[v5,2/4] mm: userfaultfd: don't pass around both mm and vma

Message ID	20230314221250.682452-3-axelrasmussen@google.com (mailing list archive)
State	Mainlined, archived
Headers	show Return-Path: <linux-fsdevel-owner@vger.kernel.org> Date: Tue, 14 Mar 2023 15:12:48 -0700 In-Reply-To: <20230314221250.682452-1-axelrasmussen@google.com> Mime-Version: 1.0 References: <20230314221250.682452-1-axelrasmussen@google.com> Message-ID: <20230314221250.682452-3-axelrasmussen@google.com> Subject: [PATCH v5 2/4] mm: userfaultfd: don't pass around both mm and vma From: Axel Rasmussen <axelrasmussen@google.com> To: Alexander Viro <viro@zeniv.linux.org.uk>, Andrew Morton <akpm@linux-foundation.org>, Hugh Dickins <hughd@google.com>, Jan Kara <jack@suse.cz>, "Liam R. Howlett" <Liam.Howlett@Oracle.com>, Matthew Wilcox <willy@infradead.org>, Mike Kravetz <mike.kravetz@oracle.com>, Mike Rapoport <rppt@kernel.org>, Muchun Song <muchun.song@linux.dev>, Nadav Amit <namit@vmware.com>, Peter Xu <peterx@redhat.com>, Shuah Khan <shuah@kernel.org> Cc: James Houghton <jthoughton@google.com>, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org, Axel Rasmussen <axelrasmussen@google.com> Content-Type: text/plain; charset="UTF-8" Precedence: bulk
Series	mm: userfaultfd: refactor and add UFFDIO_CONTINUE_MODE_WP \| expand [v5,0/4] mm: userfaultfd: refactor and add UFFDIO_CONTINUE_MODE_WP [v5,1/4] mm: userfaultfd: rename functions for clarity + consistency [v5,2/4] mm: userfaultfd: don't pass around both mm and vma [v5,3/4] mm: userfaultfd: combine 'mode' and 'wp_copy' arguments [v5,4/4] mm: userfaultfd: add UFFDIO_CONTINUE_MODE_WP to install WP PTEs

diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c index 365bf00dd8dd..84d5d402214a 100644 --- a/fs/userfaultfd.c +++ b/fs/userfaultfd.c @@ -1629,7 +1629,7 @@ static int userfaultfd_unregister(struct userfaultfd_ctx *ctx, /* Reset ptes for the whole vma range if wr-protected */ if (userfaultfd_wp(vma)) - uffd_wp_range(mm, vma, start, vma_end - start, false); + uffd_wp_range(vma, start, vma_end - start, false); new_flags = vma->vm_flags & ~__VM_UFFD_FLAGS; prev = vma_merge(&vmi, mm, prev, start, vma_end, new_flags, diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h index 8f0467bf1cbd..8b9325f77ac3 100644 --- a/include/linux/hugetlb.h +++ b/include/linux/hugetlb.h @@ -158,7 +158,7 @@ unsigned long hugetlb_total_pages(void); vm_fault_t hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma, unsigned long address, unsigned int flags); #ifdef CONFIG_USERFAULTFD -int hugetlb_mfill_atomic_pte(struct mm_struct *dst_mm, pte_t *dst_pte, +int hugetlb_mfill_atomic_pte(pte_t *dst_pte, struct vm_area_struct *dst_vma, unsigned long dst_addr, unsigned long src_addr, @@ -393,8 +393,7 @@ static inline void hugetlb_free_pgd_range(struct mmu_gather *tlb, } #ifdef CONFIG_USERFAULTFD -static inline int hugetlb_mfill_atomic_pte(struct mm_struct *dst_mm, - pte_t *dst_pte, +static inline int hugetlb_mfill_atomic_pte(pte_t *dst_pte, struct vm_area_struct *dst_vma, unsigned long dst_addr, unsigned long src_addr, diff --git a/include/linux/shmem_fs.h b/include/linux/shmem_fs.h index 103d1000a5a2..b82916c25e61 100644 --- a/include/linux/shmem_fs.h +++ b/include/linux/shmem_fs.h @@ -151,14 +151,14 @@ extern void shmem_uncharge(struct inode *inode, long pages); #ifdef CONFIG_USERFAULTFD #ifdef CONFIG_SHMEM -extern int shmem_mfill_atomic_pte(struct mm_struct *dst_mm, pmd_t *dst_pmd, +extern int shmem_mfill_atomic_pte(pmd_t *dst_pmd, struct vm_area_struct *dst_vma, unsigned long dst_addr, unsigned long src_addr, bool zeropage, bool wp_copy, struct page **pagep); #else /* !CONFIG_SHMEM */ -#define shmem_mfill_atomic_pte(dst_mm, dst_pmd, dst_vma, dst_addr, \ +#define shmem_mfill_atomic_pte(dst_pmd, dst_vma, dst_addr, \ src_addr, zeropage, wp_copy, pagep) ({ BUG(); 0; }) #endif /* CONFIG_SHMEM */ #endif /* CONFIG_USERFAULTFD */ diff --git a/include/linux/userfaultfd_k.h b/include/linux/userfaultfd_k.h index 468080125612..ba79e296fcc7 100644 --- a/include/linux/userfaultfd_k.h +++ b/include/linux/userfaultfd_k.h @@ -56,7 +56,7 @@ enum mcopy_atomic_mode { MCOPY_ATOMIC_CONTINUE, }; -extern int mfill_atomic_install_pte(struct mm_struct *dst_mm, pmd_t *dst_pmd, +extern int mfill_atomic_install_pte(pmd_t *dst_pmd, struct vm_area_struct *dst_vma, unsigned long dst_addr, struct page *page, bool newly_allocated, bool wp_copy); @@ -73,7 +73,7 @@ extern ssize_t mfill_atomic_continue(struct mm_struct *dst_mm, unsigned long dst extern int mwriteprotect_range(struct mm_struct *dst_mm, unsigned long start, unsigned long len, bool enable_wp, atomic_t *mmap_changing); -extern long uffd_wp_range(struct mm_struct *dst_mm, struct vm_area_struct *vma, +extern long uffd_wp_range(struct vm_area_struct *vma, unsigned long start, unsigned long len, bool enable_wp); /* mm helpers */ diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 4c9276549394..fe043034ab46 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -6157,8 +6157,7 @@ vm_fault_t hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma, * Used by userfaultfd UFFDIO_* ioctls. Based on userfaultfd's mfill_atomic_pte * with modifications for hugetlb pages. */ -int hugetlb_mfill_atomic_pte(struct mm_struct *dst_mm, - pte_t *dst_pte, +int hugetlb_mfill_atomic_pte(pte_t *dst_pte, struct vm_area_struct *dst_vma, unsigned long dst_addr, unsigned long src_addr, @@ -6166,6 +6165,7 @@ int hugetlb_mfill_atomic_pte(struct mm_struct *dst_mm, struct page **pagep, bool wp_copy) { + struct mm_struct *dst_mm = dst_vma->vm_mm; bool is_continue = (mode == MCOPY_ATOMIC_CONTINUE); struct hstate *h = hstate_vma(dst_vma); struct address_space *mapping = dst_vma->vm_file->f_mapping; diff --git a/mm/shmem.c b/mm/shmem.c index 448f393d8ab2..1d751b6cf1ac 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -2415,8 +2415,7 @@ static struct inode *shmem_get_inode(struct mnt_idmap *idmap, struct super_block } #ifdef CONFIG_USERFAULTFD -int shmem_mfill_atomic_pte(struct mm_struct *dst_mm, - pmd_t *dst_pmd, +int shmem_mfill_atomic_pte(pmd_t *dst_pmd, struct vm_area_struct *dst_vma, unsigned long dst_addr, unsigned long src_addr, @@ -2506,11 +2505,11 @@ int shmem_mfill_atomic_pte(struct mm_struct *dst_mm, goto out_release; ret = shmem_add_to_page_cache(folio, mapping, pgoff, NULL, - gfp & GFP_RECLAIM_MASK, dst_mm); + gfp & GFP_RECLAIM_MASK, dst_vma->vm_mm); if (ret) goto out_release; - ret = mfill_atomic_install_pte(dst_mm, dst_pmd, dst_vma, dst_addr, + ret = mfill_atomic_install_pte(dst_pmd, dst_vma, dst_addr, &folio->page, true, wp_copy); if (ret) goto out_delete_from_cache; diff --git a/mm/userfaultfd.c b/mm/userfaultfd.c index 84db5b2fad3a..4fc373476739 100644 --- a/mm/userfaultfd.c +++ b/mm/userfaultfd.c @@ -55,12 +55,13 @@ struct vm_area_struct *find_dst_vma(struct mm_struct *dst_mm, * This function handles both MCOPY_ATOMIC_NORMAL and _CONTINUE for both shmem * and anon, and for both shared and private VMAs. */ -int mfill_atomic_install_pte(struct mm_struct *dst_mm, pmd_t *dst_pmd, +int mfill_atomic_install_pte(pmd_t *dst_pmd, struct vm_area_struct *dst_vma, unsigned long dst_addr, struct page *page, bool newly_allocated, bool wp_copy) { int ret; + struct mm_struct *dst_mm = dst_vma->vm_mm; pte_t _dst_pte, *dst_pte; bool writable = dst_vma->vm_flags & VM_WRITE; bool vm_shared = dst_vma->vm_flags & VM_SHARED; @@ -127,8 +128,7 @@ int mfill_atomic_install_pte(struct mm_struct *dst_mm, pmd_t *dst_pmd, return ret; } -static int mfill_atomic_pte_copy(struct mm_struct *dst_mm, - pmd_t *dst_pmd, +static int mfill_atomic_pte_copy(pmd_t *dst_pmd, struct vm_area_struct *dst_vma, unsigned long dst_addr, unsigned long src_addr, @@ -190,10 +190,10 @@ static int mfill_atomic_pte_copy(struct mm_struct *dst_mm, __SetPageUptodate(page); ret = -ENOMEM; - if (mem_cgroup_charge(page_folio(page), dst_mm, GFP_KERNEL)) + if (mem_cgroup_charge(page_folio(page), dst_vma->vm_mm, GFP_KERNEL)) goto out_release; - ret = mfill_atomic_install_pte(dst_mm, dst_pmd, dst_vma, dst_addr, + ret = mfill_atomic_install_pte(dst_pmd, dst_vma, dst_addr, page, true, wp_copy); if (ret) goto out_release; @@ -204,8 +204,7 @@ static int mfill_atomic_pte_copy(struct mm_struct *dst_mm, goto out; } -static int mfill_atomic_pte_zeropage(struct mm_struct *dst_mm, - pmd_t *dst_pmd, +static int mfill_atomic_pte_zeropage(pmd_t *dst_pmd, struct vm_area_struct *dst_vma, unsigned long dst_addr) { @@ -217,7 +216,7 @@ static int mfill_atomic_pte_zeropage(struct mm_struct *dst_mm, _dst_pte = pte_mkspecial(pfn_pte(my_zero_pfn(dst_addr), dst_vma->vm_page_prot)); - dst_pte = pte_offset_map_lock(dst_mm, dst_pmd, dst_addr, &ptl); + dst_pte = pte_offset_map_lock(dst_vma->vm_mm, dst_pmd, dst_addr, &ptl); if (dst_vma->vm_file) { /* the shmem MAP_PRIVATE case requires checking the i_size */ inode = dst_vma->vm_file->f_inode; @@ -230,7 +229,7 @@ static int mfill_atomic_pte_zeropage(struct mm_struct *dst_mm, ret = -EEXIST; if (!pte_none(*dst_pte)) goto out_unlock; - set_pte_at(dst_mm, dst_addr, dst_pte, _dst_pte); + set_pte_at(dst_vma->vm_mm, dst_addr, dst_pte, _dst_pte); /* No need to invalidate - it was non-present before */ update_mmu_cache(dst_vma, dst_addr, dst_pte); ret = 0; @@ -240,8 +239,7 @@ static int mfill_atomic_pte_zeropage(struct mm_struct *dst_mm, } /* Handles UFFDIO_CONTINUE for all shmem VMAs (shared or private). */ -static int mfill_atomic_pte_continue(struct mm_struct *dst_mm, - pmd_t *dst_pmd, +static int mfill_atomic_pte_continue(pmd_t *dst_pmd, struct vm_area_struct *dst_vma, unsigned long dst_addr, bool wp_copy) @@ -269,7 +267,7 @@ static int mfill_atomic_pte_continue(struct mm_struct *dst_mm, goto out_release; } - ret = mfill_atomic_install_pte(dst_mm, dst_pmd, dst_vma, dst_addr, + ret = mfill_atomic_install_pte(dst_pmd, dst_vma, dst_addr, page, false, wp_copy); if (ret) goto out_release; @@ -310,7 +308,7 @@ static pmd_t *mm_alloc_pmd(struct mm_struct *mm, unsigned long address) * mfill_atomic processing for HUGETLB vmas. Note that this routine is * called with mmap_lock held, it will release mmap_lock before returning. */ -static __always_inline ssize_t mfill_atomic_hugetlb(struct mm_struct *dst_mm, +static __always_inline ssize_t mfill_atomic_hugetlb( struct vm_area_struct *dst_vma, unsigned long dst_start, unsigned long src_start, @@ -318,6 +316,7 @@ static __always_inline ssize_t mfill_atomic_hugetlb(struct mm_struct *dst_mm, enum mcopy_atomic_mode mode, bool wp_copy) { + struct mm_struct *dst_mm = dst_vma->vm_mm; int vm_shared = dst_vma->vm_flags & VM_SHARED; ssize_t err; pte_t *dst_pte; @@ -411,7 +410,7 @@ static __always_inline ssize_t mfill_atomic_hugetlb(struct mm_struct *dst_mm, goto out_unlock; } - err = hugetlb_mfill_atomic_pte(dst_mm, dst_pte, dst_vma, + err = hugetlb_mfill_atomic_pte(dst_pte, dst_vma, dst_addr, src_addr, mode, &page, wp_copy); @@ -463,17 +462,15 @@ static __always_inline ssize_t mfill_atomic_hugetlb(struct mm_struct *dst_mm, } #else /* !CONFIG_HUGETLB_PAGE */ /* fail at build time if gcc attempts to use this */ -extern ssize_t mfill_atomic_hugetlb(struct mm_struct *dst_mm, - struct vm_area_struct *dst_vma, - unsigned long dst_start, - unsigned long src_start, - unsigned long len, - enum mcopy_atomic_mode mode, - bool wp_copy); +extern ssize_t mfill_atomic_hugetlb(struct vm_area_struct *dst_vma, + unsigned long dst_start, + unsigned long src_start, + unsigned long len, + enum mcopy_atomic_mode mode, + bool wp_copy); #endif /* CONFIG_HUGETLB_PAGE */ -static __always_inline ssize_t mfill_atomic_pte(struct mm_struct *dst_mm, - pmd_t *dst_pmd, +static __always_inline ssize_t mfill_atomic_pte(pmd_t *dst_pmd, struct vm_area_struct *dst_vma, unsigned long dst_addr, unsigned long src_addr, @@ -484,7 +481,7 @@ static __always_inline ssize_t mfill_atomic_pte(struct mm_struct *dst_mm, ssize_t err; if (mode == MCOPY_ATOMIC_CONTINUE) { - return mfill_atomic_pte_continue(dst_mm, dst_pmd, dst_vma, + return mfill_atomic_pte_continue(dst_pmd, dst_vma, dst_addr, wp_copy); } @@ -500,14 +497,14 @@ static __always_inline ssize_t mfill_atomic_pte(struct mm_struct *dst_mm, */ if (!(dst_vma->vm_flags & VM_SHARED)) { if (mode == MCOPY_ATOMIC_NORMAL) - err = mfill_atomic_pte_copy(dst_mm, dst_pmd, dst_vma, + err = mfill_atomic_pte_copy(dst_pmd, dst_vma, dst_addr, src_addr, page, wp_copy); else - err = mfill_atomic_pte_zeropage(dst_mm, dst_pmd, + err = mfill_atomic_pte_zeropage(dst_pmd, dst_vma, dst_addr); } else { - err = shmem_mfill_atomic_pte(dst_mm, dst_pmd, dst_vma, + err = shmem_mfill_atomic_pte(dst_pmd, dst_vma, dst_addr, src_addr, mode != MCOPY_ATOMIC_NORMAL, wp_copy, page); @@ -588,7 +585,7 @@ static __always_inline ssize_t mfill_atomic(struct mm_struct *dst_mm, * If this is a HUGETLB vma, pass off to appropriate routine */ if (is_vm_hugetlb_page(dst_vma)) - return mfill_atomic_hugetlb(dst_mm, dst_vma, dst_start, + return mfill_atomic_hugetlb(dst_vma, dst_start, src_start, len, mcopy_mode, wp_copy); @@ -641,7 +638,7 @@ static __always_inline ssize_t mfill_atomic(struct mm_struct *dst_mm, BUG_ON(pmd_none(*dst_pmd)); BUG_ON(pmd_trans_huge(*dst_pmd)); - err = mfill_atomic_pte(dst_mm, dst_pmd, dst_vma, dst_addr, + err = mfill_atomic_pte(dst_pmd, dst_vma, dst_addr, src_addr, &page, mcopy_mode, wp_copy); cond_resched(); @@ -710,7 +707,7 @@ ssize_t mfill_atomic_continue(struct mm_struct *dst_mm, unsigned long start, mmap_changing, 0); } -long uffd_wp_range(struct mm_struct *dst_mm, struct vm_area_struct *dst_vma, +long uffd_wp_range(struct vm_area_struct *dst_vma, unsigned long start, unsigned long len, bool enable_wp) { unsigned int mm_cp_flags; @@ -730,7 +727,7 @@ long uffd_wp_range(struct mm_struct *dst_mm, struct vm_area_struct *dst_vma, */ if (!enable_wp && vma_wants_manual_pte_write_upgrade(dst_vma)) mm_cp_flags |= MM_CP_TRY_CHANGE_WRITABLE; - tlb_gather_mmu(&tlb, dst_mm); + tlb_gather_mmu(&tlb, dst_vma->vm_mm); ret = change_protection(&tlb, dst_vma, start, start + len, mm_cp_flags); tlb_finish_mmu(&tlb); @@ -782,7 +779,7 @@ int mwriteprotect_range(struct mm_struct *dst_mm, unsigned long start, goto out_unlock; } - err = uffd_wp_range(dst_mm, dst_vma, start, len, enable_wp); + err = uffd_wp_range(dst_vma, start, len, enable_wp); /* Return 0 on success, <0 on failures */ if (err > 0)

[v5,2/4] mm: userfaultfd: don't pass around both mm and vma

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