4af0e5bb95
In spite of switching to paged allocation of Rx buffers, the driver still called dma_unmap_single() in the Rx queues tear-down path. The DMA region unmapping code in free_skb_rx_queue() basically predates the introduction of paged allocation to the driver. While being refactored, it apparently hasn't reflected the change in the DMA API usage by its counterpart gfar_new_page(). As a result, setting an interface to the DOWN state now yields the following: # ip link set eth2 down fsl-gianfar ffe24000.ethernet: DMA-API: device driver frees DMA memory with wrong function [device address=0x000000001ecd0000] [size=40] ------------[ cut here ]------------ WARNING: CPU: 1 PID: 189 at lib/dma-debug.c:1123 check_unmap+0x8e0/0xa28 CPU: 1 PID: 189 Comm: ip Tainted: G O 4.9.5 #1 task: dee73400 task.stack: dede2000 NIP: c02101e8 LR: c02101e8 CTR: c0260d74 REGS: dede3bb0 TRAP: 0700 Tainted: G O (4.9.5) MSR: 00021000 <CE,ME> CR: 28002222 XER: 00000000 GPR00: c02101e8 dede3c60 dee73400 000000b6 dfbd033c dfbd36c4 1f622000 dede2000 GPR08: 00000007 c05b1634 1f622000 00000000 22002484 100a9904 00000000 00000000 GPR16: 00000000 db4c849c 00000002 db4c8480 00000001 df142240 db4c84bc 00000000 GPR24: c0706148 c0700000 00029000 c07552e8 c07323b4 dede3cb8 c07605e0 db535540 NIP [c02101e8] check_unmap+0x8e0/0xa28 LR [c02101e8] check_unmap+0x8e0/0xa28 Call Trace: [dede3c60] [c02101e8] check_unmap+0x8e0/0xa28 (unreliable) [dede3cb0] [c02103b8] debug_dma_unmap_page+0x88/0x9c [dede3d30] [c02dffbc] free_skb_resources+0x2c4/0x404 [dede3d80] [c02e39b4] gfar_close+0x24/0xc8 [dede3da0] [c0361550] __dev_close_many+0xa0/0xf8 [dede3dd0] [c03616f0] __dev_close+0x2c/0x4c [dede3df0] [c036b1b8] __dev_change_flags+0xa0/0x174 [dede3e10] [c036b2ac] dev_change_flags+0x20/0x60 [dede3e30] [c03e130c] devinet_ioctl+0x540/0x824 [dede3e90] [c0347dcc] sock_ioctl+0x134/0x298 [dede3eb0] [c0111814] do_vfs_ioctl+0xac/0x854 [dede3f20] [c0111ffc] SyS_ioctl+0x40/0x74 [dede3f40] [c000f290] ret_from_syscall+0x0/0x3c --- interrupt: c01 at 0xff45da0 LR = 0xff45cd0 Instruction dump: 811d001c 7c66482e 813d0020 9061000c 807f000c 5463103a 7cc6182e 3c60c052 386309ac 90c10008 4cc63182 4826b845 <0fe00000> 4bfffa60 3c80c052 388402c4 ---[ end trace 695ae6d7ac1d0c47 ]--- Mapped at: [<c02e22a8>] gfar_alloc_rx_buffs+0x178/0x248 [<c02e3ef0>] startup_gfar+0x368/0x570 [<c036aeb4>] __dev_open+0xdc/0x150 [<c036b1b8>] __dev_change_flags+0xa0/0x174 [<c036b2ac>] dev_change_flags+0x20/0x60 Even though the issue was discovered in 4.9 kernel, the code in question is identical in the current net and net-next trees. Fixes: 75354148ce69 ("gianfar: Add paged allocation and Rx S/G") Signed-off-by: Arseny Solokha <asolokha@kb.kras.ru> Acked-by: Claudiu Manoil <claudiu.manoil@nxp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.