From: Wang ShaoBo bobo.shaobowang@huawei.com

hulk inclusion category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I7R0WK

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BUG 'sleeping function called from invalid context' reported when setup MPAM driver, it was blamed to bc9e3f9895ef2 ("arm64/mpam: Fix mpam corrupt when cpu online"), which reported a 'Bad PC' BUG, but missing the right conclusion, finally disabling irqs before calling cpuhp_setup_state() may only affect the probability of reproduction.

The reason why triggerring 'Bad PC' BUG report is because mpam_enable() is __init type function, and may schedule out after calling __cpuhp_setup_state()->__might_sleep(), so the space of mpam_enable() might be freed after scheduling back.

As we have changed mpam_enable() to non-init type function, we can revert commit bc9e3f9895ef2 directly, to solve these both two problems.

Fixes: bc9e3f9895ef2 ("arm64/mpam: Fix mpam corrupt when cpu online") Signed-off-by: Wang ShaoBo bobo.shaobowang@huawei.com Signed-off-by: Yu Liao liaoyu15@huawei.com --- arch/arm64/kernel/mpam/mpam_device.c | 2 -- 1 file changed, 2 deletions(-)

diff --git a/arch/arm64/kernel/mpam/mpam_device.c b/arch/arm64/kernel/mpam/mpam_device.c index 96288f66f619..b3de7f518423 100644 --- a/arch/arm64/kernel/mpam/mpam_device.c +++ b/arch/arm64/kernel/mpam/mpam_device.c @@ -621,11 +621,9 @@ static void mpam_enable(struct work_struct *work) pr_err("Failed to setup/init resctrl\n"); mutex_unlock(&mpam_devices_lock);

- local_irq_disable(); mpam_cpuhp_state = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "mpam:online", mpam_cpu_online, mpam_cpu_offline); - local_irq_enable(); if (mpam_cpuhp_state <= 0) pr_err("Failed to re-register 'dyn' cpuhp callbacks"); mutex_unlock(&mpam_cpuhp_lock);