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    Subject[PATCH 5.2 137/413] arm64: Do not enable IRQs for ct_user_exit
    Date
    [ Upstream commit 9034f6251572a4744597c51dea5ab73a55f2b938 ]

    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.

    Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
    Acked-by: Mark Rutland <mark.rutland@arm.com>
    Reviewed-by: James Morse <james.morse@arm.com>
    Cc: Will Deacon <will.deacon@arm.com>
    Signed-off-by: Julien Thierry <julien.thierry@arm.com>
    Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
    Signed-off-by: Sasha Levin <sashal@kernel.org>
    ---
    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 2df8d0a1d980..dbe467686332 100644
    --- a/arch/arm64/kernel/entry.S
    +++ b/arch/arm64/kernel/entry.S
    @@ -859,7 +859,7 @@ 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:
    @@ -911,7 +911,7 @@ 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)
    --
    2.20.1


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