| Message ID | a2d3210b-290f-4397-9c3e-efdcca94d8ac@moroto.mountain (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm/imagination: fix off by one in pvr_vm_mips_init() error handling | expand |
On Thu, 2023-11-30 at 10:27 +0300, Dan Carpenter wrote: > If the call to vmap() fails the "page_nr" is one element beyond the end > of the mips_data->pt_dma_addr[] and mips_data->pt_pages[] arrays. > > The way that this is traditionally written is that we clean up the > partial loop iteration before the goto and then we can say > while (--i >= 0). At that point we know that all the elements thus > far are initialized so we don't need to have NULL checks. > > Fixes: 927f3e0253c1 ("drm/imagination: Implement MIPS firmware processor and MMU support") > Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org> Reviewed-by: Frank Binns <frank.binns@imgtec.com> > --- > drivers/gpu/drm/imagination/pvr_vm_mips.c | 11 +++++------ > 1 file changed, 5 insertions(+), 6 deletions(-) > > diff --git a/drivers/gpu/drm/imagination/pvr_vm_mips.c b/drivers/gpu/drm/imagination/pvr_vm_mips.c > index 7268cf6e630b..2bc7181a4c3e 100644 > --- a/drivers/gpu/drm/imagination/pvr_vm_mips.c > +++ b/drivers/gpu/drm/imagination/pvr_vm_mips.c > @@ -57,6 +57,7 @@ pvr_vm_mips_init(struct pvr_device *pvr_dev) > PAGE_SIZE, DMA_TO_DEVICE); > if (dma_mapping_error(dev, mips_data->pt_dma_addr[page_nr])) { > err = -ENOMEM; > + __free_page(mips_data->pt_pages[page_nr]); > goto err_free_pages; > } > } > @@ -79,13 +80,11 @@ pvr_vm_mips_init(struct pvr_device *pvr_dev) > return 0; > > err_free_pages: > - for (; page_nr >= 0; page_nr--) { > - if (mips_data->pt_dma_addr[page_nr]) > - dma_unmap_page(from_pvr_device(pvr_dev)->dev, > - mips_data->pt_dma_addr[page_nr], PAGE_SIZE, DMA_TO_DEVICE); > + while (--page_nr >= 0) { > + dma_unmap_page(from_pvr_device(pvr_dev)->dev, > + mips_data->pt_dma_addr[page_nr], PAGE_SIZE, DMA_TO_DEVICE); > > - if (mips_data->pt_pages[page_nr]) > - __free_page(mips_data->pt_pages[page_nr]); > + __free_page(mips_data->pt_pages[page_nr]); > } > > return err;
On Thu, 30 Nov 2023 10:27:15 +0300, Dan Carpenter wrote: > If the call to vmap() fails the "page_nr" is one element beyond the end > of the mips_data->pt_dma_addr[] and mips_data->pt_pages[] arrays. > > The way that this is traditionally written is that we clean up the > partial loop iteration before the goto and then we can say > while (--i >= 0). At that point we know that all the elements thus > far are initialized so we don't need to have NULL checks. > > [...] Applied to drm/drm-misc (drm-misc-next). Thanks! Maxime
diff --git a/drivers/gpu/drm/imagination/pvr_vm_mips.c b/drivers/gpu/drm/imagination/pvr_vm_mips.c index 7268cf6e630b..2bc7181a4c3e 100644 --- a/drivers/gpu/drm/imagination/pvr_vm_mips.c +++ b/drivers/gpu/drm/imagination/pvr_vm_mips.c @@ -57,6 +57,7 @@ pvr_vm_mips_init(struct pvr_device *pvr_dev) PAGE_SIZE, DMA_TO_DEVICE); if (dma_mapping_error(dev, mips_data->pt_dma_addr[page_nr])) { err = -ENOMEM; + __free_page(mips_data->pt_pages[page_nr]); goto err_free_pages; } } @@ -79,13 +80,11 @@ pvr_vm_mips_init(struct pvr_device *pvr_dev) return 0; err_free_pages: - for (; page_nr >= 0; page_nr--) { - if (mips_data->pt_dma_addr[page_nr]) - dma_unmap_page(from_pvr_device(pvr_dev)->dev, - mips_data->pt_dma_addr[page_nr], PAGE_SIZE, DMA_TO_DEVICE); + while (--page_nr >= 0) { + dma_unmap_page(from_pvr_device(pvr_dev)->dev, + mips_data->pt_dma_addr[page_nr], PAGE_SIZE, DMA_TO_DEVICE); - if (mips_data->pt_pages[page_nr]) - __free_page(mips_data->pt_pages[page_nr]); + __free_page(mips_data->pt_pages[page_nr]); } return err;
If the call to vmap() fails the "page_nr" is one element beyond the end of the mips_data->pt_dma_addr[] and mips_data->pt_pages[] arrays. The way that this is traditionally written is that we clean up the partial loop iteration before the goto and then we can say while (--i >= 0). At that point we know that all the elements thus far are initialized so we don't need to have NULL checks. Fixes: 927f3e0253c1 ("drm/imagination: Implement MIPS firmware processor and MMU support") Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org> --- drivers/gpu/drm/imagination/pvr_vm_mips.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-)