diff options
| author | Andi Kleen <ak@suse.de> | 2005-07-28 21:15:45 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2005-07-28 21:46:01 -0700 |
| commit | b6a68a16dc15c65fe76acb7502a806ae415cd3e4 (patch) | |
| tree | 8e509a3818fe4670f2a1f5789a17e3ef12a9aab5 | |
| parent | 2275cfa8bcb833cdac7dcc616d11306ca35eec58 (diff) | |
| download | linux-b6a68a16dc15c65fe76acb7502a806ae415cd3e4.tar.bz2 | |
[PATCH] x86_64: Turn BUG data into valid instruction
This avoids confusing the disassembler. Costs 2 bytes per BUG.
Thanks to Suresh Siddha and Jan Beulich for suggesting suitable instructions.
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
| -rw-r--r-- | include/asm-x86_64/bug.h | 13 |
1 files changed, 10 insertions, 3 deletions
diff --git a/include/asm-x86_64/bug.h b/include/asm-x86_64/bug.h index 3d2a666a5dd5..eed785667289 100644 --- a/include/asm-x86_64/bug.h +++ b/include/asm-x86_64/bug.h @@ -8,17 +8,24 @@ * this frame. */ struct bug_frame { - unsigned char ud2[2]; + unsigned char ud2[2]; + unsigned char mov; /* should use 32bit offset instead, but the assembler doesn't like it */ char *filename; + unsigned char ret; unsigned short line; } __attribute__((packed)); #ifdef CONFIG_BUG #define HAVE_ARCH_BUG -#define BUG() \ - asm volatile("ud2 ; .quad %c1 ; .short %c0" :: \ +/* 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 ; .byte 0xa3 ; .quad %c1 ; .byte 0xc2 ; .short %c0" :: \ "i"(__LINE__), "i" (__stringify(__FILE__))) void out_of_line_bug(void); #else |