linux/arch/x86/include/asm/linkage.h
Cyrill Gorcunov 3b6c52b5b6 x86: introduce ENTRY(KPROBE_ENTRY)_X86 assembly helpers to catch unbalanced declaration v3
Impact: make ENTRY()/END() macros more capable

It's usefull to catch unbalanced or messed or mixed declarations of ENTRY and
KPROBES. These macros would help a bit.

For example the following code would compile without problems

        ENTRY_X86(mcount)
                retq
        END_X86(mcount)

But if you forget and mess the following form

        ENTRY_X86(mcount)
                retq
        END(mcount)

        ENTRY_X86(ftrace_caller)

The assembler will issue the following message:
Error: ENTRY_X86/KPROBE_X86 unbalanced,missed,mixed

Actually the checking is performed at every _X86 macro
so maybe it's good idea to put ENTRY_KPROBE_FINAL_X86
at the end of .S file to be sure you didn't miss anything.

Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
Cc: Alexander van Heukelum <heukelum@mailshack.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-23 19:57:01 +01:00

122 lines
3.3 KiB
C

#ifndef _ASM_X86_LINKAGE_H
#define _ASM_X86_LINKAGE_H
#undef notrace
#define notrace __attribute__((no_instrument_function))
#ifdef CONFIG_X86_64
#define __ALIGN .p2align 4,,15
#define __ALIGN_STR ".p2align 4,,15"
#endif
#ifdef CONFIG_X86_32
#define asmlinkage CPP_ASMLINKAGE __attribute__((regparm(0)))
/*
* For 32-bit UML - mark functions implemented in assembly that use
* regparm input parameters:
*/
#define asmregparm __attribute__((regparm(3)))
/*
* Make sure the compiler doesn't do anything stupid with the
* arguments on the stack - they are owned by the *caller*, not
* the callee. This just fools gcc into not spilling into them,
* and keeps it from doing tailcall recursion and/or using the
* stack slots for temporaries, since they are live and "used"
* all the way to the end of the function.
*
* NOTE! On x86-64, all the arguments are in registers, so this
* only matters on a 32-bit kernel.
*/
#define asmlinkage_protect(n, ret, args...) \
__asmlinkage_protect##n(ret, ##args)
#define __asmlinkage_protect_n(ret, args...) \
__asm__ __volatile__ ("" : "=r" (ret) : "0" (ret), ##args)
#define __asmlinkage_protect0(ret) \
__asmlinkage_protect_n(ret)
#define __asmlinkage_protect1(ret, arg1) \
__asmlinkage_protect_n(ret, "g" (arg1))
#define __asmlinkage_protect2(ret, arg1, arg2) \
__asmlinkage_protect_n(ret, "g" (arg1), "g" (arg2))
#define __asmlinkage_protect3(ret, arg1, arg2, arg3) \
__asmlinkage_protect_n(ret, "g" (arg1), "g" (arg2), "g" (arg3))
#define __asmlinkage_protect4(ret, arg1, arg2, arg3, arg4) \
__asmlinkage_protect_n(ret, "g" (arg1), "g" (arg2), "g" (arg3), \
"g" (arg4))
#define __asmlinkage_protect5(ret, arg1, arg2, arg3, arg4, arg5) \
__asmlinkage_protect_n(ret, "g" (arg1), "g" (arg2), "g" (arg3), \
"g" (arg4), "g" (arg5))
#define __asmlinkage_protect6(ret, arg1, arg2, arg3, arg4, arg5, arg6) \
__asmlinkage_protect_n(ret, "g" (arg1), "g" (arg2), "g" (arg3), \
"g" (arg4), "g" (arg5), "g" (arg6))
#endif
#ifdef CONFIG_X86_ALIGNMENT_16
#define __ALIGN .align 16,0x90
#define __ALIGN_STR ".align 16,0x90"
#endif
/*
* to check ENTRY_X86/END_X86 and
* KPROBE_ENTRY_X86/KPROBE_END_X86
* unbalanced-missed-mixed appearance
*/
#define __set_entry_x86 .set ENTRY_X86_IN, 0
#define __unset_entry_x86 .set ENTRY_X86_IN, 1
#define __set_kprobe_x86 .set KPROBE_X86_IN, 0
#define __unset_kprobe_x86 .set KPROBE_X86_IN, 1
#define __macro_err_x86 .error "ENTRY_X86/KPROBE_X86 unbalanced,missed,mixed"
#define __check_entry_x86 \
.ifdef ENTRY_X86_IN; \
.ifeq ENTRY_X86_IN; \
__macro_err_x86; \
.abort; \
.endif; \
.endif
#define __check_kprobe_x86 \
.ifdef KPROBE_X86_IN; \
.ifeq KPROBE_X86_IN; \
__macro_err_x86; \
.abort; \
.endif; \
.endif
#define __check_entry_kprobe_x86 \
__check_entry_x86; \
__check_kprobe_x86
#define ENTRY_KPROBE_FINAL_X86 __check_entry_kprobe_x86
#define ENTRY_X86(name) \
__check_entry_kprobe_x86; \
__set_entry_x86; \
.globl name; \
__ALIGN; \
name:
#define END_X86(name) \
__unset_entry_x86; \
__check_entry_kprobe_x86; \
.size name, .-name
#define KPROBE_ENTRY_X86(name) \
__check_entry_kprobe_x86; \
__set_kprobe_x86; \
.pushsection .kprobes.text, "ax"; \
.globl name; \
__ALIGN; \
name:
#define KPROBE_END_X86(name) \
__unset_kprobe_x86; \
__check_entry_kprobe_x86; \
.size name, .-name; \
.popsection
#endif /* _ASM_X86_LINKAGE_H */