| Message ID | cbd13a3db3924a67f8aa8a352f04c883c47d8815.1456856051.git.robin.murphy@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, Mar 01, 2016 at 06:17:38PM +0000, Robin Murphy wrote: > Whilst the default SLUB allocator happily just merges the original > allocation flags from kmem_cache_create() with those passed through > kmem_cache_alloc(), there is a code path in the SLAB allocator which > will aggressively BUG_ON() if the cache was created with SLAB_CACHE_DMA > but GFP_DMA is not specified for an allocation. It would be nice to include the backtrace here. > Keep the peace by adding GFP_DMA when allocating a table. > > Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> > Signed-off-by: Robin Murphy <robin.murphy@arm.com> > --- > drivers/iommu/io-pgtable-arm-v7s.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/iommu/io-pgtable-arm-v7s.c b/drivers/iommu/io-pgtable-arm-v7s.c > index 9fcceb1..9488e3c 100644 > --- a/drivers/iommu/io-pgtable-arm-v7s.c > +++ b/drivers/iommu/io-pgtable-arm-v7s.c > @@ -192,7 +192,7 @@ static void *__arm_v7s_alloc_table(int lvl, gfp_t gfp, > if (lvl == 1) > table = (void *)__get_dma_pages(__GFP_ZERO, get_order(size)); > else if (lvl == 2) > - table = kmem_cache_zalloc(data->l2_tables, gfp); > + table = kmem_cache_zalloc(data->l2_tables, gfp | GFP_DMA); > if (table && !selftest_running) { > dma = dma_map_single(dev, table, size, DMA_TO_DEVICE); > if (dma_mapping_error(dev, dma)) Acked-by: Will Deacon <will.deacon@arm.com> Will
diff --git a/drivers/iommu/io-pgtable-arm-v7s.c b/drivers/iommu/io-pgtable-arm-v7s.c index 9fcceb1..9488e3c 100644 --- a/drivers/iommu/io-pgtable-arm-v7s.c +++ b/drivers/iommu/io-pgtable-arm-v7s.c @@ -192,7 +192,7 @@ static void *__arm_v7s_alloc_table(int lvl, gfp_t gfp, if (lvl == 1) table = (void *)__get_dma_pages(__GFP_ZERO, get_order(size)); else if (lvl == 2) - table = kmem_cache_zalloc(data->l2_tables, gfp); + table = kmem_cache_zalloc(data->l2_tables, gfp | GFP_DMA); if (table && !selftest_running) { dma = dma_map_single(dev, table, size, DMA_TO_DEVICE); if (dma_mapping_error(dev, dma))
Whilst the default SLUB allocator happily just merges the original allocation flags from kmem_cache_create() with those passed through kmem_cache_alloc(), there is a code path in the SLAB allocator which will aggressively BUG_ON() if the cache was created with SLAB_CACHE_DMA but GFP_DMA is not specified for an allocation. Keep the peace by adding GFP_DMA when allocating a table. Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Robin Murphy <robin.murphy@arm.com> --- drivers/iommu/io-pgtable-arm-v7s.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)