| /* Copyright (C) 2000-2018 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, see |
| <http://www.gnu.org/licenses/>. */ |
| |
| |
| #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 |
| cmp.eq p7,p0=0,in1 |
| mov r8=EINVAL |
| mov out0=in3 /* Flags are first syscall argument. */ |
| mov out1=in1 /* Stack address. */ |
| (p6) br.cond.spnt.many __syscall_error /* no NULL function pointers */ |
| (p7) br.cond.spnt.many __syscall_error /* no NULL stack pointers */ |
| ;; |
| 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 |
| ;; |
| 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 |
| mov r15=SYS_ify (exit) |
| .save rp, r0 |
| break __BREAK_SYSCALL |
| ret /* Not reached. */ |
| PSEUDO_END(__clone2) |
| |
| libc_hidden_def (__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. */ |