Nicholas Piggin c0beffc4f4 powerpc/powernv: Fix opal_event_shutdown() called with interrupts disabled
A kernel crash in process context that calls emergency_restart from
panic will end up calling opal_event_shutdown with interrupts disabled
but not in interrupt. This causes a sleeping function to be called
which gives the following warning with sysrq+c:

    Rebooting in 10 seconds..
    BUG: sleeping function called from invalid context at kernel/locking/mutex.c:238
    in_atomic(): 0, irqs_disabled(): 1, pid: 7669, name: bash
    CPU: 20 PID: 7669 Comm: bash Tainted: G      D W         4.17.0-rc5+ #3
    Call Trace:
    dump_stack+0xb0/0xf4 (unreliable)
    ___might_sleep+0x174/0x1a0
    mutex_lock+0x38/0xb0
    __free_irq+0x68/0x460
    free_irq+0x70/0xc0
    opal_event_shutdown+0xb4/0xf0
    opal_shutdown+0x24/0xa0
    pnv_shutdown+0x28/0x40
    machine_shutdown+0x44/0x60
    machine_restart+0x28/0x80
    emergency_restart+0x30/0x50
    panic+0x2a0/0x328
    oops_end+0x1ec/0x1f0
    bad_page_fault+0xe8/0x154
    handle_page_fault+0x34/0x38
    --- interrupt: 300 at sysrq_handle_crash+0x44/0x60
    LR = __handle_sysrq+0xfc/0x260
    flag_spec.62335+0x12b844/0x1e8db4 (unreliable)
    __handle_sysrq+0xfc/0x260
    write_sysrq_trigger+0xa8/0xb0
    proc_reg_write+0xac/0x110
    __vfs_write+0x6c/0x240
    vfs_write+0xd0/0x240
    ksys_write+0x6c/0x110

Fixes: 9f0fd0499d30 ("powerpc/powernv: Add a virtual irqchip for opal events")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-18 00:21:05 +10:00
..
2018-04-11 10:28:38 -07:00
2018-04-27 16:13:31 -07:00
2018-04-27 16:13:31 -07:00
2018-04-10 09:58:58 -04:00
2018-04-06 18:31:06 -07:00
2018-04-20 08:25:31 -07:00
2018-04-11 10:28:39 -07:00
2018-04-11 16:02:18 -07:00
2018-04-15 12:27:58 -07:00
2018-04-15 17:21:30 -07:00
2018-04-11 10:28:38 -07:00