[PATCH] Generic BUG for x86-64

This makes x86-64 use the generic BUG machinery.

The main advantage in using the generic BUG machinery for x86-64 is that
the inlined overhead of BUG is just the ud2a instruction; the file+line
information are no longer inlined into the instruction stream.  This
reduces cache pollution.

Signed-off-by: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Andi Kleen <ak@muc.de>
Cc: Hugh Dickens <hugh@veritas.com>
Cc: Michael Ellerman <michael@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 22 insertions, 22 deletions

diff --git a/include/asm-x86_64/bug.h b/include/asm-x86_64/bug.h
index 80ac1fe966a..68260641491 100644
--- a/include/asm-x86_64/bug.h
+++ b/include/asm-x86_64/bug.h
@@ -1,30 +1,30 @@
 #ifndef __ASM_X8664_BUG_H
 #define __ASM_X8664_BUG_H 1
 
-#include <linux/stringify.h>
-
-/*
- * Tell the user there is some problem.  The exception handler decodes 
- * this frame.
- */
-struct bug_frame {
-        unsigned char ud2[2];
-        unsigned char push;
-        signed int filename;
-        unsigned char ret;
-        unsigned short line;
-} __attribute__((packed));
-
 #ifdef CONFIG_BUG
 #define HAVE_ARCH_BUG
-/* We turn the bug frame into valid instructions to not confuse
-   the disassembler. Thanks to Jan Beulich & Suresh Siddha
-   for nice instruction selection.
-   The magic numbers generate mov $64bitimm,%eax ; ret $offset. */
-#define BUG()                                                           \
-        asm volatile(                                                   \
-        "ud2 ; pushq $%c1 ; ret $%c0" ::                                \
-                     "i"(__LINE__), "i" (__FILE__))
+
+#ifdef CONFIG_DEBUG_BUGVERBOSE
+#define BUG()                                                           \
+        do {                                                            \
+                asm volatile("1:\tud2\n"                                \
+                             ".pushsection __bug_table,\"a\"\n"         \
+                             "2:\t.quad 1b, %c0\n"                      \
+                             "\t.word %c1, 0\n"                         \
+                             "\t.org 2b+%c2\n"                          \
+                             ".popsection"                              \
+                             : : "i" (__FILE__), "i" (__LINE__),        \
+                                "i" (sizeof(struct bug_entry)));        \
+                for(;;) ;                                               \
+        } while(0)
+#else
+#define BUG()                                                           \
+        do {                                                            \
+                asm volatile("ud2");                                    \
+                for(;;) ;                                               \
+        } while(0)
+#endif
+
 void out_of_line_bug(void);
 #else
 static inline void out_of_line_bug(void) { }