diff options
Diffstat (limited to 'sysdeps/unix/sysv/linux/alpha/clone.S')
| -rw-r--r-- | sysdeps/unix/sysv/linux/alpha/clone.S | 118 |
1 files changed, 118 insertions, 0 deletions
diff --git a/sysdeps/unix/sysv/linux/alpha/clone.S b/sysdeps/unix/sysv/linux/alpha/clone.S new file mode 100644 index 0000000000..a1ef324956 --- /dev/null +++ b/sysdeps/unix/sysv/linux/alpha/clone.S @@ -0,0 +1,118 @@ +/* Copyright (C) 1996 Free Software Foundation, Inc. + Contributed by Richard Henderson (rth@tamu.edu) + +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., 675 Mass Ave, +Cambridge, MA 02139, 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 <sysdep.h> +#include <errnos.h> + +/* int clone(int (*fn)(), void *child_stack, int flags, int nargs, ...) */ + + .text +ENTRY(__clone) + lda sp,-16(sp) + .frame sp,16,$26,0 + /* Save rest of argument registers for varargs-type work. */ + stq a4,0(sp) + stq a5,8(sp) + .prologue 1 + + /* Sanity check arguments. */ + sextl a3,a3 + ldiq v0,EINVAL + beq a0,$error /* no NULL function pointers */ + beq a1,$error /* no NULL stack pointers */ + blt a3,$error /* no negative argument counts */ + + /* Allocate space on the new stack and copy args over */ + mov a3,t0 /* save nargs for thread_start */ + s8addq a3,sp,t1 +1: ldq t2,-8(t1) + subq t1,8,t1 + stq t2,-8(a1) + subq a3,1,a3 + subq a1,8,a1 + bne a3,1b + + /* Do the system call */ + mov a0,pv /* get fn ptr out of the way */ + mov a2,a0 + ldiq v0,__NR_clone + call_pal PAL_callsys + + bne a3,$error + beq v0,thread_start + + /* Successful return from the parent */ + lda sp,16(sp) + ret + + /* Something bad happened -- no child created */ +$error: + br gp,1f +1: ldgp gp,0(gp) + lda sp,16(sp) + jmp zero,__syscall_error + + 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, $pv=fn, $sp=&arg[0]. */ + + .ent thread_start +thread_start: + .frame fp,0,zero,0 + mov zero,fp + .prologue 0 + + /* Calculate address of jump into argument loading code */ + cmple t0,6,t2 /* no more than 6 args in registers */ + cmoveq t2,6,t0 + br v0,1f /* find address of arg0 */ +1: lda v0,$arg0-1b(v0) + s4addq t0,zero,t1 + subq v0,t1,v0 + jmp (v0) + + /* Load the integer register arguments */ + ldq a5,40(sp) + ldq a4,32(sp) + ldq a3,24(sp) + ldq a2,16(sp) + ldq a1,8(sp) + ldq a0,0(sp) +$arg0: + + /* Adjust stack to remove the arguments we just loaded */ + s8addq t0,sp,sp + + /* Call the user's function */ + jsr ra,(pv) + ldgp gp,0(ra) + + /* Call _exit rather than doing it inline for breakpoint purposes */ + mov v0,a0 + jsr ra,_exit + + .end thread_start + +weak_alias(__clone, clone) |