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Peter Anvin" , Andy Lutomirski , Dave Hansen , Fei Li , Nathan Chancellor Subject: [PATCH v2 1/3] [mm-unstable] Revert "mm: move follow_phys to arch/x86/mm/pat/memtype.c" Date: Wed, 3 Apr 2024 23:21:29 +0200 Message-ID: <20240403212131.929421-2-david@redhat.com> In-Reply-To: <20240403212131.929421-1-david@redhat.com> References: <20240403212131.929421-1-david@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.3 X-Rspamd-Queue-Id: 42F3D180016 X-Rspam-User: X-Stat-Signature: csxbhktwikhkfaa5n1icefbioeyied5h X-Rspamd-Server: rspam03 X-HE-Tag: 1712179308-911680 X-HE-Meta: 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 eVCosNVJ q8OhhZiKhJmQwDcLt+yJJm2RiCKcQsRkSJ+emM+0ZVzfOBndKEuVJnVKSQab2NteMZH0T60g8Cv4FLs9xqYPzik+zIgRCh+xxp++EvAeYTsK4GaCkecTMLA3+qkhpgFPKwrl4SR0eJuK0LdHVH1WPsO49pG0Rjiyup/AKd1iOHsSYNFuArwJv8D+AmA6zu7qjBhT1WabAlVc59ZDoX/ThnVWpv4ZBTRXKIGYL 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: Revert mm-unstable patches: * mm-move-follow_phys-to-arch-x86-mm-pat-memtypec-fix-2 * mm-move-follow_phys-to-arch-x86-mm-pat-memtypec-fix * mm: move follow_phys to arch/x86/mm/pat/memtype.c Signed-off-by: David Hildenbrand --- arch/x86/mm/pat/memtype.c | 24 ++---------------------- include/linux/mm.h | 2 ++ mm/memory.c | 28 ++++++++++++++++++++++++++++ 3 files changed, 32 insertions(+), 22 deletions(-) diff --git a/arch/x86/mm/pat/memtype.c b/arch/x86/mm/pat/memtype.c index 143d1e3d3fd2..0d72183b5dd0 100644 --- a/arch/x86/mm/pat/memtype.c +++ b/arch/x86/mm/pat/memtype.c @@ -39,7 +39,6 @@ #include #include #include -#include #include #include @@ -948,25 +947,6 @@ static void free_pfn_range(u64 paddr, unsigned long size) memtype_free(paddr, paddr + size); } -static int follow_phys(struct vm_area_struct *vma, unsigned long *prot, - resource_size_t *phys) -{ - pte_t *ptep, pte; - spinlock_t *ptl; - - if (!(vma->vm_flags & (VM_IO | VM_PFNMAP))) - return -EINVAL; - - if (follow_pte(vma->vm_mm, vma->vm_start, &ptep, &ptl)) - return -EINVAL; - - pte = ptep_get(ptep); - *prot = pgprot_val(pte_pgprot(pte)); - *phys = (resource_size_t)pte_pfn(pte) << PAGE_SHIFT; - pte_unmap_unlock(ptep, ptl); - return 0; -} - /* * track_pfn_copy is called when vma that is covering the pfnmap gets * copied through copy_page_range(). @@ -986,7 +966,7 @@ int track_pfn_copy(struct vm_area_struct *vma) * reserve the whole chunk covered by vma. We need the * starting address and protection from pte. */ - if (follow_phys(vma, &prot, &paddr)) { + if (follow_phys(vma, vma->vm_start, 0, &prot, &paddr)) { WARN_ON_ONCE(1); return -EINVAL; } @@ -1073,7 +1053,7 @@ void untrack_pfn(struct vm_area_struct *vma, unsigned long pfn, /* free the chunk starting from pfn or the whole chunk */ paddr = (resource_size_t)pfn << PAGE_SHIFT; if (!paddr && !size) { - if (follow_phys(vma, &prot, &paddr)) { + if (follow_phys(vma, vma->vm_start, 0, &prot, &paddr)) { WARN_ON_ONCE(1); return; } diff --git a/include/linux/mm.h b/include/linux/mm.h index bc0cd34a8042..97e779993c74 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -2424,6 +2424,8 @@ int copy_page_range(struct vm_area_struct *dst_vma, struct vm_area_struct *src_vma); int follow_pte(struct mm_struct *mm, unsigned long address, pte_t **ptepp, spinlock_t **ptlp); +int follow_phys(struct vm_area_struct *vma, unsigned long address, + unsigned int flags, unsigned long *prot, resource_size_t *phys); int generic_access_phys(struct vm_area_struct *vma, unsigned long addr, void *buf, int len, int write); diff --git a/mm/memory.c b/mm/memory.c index 912cd738ec03..1211e2090c1a 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -5987,6 +5987,34 @@ int follow_pte(struct mm_struct *mm, unsigned long address, EXPORT_SYMBOL_GPL(follow_pte); #ifdef CONFIG_HAVE_IOREMAP_PROT +int follow_phys(struct vm_area_struct *vma, + unsigned long address, unsigned int flags, + unsigned long *prot, resource_size_t *phys) +{ + int ret = -EINVAL; + pte_t *ptep, pte; + spinlock_t *ptl; + + if (!(vma->vm_flags & (VM_IO | VM_PFNMAP))) + goto out; + + if (follow_pte(vma->vm_mm, address, &ptep, &ptl)) + goto out; + pte = ptep_get(ptep); + + if ((flags & FOLL_WRITE) && !pte_write(pte)) + goto unlock; + + *prot = pgprot_val(pte_pgprot(pte)); + *phys = (resource_size_t)pte_pfn(pte) << PAGE_SHIFT; + + ret = 0; +unlock: + pte_unmap_unlock(ptep, ptl); +out: + return ret; +} + /** * generic_access_phys - generic implementation for iomem mmap access * @vma: the vma to access From patchwork Wed Apr 3 21:21:30 2024 Content-Type: text/plain; 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Peter Anvin" , Andy Lutomirski , Dave Hansen , Fei Li , Nathan Chancellor , Wupeng Ma , Ingo Molnar Subject: [PATCH v2 2/3] x86/mm/pat: fix VM_PAT handling in COW mappings Date: Wed, 3 Apr 2024 23:21:30 +0200 Message-ID: <20240403212131.929421-3-david@redhat.com> In-Reply-To: <20240403212131.929421-1-david@redhat.com> References: <20240403212131.929421-1-david@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.3 X-Rspamd-Server: rspam09 X-Rspamd-Queue-Id: 91C73140018 X-Stat-Signature: 8ewz3op1rmn9m9krqomasbafc5r16fde X-Rspam-User: X-HE-Tag: 1712179313-274039 X-HE-Meta: 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 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: PAT handling won't do the right thing in COW mappings: the first PTE (or, in fact, all PTEs) can be replaced during write faults to point at anon folios. Reliably recovering the correct PFN and cachemode using follow_phys() from PTEs will not work in COW mappings. Using follow_phys(), we might just get the address+protection of the anon folio (which is very wrong), or fail on swap/nonswap entries, failing follow_phys() and triggering a WARN_ON_ONCE() in untrack_pfn() and track_pfn_copy(), not properly calling free_pfn_range(). In free_pfn_range(), we either wouldn't call memtype_free() or would call it with the wrong range, possibly leaking memory. To fix that, let's update follow_phys() to refuse returning anon folios, and fallback to using the stored PFN inside vma->vm_pgoff for COW mappings if we run into that. We will now properly handle untrack_pfn() with COW mappings, where we don't need the cachemode. We'll have to fail fork()->track_pfn_copy() if the first page was replaced by an anon folio, though: we'd have to store the cachemode in the VMA to make this work, likely growing the VMA size. For now, lets keep it simple and let track_pfn_copy() just fail in that case: it would have failed in the past with swap/nonswap entries already, and it would have done the wrong thing with anon folios. Simple reproducer to trigger the WARN_ON_ONCE() in untrack_pfn(): <--- C reproducer ---> #include #include #include #include int main(void) { struct io_uring_params p = {}; int ring_fd; size_t size; char *map; ring_fd = io_uring_setup(1, &p); if (ring_fd < 0) { perror("io_uring_setup"); return 1; } size = p.sq_off.array + p.sq_entries * sizeof(unsigned); /* Map the submission queue ring MAP_PRIVATE */ map = mmap(0, size, PROT_READ | PROT_WRITE, MAP_PRIVATE, ring_fd, IORING_OFF_SQ_RING); if (map == MAP_FAILED) { perror("mmap"); return 1; } /* We have at least one page. Let's COW it. */ *map = 0; pause(); return 0; } <--- C reproducer ---> On a system with 16 GiB RAM and swap configured: # ./iouring & # memhog 16G # killall iouring [ 301.552930] ------------[ cut here ]------------ [ 301.553285] WARNING: CPU: 7 PID: 1402 at arch/x86/mm/pat/memtype.c:1060 untrack_pfn+0xf4/0x100 [ 301.553989] Modules linked in: binfmt_misc nft_fib_inet nft_fib_ipv4 nft_fib_ipv6 nft_fib nft_reject_g [ 301.558232] CPU: 7 PID: 1402 Comm: iouring Not tainted 6.7.5-100.fc38.x86_64 #1 [ 301.558772] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebu4 [ 301.559569] RIP: 0010:untrack_pfn+0xf4/0x100 [ 301.559893] Code: 75 c4 eb cf 48 8b 43 10 8b a8 e8 00 00 00 3b 6b 28 74 b8 48 8b 7b 30 e8 ea 1a f7 000 [ 301.561189] RSP: 0018:ffffba2c0377fab8 EFLAGS: 00010282 [ 301.561590] RAX: 00000000ffffffea RBX: ffff9208c8ce9cc0 RCX: 000000010455e047 [ 301.562105] RDX: 07fffffff0eb1e0a RSI: 0000000000000000 RDI: ffff9208c391d200 [ 301.562628] RBP: 0000000000000000 R08: ffffba2c0377fab8 R09: 0000000000000000 [ 301.563145] R10: ffff9208d2292d50 R11: 0000000000000002 R12: 00007fea890e0000 [ 301.563669] R13: 0000000000000000 R14: ffffba2c0377fc08 R15: 0000000000000000 [ 301.564186] FS: 0000000000000000(0000) GS:ffff920c2fbc0000(0000) knlGS:0000000000000000 [ 301.564773] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 301.565197] CR2: 00007fea88ee8a20 CR3: 00000001033a8000 CR4: 0000000000750ef0 [ 301.565725] PKRU: 55555554 [ 301.565944] Call Trace: [ 301.566148] [ 301.566325] ? untrack_pfn+0xf4/0x100 [ 301.566618] ? __warn+0x81/0x130 [ 301.566876] ? untrack_pfn+0xf4/0x100 [ 301.567163] ? report_bug+0x171/0x1a0 [ 301.567466] ? handle_bug+0x3c/0x80 [ 301.567743] ? exc_invalid_op+0x17/0x70 [ 301.568038] ? asm_exc_invalid_op+0x1a/0x20 [ 301.568363] ? untrack_pfn+0xf4/0x100 [ 301.568660] ? untrack_pfn+0x65/0x100 [ 301.568947] unmap_single_vma+0xa6/0xe0 [ 301.569247] unmap_vmas+0xb5/0x190 [ 301.569532] exit_mmap+0xec/0x340 [ 301.569801] __mmput+0x3e/0x130 [ 301.570051] do_exit+0x305/0xaf0 ... Reported-by: Wupeng Ma Closes: https://lkml.kernel.org/r/20240227122814.3781907-1-mawupeng1@huawei.com Fixes: b1a86e15dc03 ("x86, pat: remove the dependency on 'vm_pgoff' in track/untrack pfn vma routines") Fixes: 5899329b1910 ("x86: PAT: implement track/untrack of pfnmap regions for x86 - v3") Acked-by: Ingo Molnar Cc: Dave Hansen Cc: Andy Lutomirski Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Ingo Molnar Cc: Borislav Petkov Cc: "H. Peter Anvin" Cc: Andrew Morton Signed-off-by: David Hildenbrand --- arch/x86/mm/pat/memtype.c | 49 ++++++++++++++++++++++++++++----------- mm/memory.c | 4 ++++ 2 files changed, 39 insertions(+), 14 deletions(-) diff --git a/arch/x86/mm/pat/memtype.c b/arch/x86/mm/pat/memtype.c index 0d72183b5dd0..36b603d0cdde 100644 --- a/arch/x86/mm/pat/memtype.c +++ b/arch/x86/mm/pat/memtype.c @@ -947,6 +947,38 @@ static void free_pfn_range(u64 paddr, unsigned long size) memtype_free(paddr, paddr + size); } +static int get_pat_info(struct vm_area_struct *vma, resource_size_t *paddr, + pgprot_t *pgprot) +{ + unsigned long prot; + + VM_WARN_ON_ONCE(!(vma->vm_flags & VM_PAT)); + + /* + * We need the starting PFN and cachemode used for track_pfn_remap() + * that covered the whole VMA. For most mappings, we can obtain that + * information from the page tables. For COW mappings, we might now + * suddenly have anon folios mapped and follow_phys() will fail. + * + * Fallback to using vma->vm_pgoff, see remap_pfn_range_notrack(), to + * detect the PFN. If we need the cachemode as well, we're out of luck + * for now and have to fail fork(). + */ + if (!follow_phys(vma, vma->vm_start, 0, &prot, paddr)) { + if (pgprot) + *pgprot = __pgprot(prot); + return 0; + } + if (is_cow_mapping(vma->vm_flags)) { + if (pgprot) + return -EINVAL; + *paddr = (resource_size_t)vma->vm_pgoff << PAGE_SHIFT; + return 0; + } + WARN_ON_ONCE(1); + return -EINVAL; +} + /* * track_pfn_copy is called when vma that is covering the pfnmap gets * copied through copy_page_range(). @@ -957,20 +989,13 @@ static void free_pfn_range(u64 paddr, unsigned long size) int track_pfn_copy(struct vm_area_struct *vma) { resource_size_t paddr; - unsigned long prot; unsigned long vma_size = vma->vm_end - vma->vm_start; pgprot_t pgprot; if (vma->vm_flags & VM_PAT) { - /* - * reserve the whole chunk covered by vma. We need the - * starting address and protection from pte. - */ - if (follow_phys(vma, vma->vm_start, 0, &prot, &paddr)) { - WARN_ON_ONCE(1); + if (get_pat_info(vma, &paddr, &pgprot)) return -EINVAL; - } - pgprot = __pgprot(prot); + /* reserve the whole chunk covered by vma. */ return reserve_pfn_range(paddr, vma_size, &pgprot, 1); } @@ -1045,7 +1070,6 @@ void untrack_pfn(struct vm_area_struct *vma, unsigned long pfn, unsigned long size, bool mm_wr_locked) { resource_size_t paddr; - unsigned long prot; if (vma && !(vma->vm_flags & VM_PAT)) return; @@ -1053,11 +1077,8 @@ void untrack_pfn(struct vm_area_struct *vma, unsigned long pfn, /* free the chunk starting from pfn or the whole chunk */ paddr = (resource_size_t)pfn << PAGE_SHIFT; if (!paddr && !size) { - if (follow_phys(vma, vma->vm_start, 0, &prot, &paddr)) { - WARN_ON_ONCE(1); + if (get_pat_info(vma, &paddr, NULL)) return; - } - size = vma->vm_end - vma->vm_start; } free_pfn_range(paddr, size); diff --git a/mm/memory.c b/mm/memory.c index 1211e2090c1a..1e9a0288fdaf 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -6002,6 +6002,10 @@ int follow_phys(struct vm_area_struct *vma, goto out; pte = ptep_get(ptep); + /* Never return PFNs of anon folios in COW mappings. */ + if (vm_normal_folio(vma, address, pte)) + goto unlock; + if ((flags & FOLL_WRITE) && !pte_write(pte)) goto unlock; From patchwork Wed Apr 3 21:21:31 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Hildenbrand X-Patchwork-Id: 13616713 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 111B8CD1288 for ; Wed, 3 Apr 2024 21:22:00 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 942476B0099; Wed, 3 Apr 2024 17:21:59 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 8F2B06B009A; Wed, 3 Apr 2024 17:21:59 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 793076B009B; Wed, 3 Apr 2024 17:21:59 -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 56B5E6B0099 for ; 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Wed, 3 Apr 2024 21:21:48 +0000 (UTC) From: David Hildenbrand To: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org, x86@kernel.org, David Hildenbrand , Andrew Morton , Peter Zijlstra , Ingo Molnar , Thomas Gleixner , Christoph Hellwig , Borislav Petkov , "H. Peter Anvin" , Andy Lutomirski , Dave Hansen , Fei Li , Nathan Chancellor , Ingo Molnar Subject: [PATCH v2 3/3] mm: move follow_phys to arch/x86/mm/pat/memtype.c Date: Wed, 3 Apr 2024 23:21:31 +0200 Message-ID: <20240403212131.929421-4-david@redhat.com> In-Reply-To: <20240403212131.929421-1-david@redhat.com> References: <20240403212131.929421-1-david@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.3 X-Rspamd-Queue-Id: 62CA240011 X-Rspam-User: X-Rspamd-Server: rspam02 X-Stat-Signature: hwyxbqn5xdiwxh6ghet4nokc6k4r7dei X-HE-Tag: 1712179317-286586 X-HE-Meta: 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 rG4EXyKA vPfAD5uZVUd36LI1MFRWYRINvk+VN/fvxyWKxph7J/vs8o1GsRgeJlZ8xGJS2SsATFQRCEU0QOoeegiLXAoJ82WV0aSRL9wqeS+uHjC/AcCGqdh5WJWyM1+YecxekvCNYTppBig8pjap0u39MRXzU+sQRxM1EOxCjfnBGprhYEZKwxfQtpYfaJzNVXQtNcRILMnIkrxdApifmtBd6nQTuL+vnjW7wCN4vTunE30bQLTyDlSWviYw2xDjnjlh2NwSJUK4vwkMW5YYCDRhOQ1uNr0hAU+5OZeU1hJP5ONvi7vOs0RUJbgAq9YsLwCw6mYBgtsnAQcg6WJ9rAK5XU3xE5LinEOdoM2kVeYot/tqf+vmQ+H8= 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: From: Christoph Hellwig follow_phys is only used by two callers in arch/x86/mm/pat/memtype.c. Move it there and hardcode the two arguments that get the same values passed by both callers. Link: https://lkml.kernel.org/r/20240324234542.2038726-4-hch@lst.de Signed-off-by: Christoph Hellwig Reviewed-by: David Hildenbrand Cc: Andy Lutomirski Cc: Dave Hansen Cc: Fei Li Cc: Ingo Molnar Cc: Peter Zijlstra Cc: Nathan Chancellor Signed-off-by: David Hildenbrand # rebased, applied fixups --- arch/x86/mm/pat/memtype.c | 29 ++++++++++++++++++++++++++++- include/linux/mm.h | 2 -- mm/memory.c | 32 -------------------------------- 3 files changed, 28 insertions(+), 35 deletions(-) diff --git a/arch/x86/mm/pat/memtype.c b/arch/x86/mm/pat/memtype.c index 36b603d0cdde..d01c3b0bd6eb 100644 --- a/arch/x86/mm/pat/memtype.c +++ b/arch/x86/mm/pat/memtype.c @@ -39,6 +39,7 @@ #include #include #include +#include #include #include @@ -947,6 +948,32 @@ static void free_pfn_range(u64 paddr, unsigned long size) memtype_free(paddr, paddr + size); } +static int follow_phys(struct vm_area_struct *vma, unsigned long *prot, + resource_size_t *phys) +{ + pte_t *ptep, pte; + spinlock_t *ptl; + + if (!(vma->vm_flags & (VM_IO | VM_PFNMAP))) + return -EINVAL; + + if (follow_pte(vma->vm_mm, vma->vm_start, &ptep, &ptl)) + return -EINVAL; + + pte = ptep_get(ptep); + + /* Never return PFNs of anon folios in COW mappings. */ + if (vm_normal_folio(vma, vma->vm_start, pte)) { + pte_unmap_unlock(ptep, ptl); + return -EINVAL; + } + + *prot = pgprot_val(pte_pgprot(pte)); + *phys = (resource_size_t)pte_pfn(pte) << PAGE_SHIFT; + pte_unmap_unlock(ptep, ptl); + return 0; +} + static int get_pat_info(struct vm_area_struct *vma, resource_size_t *paddr, pgprot_t *pgprot) { @@ -964,7 +991,7 @@ static int get_pat_info(struct vm_area_struct *vma, resource_size_t *paddr, * detect the PFN. If we need the cachemode as well, we're out of luck * for now and have to fail fork(). */ - if (!follow_phys(vma, vma->vm_start, 0, &prot, paddr)) { + if (!follow_phys(vma, &prot, paddr)) { if (pgprot) *pgprot = __pgprot(prot); return 0; diff --git a/include/linux/mm.h b/include/linux/mm.h index 97e779993c74..bc0cd34a8042 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -2424,8 +2424,6 @@ int copy_page_range(struct vm_area_struct *dst_vma, struct vm_area_struct *src_vma); int follow_pte(struct mm_struct *mm, unsigned long address, pte_t **ptepp, spinlock_t **ptlp); -int follow_phys(struct vm_area_struct *vma, unsigned long address, - unsigned int flags, unsigned long *prot, resource_size_t *phys); int generic_access_phys(struct vm_area_struct *vma, unsigned long addr, void *buf, int len, int write); diff --git a/mm/memory.c b/mm/memory.c index 1e9a0288fdaf..912cd738ec03 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -5987,38 +5987,6 @@ int follow_pte(struct mm_struct *mm, unsigned long address, EXPORT_SYMBOL_GPL(follow_pte); #ifdef CONFIG_HAVE_IOREMAP_PROT -int follow_phys(struct vm_area_struct *vma, - unsigned long address, unsigned int flags, - unsigned long *prot, resource_size_t *phys) -{ - int ret = -EINVAL; - pte_t *ptep, pte; - spinlock_t *ptl; - - if (!(vma->vm_flags & (VM_IO | VM_PFNMAP))) - goto out; - - if (follow_pte(vma->vm_mm, address, &ptep, &ptl)) - goto out; - pte = ptep_get(ptep); - - /* Never return PFNs of anon folios in COW mappings. */ - if (vm_normal_folio(vma, address, pte)) - goto unlock; - - if ((flags & FOLL_WRITE) && !pte_write(pte)) - goto unlock; - - *prot = pgprot_val(pte_pgprot(pte)); - *phys = (resource_size_t)pte_pfn(pte) << PAGE_SHIFT; - - ret = 0; -unlock: - pte_unmap_unlock(ptep, ptl); -out: - return ret; -} - /** * generic_access_phys - generic implementation for iomem mmap access * @vma: the vma to access