2019-04-29 16:04:04

by Julien Thierry

[permalink] [raw]
Subject: [PATCH v2 1/5] arm64: Do not enable IRQs for ct_user_exit

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 <[email protected]>
Cc:Catalin Marinas <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Marc Zyngier <[email protected]>
---
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 c50a7a7..6a38903 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)
--
1.9.1