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: Dave Hansen <dave.hansen@linux.intel.com>
This commit is contained in:
Dave Hansen 2020-01-23 10:41:14 -08:00 committed by Dave Hansen
parent 3a1255396b
commit 4ba68d0005
2 changed files with 0 additions and 29 deletions

View File

@ -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

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@ -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