[PATCH AUTOSEL 5.1 123/219] arm64: Do not enable IRQs for ct_user_exit

Sasha Levin
2019-07-15T14:10:46Z

From: Julien Thierry <julien.thierry@arm.com>

[ 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 c50a7a75f2e0..6a3890393963 100644
--- a/arch/arm64/kernel/entry.S
+++ b/arch/arm64/kernel/entry.S
@@ -855,7 +855,7 @@ 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:
@@ -907,7 +907,7 @@ 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