Hello Christoph,
5.3-rc1 crashes for me when run in qemu with scsi disks.
Quick investigation shows that the following triggers a BUG_ON:
diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index e11b115dd0e4..4465e352b8dd 100644
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -689,6 +689,7 @@ static inline int dma_coerce_mask_and_coherent(struct
device *dev, u64 mask)
*/
static inline bool dma_addressing_limited(struct device *dev)
{
+ BUG_ON(!(dev->dma_mask));
return min_not_zero(*dev->dma_mask, dev->bus_dma_mask) <
dma_get_required_mask(dev);
Otherwise here is what the real backtrace looks like:
[ 5.387839] scsi host0: Virtio SCSI HBA
[ 5.389860] BUG: kernel NULL pointer dereference, address: 0000000000000000
[ 5.390217] #PF: supervisor read access in kernel mode
[ 5.390520] #PF: error_code(0x0000) - not-present page
[ 5.390813] PGD 0 P4D 0
[ 5.391007] Oops: 0000 [#1] SMP
[ 5.391007] CPU: 3 PID: 1 Comm: swapper/0 Not tainted 5.3.0-rc1-default #578
[ 5.391007] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
1.10.2-1ubuntu1 04/01/2014
[ 5.391007] RIP: 0010:dma_direct_max_mapping_size+0x21/0x80
[ 5.391007] Code: 0f b6 c0 c3 0f 1f 44 00 00 0f 1f 44 00 00 55 53 48 89 fb
e8 f1 0e 00 00 84 c0 74 42 48 8b 83 e8 01 00 00 48 8b ab f8 01 00 00 <48> 8b 00
48 85 c0 74 0c 48 85 ed 74 31 48 39 c5 48 0f 47 e8 48 89
[ 5.391007] RSP: 0000:ffffb0edc0013ac0 EFLAGS: 00010202
[ 5.391007] RAX: 0000000000000000 RBX: ffff9216f9d8b838 RCX: 0000000000000000
[ 5.391007] RDX: 0000000000000000 RSI: 000000000000007e RDI: ffff9216f9d8b838
[ 5.391007] RBP: 0000000000000000 R08: 0000000249ffd97b R09: 0000000000000001
[ 5.391007] R10: 0000000000000000 R11: 0000000000000000 R12: ffff9216f9d8b838
[ 5.391007] R13: 000000000000ffff R14: ffff9216f7348580 R15: 0000000000000000
[ 5.391007] FS: 0000000000000000(0000) GS:ffff9216fba00000(0000)
knlGS:0000000000000000
[ 5.391007] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 5.391007] CR2: 0000000000000000 CR3: 000000007a211000 CR4: 00000000000006e0
[ 5.391007] Call Trace:
[ 5.391007] __scsi_init_queue+0x75/0x130
[ 5.391007] scsi_mq_alloc_queue+0x34/0x50
[ 5.391007] scsi_alloc_sdev+0x232/0x300
[ 5.391007] scsi_probe_and_add_lun+0x482/0xda0
[ 5.391007] ? scsi_alloc_target+0x282/0x340
[ 5.391007] __scsi_scan_target+0xe6/0x610
[ 5.391007] ? sched_clock_local+0x12/0x80
[ 5.391007] ? sched_clock_cpu+0x94/0xc0
[ 5.391007] scsi_scan_channel.part.15+0x55/0x70
[ 5.391007] scsi_scan_host_selected+0xd7/0x180
[ 5.391007] virtscsi_probe+0x6f6/0x710
[ 5.391007] ? msi_get_domain_info+0x10/0x10
[ 5.391007] virtio_dev_probe+0x147/0x1d0
[ 5.391007] really_probe+0xd6/0x3b0
[ 5.391007] ? set_debug_rodata+0x11/0x11
[ 5.391007] device_driver_attach+0x4f/0x60
[ 5.391007] __driver_attach+0x99/0x130
[ 5.391007] ? device_driver_attach+0x60/0x60
[ 5.391007] bus_for_each_dev+0x76/0xc0
[ 5.391007] bus_add_driver+0x144/0x220
[ 5.391007] ? sym2_init+0xf6/0xf6
[ 5.391007] driver_register+0x5b/0xe0
[ 5.391007] ? sym2_init+0xf6/0xf6
[ 5.391007] init+0x86/0xcc
[ 5.391007] do_one_initcall+0x5a/0x2d4
[ 5.391007] ? set_debug_rodata+0x11/0x11
[ 5.391007] ? rcu_read_lock_sched_held+0x74/0x80
[ 5.391007] kernel_init_freeable+0x139/0x1c9
[ 5.391007] ? rest_init+0x260/0x260
[ 5.391007] kernel_init+0xa/0x100
[ 5.391007] ret_from_fork+0x24/0x30
[ 5.391007] Modules linked in:
[ 5.391007] CR2: 0000000000000000
[ 5.391007] ---[ end trace 03e50b8909d2f2e5 ]---
[ 5.391007] RIP: 0010:dma_direct_max_mapping_size+0x21/0x80
[ 5.391007] Code: 0f b6 c0 c3 0f 1f 44 00 00 0f 1f 44 00 00 55 53 48 89 fb
e8 f1 0e 00 00 84 c0 74 42 48 8b 83 e8 01 00 00 48 8b ab f8 01 00 00 <48> 8b 00
48 85 c0 74 0c 48 85 ed 74 31 48 39 c5 48 0f 47 e8 48 89
[ 5.391007] RSP: 0000:ffffb0edc0013ac0 EFLAGS: 00010202
[ 5.391007] RAX: 0000000000000000 RBX: ffff9216f9d8b838 RCX: 0000000000000000
[ 5.391007] RDX: 0000000000000000 RSI: 000000000000007e RDI: ffff9216f9d8b838
[ 5.391007] RBP: 0000000000000000 R08: 0000000249ffd97b R09: 0000000000000001
[ 5.391007] R10: 0000000000000000 R11: 0000000000000000 R12: ffff9216f9d8b838
[ 5.391007] R13: 000000000000ffff R14: ffff9216f7348580 R15: 0000000000000000
[ 5.391007] FS: 0000000000000000(0000) GS:ffff9216fba00000(0000)
knlGS:0000000000000000
[ 5.391007] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 5.391007] CR2: 0000000000000000 CR3: 000000007a211000 CR4: 00000000000006e0
[ 5.391007] BUG: sleeping function called from invalid context at
./include/linux/percpu-rwsem.h:38
[ 5.391007] in_atomic(): 0, irqs_disabled(): 1, pid: 1, name: swapper/0
[ 5.391007] INFO: lockdep is turned off.
[ 5.391007] irq event stamp: 13427044
[ 5.391007] hardirqs last enabled at (13427043): [<ffffffff92215b9b>]
__slab_alloc+0x4b/0x80
[ 5.391007] hardirqs last disabled at (13427044): [<ffffffff92001a4a>]
trace_hardirqs_off_thunk+0x1a/0x20
[ 5.391007] softirqs last enabled at (13425414): [<ffffffff92c0032c>]
__do_softirq+0x32c/0x430
[ 5.391007] softirqs last disabled at (13425375): [<ffffffff9206fc03>]
irq_exit+0xb3/0xc0
[ 5.391007] CPU: 3 PID: 1 Comm: swapper/0 Tainted: G D
5.3.0-rc1-default #578
[ 5.391007] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
1.10.2-1ubuntu1 04/01/2014
[ 5.391007] Call Trace:
[ 5.391007] dump_stack+0x67/0x9b
[ 5.391007] ___might_sleep+0x152/0x240
[ 5.391007] exit_signals+0x30/0x320
[ 5.391007] do_exit+0xb8/0xca0
[ 5.391007] rewind_stack_do_exit+0x17/0x20
[ 5.419466] Kernel panic - not syncing: Attempted to kill init!
exitcode=0x00000009
[ 5.420114] Kernel Offset: 0x11000000 from 0xffffffff81000000 (relocation
range: 0xffffffff80000000-0xffffffffbfffffff)
[ 5.420667] ---[ end Kernel panic - not syncing: Attempted to kill init!
exitcode=0x00000009 ]---
