From: Will Deacon <will.deacon@arm.com>
Date: Thu, 10 Aug 2017 12:04:48 +0000 (+0100)
Subject: arm64: mm: Temporarily disable ARM64_SW_TTBR0_PAN
X-Git-Tag: v4.14.20~172
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=59f47f9dcdcde20e0a20c434f18bcc50c7c824e4;p=thirdparty%2Fkernel%2Fstable.git

arm64: mm: Temporarily disable ARM64_SW_TTBR0_PAN


Commit 376133b7edc2 upstream.

We're about to rework the way ASIDs are allocated, switch_mm is
implemented and low-level kernel entry/exit is handled, so keep the
ARM64_SW_TTBR0_PAN code out of the way whilst we do the heavy lifting.

It will be re-enabled in a subsequent patch.

Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Laura Abbott <labbott@redhat.com>
Tested-by: Shanker Donthineni <shankerd@codeaurora.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 8f73eaccf50a8..63ff04fe03e10 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -882,6 +882,7 @@ endif
 
 config ARM64_SW_TTBR0_PAN
 	bool "Emulate Privileged Access Never using TTBR0_EL1 switching"
+	depends on BROKEN       # Temporary while switch_mm is reworked
 	help
 	  Enabling this option prevents the kernel from accessing
 	  user-space memory directly by pointing TTBR0_EL1 to a reserved