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-rw-r--r--fs/userfaultfd.c5
-rw-r--r--include/linux/hugetlb.h10
-rw-r--r--include/linux/shmem_fs.h5
-rw-r--r--include/linux/userfaultfd_k.h46
-rw-r--r--mm/hugetlb.c12
-rw-r--r--mm/shmem.c7
-rw-r--r--mm/userfaultfd.c76
7 files changed, 84 insertions, 77 deletions
diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c
index d8d432ca81e6..8971c3613cc6 100644
--- a/fs/userfaultfd.c
+++ b/fs/userfaultfd.c
@@ -1729,6 +1729,7 @@ static int userfaultfd_copy(struct userfaultfd_ctx *ctx,
struct uffdio_copy uffdio_copy;
struct uffdio_copy __user *user_uffdio_copy;
struct userfaultfd_wake_range range;
+ uffd_flags_t flags = 0;
user_uffdio_copy = (struct uffdio_copy __user *) arg;
@@ -1755,10 +1756,12 @@ static int userfaultfd_copy(struct userfaultfd_ctx *ctx,
goto out;
if (uffdio_copy.mode & ~(UFFDIO_COPY_MODE_DONTWAKE|UFFDIO_COPY_MODE_WP))
goto out;
+ if (uffdio_copy.mode & UFFDIO_COPY_MODE_WP)
+ flags |= MFILL_ATOMIC_WP;
if (mmget_not_zero(ctx->mm)) {
ret = mfill_atomic_copy(ctx->mm, uffdio_copy.dst, uffdio_copy.src,
uffdio_copy.len, &ctx->mmap_changing,
- uffdio_copy.mode);
+ flags);
mmput(ctx->mm);
} else {
return -ESRCH;
diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index 3cb7cd853fa8..2a758bcd6719 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -162,9 +162,8 @@ int hugetlb_mfill_atomic_pte(pte_t *dst_pte,
struct vm_area_struct *dst_vma,
unsigned long dst_addr,
unsigned long src_addr,
- enum mcopy_atomic_mode mode,
- struct page **pagep,
- bool wp_copy);
+ uffd_flags_t flags,
+ struct page **pagep);
#endif /* CONFIG_USERFAULTFD */
bool hugetlb_reserve_pages(struct inode *inode, long from, long to,
struct vm_area_struct *vma,
@@ -397,9 +396,8 @@ 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,
- enum mcopy_atomic_mode mode,
- struct page **pagep,
- bool wp_copy)
+ uffd_flags_t flags,
+ struct page **pagep)
{
BUG();
return 0;
diff --git a/include/linux/shmem_fs.h b/include/linux/shmem_fs.h
index 922a2b45fe6f..3bb8d21edbb3 100644
--- a/include/linux/shmem_fs.h
+++ b/include/linux/shmem_fs.h
@@ -9,6 +9,7 @@
#include <linux/percpu_counter.h>
#include <linux/xattr.h>
#include <linux/fs_parser.h>
+#include <linux/userfaultfd_k.h>
/* inode in-kernel data */
@@ -156,11 +157,11 @@ 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,
+ uffd_flags_t flags,
struct page **pagep);
#else /* !CONFIG_SHMEM */
#define shmem_mfill_atomic_pte(dst_pmd, dst_vma, dst_addr, \
- src_addr, zeropage, wp_copy, pagep) ({ BUG(); 0; })
+ src_addr, flags, pagep) ({ BUG(); 0; })
#endif /* CONFIG_SHMEM */
#endif /* CONFIG_USERFAULTFD */
diff --git a/include/linux/userfaultfd_k.h b/include/linux/userfaultfd_k.h
index 9458cd94a508..4c477dece540 100644
--- a/include/linux/userfaultfd_k.h
+++ b/include/linux/userfaultfd_k.h
@@ -40,30 +40,44 @@ extern int sysctl_unprivileged_userfaultfd;
extern vm_fault_t handle_userfault(struct vm_fault *vmf, unsigned long reason);
-/*
- * The mode of operation for __mcopy_atomic and its helpers.
- *
- * This is almost an implementation detail (mcopy_atomic below doesn't take this
- * as a parameter), but it's exposed here because memory-kind-specific
- * implementations (e.g. hugetlbfs) need to know the mode of operation.
- */
-enum mcopy_atomic_mode {
- /* A normal copy_from_user into the destination range. */
- MCOPY_ATOMIC_NORMAL,
- /* Don't copy; map the destination range to the zero page. */
- MCOPY_ATOMIC_ZEROPAGE,
- /* Just install pte(s) with the existing page(s) in the page cache. */
- MCOPY_ATOMIC_CONTINUE,
+/* A combined operation mode + behavior flags. */
+typedef unsigned int __bitwise uffd_flags_t;
+
+/* Mutually exclusive modes of operation. */
+enum mfill_atomic_mode {
+ MFILL_ATOMIC_COPY,
+ MFILL_ATOMIC_ZEROPAGE,
+ MFILL_ATOMIC_CONTINUE,
+ NR_MFILL_ATOMIC_MODES,
};
+#define MFILL_ATOMIC_MODE_BITS (const_ilog2(NR_MFILL_ATOMIC_MODES - 1) + 1)
+#define MFILL_ATOMIC_BIT(nr) BIT(MFILL_ATOMIC_MODE_BITS + (nr))
+#define MFILL_ATOMIC_FLAG(nr) ((__force uffd_flags_t) MFILL_ATOMIC_BIT(nr))
+#define MFILL_ATOMIC_MODE_MASK ((__force uffd_flags_t) (MFILL_ATOMIC_BIT(0) - 1))
+
+static inline bool uffd_flags_mode_is(uffd_flags_t flags, enum mfill_atomic_mode expected)
+{
+ return (flags & MFILL_ATOMIC_MODE_MASK) == ((__force uffd_flags_t) expected);
+}
+
+static inline uffd_flags_t uffd_flags_set_mode(uffd_flags_t flags, enum mfill_atomic_mode mode)
+{
+ flags &= ~MFILL_ATOMIC_MODE_MASK;
+ return flags | ((__force uffd_flags_t) mode);
+}
+
+/* Flags controlling behavior. These behavior changes are mode-independent. */
+#define MFILL_ATOMIC_WP MFILL_ATOMIC_FLAG(0)
+
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);
+ bool newly_allocated, uffd_flags_t flags);
extern ssize_t mfill_atomic_copy(struct mm_struct *dst_mm, unsigned long dst_start,
unsigned long src_start, unsigned long len,
- atomic_t *mmap_changing, __u64 mode);
+ atomic_t *mmap_changing, uffd_flags_t flags);
extern ssize_t mfill_atomic_zeropage(struct mm_struct *dst_mm,
unsigned long dst_start,
unsigned long len,
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 6dc32cccbd9b..8bfd07f4c143 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -6163,12 +6163,12 @@ int hugetlb_mfill_atomic_pte(pte_t *dst_pte,
struct vm_area_struct *dst_vma,
unsigned long dst_addr,
unsigned long src_addr,
- enum mcopy_atomic_mode mode,
- struct page **pagep,
- bool wp_copy)
+ uffd_flags_t flags,
+ struct page **pagep)
{
struct mm_struct *dst_mm = dst_vma->vm_mm;
- bool is_continue = (mode == MCOPY_ATOMIC_CONTINUE);
+ bool is_continue = uffd_flags_mode_is(flags, MFILL_ATOMIC_CONTINUE);
+ bool wp_enabled = (flags & MFILL_ATOMIC_WP);
struct hstate *h = hstate_vma(dst_vma);
struct address_space *mapping = dst_vma->vm_file->f_mapping;
pgoff_t idx = vma_hugecache_offset(h, dst_vma, dst_addr);
@@ -6303,7 +6303,7 @@ int hugetlb_mfill_atomic_pte(pte_t *dst_pte,
* For either: (1) CONTINUE on a non-shared VMA, or (2) UFFDIO_COPY
* with wp flag set, don't set pte write bit.
*/
- if (wp_copy || (is_continue && !vm_shared))
+ if (wp_enabled || (is_continue && !vm_shared))
writable = 0;
else
writable = dst_vma->vm_flags & VM_WRITE;
@@ -6318,7 +6318,7 @@ int hugetlb_mfill_atomic_pte(pte_t *dst_pte,
_dst_pte = huge_pte_mkdirty(_dst_pte);
_dst_pte = pte_mkyoung(_dst_pte);
- if (wp_copy)
+ if (wp_enabled)
_dst_pte = huge_pte_mkuffd_wp(_dst_pte);
set_huge_pte_at(dst_mm, dst_addr, dst_pte, _dst_pte);
diff --git a/mm/shmem.c b/mm/shmem.c
index 9d13b9a64144..b185c1db3009 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -76,7 +76,6 @@ static struct vfsmount *shm_mnt;
#include <linux/syscalls.h>
#include <linux/fcntl.h>
#include <uapi/linux/memfd.h>
-#include <linux/userfaultfd_k.h>
#include <linux/rmap.h>
#include <linux/uuid.h>
@@ -2433,7 +2432,7 @@ 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,
+ uffd_flags_t flags,
struct page **pagep)
{
struct inode *inode = file_inode(dst_vma->vm_file);
@@ -2465,7 +2464,7 @@ int shmem_mfill_atomic_pte(pmd_t *dst_pmd,
if (!folio)
goto out_unacct_blocks;
- if (!zeropage) { /* COPY */
+ if (uffd_flags_mode_is(flags, MFILL_ATOMIC_COPY)) {
page_kaddr = kmap_local_folio(folio, 0);
/*
* The read mmap_lock is held here. Despite the
@@ -2524,7 +2523,7 @@ int shmem_mfill_atomic_pte(pmd_t *dst_pmd,
goto out_release;
ret = mfill_atomic_install_pte(dst_pmd, dst_vma, dst_addr,
- &folio->page, true, wp_copy);
+ &folio->page, true, flags);
if (ret)
goto out_delete_from_cache;
diff --git a/mm/userfaultfd.c b/mm/userfaultfd.c
index c3cc6cb04548..a9b19b39413d 100644
--- a/mm/userfaultfd.c
+++ b/mm/userfaultfd.c
@@ -58,7 +58,7 @@ struct vm_area_struct *find_dst_vma(struct mm_struct *dst_mm,
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)
+ bool newly_allocated, uffd_flags_t flags)
{
int ret;
struct mm_struct *dst_mm = dst_vma->vm_mm;
@@ -77,7 +77,7 @@ int mfill_atomic_install_pte(pmd_t *dst_pmd,
writable = false;
if (writable)
_dst_pte = pte_mkwrite(_dst_pte);
- if (wp_copy)
+ if (flags & MFILL_ATOMIC_WP)
_dst_pte = pte_mkuffd_wp(_dst_pte);
dst_pte = pte_offset_map_lock(dst_mm, dst_pmd, dst_addr, &ptl);
@@ -132,8 +132,8 @@ static int mfill_atomic_pte_copy(pmd_t *dst_pmd,
struct vm_area_struct *dst_vma,
unsigned long dst_addr,
unsigned long src_addr,
- struct page **pagep,
- bool wp_copy)
+ uffd_flags_t flags,
+ struct page **pagep)
{
void *page_kaddr;
int ret;
@@ -194,7 +194,7 @@ static int mfill_atomic_pte_copy(pmd_t *dst_pmd,
goto out_release;
ret = mfill_atomic_install_pte(dst_pmd, dst_vma, dst_addr,
- page, true, wp_copy);
+ page, true, flags);
if (ret)
goto out_release;
out:
@@ -242,7 +242,7 @@ out_unlock:
static int mfill_atomic_pte_continue(pmd_t *dst_pmd,
struct vm_area_struct *dst_vma,
unsigned long dst_addr,
- bool wp_copy)
+ uffd_flags_t flags)
{
struct inode *inode = file_inode(dst_vma->vm_file);
pgoff_t pgoff = linear_page_index(dst_vma, dst_addr);
@@ -268,7 +268,7 @@ static int mfill_atomic_pte_continue(pmd_t *dst_pmd,
}
ret = mfill_atomic_install_pte(dst_pmd, dst_vma, dst_addr,
- page, false, wp_copy);
+ page, false, flags);
if (ret)
goto out_release;
@@ -313,8 +313,7 @@ static __always_inline ssize_t mfill_atomic_hugetlb(
unsigned long dst_start,
unsigned long src_start,
unsigned long len,
- enum mcopy_atomic_mode mode,
- bool wp_copy)
+ uffd_flags_t flags)
{
struct mm_struct *dst_mm = dst_vma->vm_mm;
int vm_shared = dst_vma->vm_flags & VM_SHARED;
@@ -334,7 +333,7 @@ static __always_inline ssize_t mfill_atomic_hugetlb(
* by THP. Since we can not reliably insert a zero page, this
* feature is not supported.
*/
- if (mode == MCOPY_ATOMIC_ZEROPAGE) {
+ if (uffd_flags_mode_is(flags, MFILL_ATOMIC_ZEROPAGE)) {
mmap_read_unlock(dst_mm);
return -EINVAL;
}
@@ -402,7 +401,7 @@ retry:
goto out_unlock;
}
- if (mode != MCOPY_ATOMIC_CONTINUE &&
+ if (!uffd_flags_mode_is(flags, MFILL_ATOMIC_CONTINUE) &&
!huge_pte_none_mostly(huge_ptep_get(dst_pte))) {
err = -EEXIST;
hugetlb_vma_unlock_read(dst_vma);
@@ -410,9 +409,8 @@ retry:
goto out_unlock;
}
- err = hugetlb_mfill_atomic_pte(dst_pte, dst_vma,
- dst_addr, src_addr, mode, &page,
- wp_copy);
+ err = hugetlb_mfill_atomic_pte(dst_pte, dst_vma, dst_addr,
+ src_addr, flags, &page);
hugetlb_vma_unlock_read(dst_vma);
mutex_unlock(&hugetlb_fault_mutex_table[hash]);
@@ -466,23 +464,21 @@ 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);
+ uffd_flags_t flags);
#endif /* CONFIG_HUGETLB_PAGE */
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,
- struct page **page,
- enum mcopy_atomic_mode mode,
- bool wp_copy)
+ uffd_flags_t flags,
+ struct page **pagep)
{
ssize_t err;
- if (mode == MCOPY_ATOMIC_CONTINUE) {
+ if (uffd_flags_mode_is(flags, MFILL_ATOMIC_CONTINUE)) {
return mfill_atomic_pte_continue(dst_pmd, dst_vma,
- dst_addr, wp_copy);
+ dst_addr, flags);
}
/*
@@ -496,18 +492,17 @@ static __always_inline ssize_t mfill_atomic_pte(pmd_t *dst_pmd,
* and not in the radix tree.
*/
if (!(dst_vma->vm_flags & VM_SHARED)) {
- if (mode == MCOPY_ATOMIC_NORMAL)
+ if (uffd_flags_mode_is(flags, MFILL_ATOMIC_COPY))
err = mfill_atomic_pte_copy(dst_pmd, dst_vma,
- dst_addr, src_addr, page,
- wp_copy);
+ dst_addr, src_addr,
+ flags, pagep);
else
err = mfill_atomic_pte_zeropage(dst_pmd,
dst_vma, dst_addr);
} else {
err = shmem_mfill_atomic_pte(dst_pmd, dst_vma,
dst_addr, src_addr,
- mode != MCOPY_ATOMIC_NORMAL,
- wp_copy, page);
+ flags, pagep);
}
return err;
@@ -517,9 +512,8 @@ static __always_inline ssize_t mfill_atomic(struct mm_struct *dst_mm,
unsigned long dst_start,
unsigned long src_start,
unsigned long len,
- enum mcopy_atomic_mode mcopy_mode,
atomic_t *mmap_changing,
- __u64 mode)
+ uffd_flags_t flags)
{
struct vm_area_struct *dst_vma;
ssize_t err;
@@ -527,7 +521,6 @@ static __always_inline ssize_t mfill_atomic(struct mm_struct *dst_mm,
unsigned long src_addr, dst_addr;
long copied;
struct page *page;
- bool wp_copy;
/*
* Sanitize the command parameters:
@@ -577,8 +570,7 @@ retry:
* validate 'mode' now that we know the dst_vma: don't allow
* a wrprotect copy if the userfaultfd didn't register as WP.
*/
- wp_copy = mode & UFFDIO_COPY_MODE_WP;
- if (wp_copy && !(dst_vma->vm_flags & VM_UFFD_WP))
+ if ((flags & MFILL_ATOMIC_WP) && !(dst_vma->vm_flags & VM_UFFD_WP))
goto out_unlock;
/*
@@ -586,12 +578,12 @@ retry:
*/
if (is_vm_hugetlb_page(dst_vma))
return mfill_atomic_hugetlb(dst_vma, dst_start,
- src_start, len, mcopy_mode,
- wp_copy);
+ src_start, len, flags);
if (!vma_is_anonymous(dst_vma) && !vma_is_shmem(dst_vma))
goto out_unlock;
- if (!vma_is_shmem(dst_vma) && mcopy_mode == MCOPY_ATOMIC_CONTINUE)
+ if (!vma_is_shmem(dst_vma) &&
+ uffd_flags_mode_is(flags, MFILL_ATOMIC_CONTINUE))
goto out_unlock;
/*
@@ -639,7 +631,7 @@ retry:
BUG_ON(pmd_trans_huge(*dst_pmd));
err = mfill_atomic_pte(dst_pmd, dst_vma, dst_addr,
- src_addr, &page, mcopy_mode, wp_copy);
+ src_addr, flags, &page);
cond_resched();
if (unlikely(err == -ENOENT)) {
@@ -687,24 +679,24 @@ out:
ssize_t mfill_atomic_copy(struct mm_struct *dst_mm, unsigned long dst_start,
unsigned long src_start, unsigned long len,
- atomic_t *mmap_changing, __u64 mode)
+ atomic_t *mmap_changing, uffd_flags_t flags)
{
- return mfill_atomic(dst_mm, dst_start, src_start, len,
- MCOPY_ATOMIC_NORMAL, mmap_changing, mode);
+ return mfill_atomic(dst_mm, dst_start, src_start, len, mmap_changing,
+ uffd_flags_set_mode(flags, MFILL_ATOMIC_COPY));
}
ssize_t mfill_atomic_zeropage(struct mm_struct *dst_mm, unsigned long start,
unsigned long len, atomic_t *mmap_changing)
{
- return mfill_atomic(dst_mm, start, 0, len, MCOPY_ATOMIC_ZEROPAGE,
- mmap_changing, 0);
+ return mfill_atomic(dst_mm, start, 0, len, mmap_changing,
+ uffd_flags_set_mode(0, MFILL_ATOMIC_ZEROPAGE));
}
ssize_t mfill_atomic_continue(struct mm_struct *dst_mm, unsigned long start,
unsigned long len, atomic_t *mmap_changing)
{
- return mfill_atomic(dst_mm, start, 0, len, MCOPY_ATOMIC_CONTINUE,
- mmap_changing, 0);
+ return mfill_atomic(dst_mm, start, 0, len, mmap_changing,
+ uffd_flags_set_mode(0, MFILL_ATOMIC_CONTINUE));
}
long uffd_wp_range(struct vm_area_struct *dst_vma,
generated by cgit (git 2.34.1) at 2024-05-28 06:44:37 +0000