On Fri, Feb 03, 2017 at 09:52:21AM -0800, Laura Abbott wrote: > There are multiple architectures that support CONFIG_DEBUG_RODATA and > CONFIG_SET_MODULE_RONX. These options also now have the ability to be > turned off at runtime. Move these to an architecture independent > location and make these options def_bool y for almost all of those > arches. > > Signed-off-by: Laura Abbott <labbott@xxxxxxxxxx> >From my POV this looks good. FWIW: Acked-by: Mark Rutland <mark.rutland@xxxxxxx> Mark. > --- > v2: This patch is now doing just the refactor of the existing config options. > --- > arch/Kconfig | 28 ++++++++++++++++++++++++++++ > arch/arm/Kconfig | 3 +++ > arch/arm/Kconfig.debug | 11 ----------- > arch/arm/mm/Kconfig | 12 ------------ > arch/arm64/Kconfig | 5 ++--- > arch/arm64/Kconfig.debug | 11 ----------- > arch/parisc/Kconfig | 1 + > arch/parisc/Kconfig.debug | 11 ----------- > arch/s390/Kconfig | 5 ++--- > arch/s390/Kconfig.debug | 3 --- > arch/x86/Kconfig | 5 ++--- > arch/x86/Kconfig.debug | 11 ----------- > 12 files changed, 38 insertions(+), 68 deletions(-) > > diff --git a/arch/Kconfig b/arch/Kconfig > index 99839c2..22ee01e 100644 > --- a/arch/Kconfig > +++ b/arch/Kconfig > @@ -781,4 +781,32 @@ config VMAP_STACK > the stack to map directly to the KASAN shadow map using a formula > that is incorrect if the stack is in vmalloc space. > > +config ARCH_NO_STRICT_RWX_DEFAULTS > + def_bool n > + > +config ARCH_HAS_STRICT_KERNEL_RWX > + def_bool n > + > +config DEBUG_RODATA > + def_bool y if !ARCH_NO_STRICT_RWX_DEFAULTS > + prompt "Make kernel text and rodata read-only" if ARCH_NO_STRICT_RWX_DEFAULTS > + depends on ARCH_HAS_STRICT_KERNEL_RWX > + help > + If this is set, kernel text and rodata memory will be made read-only, > + and non-text memory will be made non-executable. This provides > + protection against certain security exploits (e.g. executing the heap > + or modifying text) > + > +config ARCH_HAS_STRICT_MODULE_RWX > + def_bool n > + > +config DEBUG_SET_MODULE_RONX > + def_bool y if !ARCH_NO_STRICT_RWX_DEFAULTS > + prompt "Set loadable kenrel module data as NX and text as RO" if ARCH_NO_STRICT_RWX_DEFAULTS > + depends on ARCH_HAS_STRICT_MODULE_RWX && MODULES > + help > + If this is set, module text and rodata memory will be made read-only, > + and non-text memory will be made non-executable. This provides > + protection against certain security exploits (e.g. writing to text) > + > source "kernel/gcov/Kconfig" > diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig > index 186c4c2..aa73ca8 100644 > --- a/arch/arm/Kconfig > +++ b/arch/arm/Kconfig > @@ -4,10 +4,13 @@ config ARM > select ARCH_CLOCKSOURCE_DATA > select ARCH_HAS_DEVMEM_IS_ALLOWED > select ARCH_HAS_ELF_RANDOMIZE > + select ARCH_HAS_STRICT_KERNEL_RWX if MMU && !XIP_KERNEL > + select ARCH_HAS_STRICT_MODULE_RWX if MMU > select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST > select ARCH_HAVE_CUSTOM_GPIO_H > select ARCH_HAS_GCOV_PROFILE_ALL > select ARCH_MIGHT_HAVE_PC_PARPORT > + select ARCH_NO_STRICT_RWX_DEFAULTS if !CPU_V7 > select ARCH_SUPPORTS_ATOMIC_RMW > select ARCH_USE_BUILTIN_BSWAP > select ARCH_USE_CMPXCHG_LOCKREF > diff --git a/arch/arm/Kconfig.debug b/arch/arm/Kconfig.debug > index d83f7c3..426d271 100644 > --- a/arch/arm/Kconfig.debug > +++ b/arch/arm/Kconfig.debug > @@ -1738,17 +1738,6 @@ config PID_IN_CONTEXTIDR > additional instructions during context switch. Say Y here only if you > are planning to use hardware trace tools with this kernel. > > -config DEBUG_SET_MODULE_RONX > - bool "Set loadable kernel module data as NX and text as RO" > - depends on MODULES && MMU > - ---help--- > - This option helps catch unintended modifications to loadable > - kernel module's text and read-only data. It also prevents execution > - of module data. Such protection may interfere with run-time code > - patching and dynamic kernel tracing - and they might also protect > - against certain classes of kernel exploits. > - If in doubt, say "N". > - > source "drivers/hwtracing/coresight/Kconfig" > > endmenu > diff --git a/arch/arm/mm/Kconfig b/arch/arm/mm/Kconfig > index f68e8ec..419a035 100644 > --- a/arch/arm/mm/Kconfig > +++ b/arch/arm/mm/Kconfig > @@ -1051,18 +1051,6 @@ config ARCH_SUPPORTS_BIG_ENDIAN > This option specifies the architecture can support big endian > operation. > > -config DEBUG_RODATA > - bool "Make kernel text and rodata read-only" > - depends on MMU && !XIP_KERNEL > - default y if CPU_V7 > - help > - If this is set, kernel text and rodata memory will be made > - read-only, and non-text kernel memory will be made non-executable. > - The tradeoff is that each region is padded to section-size (1MiB) > - boundaries (because their permissions are different and splitting > - the 1M pages into 4K ones causes TLB performance problems), which > - can waste memory. > - > config DEBUG_ALIGN_RODATA > bool "Make rodata strictly non-executable" > depends on DEBUG_RODATA > diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig > index 1117421..e1efbcc 100644 > --- a/arch/arm64/Kconfig > +++ b/arch/arm64/Kconfig > @@ -13,6 +13,8 @@ config ARM64 > select ARCH_HAS_GIGANTIC_PAGE > select ARCH_HAS_KCOV > select ARCH_HAS_SG_CHAIN > + select ARCH_HAS_STRICT_KERNEL_RWX > + select ARCH_HAS_STRICT_MODULE_RWX > select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST > select ARCH_USE_CMPXCHG_LOCKREF > select ARCH_SUPPORTS_ATOMIC_RMW > @@ -123,9 +125,6 @@ config ARCH_PHYS_ADDR_T_64BIT > config MMU > def_bool y > > -config DEBUG_RODATA > - def_bool y > - > config ARM64_PAGE_SHIFT > int > default 16 if ARM64_64K_PAGES > diff --git a/arch/arm64/Kconfig.debug b/arch/arm64/Kconfig.debug > index d1ebd46..939815e 100644 > --- a/arch/arm64/Kconfig.debug > +++ b/arch/arm64/Kconfig.debug > @@ -71,17 +71,6 @@ config DEBUG_WX > > If in doubt, say "Y". > > -config DEBUG_SET_MODULE_RONX > - bool "Set loadable kernel module data as NX and text as RO" > - depends on MODULES > - default y > - help > - Is this is set, kernel module text and rodata will be made read-only. > - This is to help catch accidental or malicious attempts to change the > - kernel's executable code. > - > - If in doubt, say Y. > - > config DEBUG_ALIGN_RODATA > depends on DEBUG_RODATA > bool "Align linker sections up to SECTION_SIZE" > diff --git a/arch/parisc/Kconfig b/arch/parisc/Kconfig > index 3a71f38..ad294b3 100644 > --- a/arch/parisc/Kconfig > +++ b/arch/parisc/Kconfig > @@ -8,6 +8,7 @@ config PARISC > select HAVE_SYSCALL_TRACEPOINTS > select ARCH_WANT_FRAME_POINTERS > select ARCH_HAS_ELF_RANDOMIZE > + select ARCH_HAS_STRICT_KERNEL_RWX > select RTC_CLASS > select RTC_DRV_GENERIC > select INIT_ALL_POSSIBLE > diff --git a/arch/parisc/Kconfig.debug b/arch/parisc/Kconfig.debug > index 68b7cbd..0d856b9 100644 > --- a/arch/parisc/Kconfig.debug > +++ b/arch/parisc/Kconfig.debug > @@ -5,15 +5,4 @@ source "lib/Kconfig.debug" > config TRACE_IRQFLAGS_SUPPORT > def_bool y > > -config DEBUG_RODATA > - bool "Write protect kernel read-only data structures" > - depends on DEBUG_KERNEL > - default y > - help > - Mark the kernel read-only data as write-protected in the pagetables, > - in order to catch accidental (and incorrect) writes to such const > - data. This option may have a slight performance impact because a > - portion of the kernel code won't be covered by a TLB anymore. > - If in doubt, say "N". > - > endmenu > diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig > index c6722112..53bb0e3 100644 > --- a/arch/s390/Kconfig > +++ b/arch/s390/Kconfig > @@ -62,9 +62,6 @@ config PCI_QUIRKS > config ARCH_SUPPORTS_UPROBES > def_bool y > > -config DEBUG_RODATA > - def_bool y > - > config S390 > def_bool y > select ARCH_HAS_DEVMEM_IS_ALLOWED > @@ -73,6 +70,8 @@ config S390 > select ARCH_HAS_GIGANTIC_PAGE > select ARCH_HAS_KCOV > select ARCH_HAS_SG_CHAIN > + select ARCH_HAS_STRICT_KERNEL_RWX > + select ARCH_HAS_STRICT_MODULE_RWX > select ARCH_HAS_UBSAN_SANITIZE_ALL > select ARCH_HAVE_NMI_SAFE_CMPXCHG > select ARCH_INLINE_READ_LOCK > diff --git a/arch/s390/Kconfig.debug b/arch/s390/Kconfig.debug > index 26c5d5be..57f8ea9 100644 > --- a/arch/s390/Kconfig.debug > +++ b/arch/s390/Kconfig.debug > @@ -17,7 +17,4 @@ config S390_PTDUMP > kernel. > If in doubt, say "N" > > -config DEBUG_SET_MODULE_RONX > - def_bool y > - depends on MODULES > endmenu > diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig > index e487493..13e1bf4 100644 > --- a/arch/x86/Kconfig > +++ b/arch/x86/Kconfig > @@ -54,6 +54,8 @@ config X86 > select ARCH_HAS_MMIO_FLUSH > select ARCH_HAS_PMEM_API if X86_64 > select ARCH_HAS_SG_CHAIN > + select ARCH_HAS_STRICT_KERNEL_RWX > + select ARCH_HAS_STRICT_MODULE_RWX > select ARCH_HAS_UBSAN_SANITIZE_ALL > select ARCH_HAVE_NMI_SAFE_CMPXCHG > select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI > @@ -309,9 +311,6 @@ config ARCH_SUPPORTS_UPROBES > config FIX_EARLYCON_MEM > def_bool y > > -config DEBUG_RODATA > - def_bool y > - > config PGTABLE_LEVELS > int > default 4 if X86_64 > diff --git a/arch/x86/Kconfig.debug b/arch/x86/Kconfig.debug > index 67eec55..69cdd0b 100644 > --- a/arch/x86/Kconfig.debug > +++ b/arch/x86/Kconfig.debug > @@ -109,17 +109,6 @@ config DEBUG_WX > > If in doubt, say "Y". > > -config DEBUG_SET_MODULE_RONX > - bool "Set loadable kernel module data as NX and text as RO" > - depends on MODULES > - ---help--- > - This option helps catch unintended modifications to loadable > - kernel module's text and read-only data. It also prevents execution > - of module data. Such protection may interfere with run-time code > - patching and dynamic kernel tracing - and they might also protect > - against certain classes of kernel exploits. > - If in doubt, say "N". > - > config DEBUG_NX_TEST > tristate "Testcase for the NX non-executable stack feature" > depends on DEBUG_KERNEL && m > -- > 2.7.4 > -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
