[PATCH] arm64: Re-enable PAN on uaccess_enable

[Marc Zyngier]

Commit 4b65a5db3627 ("arm64: Introduce uaccess_{disable,enable}
functionality based on TTBR0_EL1") added conditional PAN
enable/disable. Unfortunately, a typo prevents PAN from being
re-enabled once it has been disabled.

Restore the PAN functionnality by adding the missing '!'.

Fixes: b65a5db3627 ("arm64: Introduce uaccess_{disable,enable} functionality based on TTBR0_EL1")
Reported-by: Christoffer Dall <christoffer.dall at linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier at arm.com>
---
Christoffer, any chance you could give this a go and let me know
if that fixes your issues?

 arch/arm64/include/asm/uaccess.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm64/include/asm/uaccess.h b/arch/arm64/include/asm/uaccess.h
index 6986f56..d26750c 100644
--- a/arch/arm64/include/asm/uaccess.h
+++ b/arch/arm64/include/asm/uaccess.h
@@ -188,7 +188,7 @@ do {									\
 
 #define __uaccess_enable(alt)						\
 do {									\
-	if (uaccess_ttbr0_enable())					\
+	if (!uaccess_ttbr0_enable())					\
 		asm(ALTERNATIVE("nop", SET_PSTATE_PAN(0), alt,		\
 				CONFIG_ARM64_PAN));			\
 } while (0)
-- 
2.1.4