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SubjectRe: [PATCH v4 1/8] arm64: Do not enable IRQs for ct_user_exit
On Tue, Jun 11, 2019 at 10:38:06AM +0100, Julien Thierry wrote:
> For el0_dbg and el0_error, DAIF bits get explicitly cleared before
> calling ct_user_exit.
>
> When context tracking is disabled, DAIF gets set (almost) immediately
> after. When context tracking is enabled, among the first things done
> is disabling IRQs.
>
> What is actually needed is:
> - PSR.D = 0 so the system can be debugged (should be already the case)
> - PSR.A = 0 so async error can be handled during context tracking
>
> Do not clear PSR.I in those two locations.
>
> Signed-off-by: Julien Thierry <julien.thierry@arm.com>
> Reviewed-by: James Morse <james.morse@arm.com>
> Cc:Catalin Marinas <catalin.marinas@arm.com>
> Cc: Will Deacon <will.deacon@arm.com>
> Cc: Mark Rutland <mark.rutland@arm.com>
> Cc: Marc Zyngier <marc.zyngier@arm.com>

Acked-by: Mark Rutland <mark.rutland@arm.com>

Mark.

> ---
> arch/arm64/kernel/entry.S | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
> index cd0c7af..89ab6bd 100644
> --- a/arch/arm64/kernel/entry.S
> +++ b/arch/arm64/kernel/entry.S
> @@ -870,7 +870,7 @@ el0_dbg:
> mov x1, x25
> mov x2, sp
> bl do_debug_exception
> - enable_daif
> + enable_da_f
> ct_user_exit
> b ret_to_user
> el0_inv:
> @@ -922,7 +922,7 @@ el0_error_naked:
> enable_dbg
> mov x0, sp
> bl do_serror
> - enable_daif
> + enable_da_f
> ct_user_exit
> b ret_to_user
> ENDPROC(el0_error)
> --
> 1.9.1

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