Commit 4ba68d00 authored by Dave Hansen's avatar Dave Hansen Committed by Dave Hansen
Browse files

x86/mpx: remove build infrastructure 



From: Dave Hansen <dave.hansen@linux.intel.com>

MPX is being removed from the kernel due to a lack of support
in the toolchain going forward (gcc).

Remove the Kconfig option and the Makefile line.  This makes
arch/x86/mm/mpx.c and anything under an #ifdef for
X86_INTEL_MPX dead code.

Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: x86@kernel.org
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarDave Hansen <dave.hansen@linux.intel.com>
parent 3a125539

arch/x86/Kconfig

+0 −28
Original line number Diff line number Diff line
@@ -1896,34 +1896,6 @@ config X86_INTEL_UMIP 
	  specific cases in protected and virtual-8086 modes. Emulated

	  results are dummy.



config X86_INTEL_MPX

	prompt "Intel MPX (Memory Protection Extensions)"

	def_bool n

	# Note: only available in 64-bit mode due to VMA flags shortage

	depends on CPU_SUP_INTEL && X86_64

	select ARCH_USES_HIGH_VMA_FLAGS

	---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.



	  This option enables running applications which are

	  instrumented or otherwise use MPX.  It does not use MPX

	  itself inside the kernel or to protect the kernel

	  against bad memory references.



	  Enabling this option will make the kernel larger:

	  ~8k of kernel text and 36 bytes of data on a 64-bit

	  defconfig.  It adds a long to the 'mm_struct' which

	  will increase the kernel memory overhead of each

	  process and adds some branches to paths used during

	  exec() and munmap().



	  For details, see Documentation/x86/intel_mpx.rst



	  If unsure, say N.



config X86_INTEL_MEMORY_PROTECTION_KEYS

	prompt "Intel Memory Protection Keys"

	def_bool y

arch/x86/mm/Makefile

+0 −1
Original line number Diff line number Diff line
@@ -45,7 +45,6 @@ obj-$(CONFIG_AMD_NUMA) += amdtopology.o 
obj-$(CONFIG_ACPI_NUMA)		+= srat.o

obj-$(CONFIG_NUMA_EMU)		+= numa_emulation.o



obj-$(CONFIG_X86_INTEL_MPX)			+= mpx.o

obj-$(CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS)	+= pkeys.o

obj-$(CONFIG_RANDOMIZE_MEMORY)			+= kaslr.o

obj-$(CONFIG_PAGE_TABLE_ISOLATION)		+= pti.o

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