[PATCH v4] firmware: arm_sdei: Fix sleep from invalid context BUG

[Will Deacon]

On Thu, 16 Feb 2023 09:49:19 +0100, Pierre Gondois wrote:
> Running a preemp_rt kernel based on vv6.2-rc3-rt1 based kernel on an
> Ampere Altra triggers:
>   BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:46
>   in_atomic(): 0, irqs_disabled(): 128, non_block: 0, pid: 24, name: cpuhp/0
>   preempt_count: 0, expected: 0
>   RCU nest depth: 0, expected: 0
>   3 locks held by cpuhp/0/24:
>     #0: ffffda30217c70d0 (cpu_hotplug_lock){++++}-{0:0}, at: cpuhp_thread_fun+0x5c/0x248
>     #1: ffffda30217c7120 (cpuhp_state-up){+.+.}-{0:0}, at: cpuhp_thread_fun+0x5c/0x248
>     #2: ffffda3021c711f0 (sdei_list_lock){....}-{3:3}, at: sdei_cpuhp_up+0x3c/0x130
>   irq event stamp: 36
>   hardirqs last  enabled at (35): [<ffffda301e85b7bc>] finish_task_switch+0xb4/0x2b0
>   hardirqs last disabled at (36): [<ffffda301e812fec>] cpuhp_thread_fun+0x21c/0x248
>   softirqs last  enabled at (0): [<ffffda301e80b184>] copy_process+0x63c/0x1ac0
>   softirqs last disabled at (0): [<0000000000000000>] 0x0
>   CPU: 0 PID: 24 Comm: cpuhp/0 Not tainted 5.19.0-rc3-rt5-[...]
>   Hardware name: WIWYNN Mt.Jade Server [...]
>   Call trace:
>     dump_backtrace+0x114/0x120
>     show_stack+0x20/0x70
>     dump_stack_lvl+0x9c/0xd8
>     dump_stack+0x18/0x34
>     __might_resched+0x188/0x228
>     rt_spin_lock+0x70/0x120
>     sdei_cpuhp_up+0x3c/0x130
>     cpuhp_invoke_callback+0x250/0xf08
>     cpuhp_thread_fun+0x120/0x248
>     smpboot_thread_fn+0x280/0x320
>     kthread+0x130/0x140
>     ret_from_fork+0x10/0x20
> 
> [...]

Applied to arm64 (for-next/misc), thanks!

[1/1] firmware: arm_sdei: Fix sleep from invalid context BUG
      https://git.kernel.org/arm64/c/d2c48b2387eb

Cheers,
-- 
Will

https://fixes.arm64.dev
https://next.arm64.dev
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