On 12/10/2014 11:05 AM, Linus Torvalds wrote: > On Tue, Dec 9, 2014 at 6:08 AM, Thomas Gleixner <t...@linutronix.de> wrote: > Why would I want to enable this in my kernel when there are no actual > CPU's out yet that support it? And even when there are, why would I do > it if the CPU I have doesn't support it?
There's no good reason to enable it except for testing (compile, or making sure we didn't screw up the #BR code for CPUs without MPX). Patch is attached to add the following: > config X86_INTEL_MPX > prompt "Intel MPX (Memory Protection Extensions)" if EXPERT > def_bool y > depends on CPU_SUP_INTEL > ---help--- > MPX provides hardware features that can be used in > conjunction with compiler-instrumented code to check > memory references. It is designed to detect buffer > overflow or underflow bugs. > > Enabling this option will make the kernel larger and > slightly increase the size of some data structures. > > If unsure, say Y.
From: Dave Hansen <dave.han...@linux.intel.com> Give MPX a real config option. The CPUs that support it (referenced here): https://software.intel.com/en-us/forums/topic/402393 are not available publicly, so we need to make it somewhat easy to disable. Signed-off-by: Dave Hansen <dave.han...@linux.intel.com> --- b/arch/x86/Kconfig | 19 +++++++++++++++---- 1 file changed, 15 insertions(+), 4 deletions(-) diff -puN arch/x86/Kconfig~x86-mpx-real-config-option arch/x86/Kconfig --- a/arch/x86/Kconfig~x86-mpx-real-config-option 2014-12-10 11:19:13.638835732 -0800 +++ b/arch/x86/Kconfig 2014-12-10 11:30:27.080209235 -0800 @@ -248,10 +248,6 @@ config HAVE_INTEL_TXT def_bool y depends on INTEL_IOMMU && ACPI -config X86_INTEL_MPX - def_bool y - depends on CPU_SUP_INTEL - config X86_32_SMP def_bool y depends on X86_32 && SMP @@ -1575,6 +1571,21 @@ config X86_SMAP If unsure, say Y. +config X86_INTEL_MPX + prompt "Intel MPX (Memory Protection Extensions)" if EXPERT + def_bool y + depends on CPU_SUP_INTEL + ---help--- + MPX provides hardware features that can be used in + conjunction with compiler-instrumented code to check + memory references. It is designed to detect buffer + overflow or underflow bugs. + + Enabling this option will make the kernel larger and + slightly increase the size of some data structures. + + If unsure, say Y. + config EFI bool "EFI runtime service support" depends on ACPI _
