CHROMIUM: dma-buf: restore args on failure of dma_buf_mmap

Callers to dma_buf_mmap expect to fput() the vma struct's vm_file
themselves on failure.  Not restoring the struct's data on failure
causes a double-decrement of the vm_file's refcount.

Signed-off-by: John Sheu <sheu@google.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
This commit is contained in:
John Sheu 2013-02-11 17:50:24 -08:00 коммит произвёл Sumit Semwal
Родитель f00b4dad9d
Коммит 495c10cc1c
1 изменённых файлов: 17 добавлений и 6 удалений

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@ -447,6 +447,9 @@ EXPORT_SYMBOL_GPL(dma_buf_kunmap);
int dma_buf_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma,
unsigned long pgoff)
{
struct file *oldfile;
int ret;
if (WARN_ON(!dmabuf || !vma))
return -EINVAL;
@ -460,14 +463,22 @@ int dma_buf_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma,
return -EINVAL;
/* readjust the vma */
if (vma->vm_file)
fput(vma->vm_file);
vma->vm_file = get_file(dmabuf->file);
get_file(dmabuf->file);
oldfile = vma->vm_file;
vma->vm_file = dmabuf->file;
vma->vm_pgoff = pgoff;
return dmabuf->ops->mmap(dmabuf, vma);
ret = dmabuf->ops->mmap(dmabuf, vma);
if (ret) {
/* restore old parameters on failure */
vma->vm_file = oldfile;
fput(dmabuf->file);
} else {
if (oldfile)
fput(oldfile);
}
return ret;
}
EXPORT_SYMBOL_GPL(dma_buf_mmap);