diff options
Diffstat (limited to 'sysdeps/unix/sysv/linux/nios2/clone.S')
| -rw-r--r-- | sysdeps/unix/sysv/linux/nios2/clone.S | 107 |
1 files changed, 107 insertions, 0 deletions
diff --git a/sysdeps/unix/sysv/linux/nios2/clone.S b/sysdeps/unix/sysv/linux/nios2/clone.S new file mode 100644 index 0000000000..9fab461803 --- /dev/null +++ b/sysdeps/unix/sysv/linux/nios2/clone.S @@ -0,0 +1,107 @@ +/* clone() implementation for Nios II. + Copyright (C) 2008-2015 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Andrew Jenner <andrew@codesourcery.com>, 2008. + + 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/>. */ + +/* 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> +#define _ERRNO_H 1 +#include <bits/errno.h> +#include <tcb-offsets.h> + +#define CLONE_VM 0x00000100 +#define CLONE_THREAD 0x00010000 + +/* int clone(int (*fn)(void *arg), void *child_stack, int flags, void *arg, + void *parent_tidptr, void *tls, void *child_tidptr) */ + + .text +ENTRY(__clone) + /* Sanity check arguments. */ + movi r2, EINVAL + /* No NULL function pointers. */ + beq r4, zero, SYSCALL_ERROR_LABEL + /* No NULL stack pointers. */ + beq r5, zero, SYSCALL_ERROR_LABEL + + subi r5, r5, 8 /* Reserve argument save space. */ + stw r4, 4(r5) /* Save function pointer. */ + stw r7, 0(r5) /* Save argument pointer. */ + + /* Load arguments. */ + mov r4, r6 + ldw r6, 0(sp) + ldw r7, 8(sp) + ldw r8, 4(sp) + + /* Do the system call. */ + movi r2, SYS_ify (clone) + + /* End FDE now, because in the child the unwind info will be + wrong. */ + cfi_endproc + trap + + /* Check for errors. */ + bne r7, zero, SYSCALL_ERROR_LABEL + /* See if we're on the newly created thread. */ + beq r2, zero, thread_start + /* Successful return from the parent */ + ret + +thread_start: + cfi_startproc + cfi_undefined (ra) + + /* We expect the argument registers to be preserved across system + calls and across task cloning, so flags should be in r4 here. */ + andhi r2, r4, %hi(CLONE_THREAD) + bne r2, zero, 2f + andi r3, r4, CLONE_VM + movi r2, -1 + bne r3, zero, 3f + DO_CALL (getpid, 0) +3: + stw r2, PID_OFFSET(r23) + stw r2, TID_OFFSET(r23) +2: + ldw r5, 4(sp) /* Function pointer. */ + ldw r4, 0(sp) /* Argument pointer. */ + addi sp, sp, 8 + + /* Call the user's function. */ + callr r5 + + /* _exit with the result. */ + mov r4, r2 +#ifdef PIC + nextpc r22 +1: movhi r8, %hiadj(_gp_got - 1b) + addi r8, r8, %lo(_gp_got - 1b) + add r22, r22, r8 + ldw r8, %call(HIDDEN_JUMPTARGET(_exit))(r22) + jmp r8 +#else + jmpi _exit +#endif + cfi_endproc + + cfi_startproc +PSEUDO_END (__clone) +weak_alias (__clone, clone) |