From 048b31ca97eaa33a74237ed7ef542503da9c0505 Mon Sep 17 00:00:00 2001 From: Robin Murphy Date: Tue, 1 Mar 2016 19:07:03 +0000 Subject: [PATCH] iommu/io-pgtable-armv7s: Fix kmem_cache_alloc() flags 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: kernel BUG at mm/slab.c:2536! Internal error: Oops - BUG: 0 [#1] SMP ARM Modules linked in:[ 1.299311] Modules linked in: CPU: 1 PID: 1 Comm: swapper/0 Not tainted 4.5.0-rc6-koelsch-05892-ge7e45ad53ab6795e #2270 Hardware name: Generic R8A7791 (Flattened Device Tree) task: ef422040 ti: ef442000 task.ti: ef442000 PC is at cache_alloc_refill+0x2a0/0x530 LR is at _raw_spin_unlock+0x8/0xc ... [] (cache_alloc_refill) from [] (kmem_cache_alloc+0x7c/0xd4) [] (kmem_cache_alloc) from [] (__arm_v7s_alloc_table+0x5c/0x278) [] (__arm_v7s_alloc_table) from [] (__arm_v7s_map.constprop.6+0x68/0x25c) [] (__arm_v7s_map.constprop.6) from [] (arm_v7s_map+0x34/0xa4) [] (arm_v7s_map) from [] (arm_v7s_do_selftests+0x140/0x418) [] (arm_v7s_do_selftests) from [] (do_one_initcall+0x100/0x1b4) [] (do_one_initcall) from [] (kernel_init_freeable+0x120/0x1e8) [] (kernel_init_freeable) from [] (kernel_init+0x8/0xec) [] (kernel_init) from [] (ret_from_fork+0x14/0x2c) Code: 1a000003 e7f001f2 e3130001 0a000000 (e7f001f2) ---[ end trace 190f6f6b84352efd ]--- Keep the peace by adding GFP_DMA when allocating a table. Reported-by: Geert Uytterhoeven Acked-by: Will Deacon Signed-off-by: Robin Murphy Tested-by: Geert Uytterhoeven Signed-off-by: Joerg Roedel --- 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 9fcceb135f51..9488e3c97bcb 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))