| Message ID | 526555051e63e72a4b1e68461e51a7b6e33df352.1456859025.git.robin.murphy@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, Mar 1, 2016 at 8:07 PM, Robin Murphy <robin.murphy@arm.com> 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: > > 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 > ... > [<c02c6928>] (cache_alloc_refill) from [<c02c6630>] (kmem_cache_alloc+0x7c/0xd4) > [<c02c6630>] (kmem_cache_alloc) from [<c04444bc>] > (__arm_v7s_alloc_table+0x5c/0x278) > [<c04444bc>] (__arm_v7s_alloc_table) from [<c0444e1c>] > (__arm_v7s_map.constprop.6+0x68/0x25c) > [<c0444e1c>] (__arm_v7s_map.constprop.6) from [<c0445044>] > (arm_v7s_map+0x34/0xa4) > [<c0445044>] (arm_v7s_map) from [<c0c18ee4>] (arm_v7s_do_selftests+0x140/0x418) > [<c0c18ee4>] (arm_v7s_do_selftests) from [<c0201760>] > (do_one_initcall+0x100/0x1b4) > [<c0201760>] (do_one_initcall) from [<c0c00d4c>] > (kernel_init_freeable+0x120/0x1e8) > [<c0c00d4c>] (kernel_init_freeable) from [<c067a364>] (kernel_init+0x8/0xec) > [<c067a364>] (kernel_init) from [<c0206b68>] (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. Thanks, this makes the test succeed: arm-v7s io-pgtable: self test ok > Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> > Acked-by: Will Deacon <will.deacon@arm.com> > Signed-off-by: Robin Murphy <robin.murphy@arm.com> Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds
On Tue, Mar 01, 2016 at 07:07:03PM +0000, Robin Murphy wrote: > v2: Add the backtrace to the commit log, add Will's ack. > > drivers/iommu/io-pgtable-arm-v7s.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) Applied, thanks.
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))