On Tue, 2012-02-21 at 18:32 +1100, Michael Ellerman wrote:
> In commit 54321242afe ("Disable interrupts early in Program Check"), we
> switched from enabling to disabling interrupts in program_check_common.
>
> Whereas ENABLE_INTS leaves r3 untouched, if lockdep is enabled DISABLE_INTS
> calls into lockdep code and will clobber r3. That means we pass a bogus
> struct pt_regs* into program_check_exception() and all hell breaks loose.
>
> So load our regs pointer into r3 after we call DISABLE_INTS.
Ah nice catch, thanks !
Cheers,
Ben.
> Signed-off-by: Michael Ellerman <mich...@ellerman.id.au>
> ---
> arch/powerpc/kernel/exceptions-64s.S | 2 +-
> 1 files changed, 1 insertions(+), 1 deletions(-)
>
> diff --git a/arch/powerpc/kernel/exceptions-64s.S
> b/arch/powerpc/kernel/exceptions-64s.S
> index 3844ca7..15c5a4f 100644
> --- a/arch/powerpc/kernel/exceptions-64s.S
> +++ b/arch/powerpc/kernel/exceptions-64s.S
> @@ -774,8 +774,8 @@ alignment_common:
> program_check_common:
> EXCEPTION_PROLOG_COMMON(0x700, PACA_EXGEN)
> bl .save_nvgprs
> - addi r3,r1,STACK_FRAME_OVERHEAD
> DISABLE_INTS
> + addi r3,r1,STACK_FRAME_OVERHEAD
> bl .program_check_exception
> b .ret_from_except
>
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