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| author | Jan Beulich <jbeulich@novell.com> | 2005-09-12 18:49:25 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2005-09-12 10:50:58 -0700 |
| commit | 049cdefe19f95b67b06b70915cd8e4ae7173337a (patch) | |
| tree | 42a0846ec18e3c4f705f8f167890675c5978a814 | |
| parent | c47a3167d0454c0af5fb0a0322b01a0e3487798e (diff) | |
| download | blackbird-op-linux-049cdefe19f95b67b06b70915cd8e4ae7173337a.tar.gz blackbird-op-linux-049cdefe19f95b67b06b70915cd8e4ae7173337a.zip | |
[PATCH] x86-64: reduce x86-64 bug frame by 4 bytes
As mentioned before, the size of the bug frame can be further reduced while
continuing to use instructions to encode the information.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
| -rw-r--r-- | arch/x86_64/kernel/traps.c | 8 | ||||
| -rw-r--r-- | include/asm-x86_64/bug.h | 10 |
2 files changed, 8 insertions, 10 deletions
diff --git a/arch/x86_64/kernel/traps.c b/arch/x86_64/kernel/traps.c index 1dfeb07d31cc..b5e09e6b5536 100644 --- a/arch/x86_64/kernel/traps.c +++ b/arch/x86_64/kernel/traps.c @@ -321,13 +321,13 @@ void handle_BUG(struct pt_regs *regs) if (__copy_from_user(&f, (struct bug_frame *) regs->rip, sizeof(struct bug_frame))) return; - if ((unsigned long)f.filename < __PAGE_OFFSET || + if (f.filename >= 0 || f.ud2[0] != 0x0f || f.ud2[1] != 0x0b) return; - if (__get_user(tmp, f.filename)) - f.filename = "unmapped filename"; + if (__get_user(tmp, (char *)(long)f.filename)) + f.filename = (int)(long)"unmapped filename"; printk("----------- [cut here ] --------- [please bite here ] ---------\n"); - printk(KERN_ALERT "Kernel BUG at %.50s:%d\n", f.filename, f.line); + printk(KERN_ALERT "Kernel BUG at %.50s:%d\n", (char *)(long)f.filename, f.line); } #ifdef CONFIG_BUG diff --git a/include/asm-x86_64/bug.h b/include/asm-x86_64/bug.h index eed785667289..80ac1fe966ac 100644 --- a/include/asm-x86_64/bug.h +++ b/include/asm-x86_64/bug.h @@ -9,10 +9,8 @@ */ struct bug_frame { unsigned char ud2[2]; - unsigned char mov; - /* should use 32bit offset instead, but the assembler doesn't - like it */ - char *filename; + unsigned char push; + signed int filename; unsigned char ret; unsigned short line; } __attribute__((packed)); @@ -25,8 +23,8 @@ struct bug_frame { 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__))) + "ud2 ; pushq $%c1 ; ret $%c0" :: \ + "i"(__LINE__), "i" (__FILE__)) void out_of_line_bug(void); #else static inline void out_of_line_bug(void) { } |
