1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
|
#ifndef _BITS_SYSCALLS_H
#define _BITS_SYSCALLS_H
#ifndef _SYSCALL_H
# error "Never use <bits/syscalls.h> directly; include <sys/syscall.h> instead."
#endif
/*
* Some of the sneaky macros in the code were taken from
* glibc-2.2.5/sysdeps/unix/sysv/linux/i386/sysdep.h
*/
#ifndef __ASSEMBLER__
#include <errno.h>
/* We need some help from the assembler to generate optimal code.
* We define some macros here which later will be used. */
#if defined __SUPPORT_LD_DEBUG__ && defined __DOMULTI__
#error LD debugging and DOMULTI are incompatible
#endif
__asm__ (
#ifdef __DOMULTI__
/* Protect against asm macro redefinition (happens in __DOMULTI__ mode).
* Unfortunately, it ends up visible in .o files. */
".ifndef _BITS_SYSCALLS_ASM\n\t"
".set _BITS_SYSCALLS_ASM,1\n\t"
#endif
".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"
/* Loading param #1 (ebx) is done by loading it into
* another register, and then performing bpushl+bmovl,
* since we must preserve ebx */
".macro bpushl name reg\n\t"
".if 1 - \\name\n\t" /* if reg!=ebx... */
".if 2 - \\name\n\t" /* if reg can't be clobbered... */
"pushl %ebx\n\t" /* save ebx on stack */
".else\n\t"
"xchgl \\reg, %ebx\n\t" /* else save ebx in reg, and load reg to ebx */
".endif\n\t"
".endif\n\t"
".endm\n\t"
".macro bmovl name reg\n\t"
".if 1 - \\name\n\t"
".if 2 - \\name\n\t" /* if reg can't be clobbered... */
"movl \\reg, %ebx\n\t" /* load reg to ebx */
".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" /* if reg can't be clobbered... */
"popl %ebx\n\t" /* restore ebx from stack */
".else\n\t"
"xchgl \\reg, %ebx\n\t" /* else restore ebx from reg */
".endif\n\t"
".endif\n\t"
".endm\n\t"
#ifdef __DOMULTI__
".endif\n\t" /* _BITS_SYSCALLS_ASM */
#endif
);
#define INTERNAL_SYSCALL_NCS(name, err, nr, args...) \
({ \
register unsigned int resultvar; \
__asm__ __volatile__ ( \
LOADARGS_##nr \
"movl %1, %%eax\n\t" \
"int $0x80\n\t" \
RESTOREARGS_##nr \
: "=a" (resultvar) \
: "i" (name) ASMFMT_##nr(args) : "memory", "cc" \
); \
(int) resultvar; \
})
#define LOADARGS_0
#define LOADARGS_1 "bpushl .L__X'%k2, %k2\n\t" "bmovl .L__X'%k2, %k2\n\t"
#define LOADARGS_2 LOADARGS_1
#define LOADARGS_3 LOADARGS_1
#define LOADARGS_4 LOADARGS_1
#define LOADARGS_5 LOADARGS_1
#define LOADARGS_6 LOADARGS_1 "push %%ebp\n\t" "movl %7, %%ebp\n\t"
#define RESTOREARGS_0
#define RESTOREARGS_1 "bpopl .L__X'%k2, %k2\n\t"
#define RESTOREARGS_2 RESTOREARGS_1
#define RESTOREARGS_3 RESTOREARGS_1
#define RESTOREARGS_4 RESTOREARGS_1
#define RESTOREARGS_5 RESTOREARGS_1
#define RESTOREARGS_6 "pop %%ebp\n\t" RESTOREARGS_1
#define ASMFMT_0()
/* "acdSD" constraint would work too, but "SD" would use esi/edi and cause
* them to be pushed/popped by compiler, "a" would use eax and cause ebx
* to be saved/restored on stack, not in register. Narrowing choice down
* to "ecx or edx" results in smaller and faster code: */
#define ASMFMT_1(arg1) \
, "cd" (arg1)
/* Can use "adSD" constraint here: */
#define ASMFMT_2(arg1, arg2) \
, "d" (arg1), "c" (arg2)
/* Can use "aSD" constraint here: */
#define ASMFMT_3(arg1, arg2, arg3) \
, "a" (arg1), "c" (arg2), "d" (arg3)
/* Can use "aD" constraint here: */
#define ASMFMT_4(arg1, arg2, arg3, arg4) \
, "a" (arg1), "c" (arg2), "d" (arg3), "S" (arg4)
#define ASMFMT_5(arg1, arg2, arg3, arg4, arg5) \
, "a" (arg1), "c" (arg2), "d" (arg3), "S" (arg4), "D" (arg5)
#define ASMFMT_6(arg1, arg2, arg3, arg4, arg5, arg6) \
, "a" (arg1), "c" (arg2), "d" (arg3), "S" (arg4), "D" (arg5), "m" (arg6)
#endif /* __ASSEMBLER__ */
#endif /* _BITS_SYSCALLS_H */
|
