diff options
Diffstat (limited to 'libc/sysdeps/linux/ia64/clone2.S')
| -rw-r--r-- | libc/sysdeps/linux/ia64/clone2.S | 105 |
1 files changed, 105 insertions, 0 deletions
diff --git a/libc/sysdeps/linux/ia64/clone2.S b/libc/sysdeps/linux/ia64/clone2.S new file mode 100644 index 000000000..af621662c --- /dev/null +++ b/libc/sysdeps/linux/ia64/clone2.S @@ -0,0 +1,105 @@ +/* Copyright (C) 2000, 2001, 2003, 2004 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 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 + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307 USA. */ + +#include "sysdep.h" + +#include "sysdep.h" +#include <asm/errno.h> + + +/* int __clone2(int (*fn) (void *arg), void *child_stack_base, */ +/* size_t child_stack_size, int flags, void *arg, */ +/* pid_t *parent_tid, void *tls, pid_t *child_tid) */ + +#define CHILD p8 +#define PARENT p9 + +ENTRY(__clone2) + .prologue + alloc r2=ar.pfs,8,1,6,0 + cmp.eq p6,p0=0,in0 + mov r8=EINVAL + mov out0=in3 /* Flags are first syscall argument. */ + mov out1=in1 /* Stack address. */ +(p6) br.cond.spnt.many __syscall_error + ;; + mov out2=in2 /* Stack size. */ + mov out3=in5 /* Parent TID Pointer */ + mov out4=in7 /* Child TID Pointer */ + mov out5=in6 /* TLS pointer */ + /* + * clone2() is special: the child cannot execute br.ret right + * after the system call returns, because it starts out + * executing on an empty stack. Because of this, we can't use + * the new (lightweight) syscall convention here. Instead, we + * just fall back on always using "break". + * + * Furthermore, since the child starts with an empty stack, we + * need to avoid unwinding past invalid memory. To that end, + * we'll pretend now that __clone2() is the end of the + * call-chain. This is wrong for the parent, but only until + * it returns from clone2() but it's better than the + * alternative. + */ + mov r15=SYS_ify (clone2) + .save rp, r0 + break __BREAK_SYSCALL + .body + cmp.eq p6,p0=-1,r10 + cmp.eq CHILD,PARENT=0,r8 /* Are we the child? */ +(p6) br.cond.spnt.many __syscall_error + ;; +(CHILD) mov loc0=gp +(PARENT) ret + ;; +#ifdef RESET_PID + tbit.nz p6,p0=in3,16 /* CLONE_THREAD */ + tbit.z p7,p10=in3,8 /* CLONE_VM */ +(p6) br.cond.dptk 1f + ;; + mov r15=SYS_ify (getpid) +(p10) addl r8=-1,r0 +(p7) break __BREAK_SYSCALL + ;; + add r9=PID,r13 + add r10=TID,r13 + ;; + st4 [r9]=r8 + st4 [r10]=r8 + ;; +#endif +1: ld8 out1=[in0],8 /* Retrieve code pointer. */ + mov out0=in4 /* Pass proper argument to fn */ + ;; + ld8 gp=[in0] /* Load function gp. */ + mov b6=out1 + br.call.dptk.many rp=b6 /* Call fn(arg) in the child */ + ;; + mov out0=r8 /* Argument to _exit */ + mov gp=loc0 + .globl HIDDEN_JUMPTARGET(_exit) + br.call.dpnt.many rp=HIDDEN_JUMPTARGET(_exit) + /* call _exit with result from fn. */ + ret /* Not reached. */ +PSEUDO_END(__clone2) + +/* For now we leave __clone undefined. This is unlikely to be a */ +/* problem, since at least the i386 __clone in glibc always failed */ +/* with a 0 sp (eventhough the kernel explicitly handled it). */ +/* Thus all such calls needed to pass an explicit sp, and as a result, */ +/* would be unlikely to work on ia64. */ |