Re: [PATCH] x86/microcode: Fix the microcode load on CPU hotplug for real

From: Borislav Petkov
Date: Tue Jun 18 2019 - 16:39:29 EST

On Tue, Jun 18, 2019 at 10:31:40PM +0200, Thomas Gleixner wrote:
> A recent change moved the microcode loader hotplug callback into the early
> startup phase, which is running with interrupts disabled. It missed that
> the callbacks invoke sysfs functions which might sleep causing nice 'might
> sleep' splats with proper debugging enabled.
> Split the callbacks and only load the microcode in the early startup phase
> and move the sysfs handling back into the later threaded and preemptible
> bringup phase where it was before.
> Fixes: 78f4e932f776 ("x86/microcode, cpuhotplug: Add a microcode loader CPU hotplug callback")
> Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Cc: stable@xxxxxxxxxxxxxxx
> ---
> arch/x86/kernel/cpu/microcode/core.c | 15 ++++++++++-----
> 1 file changed, 10 insertions(+), 5 deletions(-)

Acked-by: Borislav Petkov <bp@xxxxxxx>

Thanks for fixing that!


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