Messages in this thread Patch in this message | | | Date | Sun, 23 Nov 2008 19:14:55 +0300 | From | Cyrill Gorcunov <> | Subject | [RFC -tip] x86: introduce X86_ assembly names macros to catch unbalanced declaration |
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It's usefull to catch unbalanced or messed declarations of ENTRY and KPROBES. These macros would help a bit (at least I hope so).
For example the following code would compile without problems
X86_ENTRY(mcount) retq X86_END(mcount)
But if you forget and mess the following form
X86_ENTRY(mcount) retq END(mcount)
X86_ENTRY(ftrace_caller)
The assembler will issue the following message: Error: X86_ENTRY/KPROBE unbalanced or missed
Actually the checking is performed at every X86_ macro so maybe it's good idea to put __x86_check_entry_kprobe at the end of .S file to be sure you didn't miss anything.
Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com> ---
Anyway -- it's just a RFC -- so I hope there will not be much screams of hate :-)
arch/x86/include/asm/linkage.h | 58 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 58 insertions(+)
Index: linux-2.6.git/arch/x86/include/asm/linkage.h =================================================================== --- linux-2.6.git.orig/arch/x86/include/asm/linkage.h +++ linux-2.6.git/arch/x86/include/asm/linkage.h @@ -57,5 +57,63 @@ #define __ALIGN_STR ".align 16,0x90" #endif +/* + * to check X86_ENTRY/X86_END and + * X86_KPROBE_ENTRY/X86_KPROBE_END + * unbalanced/messed appearance + */ +#define __x86_set_entry .set _X86_ENTRY_IN, 0 +#define __x86_unset_entry .set _X86_ENTRY_IN, 1 +#define __x86_set_kprobe .set _X86_KPROBE_IN, 0 +#define __x86_unset_kprobe .set _X86_KPROBE_IN, 1 + +#define __x86_macro_err .error "X86_ENTRY/KPROBE unbalanced or missed" + +#define __x86_check_entry \ + .ifdef _X86_ENTRY_IN; \ + .ifeq _X86_ENTRY_IN; \ + __x86_macro_err; \ + .abort; \ + .endif; \ + .endif + +#define __x86_check_kprobe \ + .ifdef _X86_KPROBE_IN; \ + .ifeq _X86_KPROBE_IN; \ + __x86_macro_err; \ + .abort; \ + .endif; \ + .endif + +#define __x86_check_entry_kprobe \ + __x86_check_entry; \ + __x86_check_kprobe + +#define X86_ENTRY(name) \ + __x86_check_entry_kprobe; \ + __x86_set_entry; \ + .globl name; \ + __ALIGN; \ + name: + +#define X86_KPROBE_ENTRY(name) \ + __x86_check_entry_kprobe; \ + __x86_set_kprobe; \ + .pushsection .kprobes.text, "ax"; \ + .globl name; \ + __ALIGN; \ + name: + +#define X86_KPROBE_END(name) \ + __x86_unset_kprobe; \ + __x86_check_entry_kprobe; \ + .size name, .-name; \ + .popsection + +#define X86_END(name) \ + __x86_unset_entry; \ + __x86_check_entry_kprobe; \ + .size name, .-name + #endif /* _ASM_X86_LINKAGE_H */
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