From 256ff1cf6b44cba9c9c2059f4516259e9319a808 Mon Sep 17 00:00:00 2001 From: Marek Szyprowski Date: Tue, 15 Nov 2016 14:00:53 +0100 Subject: [PATCH] ARM: 8628/1: dma-mapping: preallocate DMA-debug hash tables in core_initcall fs_initcall is definitely too late to initialize DMA-debug hash tables, because some drivers might get probed and use DMA mapping framework already in core_initcall. Late initialization of DMA-debug results in false warning about accessing memory, that was not allocated, like this one: ------------[ cut here ]------------ WARNING: CPU: 5 PID: 1 at lib/dma-debug.c:1104 check_unmap+0xa1c/0xe50 exynos-sysmmu 10a60000.sysmmu: DMA-API: device driver tries to free DMA memory it has not allocated [device address=0x000000006ebd0000] [size=16384 bytes] Modules linked in: CPU: 5 PID: 1 Comm: swapper/0 Not tainted 4.9.0-rc5-00028-g39dde3d-dirty #44 Hardware name: SAMSUNG EXYNOS (Flattened Device Tree) [] (unwind_backtrace) from [] (show_stack+0x20/0x24) [] (show_stack) from [] (dump_stack+0x84/0xa0) [] (dump_stack) from [] (__warn+0x14c/0x180) [] (__warn) from [] (warn_slowpath_fmt+0x48/0x50) [] (warn_slowpath_fmt) from [] (check_unmap+0xa1c/0xe50) [] (check_unmap) from [] (debug_dma_unmap_page+0x98/0xc8) [] (debug_dma_unmap_page) from [] (exynos_iommu_domain_free+0x158/0x380) [] (exynos_iommu_domain_free) from [] (iommu_domain_free+0x34/0x60) [] (iommu_domain_free) from [] (release_iommu_mapping+0x30/0xb8) [] (release_iommu_mapping) from [] (arm_iommu_release_mapping+0x4c/0x50) [] (arm_iommu_release_mapping) from [] (s5p_mfc_probe+0x640/0x80c) [] (s5p_mfc_probe) from [] (platform_drv_probe+0x70/0x148) [] (platform_drv_probe) from [] (driver_probe_device+0x12c/0x6b0) [] (driver_probe_device) from [] (__driver_attach+0x128/0x17c) [] (__driver_attach) from [] (bus_for_each_dev+0x88/0xc8) [] (bus_for_each_dev) from [] (driver_attach+0x34/0x58) [] (driver_attach) from [] (bus_add_driver+0x18c/0x32c) [] (bus_add_driver) from [] (driver_register+0x98/0x148) [] (driver_register) from [] (__platform_driver_register+0x58/0x74) [] (__platform_driver_register) from [] (s5p_mfc_driver_init+0x1c/0x20) [] (s5p_mfc_driver_init) from [] (do_one_initcall+0x64/0x258) [] (do_one_initcall) from [] (kernel_init_freeable+0x3d0/0x4d0) [] (kernel_init_freeable) from [] (kernel_init+0x18/0x134) [] (kernel_init) from [] (ret_from_fork+0x14/0x3c) ---[ end trace dc54c54bd3581296 ]--- This patch moves initialization of DMA-debug to core_initcall. This is safe from the initialization perspective. dma_debug_do_init() internally calls debugfs functions and debugfs also gets initialised at core_initcall(), and that is earlier than arch code in the link order, so it will get initialized just before the DMA-debug. Reported-by: Seung-Woo Kim Signed-off-by: Marek Szyprowski Signed-off-by: Russell King --- arch/arm/mm/dma-mapping.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c index ab4f74536057..ab7710002ba6 100644 --- a/arch/arm/mm/dma-mapping.c +++ b/arch/arm/mm/dma-mapping.c @@ -1167,7 +1167,7 @@ static int __init dma_debug_do_init(void) dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES); return 0; } -fs_initcall(dma_debug_do_init); +core_initcall(dma_debug_do_init); #ifdef CONFIG_ARM_DMA_USE_IOMMU