RESEND: Re: Problem booting a PowerBook G4 Aluminum after commit cd08f109 with CONFIG_VMAP_STACK=y

[Larry Finger]

Christophe,

On 2/14/20 1:35 PM, Christophe Leroy wrote:
> --- a/arch/powerpc/kernel/head_32.S
> +++ b/arch/powerpc/kernel/head_32.S
> @@ -270,6 +270,9 @@ __secondary_hold_acknowledge:
>    * pointer when we take an exception from supervisor mode.)
>    *    -- paulus.
>    */
> +#ifdef CONFIG_PPC_CHRP
> +1:    b    machine_check_in_rtas
> +#endif
>       . = 0x200
>       DO_KVM  0x200
>   MachineCheck:
> @@ -290,12 +293,9 @@ MachineCheck:
>   7:    EXCEPTION_PROLOG_2
>       addi    r3,r1,STACK_FRAME_OVERHEAD
>   #ifdef CONFIG_PPC_CHRP
> -    bne    cr1,1f
> +    bne    cr1,1b
>   #endif
>       EXC_XFER_STD(0x200, machine_check_exception)
> -#ifdef CONFIG_PPC_CHRP
> -1:    b    machine_check_in_rtas
> -#endif
> 
>   /* Data access exception. */
>       . = 0x300

With the above changes and all the other patches applied, the machine finally 
boots. It is so bloody slow that it takes a long time to do anything, but you 
finally got all the places that needed patches. I really lost track of how many 
bugs were fixed in the process, but I can now put that old box aside until time 
for v5.7.0-rc1. As you can tell, it only gets used to verify that PPC32 is 
working on real G4 hardware. It has no real value for any other function.

Thanks for the help,

Larry