[PATCH 4/4] arm64: mm: use ARCH_HAS_DEBUG_WX instead of arch defined

From: Zong Li
Date: Tue Apr 21 2020 - 04:17:45 EST


Extract DEBUG_WX to mm/Kconfig.debug for shared use. Change to use
ARCH_HAS_DEBUG_WX instead of DEBUG_WX defined by arch port.

Signed-off-by: Zong Li <zong.li@xxxxxxxxxx>
---
arch/arm64/Kconfig | 1 +
arch/arm64/Kconfig.debug | 29 -----------------------------
2 files changed, 1 insertion(+), 29 deletions(-)

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 40fb05d96c60..a16e2ce80854 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -9,6 +9,7 @@ config ARM64
select ACPI_MCFG if (ACPI && PCI)
select ACPI_SPCR_TABLE if ACPI
select ACPI_PPTT if ACPI
+ select ARCH_HAS_DEBUG_WX
select ARCH_HAS_DEBUG_VIRTUAL
select ARCH_HAS_DEVMEM_IS_ALLOWED
select ARCH_HAS_DMA_PREP_COHERENT
diff --git a/arch/arm64/Kconfig.debug b/arch/arm64/Kconfig.debug
index a1efa246c9ed..cdf7ec0b975e 100644
--- a/arch/arm64/Kconfig.debug
+++ b/arch/arm64/Kconfig.debug
@@ -23,35 +23,6 @@ config ARM64_RANDOMIZE_TEXT_OFFSET
of TEXT_OFFSET and platforms must not require a specific
value.

-config DEBUG_WX
- bool "Warn on W+X mappings at boot"
- select PTDUMP_CORE
- ---help---
- Generate a warning if any W+X mappings are found at boot.
-
- This is useful for discovering cases where the kernel is leaving
- W+X mappings after applying NX, as such mappings are a security risk.
- This check also includes UXN, which should be set on all kernel
- mappings.
-
- Look for a message in dmesg output like this:
-
- arm64/mm: Checked W+X mappings: passed, no W+X pages found.
-
- or like this, if the check failed:
-
- arm64/mm: Checked W+X mappings: FAILED, <N> W+X pages found.
-
- Note that even if the check fails, your kernel is possibly
- still fine, as W+X mappings are not a security hole in
- themselves, what they do is that they make the exploitation
- of other unfixed kernel bugs easier.
-
- There is no runtime or memory usage effect of this option
- once the kernel has booted up - it's a one time check.
-
- If in doubt, say "Y".
-
config DEBUG_EFI
depends on EFI && DEBUG_INFO
bool "UEFI debugging"
--
2.26.1