/* Copyright (C) 2005-2013 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 <sys/syscall.h> #define _SIGNAL_H #include <bits/signum.h> #define __ASSEMBLY__ #include <linux/sched.h> /* Clone the calling process, but without copying the whole address space. The calling process is suspended until the new process exits or is replaced by a call to `execve'. Return -1 for errors, 0 to the new process, and the process ID of the new process to the old process. Note that it is important that we don't create a new stack frame for the caller. */ /* pid_t vfork(void); Implemented as __clone_syscall(CLONE_VFORK | CLONE_VM | SIGCHLD, 0) */ HIDDEN_ENTRY (__vfork) #if defined(__XTENSA_WINDOWED_ABI__) .literal .Ljumptable, 0, .L4, .L8, .L12 mov a3, a0 # move return address out of the way movi a0, .Ljumptable extui a2, a3, 30, 2 # call-size: call4/8/12 = 1/2/3 addx4 a0, a2, a0 # find return address in jumptable l32i a0, a0, 0 # exchange top 2 bits of a0 and a3: xor a2, a0, a3 extui a2, a2, 30, 2 slli a2, a2, 30 xor a0, a0, a2 xor a3, a3, a2 retw /* a7: return address */ .L4: mov a12, a2 mov a13, a3 /* use syscall 'clone' and set new stack pointer to the same address */ movi a2, SYS_ify(clone) movi a3, 0 movi a6, CLONE_VM | CLONE_VFORK | SIGCHLD syscall movi a5, -4096 mov a6, a2 mov a2, a12 mov a3, a13 bgeu a6, a5, 1f jx a7 1: call4 .Lerr /* a11: return address */ .L8: mov a12, a2 mov a13, a3 mov a14, a6 movi a2, SYS_ify(clone) movi a3, 0 movi a6, CLONE_VM | CLONE_VFORK | SIGCHLD syscall movi a9, -4096 mov a10, a2 mov a2, a12 mov a3, a13 mov a6, a14 bgeu a10, a9, 1f jx a11 1: call8 .Lerr /* a15: return address */ .L12: mov a12, a2 mov a13, a3 mov a14, a6 movi a2, SYS_ify(clone) movi a3, 0 movi a6, CLONE_VM | CLONE_VFORK | SIGCHLD syscall mov a3, a13 movi a13, -4096 mov a6, a14 mov a14, a2 mov a2, a12 bgeu a14, a13, 1f jx a15 1: call12 .Lerr .align 4 .Lerr: entry a1, 16 /* Restore return address */ extui a4, a0, 30, 2 slli a4, a4, 30 or a0, a3, a4 PSEUDO_END (__vfork) .Lpseudo_end: retw #elif defined(__XTENSA_CALL0_ABI__) /* Use syscall 'clone'. Set new stack pointer to the same address. */ movi a2, SYS_ify (clone) movi a3, 0 movi a6, CLONE_VM | CLONE_VFORK | SIGCHLD syscall movi a3, -4096 bgeu a2, a3, 1f ret 1: PSEUDO_END (__vfork) .Lpseudo_end: ret #else #error Unsupported Xtensa ABI #endif weak_alias (__vfork, vfork) libc_hidden_def(vfork)