diff options
Diffstat (limited to 'sysdeps/unix/sysv/linux/mips/clone.S')
| -rw-r--r-- | sysdeps/unix/sysv/linux/mips/clone.S | 125 |
1 files changed, 125 insertions, 0 deletions
diff --git a/sysdeps/unix/sysv/linux/mips/clone.S b/sysdeps/unix/sysv/linux/mips/clone.S new file mode 100644 index 0000000000..357f70e47f --- /dev/null +++ b/sysdeps/unix/sysv/linux/mips/clone.S @@ -0,0 +1,125 @@ +/* Copyright (C) 1996, 1997 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Ralf Baechle <ralf@gnu.ai.mit.edu>, 1996. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Library General Public License as + published by the Free Software Foundation; either version 2 of the + License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Library General Public License for more details. + + You should have received a copy of the GNU Library General Public + License along with the GNU C Library; see the file COPYING.LIB. If not, + write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, + Boston, MA 02111-1307, USA. */ + +/* clone() is even more special than fork() as it mucks with stacks + and invokes a function in the right context after its all over. */ + +#include <sys/asm.h> +#include <asm/unistd.h> +#include <sysdep.h> +#define _ERRNO_H 1 +#include <bits/errno.h> + +/* int clone(int (*fn)(), void *child_stack, int flags, int nargs, ...) */ + +#define FRAMESZ 4*SZREG +#if _MIPS_SIM == _MIPS_SIM_ABI32 +#define MAX_REG_ARGS 4 +#else +#define MAX_REG_ARGS 6 +#endif + + .text +NESTED(__clone,4*SZREG,sp) +#ifdef __PIC__ + .set noreorder + .cpload $25 + .set reorder + .cprestore 16 +#endif + PTR_SUBIU sp,FRAMESZ +#ifdef PROF + .set noat + move $1,ra + jal _mcount + .set at +#endif + + /* Sanity check arguments. */ + li v0,EINVAL + beqz a0,error /* no NULL function pointers */ + beqz a1,error /* no NULL stack pointers */ + bltz a3,error /* no negative argument counts */ + + /* Allocate space on the new stack and copy args over */ + move t0,a3 # save nargs for __thread_start + PTR_SLL t1,a3,PTR_SCALESHIFT + PTR_ADDU t1,a3,sp +1: REG_L t2,-SZREG(t1) + PTR_SUBIU t1,SZREG + REG_S t2,-SZREG(a1) + PTR_SUBIU a3,1 + PTR_SUBIU a1,SZREG + bnez a3,1b + + /* Do the system call */ + move t9,a0 # get fn ptr out of the way + move a0,a2 + li v0,__NR_clone + syscall + + bnez a3,error + beqz v0,__thread_start + + /* Successful return from the parent */ + PTR_ADDIU sp,FRAMESZ + ret + + /* Something bad happened -- no child created */ +error: + PTR_ADDIU sp,FRAMESZ +#ifdef PIC + la t9,__syscall_error + jr t9 +#else + j __syscall_error +#endif + END(__clone) + +/* Load up the arguments to the function. Put this block of code in + its own function so that we can terminate the stack trace with our + debug info. + + At this point we have t0=nargs, t9=fn, sp=&arg[0]. */ + +NESTED(__thread_start,32,sp) + /* Stackframe has been created on entry of clone() */ + /* Calculate address of jump into argument loading code */ + li t1,MAX_REG_ARGS + slt t0,t1,t2 /* max MAX_REG_ARGS args in registers */ + MOVN (t2,t1,t0) + la v0,arg0 + PTR_SLL t1,t0,PTR_SCALESHIFT + PTR_SUBU v0,t1 + jr v0 + + /* Load the integer register arguments */ + REG_L a0,SZREG(sp) +arg0: + + /* Call the user's function */ + jalr t9 + + /* Call _exit rather than doing it inline for breakpoint purposes */ + move a0,v0 + jal _exit + + END(__thread_start) + +weak_alias(__clone, clone) |