:1380:4601:e00::3 as permitted sender) smtp.mailfrom="linux-kernel+bounces-66643-ouuuleilei=gmail.com@vger.kernel.org"; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=arm.com Received: from smtp.subspace.kernel.org (wormhole.subspace.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by am.mirrors.kernel.org (Postfix) with ESMTPS id 1D65D1F23E3C for ; Thu, 15 Feb 2024 10:36:27 +0000 (UTC) Received: from localhost.localdomain (localhost.localdomain [127.0.0.1]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 77C1612DDA2; Thu, 15 Feb 2024 10:32:48 +0000 (UTC) Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 6C97312D76B for ; Thu, 15 Feb 2024 10:32:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707993166; cv=none; b=pQmcD8WL4/o7NgC9XonQByaYisgSmsSDQRge4kGsMDq9t/qfvhEbJHBXR4FGcacpN0QZniMtrKYn+tfQ/QF422NsqTLy7g823FxLwYVOdK8WF3TaW4C+A1uLSLeiwwb7E2EPcPKpYUK5aw5vIW8UxPADxKp4iePJT79avjgOqfQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707993166; c=relaxed/simple; bh=+OkHaAXcApv5i6T7H/FIyOrqmVoEbs4XCu7oHPJUMwI=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=TqKcAPRl2a3EnWrjMRE2XHVX2G+KtMYAG4lyXT6acZmU4vyf/AZQqiY/xwH4kFf8YBwBBDfwbeqc9e4pGJ1uC8FzhIzN4/1sRw7eVjjM2fUCGpFbJHuYGliSWrHUVVNHzf9LWA0Rp6kFX/506kMPVHBEFlTD2/riG8M2On+saY4= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com 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 B2453152B; Thu, 15 Feb 2024 02:33:24 -0800 (PST) Received: from e125769.cambridge.arm.com (e125769.cambridge.arm.com [10.1.196.26]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id A90E53F7B4; Thu, 15 Feb 2024 02:32:40 -0800 (PST) From: Ryan Roberts To: Catalin Marinas , Will Deacon , Ard Biesheuvel , Marc Zyngier , James Morse , Andrey Ryabinin , Andrew Morton , Matthew Wilcox , Mark Rutland , David Hildenbrand , Kefeng Wang , John Hubbard , Zi Yan , Barry Song <21cnbao@gmail.com>, Alistair Popple , Yang Shi , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , "H. Peter Anvin" Cc: Ryan Roberts , linux-arm-kernel@lists.infradead.org, x86@kernel.org, linuxppc-dev@lists.ozlabs.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [PATCH v6 07/18] arm64/mm: Convert READ_ONCE(*ptep) to ptep_get(ptep) Date: Thu, 15 Feb 2024 10:31:54 +0000 Message-Id: <20240215103205.2607016-8-ryan.roberts@arm.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20240215103205.2607016-1-ryan.roberts@arm.com> References: <20240215103205.2607016-1-ryan.roberts@arm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: 1790960903775305285 X-GMAIL-MSGID: 1790960903775305285 There are a number of places in the arch code that read a pte by using the READ_ONCE() macro. Refactor these call sites to instead use the ptep_get() helper, which itself is a READ_ONCE(). Generated code should be the same. This will benefit us when we shortly introduce the transparent contpte support. In this case, ptep_get() will become more complex so we now have all the code abstracted through it. Tested-by: John Hubbard Signed-off-by: Ryan Roberts Acked-by: Mark Rutland Acked-by: Catalin Marinas --- arch/arm64/include/asm/pgtable.h | 12 +++++++++--- arch/arm64/kernel/efi.c | 2 +- arch/arm64/mm/fault.c | 4 ++-- arch/arm64/mm/hugetlbpage.c | 6 +++--- arch/arm64/mm/kasan_init.c | 2 +- arch/arm64/mm/mmu.c | 12 ++++++------ arch/arm64/mm/pageattr.c | 4 ++-- arch/arm64/mm/trans_pgd.c | 2 +- 8 files changed, 25 insertions(+), 19 deletions(-) diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h index b6d3e9e0a946..de034ca40bad 100644 --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h @@ -275,6 +275,12 @@ static inline void set_pte(pte_t *ptep, pte_t pte) } } +#define ptep_get ptep_get +static inline pte_t ptep_get(pte_t *ptep) +{ + return READ_ONCE(*ptep); +} + extern void __sync_icache_dcache(pte_t pteval); bool pgattr_change_is_safe(u64 old, u64 new); @@ -302,7 +308,7 @@ static inline void __check_safe_pte_update(struct mm_struct *mm, pte_t *ptep, if (!IS_ENABLED(CONFIG_DEBUG_VM)) return; - old_pte = READ_ONCE(*ptep); + old_pte = ptep_get(ptep); if (!pte_valid(old_pte) || !pte_valid(pte)) return; @@ -904,7 +910,7 @@ static inline int __ptep_test_and_clear_young(pte_t *ptep) { pte_t old_pte, pte; - pte = READ_ONCE(*ptep); + pte = ptep_get(ptep); do { old_pte = pte; pte = pte_mkold(pte); @@ -986,7 +992,7 @@ static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addres { pte_t old_pte, pte; - pte = READ_ONCE(*ptep); + pte = ptep_get(ptep); do { old_pte = pte; pte = pte_wrprotect(pte); diff --git a/arch/arm64/kernel/efi.c b/arch/arm64/kernel/efi.c index 0228001347be..d0e08e93b246 100644 --- a/arch/arm64/kernel/efi.c +++ b/arch/arm64/kernel/efi.c @@ -103,7 +103,7 @@ static int __init set_permissions(pte_t *ptep, unsigned long addr, void *data) { struct set_perm_data *spd = data; const efi_memory_desc_t *md = spd->md; - pte_t pte = READ_ONCE(*ptep); + pte_t pte = ptep_get(ptep); if (md->attribute & EFI_MEMORY_RO) pte = set_pte_bit(pte, __pgprot(PTE_RDONLY)); diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c index 55f6455a8284..a254761fa1bd 100644 --- a/arch/arm64/mm/fault.c +++ b/arch/arm64/mm/fault.c @@ -191,7 +191,7 @@ static void show_pte(unsigned long addr) if (!ptep) break; - pte = READ_ONCE(*ptep); + pte = ptep_get(ptep); pr_cont(", pte=%016llx", pte_val(pte)); pte_unmap(ptep); } while(0); @@ -214,7 +214,7 @@ int ptep_set_access_flags(struct vm_area_struct *vma, pte_t entry, int dirty) { pteval_t old_pteval, pteval; - pte_t pte = READ_ONCE(*ptep); + pte_t pte = ptep_get(ptep); if (pte_same(pte, entry)) return 0; diff --git a/arch/arm64/mm/hugetlbpage.c b/arch/arm64/mm/hugetlbpage.c index 6720ec8d50e7..2892f925ed66 100644 --- a/arch/arm64/mm/hugetlbpage.c +++ b/arch/arm64/mm/hugetlbpage.c @@ -485,7 +485,7 @@ void huge_ptep_set_wrprotect(struct mm_struct *mm, size_t pgsize; pte_t pte; - if (!pte_cont(READ_ONCE(*ptep))) { + if (!pte_cont(ptep_get(ptep))) { ptep_set_wrprotect(mm, addr, ptep); return; } @@ -510,7 +510,7 @@ pte_t huge_ptep_clear_flush(struct vm_area_struct *vma, size_t pgsize; int ncontig; - if (!pte_cont(READ_ONCE(*ptep))) + if (!pte_cont(ptep_get(ptep))) return ptep_clear_flush(vma, addr, ptep); ncontig = find_num_contig(mm, addr, ptep, &pgsize); @@ -543,7 +543,7 @@ pte_t huge_ptep_modify_prot_start(struct vm_area_struct *vma, unsigned long addr * when the permission changes from executable to non-executable * in cases where cpu is affected with errata #2645198. */ - if (pte_user_exec(READ_ONCE(*ptep))) + if (pte_user_exec(ptep_get(ptep))) return huge_ptep_clear_flush(vma, addr, ptep); } return huge_ptep_get_and_clear(vma->vm_mm, addr, ptep); diff --git a/arch/arm64/mm/kasan_init.c b/arch/arm64/mm/kasan_init.c index 4c7ad574b946..c2a9f4f6c7dd 100644 --- a/arch/arm64/mm/kasan_init.c +++ b/arch/arm64/mm/kasan_init.c @@ -113,7 +113,7 @@ static void __init kasan_pte_populate(pmd_t *pmdp, unsigned long addr, memset(__va(page_phys), KASAN_SHADOW_INIT, PAGE_SIZE); next = addr + PAGE_SIZE; set_pte(ptep, pfn_pte(__phys_to_pfn(page_phys), PAGE_KERNEL)); - } while (ptep++, addr = next, addr != end && pte_none(READ_ONCE(*ptep))); + } while (ptep++, addr = next, addr != end && pte_none(ptep_get(ptep))); } static void __init kasan_pmd_populate(pud_t *pudp, unsigned long addr, diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index 3a27d887f7dd..343629a17042 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -173,7 +173,7 @@ static void init_pte(pmd_t *pmdp, unsigned long addr, unsigned long end, ptep = pte_set_fixmap_offset(pmdp, addr); do { - pte_t old_pte = READ_ONCE(*ptep); + pte_t old_pte = ptep_get(ptep); set_pte(ptep, pfn_pte(__phys_to_pfn(phys), prot)); @@ -182,7 +182,7 @@ static void init_pte(pmd_t *pmdp, unsigned long addr, unsigned long end, * only allow updates to the permission attributes. */ BUG_ON(!pgattr_change_is_safe(pte_val(old_pte), - READ_ONCE(pte_val(*ptep)))); + pte_val(ptep_get(ptep)))); phys += PAGE_SIZE; } while (ptep++, addr += PAGE_SIZE, addr != end); @@ -852,7 +852,7 @@ static void unmap_hotplug_pte_range(pmd_t *pmdp, unsigned long addr, do { ptep = pte_offset_kernel(pmdp, addr); - pte = READ_ONCE(*ptep); + pte = ptep_get(ptep); if (pte_none(pte)) continue; @@ -985,7 +985,7 @@ static void free_empty_pte_table(pmd_t *pmdp, unsigned long addr, do { ptep = pte_offset_kernel(pmdp, addr); - pte = READ_ONCE(*ptep); + pte = ptep_get(ptep); /* * This is just a sanity check here which verifies that @@ -1004,7 +1004,7 @@ static void free_empty_pte_table(pmd_t *pmdp, unsigned long addr, */ ptep = pte_offset_kernel(pmdp, 0UL); for (i = 0; i < PTRS_PER_PTE; i++) { - if (!pte_none(READ_ONCE(ptep[i]))) + if (!pte_none(ptep_get(&ptep[i]))) return; } @@ -1473,7 +1473,7 @@ pte_t ptep_modify_prot_start(struct vm_area_struct *vma, unsigned long addr, pte * when the permission changes from executable to non-executable * in cases where cpu is affected with errata #2645198. */ - if (pte_user_exec(READ_ONCE(*ptep))) + if (pte_user_exec(ptep_get(ptep))) return ptep_clear_flush(vma, addr, ptep); } return ptep_get_and_clear(vma->vm_mm, addr, ptep); diff --git a/arch/arm64/mm/pageattr.c b/arch/arm64/mm/pageattr.c index 924843f1f661..73a5e8f82586 100644 --- a/arch/arm64/mm/pageattr.c +++ b/arch/arm64/mm/pageattr.c @@ -36,7 +36,7 @@ bool can_set_direct_map(void) static int change_page_range(pte_t *ptep, unsigned long addr, void *data) { struct page_change_data *cdata = data; - pte_t pte = READ_ONCE(*ptep); + pte_t pte = ptep_get(ptep); pte = clear_pte_bit(pte, cdata->clear_mask); pte = set_pte_bit(pte, cdata->set_mask); @@ -245,5 +245,5 @@ bool kernel_page_present(struct page *page) return true; ptep = pte_offset_kernel(pmdp, addr); - return pte_valid(READ_ONCE(*ptep)); + return pte_valid(ptep_get(ptep)); } diff --git a/arch/arm64/mm/trans_pgd.c b/arch/arm64/mm/trans_pgd.c index 7b14df3c6477..f71ab4704cce 100644 --- a/arch/arm64/mm/trans_pgd.c +++ b/arch/arm64/mm/trans_pgd.c @@ -33,7 +33,7 @@ static void *trans_alloc(struct trans_pgd_info *info) static void _copy_pte(pte_t *dst_ptep, pte_t *src_ptep, unsigned long addr) { - pte_t pte = READ_ONCE(*src_ptep); + pte_t pte = ptep_get(src_ptep); if (pte_valid(pte)) { /*