[tip:x86/fpu] x86/mpx: Restrict the mmap() size check to bounds tables

[tip-bot for Dave Hansen]

Commit-ID:  eb099e5bc5457c42043e57cf0f4ce574669b9697
Gitweb:     http://git.kernel.org/tip/eb099e5bc5457c42043e57cf0f4ce574669b9697
Author:     Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
AuthorDate: Sun, 7 Jun 2015 11:37:02 -0700
Committer:  Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Tue, 9 Jun 2015 12:24:31 +0200

x86/mpx: Restrict the mmap() size check to bounds tables

The comment and code here are confusing.  We do not currently
allocate the bounds directory in the kernel.

Signed-off-by: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Reviewed-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Dave Hansen <dave@xxxxxxxx>
Cc: H. Peter Anvin <hpa@xxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/20150607183702.222CEC2A@xxxxxxxxxxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
 arch/x86/mm/mpx.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/mm/mpx.c b/arch/x86/mm/mpx.c
index 47e4a856..d6e02f3 100644
--- a/arch/x86/mm/mpx.c
+++ b/arch/x86/mm/mpx.c
@@ -46,8 +46,8 @@ static unsigned long mpx_mmap(unsigned long len)
 	vm_flags_t vm_flags;
 	struct vm_area_struct *vma;
 
-	/* Only bounds table and bounds directory can be allocated here */
-	if (len != MPX_BD_SIZE_BYTES && len != MPX_BT_SIZE_BYTES)
+	/* Only bounds table can be allocated here */
+	if (len != MPX_BT_SIZE_BYTES)
 		return -EINVAL;
 
 	down_write(&mm->mmap_sem);
--
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