| /* Copyright (C) 1996-2014 Free Software Foundation, Inc. |
| This file is part of the GNU C Library. |
| Contributed by Richard Henderson <rth@tamu.edu>, 1996. |
| |
| 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> |
| |
| #define CLONE_VM 0x00000100 |
| #define CLONE_THREAD 0x00010000 |
| |
| /* int clone(int (*fn)(void *arg), void *child_stack, int flags, |
| void *arg, pid_t *ptid, void *tls, pid_t *ctid); |
| |
| Note that everything past ARG is technically optional, based |
| on FLAGS, and that CTID is arg 7, and thus is on the stack. |
| However, since a load from top-of-stack better be legal always, |
| we don't bother checking FLAGS. */ |
| |
| .text |
| .align 4 |
| .globl __clone |
| .ent __clone |
| .usepv __clone, USEPV_PROF |
| |
| cfi_startproc |
| __clone: |
| #ifdef PROF |
| ldgp gp,0(pv) |
| lda AT, _mcount |
| jsr AT, (AT), _mcount |
| #endif |
| |
| /* Sanity check arguments. */ |
| ldiq v0, EINVAL |
| beq a0, SYSCALL_ERROR_LABEL /* no NULL function pointers */ |
| beq a1, SYSCALL_ERROR_LABEL /* no NULL stack pointers */ |
| |
| /* Save the fn ptr and arg on the new stack. */ |
| subq a1, 32, a1 |
| stq a0, 0(a1) |
| stq a3, 8(a1) |
| #ifdef RESET_PID |
| stq a2, 16(a1) |
| #endif |
| |
| /* The syscall is of the form clone(flags, usp, ptid, ctid, tls). |
| Shift the flags, ptid, ctid, tls arguments into place; the |
| child_stack argument is already correct. */ |
| mov a2, a0 |
| mov a4, a2 |
| ldq a3, 0(sp) |
| mov a5, a4 |
| |
| /* Do the system call. */ |
| ldiq v0, __NR_clone |
| call_pal PAL_callsys |
| |
| bne a3, SYSCALL_ERROR_LABEL |
| beq v0, thread_start |
| |
| /* Successful return from the parent. */ |
| ret |
| |
| PSEUDO_END(__clone) |
| cfi_endproc |
| |
| /* 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. */ |
| |
| .ent thread_start |
| cfi_startproc |
| thread_start: |
| mov 0, fp |
| cfi_def_cfa_register(fp) |
| cfi_undefined(ra) |
| |
| #ifdef RESET_PID |
| /* Check and see if we need to reset the PID. */ |
| ldq t0, 16(sp) |
| lda t1, CLONE_THREAD |
| and t0, t1, t2 |
| beq t2, 2f |
| 1: |
| #endif |
| |
| /* Load up the arguments. */ |
| ldq pv, 0(sp) |
| ldq a0, 8(sp) |
| addq sp, 32, 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 |
| #ifdef PIC |
| bsr ra, HIDDEN_JUMPTARGET(_exit) !samegp |
| #else |
| jsr ra, HIDDEN_JUMPTARGET(_exit) |
| #endif |
| |
| /* Die horribly. */ |
| halt |
| |
| #ifdef RESET_PID |
| 2: |
| rduniq |
| lda t1, CLONE_VM |
| mov v0, s0 |
| lda v0, -1 |
| and t0, t1, t2 |
| bne t2, 3f |
| lda v0, __NR_getxpid |
| callsys |
| 3: |
| stl v0, PID_OFFSET(s0) |
| stl v0, TID_OFFSET(s0) |
| br 1b |
| #endif |
| cfi_endproc |
| .end thread_start |
| |
| weak_alias (__clone, clone) |
