Black Lives Matter. Support the Equal Justice Initiative.

Text file src/syscall/asm_linux_386.s

Documentation: syscall

     1  // Copyright 2009 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  #include "textflag.h"
     6  #include "funcdata.h"
     7  
     8  //
     9  // System calls for 386, Linux
    10  //
    11  
    12  // See ../runtime/sys_linux_386.s for the reason why we always use int 0x80
    13  // instead of the glibc-specific "CALL 0x10(GS)".
    14  #define INVOKE_SYSCALL	INT	$0x80
    15  
    16  // func Syscall(trap uintptr, a1, a2, a3 uintptr) (r1, r2, err uintptr);
    17  // Trap # in AX, args in BX CX DX SI DI, return in AX
    18  TEXT ·Syscall(SB),NOSPLIT,$0-28
    19  	CALL	runtime·entersyscall(SB)
    20  	MOVL	trap+0(FP), AX	// syscall entry
    21  	MOVL	a1+4(FP), BX
    22  	MOVL	a2+8(FP), CX
    23  	MOVL	a3+12(FP), DX
    24  	MOVL	$0, SI
    25  	MOVL	$0, DI
    26  	INVOKE_SYSCALL
    27  	CMPL	AX, $0xfffff001
    28  	JLS	ok
    29  	MOVL	$-1, r1+16(FP)
    30  	MOVL	$0, r2+20(FP)
    31  	NEGL	AX
    32  	MOVL	AX, err+24(FP)
    33  	CALL	runtime·exitsyscall(SB)
    34  	RET
    35  ok:
    36  	MOVL	AX, r1+16(FP)
    37  	MOVL	DX, r2+20(FP)
    38  	MOVL	$0, err+24(FP)
    39  	CALL	runtime·exitsyscall(SB)
    40  	RET
    41  
    42  // func Syscall6(trap uintptr, a1, a2, a3, a4, a5, a6 uintptr) (r1, r2, err uintptr);
    43  TEXT ·Syscall6(SB),NOSPLIT,$0-40
    44  	CALL	runtime·entersyscall(SB)
    45  	MOVL	trap+0(FP), AX	// syscall entry
    46  	MOVL	a1+4(FP), BX
    47  	MOVL	a2+8(FP), CX
    48  	MOVL	a3+12(FP), DX
    49  	MOVL	a4+16(FP), SI
    50  	MOVL	a5+20(FP), DI
    51  	MOVL	a6+24(FP), BP
    52  	INVOKE_SYSCALL
    53  	CMPL	AX, $0xfffff001
    54  	JLS	ok6
    55  	MOVL	$-1, r1+28(FP)
    56  	MOVL	$0, r2+32(FP)
    57  	NEGL	AX
    58  	MOVL	AX, err+36(FP)
    59  	CALL	runtime·exitsyscall(SB)
    60  	RET
    61  ok6:
    62  	MOVL	AX, r1+28(FP)
    63  	MOVL	DX, r2+32(FP)
    64  	MOVL	$0, err+36(FP)
    65  	CALL	runtime·exitsyscall(SB)
    66  	RET
    67  
    68  // func RawSyscall(trap uintptr, a1, a2, a3 uintptr) (r1, r2, err uintptr);
    69  TEXT ·RawSyscall(SB),NOSPLIT,$0-28
    70  	MOVL	trap+0(FP), AX	// syscall entry
    71  	MOVL	a1+4(FP), BX
    72  	MOVL	a2+8(FP), CX
    73  	MOVL	a3+12(FP), DX
    74  	MOVL	$0, SI
    75  	MOVL	$0, DI
    76  	INVOKE_SYSCALL
    77  	CMPL	AX, $0xfffff001
    78  	JLS	ok1
    79  	MOVL	$-1, r1+16(FP)
    80  	MOVL	$0, r2+20(FP)
    81  	NEGL	AX
    82  	MOVL	AX, err+24(FP)
    83  	RET
    84  ok1:
    85  	MOVL	AX, r1+16(FP)
    86  	MOVL	DX, r2+20(FP)
    87  	MOVL	$0, err+24(FP)
    88  	RET
    89  
    90  // func RawSyscall6(trap uintptr, a1, a2, a3, a4, a5, a6 uintptr) (r1, r2, err uintptr);
    91  TEXT ·RawSyscall6(SB),NOSPLIT,$0-40
    92  	MOVL	trap+0(FP), AX	// syscall entry
    93  	MOVL	a1+4(FP), BX
    94  	MOVL	a2+8(FP), CX
    95  	MOVL	a3+12(FP), DX
    96  	MOVL	a4+16(FP), SI
    97  	MOVL	a5+20(FP), DI
    98  	MOVL	a6+24(FP), BP
    99  	INVOKE_SYSCALL
   100  	CMPL	AX, $0xfffff001
   101  	JLS	ok2
   102  	MOVL	$-1, r1+28(FP)
   103  	MOVL	$0, r2+32(FP)
   104  	NEGL	AX
   105  	MOVL	AX, err+36(FP)
   106  	RET
   107  ok2:
   108  	MOVL	AX, r1+28(FP)
   109  	MOVL	DX, r2+32(FP)
   110  	MOVL	$0, err+36(FP)
   111  	RET
   112  
   113  // func rawSyscallNoError(trap uintptr, a1, a2, a3 uintptr) (r1, r2 uintptr);
   114  TEXT ·rawSyscallNoError(SB),NOSPLIT,$0-24
   115  	MOVL	trap+0(FP), AX	// syscall entry
   116  	MOVL	a1+4(FP), BX
   117  	MOVL	a2+8(FP), CX
   118  	MOVL	a3+12(FP), DX
   119  	MOVL	$0, SI
   120  	MOVL	$0, DI
   121  	INVOKE_SYSCALL
   122  	MOVL	AX, r1+16(FP)
   123  	MOVL	DX, r2+20(FP)
   124  	RET
   125  
   126  #define SYS_SOCKETCALL 102	/* from zsysnum_linux_386.go */
   127  
   128  // func socketcall(call int, a0, a1, a2, a3, a4, a5 uintptr) (n int, err int)
   129  // Kernel interface gets call sub-number and pointer to a0.
   130  TEXT ·socketcall(SB),NOSPLIT,$0-36
   131  	CALL	runtime·entersyscall(SB)
   132  	MOVL	$SYS_SOCKETCALL, AX	// syscall entry
   133  	MOVL	call+0(FP), BX	// socket call number
   134  	LEAL	a0+4(FP), CX	// pointer to call arguments
   135  	MOVL	$0, DX
   136  	MOVL	$0, SI
   137  	MOVL	$0, DI
   138  	INVOKE_SYSCALL
   139  	CMPL	AX, $0xfffff001
   140  	JLS	oksock
   141  	MOVL	$-1, n+28(FP)
   142  	NEGL	AX
   143  	MOVL	AX, err+32(FP)
   144  	CALL	runtime·exitsyscall(SB)
   145  	RET
   146  oksock:
   147  	MOVL	AX, n+28(FP)
   148  	MOVL	$0, err+32(FP)
   149  	CALL	runtime·exitsyscall(SB)
   150  	RET
   151  
   152  // func rawsocketcall(call int, a0, a1, a2, a3, a4, a5 uintptr) (n int, err int)
   153  // Kernel interface gets call sub-number and pointer to a0.
   154  TEXT ·rawsocketcall(SB),NOSPLIT,$0-36
   155  	MOVL	$SYS_SOCKETCALL, AX	// syscall entry
   156  	MOVL	call+0(FP), BX	// socket call number
   157  	LEAL		a0+4(FP), CX	// pointer to call arguments
   158  	MOVL	$0, DX
   159  	MOVL	$0, SI
   160  	MOVL	$0, DI
   161  	INVOKE_SYSCALL
   162  	CMPL	AX, $0xfffff001
   163  	JLS	oksock1
   164  	MOVL	$-1, n+28(FP)
   165  	NEGL	AX
   166  	MOVL	AX, err+32(FP)
   167  	RET
   168  oksock1:
   169  	MOVL	AX, n+28(FP)
   170  	MOVL	$0, err+32(FP)
   171  	RET
   172  
   173  #define SYS__LLSEEK 140	/* from zsysnum_linux_386.go */
   174  // func Seek(fd int, offset int64, whence int) (newoffset int64, err int)
   175  // Implemented in assembly to avoid allocation when
   176  // taking the address of the return value newoffset.
   177  // Underlying system call is
   178  //	llseek(int fd, int offhi, int offlo, int64 *result, int whence)
   179  TEXT ·seek(SB),NOSPLIT,$0-28
   180  	CALL	runtime·entersyscall(SB)
   181  	MOVL	$SYS__LLSEEK, AX	// syscall entry
   182  	MOVL	fd+0(FP), BX
   183  	MOVL	offset_hi+8(FP), CX
   184  	MOVL	offset_lo+4(FP), DX
   185  	LEAL	newoffset_lo+16(FP), SI	// result pointer
   186  	MOVL	whence+12(FP), DI
   187  	INVOKE_SYSCALL
   188  	CMPL	AX, $0xfffff001
   189  	JLS	okseek
   190  	MOVL	$-1, newoffset_lo+16(FP)
   191  	MOVL	$-1, newoffset_hi+20(FP)
   192  	NEGL	AX
   193  	MOVL	AX, err+24(FP)
   194  	CALL	runtime·exitsyscall(SB)
   195  	RET
   196  okseek:
   197  	// system call filled in newoffset already
   198  	MOVL	$0, err+24(FP)
   199  	CALL	runtime·exitsyscall(SB)
   200  	RET
   201  

View as plain text