[PATCH] i386 / desc_empty macro is incorrect

Chuck Ebbert noticed that the desc_empty macro is incorrect.  Fix it.

Thankfully, this is not used as a security check, but it can falsely
overwrite TLS segments with carefully chosen base / limits.  I do not
believe this is an issue in practice, but it is a kernel bug.

Signed-off-by: Zachary Amsden <zach@vmware.com>
Signed-off-by: Chris Wright <chrisw@osdl.org>

[ x86-64 had the same problem, and the same fix. Linus ]

Signed-off-by: Linus Torvalds <torvalds@osdl.org>

2 files changed, 2 insertions, 2 deletions

diff --git a/include/asm-i386/processor.h b/include/asm-i386/processor.h
index 5d06e6bd6ba0..d0d8b0160090 100644
--- a/include/asm-i386/processor.h
+++ b/include/asm-i386/processor.h
@@ -29,7 +29,7 @@ struct desc_struct {
 };
 
 #define desc_empty(desc) \
-                (!((desc)->a + (desc)->b))
+                (!((desc)->a | (desc)->b))
 
 #define desc_equal(desc1, desc2) \
                 (((desc1)->a == (desc2)->a) && ((desc1)->b == (desc2)->b))
diff --git a/include/asm-x86_64/processor.h b/include/asm-x86_64/processor.h
index 106f666517bb..85549e656eeb 100644
--- a/include/asm-x86_64/processor.h
+++ b/include/asm-x86_64/processor.h
@@ -32,7 +32,7 @@
 #define ID_MASK         0x00200000
 
 #define desc_empty(desc) \
-               (!((desc)->a + (desc)->b))
+               (!((desc)->a | (desc)->b))
 
 #define desc_equal(desc1, desc2) \
                (((desc1)->a == (desc2)->a) && ((desc1)->b == (desc2)->b))