mirror of
https://github.com/torvalds/linux.git
synced 2024-12-29 06:12:08 +00:00
userfaultfd: use vma iterator
Use the vma iterator so that the iterator can be invalidated or updated to avoid each caller doing so. Link: https://lkml.kernel.org/r/20230120162650.984577-17-Liam.Howlett@oracle.com Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Liam R. Howlett
Andrew Morton
parent
27b2670112
commit
11a9b90274
@ -883,7 +883,7 @@ static int userfaultfd_release(struct inode *inode, struct file *file)
|
||||
/* len == 0 means wake all */
|
||||
struct userfaultfd_wake_range range = { .len = 0, };
|
||||
unsigned long new_flags;
|
||||
MA_STATE(mas, &mm->mm_mt, 0, 0);
|
||||
VMA_ITERATOR(vmi, mm, 0);
|
||||
|
||||
WRITE_ONCE(ctx->released, true);
|
||||
|
||||
@ -900,7 +900,7 @@ static int userfaultfd_release(struct inode *inode, struct file *file)
|
||||
*/
|
||||
mmap_write_lock(mm);
|
||||
prev = NULL;
|
||||
mas_for_each(&mas, vma, ULONG_MAX) {
|
||||
for_each_vma(vmi, vma) {
|
||||
cond_resched();
|
||||
BUG_ON(!!vma->vm_userfaultfd_ctx.ctx ^
|
||||
!!(vma->vm_flags & __VM_UFFD_FLAGS));
|
||||
@ -909,13 +909,12 @@ static int userfaultfd_release(struct inode *inode, struct file *file)
|
||||
continue;
|
||||
}
|
||||
new_flags = vma->vm_flags & ~__VM_UFFD_FLAGS;
|
||||
prev = vma_merge(mm, prev, vma->vm_start, vma->vm_end,
|
||||
prev = vmi_vma_merge(&vmi, mm, prev, vma->vm_start, vma->vm_end,
|
||||
new_flags, vma->anon_vma,
|
||||
vma->vm_file, vma->vm_pgoff,
|
||||
vma_policy(vma),
|
||||
NULL_VM_UFFD_CTX, anon_vma_name(vma));
|
||||
if (prev) {
|
||||
mas_pause(&mas);
|
||||
vma = prev;
|
||||
} else {
|
||||
prev = vma;
|
||||
@ -1302,7 +1301,7 @@ static int userfaultfd_register(struct userfaultfd_ctx *ctx,
|
||||
bool found;
|
||||
bool basic_ioctls;
|
||||
unsigned long start, end, vma_end;
|
||||
MA_STATE(mas, &mm->mm_mt, 0, 0);
|
||||
struct vma_iterator vmi;
|
||||
|
||||
user_uffdio_register = (struct uffdio_register __user *) arg;
|
||||
|
||||
@ -1344,15 +1343,11 @@ static int userfaultfd_register(struct userfaultfd_ctx *ctx,
|
||||
if (!mmget_not_zero(mm))
|
||||
goto out;
|
||||
|
||||
mmap_write_lock(mm);
|
||||
mas_set(&mas, start);
|
||||
vma = mas_find(&mas, ULONG_MAX);
|
||||
if (!vma)
|
||||
goto out_unlock;
|
||||
|
||||
/* check that there's at least one vma in the range */
|
||||
ret = -EINVAL;
|
||||
if (vma->vm_start >= end)
|
||||
mmap_write_lock(mm);
|
||||
vma_iter_init(&vmi, mm, start);
|
||||
vma = vma_find(&vmi, end);
|
||||
if (!vma)
|
||||
goto out_unlock;
|
||||
|
||||
/*
|
||||
@ -1371,7 +1366,8 @@ static int userfaultfd_register(struct userfaultfd_ctx *ctx,
|
||||
*/
|
||||
found = false;
|
||||
basic_ioctls = false;
|
||||
for (cur = vma; cur; cur = mas_next(&mas, end - 1)) {
|
||||
cur = vma;
|
||||
do {
|
||||
cond_resched();
|
||||
|
||||
BUG_ON(!!cur->vm_userfaultfd_ctx.ctx ^
|
||||
@ -1428,16 +1424,14 @@ static int userfaultfd_register(struct userfaultfd_ctx *ctx,
|
||||
basic_ioctls = true;
|
||||
|
||||
found = true;
|
||||
}
|
||||
} for_each_vma_range(vmi, cur, end);
|
||||
BUG_ON(!found);
|
||||
|
||||
mas_set(&mas, start);
|
||||
prev = mas_prev(&mas, 0);
|
||||
if (prev != vma)
|
||||
mas_next(&mas, ULONG_MAX);
|
||||
vma_iter_set(&vmi, start);
|
||||
prev = vma_prev(&vmi);
|
||||
|
||||
ret = 0;
|
||||
do {
|
||||
for_each_vma_range(vmi, vma, end) {
|
||||
cond_resched();
|
||||
|
||||
BUG_ON(!vma_can_userfault(vma, vm_flags));
|
||||
@ -1458,30 +1452,25 @@ static int userfaultfd_register(struct userfaultfd_ctx *ctx,
|
||||
vma_end = min(end, vma->vm_end);
|
||||
|
||||
new_flags = (vma->vm_flags & ~__VM_UFFD_FLAGS) | vm_flags;
|
||||
prev = vma_merge(mm, prev, start, vma_end, new_flags,
|
||||
prev = vmi_vma_merge(&vmi, mm, prev, start, vma_end, new_flags,
|
||||
vma->anon_vma, vma->vm_file, vma->vm_pgoff,
|
||||
vma_policy(vma),
|
||||
((struct vm_userfaultfd_ctx){ ctx }),
|
||||
anon_vma_name(vma));
|
||||
if (prev) {
|
||||
/* vma_merge() invalidated the mas */
|
||||
mas_pause(&mas);
|
||||
vma = prev;
|
||||
goto next;
|
||||
}
|
||||
if (vma->vm_start < start) {
|
||||
ret = split_vma(mm, vma, start, 1);
|
||||
ret = vmi_split_vma(&vmi, mm, vma, start, 1);
|
||||
if (ret)
|
||||
break;
|
||||
/* split_vma() invalidated the mas */
|
||||
mas_pause(&mas);
|
||||
}
|
||||
if (vma->vm_end > end) {
|
||||
ret = split_vma(mm, vma, end, 0);
|
||||
ret = vmi_split_vma(&vmi, mm, vma, end, 0);
|
||||
if (ret)
|
||||
break;
|
||||
/* split_vma() invalidated the mas */
|
||||
mas_pause(&mas);
|
||||
}
|
||||
next:
|
||||
/*
|
||||
@ -1498,8 +1487,8 @@ static int userfaultfd_register(struct userfaultfd_ctx *ctx,
|
||||
skip:
|
||||
prev = vma;
|
||||
start = vma->vm_end;
|
||||
vma = mas_next(&mas, end - 1);
|
||||
} while (vma);
|
||||
}
|
||||
|
||||
out_unlock:
|
||||
mmap_write_unlock(mm);
|
||||
mmput(mm);
|
||||
@ -1543,7 +1532,7 @@ static int userfaultfd_unregister(struct userfaultfd_ctx *ctx,
|
||||
bool found;
|
||||
unsigned long start, end, vma_end;
|
||||
const void __user *buf = (void __user *)arg;
|
||||
MA_STATE(mas, &mm->mm_mt, 0, 0);
|
||||
struct vma_iterator vmi;
|
||||
|
||||
ret = -EFAULT;
|
||||
if (copy_from_user(&uffdio_unregister, buf, sizeof(uffdio_unregister)))
|
||||
@ -1562,14 +1551,10 @@ static int userfaultfd_unregister(struct userfaultfd_ctx *ctx,
|
||||
goto out;
|
||||
|
||||
mmap_write_lock(mm);
|
||||
mas_set(&mas, start);
|
||||
vma = mas_find(&mas, ULONG_MAX);
|
||||
if (!vma)
|
||||
goto out_unlock;
|
||||
|
||||
/* check that there's at least one vma in the range */
|
||||
ret = -EINVAL;
|
||||
if (vma->vm_start >= end)
|
||||
vma_iter_init(&vmi, mm, start);
|
||||
vma = vma_find(&vmi, end);
|
||||
if (!vma)
|
||||
goto out_unlock;
|
||||
|
||||
/*
|
||||
@ -1587,8 +1572,8 @@ static int userfaultfd_unregister(struct userfaultfd_ctx *ctx,
|
||||
* Search for not compatible vmas.
|
||||
*/
|
||||
found = false;
|
||||
ret = -EINVAL;
|
||||
for (cur = vma; cur; cur = mas_next(&mas, end - 1)) {
|
||||
cur = vma;
|
||||
do {
|
||||
cond_resched();
|
||||
|
||||
BUG_ON(!!cur->vm_userfaultfd_ctx.ctx ^
|
||||
@ -1605,16 +1590,13 @@ static int userfaultfd_unregister(struct userfaultfd_ctx *ctx,
|
||||
goto out_unlock;
|
||||
|
||||
found = true;
|
||||
}
|
||||
} for_each_vma_range(vmi, cur, end);
|
||||
BUG_ON(!found);
|
||||
|
||||
mas_set(&mas, start);
|
||||
prev = mas_prev(&mas, 0);
|
||||
if (prev != vma)
|
||||
mas_next(&mas, ULONG_MAX);
|
||||
|
||||
vma_iter_set(&vmi, start);
|
||||
prev = vma_prev(&vmi);
|
||||
ret = 0;
|
||||
do {
|
||||
for_each_vma_range(vmi, vma, end) {
|
||||
cond_resched();
|
||||
|
||||
BUG_ON(!vma_can_userfault(vma, vma->vm_flags));
|
||||
@ -1650,26 +1632,23 @@ static int userfaultfd_unregister(struct userfaultfd_ctx *ctx,
|
||||
uffd_wp_range(mm, vma, start, vma_end - start, false);
|
||||
|
||||
new_flags = vma->vm_flags & ~__VM_UFFD_FLAGS;
|
||||
prev = vma_merge(mm, prev, start, vma_end, new_flags,
|
||||
prev = vmi_vma_merge(&vmi, mm, prev, start, vma_end, new_flags,
|
||||
vma->anon_vma, vma->vm_file, vma->vm_pgoff,
|
||||
vma_policy(vma),
|
||||
NULL_VM_UFFD_CTX, anon_vma_name(vma));
|
||||
if (prev) {
|
||||
vma = prev;
|
||||
mas_pause(&mas);
|
||||
goto next;
|
||||
}
|
||||
if (vma->vm_start < start) {
|
||||
ret = split_vma(mm, vma, start, 1);
|
||||
ret = vmi_split_vma(&vmi, mm, vma, start, 1);
|
||||
if (ret)
|
||||
break;
|
||||
mas_pause(&mas);
|
||||
}
|
||||
if (vma->vm_end > end) {
|
||||
ret = split_vma(mm, vma, end, 0);
|
||||
ret = vmi_split_vma(&vmi, mm, vma, end, 0);
|
||||
if (ret)
|
||||
break;
|
||||
mas_pause(&mas);
|
||||
}
|
||||
next:
|
||||
/*
|
||||
@ -1683,8 +1662,8 @@ static int userfaultfd_unregister(struct userfaultfd_ctx *ctx,
|
||||
skip:
|
||||
prev = vma;
|
||||
start = vma->vm_end;
|
||||
vma = mas_next(&mas, end - 1);
|
||||
} while (vma);
|
||||
}
|
||||
|
||||
out_unlock:
|
||||
mmap_write_unlock(mm);
|
||||
mmput(mm);
|
||||
|
||||
Loading…
Reference in New Issue
Block a user