x86, mpx: Add MPX-specific mmap interface
We have chosen to perform the allocation of bounds tables in
kernel (See the patch "on-demand kernel allocation of bounds
tables") and to mark these VMAs with VM_MPX.
However, there is currently no suitable interface to actually do
this. Existing interfaces, like do_mmap_pgoff(), have no way to
set a modified ->vm_ops or ->vm_flags and don't hold mmap_sem
long enough to let a caller do it.
This patch wraps mmap_region() and hold mmap_sem long enough to
make the modifications to the VMA which we need.
Also note the 32/64-bit #ifdef in the header. We actually need
to do this at runtime eventually. But, for now, we don't support
running 32-bit binaries on 64-bit kernels. Support for this will
come in later patches.
Signed-off-by: Qiaowei Ren <qiaowei.ren@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: linux-mm@kvack.org
Cc: linux-mips@linux-mips.org
Cc: Dave Hansen <dave@sr71.net>
Link: http://lkml.kernel.org/r/20141114151827.CE440F67@viggo.jf.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/arch/x86/mm/Makefile b/arch/x86/mm/Makefile
index 6a19ad9..ecfdc46 100644
--- a/arch/x86/mm/Makefile
+++ b/arch/x86/mm/Makefile
@@ -30,3 +30,5 @@
obj-$(CONFIG_NUMA_EMU) += numa_emulation.o
obj-$(CONFIG_MEMTEST) += memtest.o
+
+obj-$(CONFIG_X86_INTEL_MPX) += mpx.o