On 14 February 2013 16:16, Daniel Vetter <daniel.vet...@ffwll.ch> wrote: > On Tue, Feb 12, 2013 at 2:50 AM, <s...@google.com> wrote: >> From: John Sheu <s...@google.com> >> >> 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 <s...@google.com> > > Yeah, makes sense that this little helper here cleans up any damage it > caused when the callback fails. > > Reviewed-by: Daniel Vetter <daniel.vet...@ffwll.ch>
Thanks John, Daniel! I'll pull it in the for-next soon. Best regards, ~Sumit. >> >> --- >> drivers/base/dma-buf.c | 21 +++++++++++++++------ >> 1 files changed, 15 insertions(+), 6 deletions(-) >> >> diff --git a/drivers/base/dma-buf.c b/drivers/base/dma-buf.c >> index 09e6878..06c6225 100644 >> --- a/drivers/base/dma-buf.c >> +++ b/drivers/base/dma-buf.c >> @@ -536,6 +536,9 @@ 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; >> >> @@ -549,15 +552,21 @@ 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); >> - >> + get_file(dmabuf->file); >> + oldfile = vma->vm_file; >> vma->vm_file = dmabuf->file; >> - get_file(vma->vm_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); >> >> -- >> 1.7.8.6 >> >> >> _______________________________________________ >> Linaro-mm-sig mailing list >> linaro-mm-...@lists.linaro.org >> http://lists.linaro.org/mailman/listinfo/linaro-mm-sig > > > > -- > Daniel Vetter > Software Engineer, Intel Corporation > +41 (0) 79 365 57 48 - http://blog.ffwll.ch -- Thanks and regards, Sumit Semwal Linaro Kernel Engineer - Graphics working group Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html