MPX requires recompiling applications, which requires compiler support.
Unfortunately, GCC 9.1 is expected to be be released without support for
MPX.  This means that there was only a relatively small window where
folks could have ever used MPX.  It failed to gain wide adoption in the
industry, and Linux was the only mainstream OS to ever support it widely.

Support for the feature may also disappear on future processors.

This set completes the process that we started during the 5.4 merge window.
x86/mpx: remove MPX from arch/x86

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).

This removes all the remaining (dead at this point) MPX handling
code remaining in the tree.  The only remaining code is the XSAVE
support for MPX state which is currently needd for KVM to handle
VMs which might use MPX.

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>
15 files changed