From 61c5004022f56c443b86800e8985d8803f3a22aa Mon Sep 17 00:00:00 2001 From: Axel Rasmussen Date: Tue, 14 Mar 2023 15:12:48 -0700 Subject: mm: userfaultfd: don't pass around both mm and vma Quite a few userfaultfd functions took both mm and vma pointers as arguments. Since the mm is trivially accessible via vma->vm_mm, there's no reason to pass both; it just needlessly extends the already long argument list. Get rid of the mm pointer, where possible, to shorten the argument list. Link: https://lkml.kernel.org/r/20230314221250.682452-3-axelrasmussen@google.com Signed-off-by: Axel Rasmussen Acked-by: Peter Xu Acked-by: Mike Rapoport (IBM) Cc: Al Viro Cc: Hugh Dickins Cc: James Houghton Cc: Jan Kara Cc: Liam R. Howlett Cc: Matthew Wilcox (Oracle) Cc: Mike Kravetz Cc: Muchun Song Cc: Nadav Amit Cc: Shuah Khan Signed-off-by: Andrew Morton --- mm/hugetlb.c | 4 ++-- mm/shmem.c | 7 +++---- mm/userfaultfd.c | 61 +++++++++++++++++++++++++++----------------------------- 3 files changed, 34 insertions(+), 38 deletions(-) (limited to 'mm') diff --git a/mm/hugetlb.c b/mm/hugetlb.c index b1e474aa2fc5..6dc32cccbd9b 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -6159,8 +6159,7 @@ out_mutex: * 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, @@ -6168,6 +6167,7 @@ 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 fa6e38f2f55f..9d13b9a64144 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -2429,8 +2429,7 @@ 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, @@ -2520,11 +2519,11 @@ 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 874379ce271f..c3cc6cb04548 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 @@ out_unlock: 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 @@ out_release: 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 @@ out_unlock: } /* 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 @@ retry: 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 @@ out: } #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 @@ retry: * 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 @@ retry: 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; @@ -732,7 +729,7 @@ 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); @@ -788,7 +785,7 @@ int mwriteprotect_range(struct mm_struct *dst_mm, unsigned long start, _start = max(dst_vma->vm_start, start); _end = min(dst_vma->vm_end, end); - err = uffd_wp_range(dst_mm, dst_vma, _start, _end - _start, enable_wp); + err = uffd_wp_range(dst_vma, _start, _end - _start, enable_wp); /* Return 0 on success, <0 on failures */ if (err < 0) -- cgit v1.2.3