Messages in this thread | | | Date | Fri, 9 Jan 2009 23:33:27 +0100 | From | Joerg Roedel <> | Subject | Re: [PATCH 0/16] DMA-API debugging facility v2 |
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On Fri, Jan 09, 2009 at 01:24:24PM -0800, Michael Chan wrote: > > On Fri, 2009-01-09 at 08:19 -0800, Joerg Roedel wrote: > > > > With the code these patches introduce driver developers can find several > > bugs of misusing the DMA-API in their drivers. But be aware, it can not > > find all possible bugs. If it finds a problem it prints out messages > > like > > > > ------------[ cut here ]------------ > > WARNING: at /data2/repos/linux.trees.git/lib/dma-debug.c:231 check_unmap+0xab/0x3d9() > > Hardware name: Toonie > > bnx2 0000:01:00.0: DMA-API: device driver tries to free DMA memory it has not allocated [device address=0x00000000011] > > Modules linked in: > > Pid: 0, comm: swapper Not tainted 2.6.28 #174 > > Call Trace: > > <IRQ> [<ffffffff8105af3a>] warn_slowpath+0xd3/0xf2 > > [<ffffffff8107c36f>] ? find_usage_backwards+0xe2/0x116 > > [<ffffffff8107c36f>] ? find_usage_backwards+0xe2/0x116 > > [<ffffffff812efd16>] ? usb_hcd_link_urb_to_ep+0x94/0xa0 > > [<ffffffff8107c52b>] ? mark_lock+0x1c/0x364 > > [<ffffffff8107d8f7>] ? __lock_acquire+0xaec/0xb55 > > [<ffffffff8107c52b>] ? mark_lock+0x1c/0x364 > > [<ffffffff811e2b4b>] ? get_hash_bucket+0x28/0x33 > > [<ffffffff814b25a5>] ? _spin_lock_irqsave+0x69/0x75 > > [<ffffffff811e2b4b>] ? get_hash_bucket+0x28/0x33 > > [<ffffffff811e2ff2>] check_unmap+0xab/0x3d9 > > [<ffffffff8107c9ed>] ? trace_hardirqs_on_caller+0x108/0x14a > > [<ffffffff8107ca3c>] ? trace_hardirqs_on+0xd/0xf > > [<ffffffff811e3433>] debug_unmap_single+0x3e/0x40 > > [<ffffffff8128d2d8>] dma_unmap_single+0x3d/0x60 > > [<ffffffff8128d335>] pci_unmap_page+0x1c/0x1e > > [<ffffffff81290759>] bnx2_poll_work+0x626/0x8cb > > [<ffffffff8107d8f7>] ? __lock_acquire+0xaec/0xb55 > > [<ffffffff81070100>] ? run_posix_cpu_timers+0x49c/0x603 > > [<ffffffff81070000>] ? run_posix_cpu_timers+0x39c/0x603 > > [<ffffffff8107c52b>] ? mark_lock+0x1c/0x364 > > [<ffffffff8107d8f7>] ? __lock_acquire+0xaec/0xb55 > > [<ffffffff81292804>] bnx2_poll_msix+0x33/0x81 > > [<ffffffff813b6478>] net_rx_action+0x8a/0x139 > > [<ffffffff8105ff39>] __do_softirq+0x8b/0x147 > > [<ffffffff8102933c>] call_softirq+0x1c/0x34 > > [<ffffffff8102a611>] do_softirq+0x39/0x90 > > [<ffffffff8105fde8>] irq_exit+0x4e/0x98 > > [<ffffffff8102a5c2>] do_IRQ+0x11f/0x135 > > [<ffffffff81028b93>] ret_from_intr+0x0/0xf > > <EOI> <4>---[ end trace 4339d58302097423 ]--- > > > This was triggered during pci_unmap_page() -> dma_unmap_single() where > check_unmap() did not find the entry. > > The original mapping was done in bnx2 using pci_map_page(). I did not > see how the debug entry was added to the hash during the call to > pci_map_page() -> dma_map_page(). Did I miss something?
dma_map_page() results in dma_map_single() -> debug_map_single() call on x86. This way the entry would be added. Maybe the error from a double free?
Joerg
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