| Message ID | 1472736959-25686-1-git-send-email-vladimir.murzin@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S index 441420c..7c9bb43 100644 --- a/arch/arm64/kernel/entry.S +++ b/arch/arm64/kernel/entry.S @@ -104,7 +104,7 @@ str x20, [sp, #S_ORIG_ADDR_LIMIT] mov x20, #TASK_SIZE_64 str x20, [tsk, #TI_ADDR_LIMIT] - ALTERNATIVE(nop, SET_PSTATE_UAO(0), ARM64_HAS_UAO, CONFIG_ARM64_UAO) + /* No need to reset PSTATE.UAO, hardware's already set it to 0 for us */ .endif /* \el == 0 */ mrs x22, elr_el1 mrs x23, spsr_el1
Commit e19a6ee2460b ("arm64: kernel: Save and restore UAO and addr_limit on exception entry") states that exception handler inherits the original PSTATE.UAO value, so UAO needes to be reset explicitly. However, ARM 8.2 Extension documentation says: PSTATE.UAO is copied to SPSR_ELx.UAO and is then set to 0 on an exception taken from AArch64 to AArch64 so hardware already does the right thing. Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com> Acked-by: James Morse <james.morse@arm.com> --- arch/arm64/kernel/entry.S | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)