sysdep.h

glibc 2.9,最新版的C语言库函数

#define _POPARGS_5	_POPARGS_4; popl %edi; cfi_adjust_cfa_offset (-4); \
			cfi_restore (edi); L(POPDI1):

#define PUSHARGS_6	_PUSHARGS_6
#define DOARGS_6	_DOARGS_6 (40)
#define POPARGS_6	_POPARGS_6
#define _PUSHARGS_6	pushl %ebp; cfi_adjust_cfa_offset (4); \
			cfi_rel_offset (ebp, 0); L(PUSHBP1): _PUSHARGS_5
#define _DOARGS_6(n)	movl n(%esp), %ebp; _DOARGS_5 (n-4)
#define _POPARGS_6	_POPARGS_5; popl %ebp; cfi_adjust_cfa_offset (-4); \
			cfi_restore (ebp); L(POPBP1):

#else	/* !__ASSEMBLER__ */

/* We need some help from the assembler to generate optimal code.  We
   define some macros here which later will be used.  */
asm (".L__X'%ebx = 1\n\t"
     ".L__X'%ecx = 2\n\t"
     ".L__X'%edx = 2\n\t"
     ".L__X'%eax = 3\n\t"
     ".L__X'%esi = 3\n\t"
     ".L__X'%edi = 3\n\t"
     ".L__X'%ebp = 3\n\t"
     ".L__X'%esp = 3\n\t"
     ".macro bpushl name reg\n\t"
     ".if 1 - \\name\n\t"
     ".if 2 - \\name\n\t"
     "error\n\t"
     ".else\n\t"
     "xchgl \\reg, %ebx\n\t"
     ".endif\n\t"
     ".endif\n\t"
     ".endm\n\t"
     ".macro bpopl name reg\n\t"
     ".if 1 - \\name\n\t"
     ".if 2 - \\name\n\t"
     "error\n\t"
     ".else\n\t"
     "xchgl \\reg, %ebx\n\t"
     ".endif\n\t"
     ".endif\n\t"
     ".endm\n\t");

/* Define a macro which expands inline into the wrapper code for a system
   call.  */
#undef INLINE_SYSCALL
#define INLINE_SYSCALL(name, nr, args...) \
  ({									      \
    unsigned int resultvar = INTERNAL_SYSCALL (name, , nr, args);	      \
    if (__builtin_expect (INTERNAL_SYSCALL_ERROR_P (resultvar, ), 0))	      \
      {									      \
	__set_errno (INTERNAL_SYSCALL_ERRNO (resultvar, ));		      \
	resultvar = 0xffffffff;						      \
      }									      \
    (int) resultvar; })

/* Define a macro which expands inline into the wrapper code for a system
   call.  This use is for internal calls that do not need to handle errors
   normally.  It will never touch errno.  This returns just what the kernel
   gave back.

   The _NCS variant allows non-constant syscall numbers but it is not
   possible to use more than four parameters.  */
#undef INTERNAL_SYSCALL
#ifdef I386_USE_SYSENTER
# ifdef SHARED
#  define INTERNAL_SYSCALL(name, err, nr, args...) \
  ({									      \
    register unsigned int resultvar;					      \
    EXTRAVAR_##nr							      \
    asm volatile (							      \
    LOADARGS_##nr							      \
    "movl %1, %%eax\n\t"						      \
    "call *%%gs:%P2\n\t"						      \
    RESTOREARGS_##nr							      \
    : "=a" (resultvar)							      \
    : "i" (__NR_##name), "i" (offsetof (tcbhead_t, sysinfo))		      \
      ASMFMT_##nr(args) : "memory", "cc");				      \
    (int) resultvar; })
#  define INTERNAL_SYSCALL_NCS(name, err, nr, args...) \
  ({									      \
    register unsigned int resultvar;					      \
    EXTRAVAR_##nr							      \
    asm volatile (							      \
    LOADARGS_##nr							      \
    "call *%%gs:%P2\n\t"						      \
    RESTOREARGS_##nr							      \
    : "=a" (resultvar)							      \
    : "0" (name), "i" (offsetof (tcbhead_t, sysinfo))			      \
      ASMFMT_##nr(args) : "memory", "cc");				      \
    (int) resultvar; })
# else
#  define INTERNAL_SYSCALL(name, err, nr, args...) \
  ({									      \
    register unsigned int resultvar;					      \
    EXTRAVAR_##nr							      \
    asm volatile (							      \
    LOADARGS_##nr							      \
    "movl %1, %%eax\n\t"						      \
    "call *_dl_sysinfo\n\t"						      \
    RESTOREARGS_##nr							      \
    : "=a" (resultvar)							      \
    : "i" (__NR_##name) ASMFMT_##nr(args) : "memory", "cc");		      \
    (int) resultvar; })
#  define INTERNAL_SYSCALL_NCS(name, err, nr, args...) \
  ({									      \
    register unsigned int resultvar;					      \
    EXTRAVAR_##nr							      \
    asm volatile (							      \
    LOADARGS_##nr							      \
    "call *_dl_sysinfo\n\t"						      \
    RESTOREARGS_##nr							      \
    : "=a" (resultvar)							      \
    : "0" (name) ASMFMT_##nr(args) : "memory", "cc");			      \
    (int) resultvar; })
# endif
#else
# define INTERNAL_SYSCALL(name, err, nr, args...) \
  ({									      \
    register unsigned int resultvar;					      \
    EXTRAVAR_##nr							      \
    asm volatile (							      \
    LOADARGS_##nr							      \
    "movl %1, %%eax\n\t"						      \
    "int $0x80\n\t"							      \
    RESTOREARGS_##nr							      \
    : "=a" (resultvar)							      \
    : "i" (__NR_##name) ASMFMT_##nr(args) : "memory", "cc");		      \
    (int) resultvar; })
# define INTERNAL_SYSCALL_NCS(name, err, nr, args...) \
  ({									      \
    register unsigned int resultvar;					      \
    EXTRAVAR_##nr							      \
    asm volatile (							      \
    LOADARGS_##nr							      \
    "int $0x80\n\t"							      \
    RESTOREARGS_##nr							      \
    : "=a" (resultvar)							      \
    : "0" (name) ASMFMT_##nr(args) : "memory", "cc");			      \
    (int) resultvar; })
#endif

#undef INTERNAL_SYSCALL_DECL
#define INTERNAL_SYSCALL_DECL(err) do { } while (0)

#undef INTERNAL_SYSCALL_ERROR_P
#define INTERNAL_SYSCALL_ERROR_P(val, err) \
  ((unsigned int) (val) >= 0xfffff001u)

#undef INTERNAL_SYSCALL_ERRNO
#define INTERNAL_SYSCALL_ERRNO(val, err)	(-(val))

#define LOADARGS_0
#ifdef __PIC__
# if defined I386_USE_SYSENTER && defined SHARED
#  define LOADARGS_1 \
    "bpushl .L__X'%k3, %k3\n\t"
#  define LOADARGS_5 \
    "movl %%ebx, %4\n\t"						      \
    "movl %3, %%ebx\n\t"
# else
#  define LOADARGS_1 \
    "bpushl .L__X'%k2, %k2\n\t"
#  define LOADARGS_5 \
    "movl %%ebx, %3\n\t"						      \
    "movl %2, %%ebx\n\t"
# endif
# define LOADARGS_2	LOADARGS_1
# define LOADARGS_3 \
    "xchgl %%ebx, %%edi\n\t"
# define LOADARGS_4	LOADARGS_3
#else
# define LOADARGS_1
# define LOADARGS_2
# define LOADARGS_3
# define LOADARGS_4
# define LOADARGS_5
#endif

#define RESTOREARGS_0
#ifdef __PIC__
# if defined I386_USE_SYSENTER && defined SHARED
#  define RESTOREARGS_1 \
    "bpopl .L__X'%k3, %k3\n\t"
#  define RESTOREARGS_5 \
    "movl %4, %%ebx"
# else
#  define RESTOREARGS_1 \
    "bpopl .L__X'%k2, %k2\n\t"
#  define RESTOREARGS_5 \
    "movl %3, %%ebx"
# endif
# define RESTOREARGS_2	RESTOREARGS_1
# define RESTOREARGS_3 \
    "xchgl %%edi, %%ebx\n\t"
# define RESTOREARGS_4	RESTOREARGS_3
#else
# define RESTOREARGS_1
# define RESTOREARGS_2
# define RESTOREARGS_3
# define RESTOREARGS_4
# define RESTOREARGS_5
#endif

#define ASMFMT_0()
#ifdef __PIC__
# define ASMFMT_1(arg1) \
	, "cd" (arg1)
# define ASMFMT_2(arg1, arg2) \
	, "d" (arg1), "c" (arg2)
# define ASMFMT_3(arg1, arg2, arg3) \
	, "D" (arg1), "c" (arg2), "d" (arg3)
# define ASMFMT_4(arg1, arg2, arg3, arg4) \
	, "D" (arg1), "c" (arg2), "d" (arg3), "S" (arg4)
# define ASMFMT_5(arg1, arg2, arg3, arg4, arg5) \
	, "0" (arg1), "m" (_xv), "c" (arg2), "d" (arg3), "S" (arg4), "D" (arg5)
#else
# define ASMFMT_1(arg1) \
	, "b" (arg1)
# define ASMFMT_2(arg1, arg2) \
	, "b" (arg1), "c" (arg2)
# define ASMFMT_3(arg1, arg2, arg3) \
	, "b" (arg1), "c" (arg2), "d" (arg3)
# define ASMFMT_4(arg1, arg2, arg3, arg4) \
	, "b" (arg1), "c" (arg2), "d" (arg3), "S" (arg4)
# define ASMFMT_5(arg1, arg2, arg3, arg4, arg5) \
	, "b" (arg1), "c" (arg2), "d" (arg3), "S" (arg4), "D" (arg5)
#endif

#define EXTRAVAR_0
#define EXTRAVAR_1
#define EXTRAVAR_2
#define EXTRAVAR_3
#define EXTRAVAR_4
#ifdef __PIC__
# define EXTRAVAR_5 int _xv;
#else
# define EXTRAVAR_5
#endif

/* Consistency check for position-independent code.  */
#ifdef __PIC__
# define check_consistency()						      \
  ({ int __res;								      \
     __asm__ __volatile__						      \
       ("call __i686.get_pc_thunk.cx;"					      \
	"addl $_GLOBAL_OFFSET_TABLE_, %%ecx;"				      \
	"subl %%ebx, %%ecx;"						      \
	"je 1f;"							      \
	"ud2;"								      \
	"1:\n"								      \
	".section .gnu.linkonce.t.__i686.get_pc_thunk.cx,\"ax\",@progbits;"   \
	".globl __i686.get_pc_thunk.cx;"				      \
	".hidden __i686.get_pc_thunk.cx;"				      \
	".type __i686.get_pc_thunk.cx,@function;"			      \
	"__i686.get_pc_thunk.cx:"					      \
	"movl (%%esp), %%ecx;"						      \
	"ret;"								      \
	".previous"							      \
	: "=c" (__res));						      \
     __res; })
#endif

#endif	/* __ASSEMBLER__ */


/* Pointer mangling support.  */
#if defined NOT_IN_libc && defined IS_IN_rtld
/* We cannot use the thread descriptor because in ld.so we use setjmp
   earlier than the descriptor is initialized.  Using a global variable
   is too complicated here since we have no PC-relative addressing mode.  */
#else
# ifdef __ASSEMBLER__
#  define PTR_MANGLE(reg)	xorl %gs:POINTER_GUARD, reg;		      \
				roll $9, reg
#  define PTR_DEMANGLE(reg)	rorl $9, reg;				      \
				xorl %gs:POINTER_GUARD, reg
# else
#  define PTR_MANGLE(var)	asm ("xorl %%gs:%c2, %0\n"		      \
				     "roll $9, %0"			      \
				     : "=r" (var)			      \
				     : "0" (var),			      \
				       "i" (offsetof (tcbhead_t,	      \
						      pointer_guard)))
#  define PTR_DEMANGLE(var)	asm ("rorl $9, %0\n"			      \
				     "xorl %%gs:%c2, %0"		      \
				     : "=r" (var)			      \
				     : "0" (var),			      \
				       "i" (offsetof (tcbhead_t,	      \
						      pointer_guard)))
# endif
#endif

#endif /* linux/i386/sysdep.h */