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| author |   Christian König <christian.koenig@amd.com> | 2020-09-14 15:09:33 +0200 |
|---|---|---|
| committer | Christian König <christian.koenig@amd.com> | 2020-11-19 10:36:36 +0100 |
| commit | 295992fb815e791d14b18ef7cdbbaf1a76211a31 (patch) | |
| tree | 2b72922a11a0abd63cb11969d3fd5cd7d2874e1c /mm/util.c | |
| parent | mm: mmap: fix fput in error path v2 (diff) | |
| download | linux-dev-295992fb815e791d14b18ef7cdbbaf1a76211a31.tar.xz linux-dev-295992fb815e791d14b18ef7cdbbaf1a76211a31.zip | |
mm: introduce vma_set_file function v5
Add the new vma_set_file() function to allow changing
vma->vm_file with the necessary refcount dance.
v2: add more users of this.
v3: add missing EXPORT_SYMBOL, rebase on mmap cleanup,
add comments why we drop the reference on two occasions.
v4: make it clear that changing an anonymous vma is illegal.
v5: move vma_set_file to mm/util.c
Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> (v2)
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
Link: https://patchwork.freedesktop.org/patch/399360/
Diffstat (limited to 'mm/util.c')
| -rw-r--r-- | mm/util.c | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/mm/util.c b/mm/util.c index 4ddb6e186dd5..8c9b7d1e7c49 100644 --- a/mm/util.c +++ b/mm/util.c @@ -311,6 +311,18 @@ int vma_is_stack_for_current(struct vm_area_struct *vma) return (vma->vm_start <= KSTK_ESP(t) && vma->vm_end >= KSTK_ESP(t)); } +/* + * Change backing file, only valid to use during initial VMA setup. + */ +void vma_set_file(struct vm_area_struct *vma, struct file *file) +{ + /* Changing an anonymous vma with this is illegal */ + get_file(file); + swap(vma->vm_file, file); + fput(file); +} +EXPORT_SYMBOL(vma_set_file); + #ifndef STACK_RND_MASK #define STACK_RND_MASK (0x7ff >> (PAGE_SHIFT - 12)) /* 8MB of VA */ #endif |