[PATCH v4 1/8] arm64: Do not enable IRQs for ct_user_exit

From: Julien Thierry
Date: Tue Jun 11 2019 - 05:42:53 EST

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@xxxxxxx>
Reviewed-by: James Morse <james.morse@xxxxxxx>
Cc:Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Will Deacon <will.deacon@xxxxxxx>
Cc: Mark Rutland <mark.rutland@xxxxxxx>
Cc: Marc Zyngier <marc.zyngier@xxxxxxx>
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
b ret_to_user
@@ -922,7 +922,7 @@ el0_error_naked:
mov x0, sp
bl do_serror
- enable_daif
+ enable_da_f
b ret_to_user