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authorRussell Currey <ruscur@russell.cc>2021-06-09 04:34:29 +0300
committerMichael Ellerman <mpe@ellerman.id.au>2021-06-21 14:13:21 +0300
commitc35717c71e983ed55d61e523cbd11a798429bc82 (patch)
tree7122264a19e400783e5b9c00165307ba50cec113 /arch/powerpc/Kconfig
parent62e3d4210ac9c35783d0e8fc306df4239c540a79 (diff)
downloadlinux-c35717c71e983ed55d61e523cbd11a798429bc82.tar.xz
powerpc: Set ARCH_HAS_STRICT_MODULE_RWX
To enable strict module RWX on powerpc, set: CONFIG_STRICT_MODULE_RWX=y You should also have CONFIG_STRICT_KERNEL_RWX=y set to have any real security benefit. ARCH_HAS_STRICT_MODULE_RWX is set to require ARCH_HAS_STRICT_KERNEL_RWX. This is due to a quirk in arch/Kconfig and arch/powerpc/Kconfig that makes STRICT_MODULE_RWX *on by default* in configurations where STRICT_KERNEL_RWX is *unavailable*. Since this doesn't make much sense, and module RWX without kernel RWX doesn't make much sense, having the same dependencies as kernel RWX works around this problem. Book3s/32 603 and 604 core processors are not able to write protect kernel pages so do not set ARCH_HAS_STRICT_MODULE_RWX for Book3s/32. [jpn: - predicate on !PPC_BOOK3S_604 - make module_alloc() use PAGE_KERNEL protection] Signed-off-by: Russell Currey <ruscur@russell.cc> Signed-off-by: Jordan Niethe <jniethe5@gmail.com> Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210609013431.9805-8-jniethe5@gmail.com
Diffstat (limited to 'arch/powerpc/Kconfig')
-rw-r--r--arch/powerpc/Kconfig2
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index abfe2e9225fa..72f307f1796b 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -142,6 +142,7 @@ config PPC
select ARCH_HAS_SCALED_CPUTIME if VIRT_CPU_ACCOUNTING_NATIVE && PPC_BOOK3S_64
select ARCH_HAS_SET_MEMORY
select ARCH_HAS_STRICT_KERNEL_RWX if ((PPC_BOOK3S_64 || PPC32) && !HIBERNATION)
+ select ARCH_HAS_STRICT_MODULE_RWX if ARCH_HAS_STRICT_KERNEL_RWX && !PPC_BOOK3S_32
select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
select ARCH_HAS_UACCESS_FLUSHCACHE
select ARCH_HAS_UBSAN_SANITIZE_ALL
@@ -267,6 +268,7 @@ config PPC
select PPC_DAWR if PPC64
select RTC_LIB
select SPARSE_IRQ
+ select STRICT_KERNEL_RWX if STRICT_MODULE_RWX
select SYSCTL_EXCEPTION_TRACE
select THREAD_INFO_IN_TASK
select VIRT_TO_BUS if !PPC64