When dma_common_free_remap, the input parameter 'size' may not be page aligned. And, met kernel warning when doing iommu dma for usb on i.MX8 platform: " WARNING: CPU: 0 PID: 869 at mm/vmalloc.c:70 vunmap_page_range+0x1cc/0x1d0() Modules linked in: CPU: 0 PID: 869 Comm: kworker/u8:2 Not tainted 4.1.12-00444-gc5f9d1d-dirty #147 Hardware name: Freescale i.MX8DV Sabreauto (DT) Workqueue: ci_otg ci_otg_work Call trace: [<ffffffc000089920>] dump_backtrace+0x0/0x124 [<ffffffc000089a54>] show_stack+0x10/0x1c [<ffffffc0006d1e6c>] dump_stack+0x84/0xc8 [<ffffffc0000b4568>] warn_slowpath_common+0x98/0xd0 [<ffffffc0000b4664>] warn_slowpath_null+0x14/0x20 [<ffffffc000170348>] vunmap_page_range+0x1c8/0x1d0 [<ffffffc000170388>] unmap_kernel_range+0x20/0x88 [<ffffffc000460ad0>] dma_common_free_remap+0x74/0x84 [<ffffffc0000940d8>] __iommu_free_attrs+0x9c/0x178 [<ffffffc0005032bc>] ehci_mem_cleanup+0x140/0x194 [<ffffffc000503548>] ehci_stop+0x8c/0xdc [<ffffffc0004e8258>] usb_remove_hcd+0xf0/0x1cc [<ffffffc000516bc0>] host_stop+0x1c/0x58 [<ffffffc000514240>] ci_otg_work+0xdc/0x120 [<ffffffc0000c9c34>] process_one_work+0x134/0x33c [<ffffffc0000c9f78>] worker_thread+0x13c/0x47c [<ffffffc0000cf43c>] kthread+0xd8/0xf0 " For dma_common_pages_remap: dma_common_pages_remap |->get_vm_area_caller |->__get_vm_area_node |->size = PAGE_ALIGN(size); Round up to page aligned So, in dma_common_free_remap, we also need a page aligned size, pass 'PAGE_ALIGN(size)' to unmap_kernel_range. Signed-off-by: Peng Fan <van.freenix@xxxxxxxxx> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> --- drivers/base/dma-mapping.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/base/dma-mapping.c b/drivers/base/dma-mapping.c index d799662..261420d 100644 --- a/drivers/base/dma-mapping.c +++ b/drivers/base/dma-mapping.c @@ -334,7 +334,7 @@ void dma_common_free_remap(void *cpu_addr, size_t size, unsigned long vm_flags) return; } - unmap_kernel_range((unsigned long)cpu_addr, size); + unmap_kernel_range((unsigned long)cpu_addr, PAGE_ALIGN(size)); vunmap(cpu_addr); } #endif -- 2.6.2 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html