Hello Arnd,
Thanks for the patch. I'm slightly concerned that we've not seen this warning when
building here. I guess we need to check our CI settings...
Reviewed-by: Donald Robson <donald.robson@xxxxxxxxxx>
On Wed, 2023-11-29 at 12:33 +0100, Arnd Bergmann wrote:
> From: Arnd Bergmann <arnd@xxxxxxxx>
>
> The array size calculation in pvr_vm_mips_fini() appears to be incorrect based on
> taking the size of the pointer rather than the size of the array, which manifests
> as a warning about signed integer overflow:
>
> In file included from include/linux/kernel.h:16,
> from drivers/gpu/drm/imagination/pvr_rogue_fwif.h:10,
> from drivers/gpu/drm/imagination/pvr_ccb.h:7,
> from drivers/gpu/drm/imagination/pvr_device.h:7,
> from drivers/gpu/drm/imagination/pvr_vm_mips.c:4:
> drivers/gpu/drm/imagination/pvr_vm_mips.c: In function 'pvr_vm_mips_fini':
> include/linux/array_size.h:11:25: error: overflow in conversion from 'long unsigned int' to 'int' changes value from '18446744073709551615' to '-1' [-Werror=overflow]
> 11 | #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr))
> | ^
> drivers/gpu/drm/imagination/pvr_vm_mips.c:106:24: note: in expansion of macro 'ARRAY_SIZE'
> 106 | for (page_nr = ARRAY_SIZE(mips_data->pt_pages) - 1; page_nr >= 0; page_nr--) {
> | ^~~~~~~~~~
>
> Just use the number of array elements directly here, and in the corresponding
> init function for consistency.
>
> Fixes: 927f3e0253c1 ("drm/imagination: Implement MIPS firmware processor and MMU support")
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
> ---
> drivers/gpu/drm/imagination/pvr_vm_mips.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/imagination/pvr_vm_mips.c b/drivers/gpu/drm/imagination/pvr_vm_mips.c
> index 7268cf6e630b..6c2e4cc4e6db 100644
> --- a/drivers/gpu/drm/imagination/pvr_vm_mips.c
> +++ b/drivers/gpu/drm/imagination/pvr_vm_mips.c
> @@ -46,7 +46,7 @@ pvr_vm_mips_init(struct pvr_device *pvr_dev)
> if (!mips_data)
> return -ENOMEM;
>
> - for (page_nr = 0; page_nr < ARRAY_SIZE(mips_data->pt_pages); page_nr++) {
> + for (page_nr = 0; page_nr < PVR_MIPS_PT_PAGE_COUNT; page_nr++) {
> mips_data->pt_pages[page_nr] = alloc_page(GFP_KERNEL | __GFP_ZERO);
> if (!mips_data->pt_pages[page_nr]) {
> err = -ENOMEM;
> @@ -103,7 +103,7 @@ pvr_vm_mips_fini(struct pvr_device *pvr_dev)
> int page_nr;
>
> vunmap(mips_data->pt);
> - for (page_nr = ARRAY_SIZE(mips_data->pt_pages) - 1; page_nr >= 0; page_nr--) {
> + for (page_nr = PVR_MIPS_PT_PAGE_COUNT - 1; page_nr >= 0; page_nr--) {
> dma_unmap_page(from_pvr_device(pvr_dev)->dev,
> mips_data->pt_dma_addr[page_nr], PAGE_SIZE, DMA_TO_DEVICE);
>
