[PATCH v2 2/5] mm: userfaultfd: don't pass around both mm and vma
From: Axel Rasmussen
Date: Wed Feb 22 2023 - 19:58:20 EST
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.
Signed-off-by: Axel Rasmussen <axelrasmussen@xxxxxxxxxx>
---
fs/userfaultfd.c | 2 +-
include/linux/hugetlb.h | 5 ++-
include/linux/shmem_fs.h | 4 +--
include/linux/userfaultfd_k.h | 4 +--
mm/hugetlb.c | 9 +++--
mm/shmem.c | 7 ++--
mm/userfaultfd.c | 66 ++++++++++++++++-------------------
7 files changed, 45 insertions(+), 52 deletions(-)
diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c
index c08a26ae77d6..a95f6aaef76b 100644
--- a/fs/userfaultfd.c
+++ b/fs/userfaultfd.c
@@ -1637,7 +1637,7 @@ 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(mm, prev, start, vma_end, new_flags,
diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index 3c389b74e02d..d3fc104aab78 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -157,7 +157,7 @@ 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,
@@ -355,8 +355,7 @@ 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 d500ea967dc7..2a0b1dc0460f 100644
--- a/include/linux/shmem_fs.h
+++ b/include/linux/shmem_fs.h
@@ -149,14 +149,14 @@ 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 6c5ad5d4aa06..c6c23408d300 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 void uffd_wp_range(struct mm_struct *dst_mm, struct vm_area_struct *vma,
+extern void 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 915a390442e7..0afd2ed8ad39 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -6162,8 +6162,7 @@ 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,
@@ -6282,7 +6281,7 @@ int hugetlb_mfill_atomic_pte(struct mm_struct *dst_mm,
page_in_pagecache = true;
}
- ptl = huge_pte_lock(h, dst_mm, dst_pte);
+ ptl = huge_pte_lock(h, dst_vma->vm_mm, dst_pte);
ret = -EIO;
if (PageHWPoison(page))
@@ -6324,9 +6323,9 @@ int hugetlb_mfill_atomic_pte(struct mm_struct *dst_mm,
if (wp_copy)
_dst_pte = huge_pte_mkuffd_wp(_dst_pte);
- set_huge_pte_at(dst_mm, dst_addr, dst_pte, _dst_pte);
+ set_huge_pte_at(dst_vma->vm_mm, dst_addr, dst_pte, _dst_pte);
- hugetlb_count_add(pages_per_huge_page(h), dst_mm);
+ hugetlb_count_add(pages_per_huge_page(h), dst_vma->vm_mm);
/* No need to invalidate - it was non-present before */
update_mmu_cache(dst_vma, dst_addr, dst_pte);
diff --git a/mm/shmem.c b/mm/shmem.c
index 41f82c5a5e28..cc03c61190eb 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -2398,8 +2398,7 @@ 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,
@@ -2489,11 +2488,11 @@ 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 3980e1b7b7f8..4bf5c97c665a 100644
--- a/mm/userfaultfd.c
+++ b/mm/userfaultfd.c
@@ -55,7 +55,7 @@ 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)
@@ -93,7 +93,7 @@ int mfill_atomic_install_pte(struct mm_struct *dst_mm, pmd_t *dst_pmd,
*/
_dst_pte = pte_wrprotect(_dst_pte);
- 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 (vma_is_shmem(dst_vma)) {
/* serialize against truncate with the page table lock */
@@ -129,9 +129,9 @@ int mfill_atomic_install_pte(struct mm_struct *dst_mm, pmd_t *dst_pmd,
* Must happen after rmap, as mm_counter() checks mapping (via
* PageAnon()), which is set by __page_set_anon_rmap().
*/
- inc_mm_counter(dst_mm, mm_counter(page));
+ inc_mm_counter(dst_vma->vm_mm, mm_counter(page));
- 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);
@@ -141,8 +141,7 @@ 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,
@@ -204,10 +203,10 @@ 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;
@@ -218,8 +217,7 @@ 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)
{
@@ -231,7 +229,7 @@ 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;
@@ -244,7 +242,7 @@ 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;
@@ -254,8 +252,7 @@ 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)
@@ -283,7 +280,7 @@ 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;
@@ -324,7 +321,7 @@ 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,
@@ -332,6 +329,7 @@ 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;
@@ -425,7 +423,7 @@ 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);
@@ -477,17 +475,15 @@ 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,
@@ -498,7 +494,7 @@ 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);
}
@@ -514,14 +510,14 @@ 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);
@@ -602,7 +598,7 @@ 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);
@@ -655,7 +651,7 @@ 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();
@@ -724,7 +720,7 @@ ssize_t mfill_atomic_continue(struct mm_struct *dst_mm, unsigned long start,
mmap_changing, 0);
}
-void uffd_wp_range(struct mm_struct *dst_mm, struct vm_area_struct *dst_vma,
+void uffd_wp_range(struct vm_area_struct *dst_vma,
unsigned long start, unsigned long len, bool enable_wp)
{
struct mmu_gather tlb;
@@ -735,7 +731,7 @@ void uffd_wp_range(struct mm_struct *dst_mm, struct vm_area_struct *dst_vma,
else
newprot = vm_get_page_prot(dst_vma->vm_flags);
- tlb_gather_mmu(&tlb, dst_mm);
+ tlb_gather_mmu(&tlb, dst_vma->vm_mm);
change_protection(&tlb, dst_vma, start, start + len, newprot,
enable_wp ? MM_CP_UFFD_WP : MM_CP_UFFD_WP_RESOLVE);
tlb_finish_mmu(&tlb);
@@ -786,7 +782,7 @@ int mwriteprotect_range(struct mm_struct *dst_mm, unsigned long start,
goto out_unlock;
}
- uffd_wp_range(dst_mm, dst_vma, start, len, enable_wp);
+ uffd_wp_range(dst_vma, start, len, enable_wp);
err = 0;
out_unlock:
--
2.39.2.637.g21b0678d19-goog