| Message ID | 20220309175107.195182-1-keescook@chromium.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | ARM/dma-mapping: Remove CMA code when not built with CMA | expand |
On Wed, Mar 09, 2022 at 09:51:07AM -0800, Kees Cook wrote: > The MAX_CMA_AREAS could be set to 0, which would result in code that would > attempt to operate beyond the end of a zero-sized array. If CONFIG_CMA > is disabled, just remove this code entirely. Found when building with > -Warray-bounds: > > arch/arm/mm/dma-mapping.c:396:22: warning: array subscript <unknown> is outside array bounds of 'str > uct dma_contig_early_reserve[0]' [-Warray-bounds] > 396 | dma_mmu_remap[dma_mmu_remap_num].size = size; > | ~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~ > arch/arm/mm/dma-mapping.c:389:40: note: while referencing 'dma_mmu_remap' > 389 | static struct dma_contig_early_reserve dma_mmu_remap[MAX_CMA_AREAS] __initdata; Looks good: Reviewed-by: Christoph Hellwig <hch@lst.de>
On 09.03.22 18:51, Kees Cook wrote: > The MAX_CMA_AREAS could be set to 0, which would result in code that would > attempt to operate beyond the end of a zero-sized array. If CONFIG_CMA > is disabled, just remove this code entirely. Found when building with > -Warray-bounds: > > arch/arm/mm/dma-mapping.c:396:22: warning: array subscript <unknown> is outside array bounds of 'str > uct dma_contig_early_reserve[0]' [-Warray-bounds] > 396 | dma_mmu_remap[dma_mmu_remap_num].size = size; > | ~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~ > arch/arm/mm/dma-mapping.c:389:40: note: while referencing 'dma_mmu_remap' > 389 | static struct dma_contig_early_reserve dma_mmu_remap[MAX_CMA_AREAS] __initdata; > | ^~~~~~~~~~~~~ > > Cc: Russell King <linux@armlinux.org.uk> > Cc: Logan Gunthorpe <logang@deltatee.com> > Cc: Martin Oliveira <martin.oliveira@eideticom.com> > Cc: David Hildenbrand <david@redhat.com> > Cc: Andrew Morton <akpm@linux-foundation.org> > Cc: Stephen Rothwell <sfr@canb.auug.org.au> > Cc: Zi Yan <ziy@nvidia.com> > Cc: Hari Bathini <hbathini@linux.ibm.com> > Cc: Minchan Kim <minchan@kernel.org> > Cc: Mike Kravetz <mike.kravetz@oracle.com> > Cc: linux-arm-kernel@lists.infradead.org > Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: David Hildenbrand <david@redhat.com>
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c index 4b61541853ea..82ffac621854 100644 --- a/arch/arm/mm/dma-mapping.c +++ b/arch/arm/mm/dma-mapping.c @@ -381,6 +381,7 @@ static int __init atomic_pool_init(void) */ postcore_initcall(atomic_pool_init); +#ifdef CONFIG_CMA_AREAS struct dma_contig_early_reserve { phys_addr_t base; unsigned long size; @@ -435,6 +436,7 @@ void __init dma_contiguous_remap(void) iotable_init(&map, 1); } } +#endif static int __dma_update_pte(pte_t *pte, unsigned long addr, void *data) { diff --git a/arch/arm/mm/mm.h b/arch/arm/mm/mm.h index 9ff683612f2a..d7ffccb7fea7 100644 --- a/arch/arm/mm/mm.h +++ b/arch/arm/mm/mm.h @@ -88,6 +88,10 @@ extern phys_addr_t arm_lowmem_limit; void __init bootmem_init(void); void arm_mm_memblock_reserve(void); +#ifdef CONFIG_CMA_AREAS void dma_contiguous_remap(void); +#else +static inline void dma_contiguous_remap(void) { } +#endif unsigned long __clear_cr(unsigned long mask); diff --git a/include/linux/cma.h b/include/linux/cma.h index 90fd742fd1ef..a6f637342740 100644 --- a/include/linux/cma.h +++ b/include/linux/cma.h @@ -12,10 +12,6 @@ */ #ifdef CONFIG_CMA_AREAS #define MAX_CMA_AREAS (1 + CONFIG_CMA_AREAS) - -#else -#define MAX_CMA_AREAS (0) - #endif #define CMA_MAX_NAME 64
The MAX_CMA_AREAS could be set to 0, which would result in code that would attempt to operate beyond the end of a zero-sized array. If CONFIG_CMA is disabled, just remove this code entirely. Found when building with -Warray-bounds: arch/arm/mm/dma-mapping.c:396:22: warning: array subscript <unknown> is outside array bounds of 'str uct dma_contig_early_reserve[0]' [-Warray-bounds] 396 | dma_mmu_remap[dma_mmu_remap_num].size = size; | ~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~ arch/arm/mm/dma-mapping.c:389:40: note: while referencing 'dma_mmu_remap' 389 | static struct dma_contig_early_reserve dma_mmu_remap[MAX_CMA_AREAS] __initdata; | ^~~~~~~~~~~~~ Cc: Russell King <linux@armlinux.org.uk> Cc: Logan Gunthorpe <logang@deltatee.com> Cc: Martin Oliveira <martin.oliveira@eideticom.com> Cc: David Hildenbrand <david@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Zi Yan <ziy@nvidia.com> Cc: Hari Bathini <hbathini@linux.ibm.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: linux-arm-kernel@lists.infradead.org Signed-off-by: Kees Cook <keescook@chromium.org> --- arch/arm/mm/dma-mapping.c | 2 ++ arch/arm/mm/mm.h | 4 ++++ include/linux/cma.h | 4 ---- 3 files changed, 6 insertions(+), 4 deletions(-)