[PATCH v5 06/27] arm64: Delay daif masking for user return

[Julien Thierry]

Masking daif flags is done very early before returning to EL0.

Only toggle the interrupt masking while in the vector entry and mask daif
once in kernel_exit.

Signed-off-by: Julien Thierry <julien.thie...@arm.com>
Cc: Catalin Marinas <catalin.mari...@arm.com>
Cc: Will Deacon <will.dea...@arm.com>
Cc: Mark Rutland <mark.rutl...@arm.com>
Cc: James Morse <james.mo...@arm.com>
---
 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 09dbea22..85ce06ac 100644
--- a/arch/arm64/kernel/entry.S
+++ b/arch/arm64/kernel/entry.S
@@ -259,9 +259,9 @@ alternative_else_nop_endif
        .endm
 
        .macro  kernel_exit, el
-       .if     \el != 0
        disable_daif
 
+       .if     \el != 0
        /* Restore the task's original addr_limit. */
        ldr     x20, [sp, #S_ORIG_ADDR_LIMIT]
        str     x20, [tsk, #TSK_TI_ADDR_LIMIT]
@@ -896,7 +896,7 @@ work_pending:
  * "slow" syscall return path.
  */
 ret_to_user:
-       disable_daif
+       disable_irq                             // disable interrupts
        ldr     x1, [tsk, #TSK_TI_FLAGS]
        and     x2, x1, #_TIF_WORK_MASK
        cbnz    x2, work_pending
-- 
1.9.1