staging: unisys: visorbus: fix kernel BUG discovered by day0 testing
Kernel day0 testing robot reported a kernel BUG at drivers/base/driver.c!
with the following call stack:
[ 14.963563] ------------[ cut here ]------------
[ 14.967298] kernel BUG at drivers/base/driver.c:153!
[ 14.970948] invalid opcode: 0000 [#1] SMP
[ 14.974013] CPU: 0 PID: 1 Comm: swapper/0 Not tainted
4.11.0-rc4-00790-g0789e2c #1
[ 14.978221] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.9.3-20161025_171302-gandalf 04/01/2014
[ 14.983417] task:
ffff88001ea46040 task.stack:
ffffc90000008000
[ 14.987315] RIP: 0010:driver_register+0xa1/0xd0
[ 14.990044] RSP: 0000:
ffffc9000000be60 EFLAGS:
00010246
[ 14.993039] RAX:
0000000000000000 RBX:
ffffffff831d4c20 RCX:
0000000000000000
[ 14.997040] RDX:
000000000000004d RSI:
ffffffff831d47c0 RDI:
ffffffff831d4c20
[ 15.001511] RBP:
ffffc9000000be78 R08:
ffffc9000000be78 R09:
ffffc9000000be7c
[ 15.006163] R10:
0000000000000000 R11:
0000000000000001 R12:
0000000000000000
[ 15.010068] R13:
00000000ffffffff R14:
ffffffff832f3923 R15:
0000000000000000
[ 15.013715] FS:
0000000000000000(0000) GS:
ffff88001fa00000(0000) knlGS:
0000000000000000
[ 15.017460] CS: 0010 DS: 0000 ES: 0000 CR0:
0000000080050033
[ 15.021268] CR2:
0000000000000000 CR3:
0000000003009000 CR4:
00000000000006b0
[ 15.025633] Call Trace:
[ 15.028069] ? visorbus_register_visor_driver+0x3f/0x60
[ 15.031065] ? init_unisys+0x3a/0x90
[ 15.033562] ? device_resume_response+0x50/0x50
[ 15.036083] visorinput_init+0x10/0x20
[ 15.038937] do_one_initcall+0x9a/0x164
[ 15.041838] ? set_debug_rodata+0x12/0x12
[ 15.045333] kernel_init_freeable+0x11e/0x1a1
[ 15.048369] ? rest_init+0x80/0x80
[ 15.050813] kernel_init+0x9/0x100
[ 15.053353] ret_from_fork+0x2c/0x40
[ 15.056009] Code: ff 85 c0 41 89 c4 75 13 48 8b 7b 70 31 f6 e8 97 16 be ff 44 89 e0 5b 41 5c 5d c3 48 89 df e8 57 e1 ff ff 44 89 e0 5b 41 5c 5d c3 <0f> 0b 48 8b 33 48 c7 c7 a0 dd d5 82 e8 ec f0 6f ff 48 8b 73 08
[ 15.065144] RIP: driver_register+0xa1/0xd0 RSP:
ffffc9000000be60
[ 15.068360] ---[ end trace
7d13369c38d80a8f ]---
This bug will occur if the visorbus driver is built-in to the kernel, and
the resulting kernel is run in an environment where visorbus devices are
NOT supported, and an attempt is made to load any of the drivers: visorhba,
visornic, or visorinput.
Checked to see if we have called bus_register, if not do not call
driver_register.
Signed-off-by: David Kershner <david.kershner@unisys.com>
Fixes: 5b6f9b95f7ae ("staging: unisys: visorbus: get rid of create_bus_type.")
Reviewed-by: Tim Sell <timothy.sell@unisys.com>
Reviewed-by: David Binder <david.binder@unisys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>