Subject: Re: [PATCH] powerpc: Fix CONFIG_TRACE_IRQFLAGS with CONFIG_VMAP_STACK

From: Michael Ellerman <[email-masked]>
Date: Sat, 8 Feb 2020 23:50:05 +1100 (AEDT)

On Fri, 2020-02-07 at 17:20:57 UTC, Christophe Leroy wrote:
> When CONFIG_PROVE_LOCKING is selected together with (now default)
> CONFIG_VMAP_STACK, kernel enter deadlock during boot.
> 
> At the point of checking whether interrupts are enabled or not, the
> value of MSR saved on stack is read using the physical address of the
> stack. But at this point, when using VMAP stack the DATA MMU
> translation has already been re-enabled, leading to deadlock.
> 
> Don't use the physical address of the stack when
> CONFIG_VMAP_STACK is set.
> 
> Signed-off-by: Christophe Leroy <[email-masked]>
> Reported-by: Guenter Roeck <[email-masked]>
> Fixes: 028474876f47 ("powerpc/32: prepare for CONFIG_VMAP_STACK")

Applied to powerpc fixes, thanks.

https://git.kernel.org/powerpc/c/d4bf905307a1c90a27714ff7a9fd29b0a2ceed98

cheers