x86/mpx: Allow 32-bit binaries on 64-bit kernels again

Now that the bugs in mixed mode MPX handling are fixed, re-allow
32-bit binaries on 64-bit kernels again.

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Dave Hansen <dave@sr71.net>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20150607183706.70277DAD@viggo.jf.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/arch/x86/mm/mpx.c b/arch/x86/mm/mpx.c
index 6233d5195f0102614caa94a4d2d9f71e3f3269fd..7a657f58bbea152057262a61e325c169f78bc516 100644 (file)
--- a/arch/x86/mm/mpx.c
+++ b/arch/x86/mm/mpx.c
@@ -366,12 +366,6 @@ static __user void *mpx_get_bounds_dir(void)
        if (!cpu_feature_enabled(X86_FEATURE_MPX))
                return MPX_INVALID_BOUNDS_DIR;
 
-       /*
-        * 32-bit binaries on 64-bit kernels are currently
-        * unsupported.
-        */
-       if (IS_ENABLED(CONFIG_X86_64) && test_thread_flag(TIF_IA32))
-               return MPX_INVALID_BOUNDS_DIR;
        /*
         * The bounds directory pointer is stored in a register
         * only accessible if we first do an xsave.