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 <axelrasmussen@google.com>
Acked-by: Peter Xu <peterx@redhat.com>
Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Hugh Dickins <hughd@google.com>
Cc: James Houghton <jthoughton@google.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Nadav Amit <namit@vmware.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c
index 4aedfd98e3f52eb31fedce3100d06138870f196d..d8d432ca81e6214f4057b2c5a259b1570b50332b 100644 (file)
--- a/fs/userfaultfd.c
+++ b/fs/userfaultfd.c
@@ -1644,7 +1644,7 @@ 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 152434396c4817773d2974c5a0e9ab9151549aec..3cb7cd853fa8e57c11cd29f38e5319ee71d5ad42 100644 (file)
--- 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 50bf82b369956732b8ba1074917851e35b92ef6b..922a2b45fe6f781ac9db64e6ce8724064bf85d15 100644 (file)
--- a/include/linux/shmem_fs.h
+++ b/include/linux/shmem_fs.h
@@ -152,14 +152,14 @@ 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 ac178d810dc7245dc14a451ecb536386d1651876..9458cd94a5088dbc84d0e3fba933b81c2cb4cad9 100644 (file)
--- 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 b1e474aa2fc528c19fc0d5d0264294ebd684bfb6..6dc32cccbd9bff22687f6b69215c3c117b893698 100644 (file)
--- 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 fa6e38f2f55f401006c0b62cbc67051957675e77..9d13b9a64144d03be3e4f32096f78b83b09805ac 100644 (file)
--- 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 874379ce271f371d1398c65d7bd37680657b3221..c3cc6cb04548ce276d2969786c05b4add4aebc27 100644 (file)
--- 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)