On Tue, Jun 30, 2015 at 3:34 AM, Joerg Roedel <j...@8bytes.org> wrote: > On Tue, Jun 30, 2015 at 01:44:34AM +0800, George Wang wrote: >> diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c >> index d3e5e9a..4f6da17 100644 >> --- a/drivers/iommu/amd_iommu.c >> +++ b/drivers/iommu/amd_iommu.c >> @@ -1882,6 +1882,7 @@ static struct dma_ops_domain >> *dma_ops_domain_alloc(void) >> return NULL; >> >> spin_lock_init(&dma_dom->domain.lock); >> + mutex_init(&dma_dom->domain.api_lock); >> >> When I initialize the api_lock, then I can go forward with another problem. > > How do you trigger this? The DMA-API domains are not used via the > IOMMU-API yet, so the initializing the api-lock for it shouldn't matter. > > > Joerg >
I don't know what triger it, I just build the kernel, install, and panic. The call call trace is like below: [ 11.687392] BUG: unable to handle kernel NULL pointer dereference at (null) [ 11.690196] IP: [<ffffffff813326ef>] __list_add+0x1f/0xc0 [ 11.692026] PGD 0 [ 11.692794] Oops: 0000 [#1] SMP [ 11.693939] Modules linked in: [ 11.694997] CPU: 11 PID: 1 Comm: swapper/0 Not tainted 4.1.0-next-20150626+ #6 [ 11.697415] Hardware name: HP ProLiant DL385p Gen8, BIOS A28 02/06/2014 [ 11.699683] task: ffff880835888000 ti: ffff880236918000 task.ti: ffff880236918000 [ 11.702281] RIP: 0010:[<ffffffff813326ef>] [<ffffffff813326ef>] __list_add+0x1f/0xc0 [ 11.704935] RSP: 0018:ffff88023691b968 EFLAGS: 00010246 [ 11.706702] RAX: 00000000ffffffff RBX: ffff88023691b998 RCX: ffff880835888000 [ 11.709199] RDX: ffff880634f58468 RSI: 0000000000000000 RDI: ffff88023691b998 [ 11.711597] RBP: ffff88023691b988 R08: 0000000000000000 R09: ffff88023691bab8 [ 11.714022] R10: 00000000000f0000 R11: ffff880000000000 R12: ffff880634f58468 [ 11.716415] R13: 0000000000000000 R14: 00000000ffffffff R15: ffff880634f58468 [ 11.718909] FS: 0000000000000000(0000) GS:ffff880637d40000(0000) knlGS:0000000000000000 [ 11.721575] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [ 11.723541] CR2: 0000000000000000 CR3: 00000000019d4000 CR4: 00000000000406e0 [ 11.725960] Stack: [ 11.726632] 0000000000001000 ffff880634f58460 ffff880634f58464 ffff880835888000 [ 11.729440] ffff88023691b9e8 ffffffff8168fde1 ffff88023691b9f8 ffffffff81318798 [ 11.732131] 000000000000a1ff 000000008d3d0bb4 00002fdd3691b9e8 ffff880634f58460 [ 11.734774] Call Trace: [ 11.735635] [<ffffffff8168fde1>] __mutex_lock_slowpath+0x91/0x120 [ 11.737676] [<ffffffff81318798>] ? ida_simple_get+0x98/0x100 [ 11.739682] [<ffffffff8168fe93>] mutex_lock+0x23/0x37 [ 11.741407] [<ffffffff8143513a>] amd_iommu_map+0x4a/0x1b0 [ 11.743293] [<ffffffff8143081a>] iommu_map+0xfa/0x200 [ 11.745025] [<ffffffff81431587>] iommu_group_add_device+0x327/0x390 [ 11.747184] [<ffffffff814316fb>] iommu_group_get_forv+0x10b/0x1f0 [ 11.849564] [<ffffffff81436ac6>] amd_iommu_add_device+0x1b6/0x580 [ 11.851645] [<ffffffff8168d891>] ? __schedule+0xe1/0x890 [ 11.85350883] [<ffffffff814304db>] add_iommu_group+0x2b/0x50 [ 11.857765] [<ffffffff8144b40c>] bus_for_each_dev+0x6c/0xc0 [ 11.859752] [<ffffffff814311b4>] ? bus_set_iommu+0x54/0x100 [ 11.861698] [<ffffffff8143121e>] bus_set_iommu+0xbe/0x100 [ 11.863485] [<ffffffff81b77e46>] amd_iommu_init_api+0x17/0x19 [ 11.865473] [<ffffffff81b7993c>] state_next+0x57e/0x715 [ 11.867212] [<ffffffff81b37eec>] ? memblock_find_dma_reserve+0x177/0x177 [ 11.869577] [<ffffffff81b79aed>] iommu_go_to_state+0x1a/0x2d [ 11.871577] [<ffffffff81b79b72>] amd_iommu_init+0x15/0xfc [ 11.873425] [<ffffffff81b37eff>] pci_iommu_init+0x13/0x3e [ 11.875259] [<ffffffff8100213d>] do_one_initcall+0xcd/0x1f0 [ 11.877162] [<ffffffff81098d00>] ? parse_args+0x220/0x470 [ 11.879122] [<ffffffff810bd548>] ? __wake_up+0x48/0x60 [ 11.880872] [<ffffffff81b2e349>] kernel_inia5/0x249 [ 12.282919] [<ffffffff81b2d9dd>] ? initcall_blacklist+0xb6/0xb6 [ 12.285018] [<ffffffff8167b9a0>] ? rest_init+0x80/0x80 [ 12.286803] [<ffffffff8167b9ae>] kernel_init+0xe/0xe0 [ 12.288621] [<ffffffff81691f5f>] ret_from_fork+0x3f/0x70 [ 12.290761] [<ffffffff8167b9a0>] ? rest_init+0x80/0x80 [ 12.292516] Code: ff ff ff e9 31 ff ff ff 0f 1f 40 00 55 48 89 e5 41 55 49 89 f5 41 54 49 89 d4 53 48 89 fb 48 83 ec 08 4c 8b 42 08 49 39 f0 75 2e <4d> 8b 45 00 4d 39 c4 75 6c 4c 39 e3 74 42 4c 39 eb 74 3d 49 89 [ 12.301447] RIP [<ffffffff813326ef>] __list_add+0x1f/0xc0 [ 12.303331] RSP <ffff88023691b968> [ 12.304516] CR2: 0000000000000000 [ 12.305657] ---[ end trace 20a8e3deaab91b75 ]--- I think the the add_iommu_group->amd_iommu_add_device->init_iommu_group->iommu_group_get_for_dev->iommu_group_add_device->iommu_group_create_direct_mappings->iommu_map->amd_iommu_map->mutex_lock(&domain->api_lock) but the is initialized amd_iommu_domain_alloc->dma_ops_domain_alloc, which has not initialized the api_lock of protect_domain, so got the panic. Thanks, Xu _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
