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144 lines
3.3 KiB
ArmAsm
144 lines
3.3 KiB
ArmAsm
/* Copyright (C) 1996-2013 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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Contributed by Richard Henderson <rth@tamu.edu>, 1996.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library. If not, see
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<http://www.gnu.org/licenses/>. */
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/* clone() is even more special than fork() as it mucks with stacks
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and invokes a function in the right context after its all over. */
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#include <sysdep.h>
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#define _ERRNO_H 1
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#include <bits/errno.h>
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#define CLONE_VM 0x00000100
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#define CLONE_THREAD 0x00010000
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/* int clone(int (*fn)(void *arg), void *child_stack, int flags,
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void *arg, pid_t *ptid, void *tls, pid_t *ctid);
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Note that everything past ARG is technically optional, based
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on FLAGS, and that CTID is arg 7, and thus is on the stack.
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However, since a load from top-of-stack better be legal always,
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we don't bother checking FLAGS. */
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.text
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.align 4
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.globl __clone
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.ent __clone
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.usepv __clone, USEPV_PROF
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cfi_startproc
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__clone:
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#ifdef PROF
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ldgp gp,0(pv)
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lda AT, _mcount
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jsr AT, (AT), _mcount
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#endif
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/* Sanity check arguments. */
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ldiq v0, EINVAL
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beq a0, SYSCALL_ERROR_LABEL /* no NULL function pointers */
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beq a1, SYSCALL_ERROR_LABEL /* no NULL stack pointers */
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/* Save the fn ptr and arg on the new stack. */
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subq a1, 32, a1
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stq a0, 0(a1)
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stq a3, 8(a1)
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#ifdef RESET_PID
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stq a2, 16(a1)
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#endif
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/* The syscall is of the form clone(flags, usp, ptid, ctid, tls).
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Shift the flags, ptid, ctid, tls arguments into place; the
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child_stack argument is already correct. */
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mov a2, a0
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mov a4, a2
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ldq a3, 0(sp)
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mov a5, a4
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/* Do the system call. */
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ldiq v0, __NR_clone
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call_pal PAL_callsys
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bne a3, SYSCALL_ERROR_LABEL
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beq v0, thread_start
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/* Successful return from the parent. */
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ret
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PSEUDO_END(__clone)
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cfi_endproc
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/* Load up the arguments to the function. Put this block of code in
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its own function so that we can terminate the stack trace with our
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debug info. */
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.ent thread_start
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cfi_startproc
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thread_start:
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mov 0, fp
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cfi_def_cfa_register(fp)
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cfi_undefined(ra)
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#ifdef RESET_PID
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/* Check and see if we need to reset the PID. */
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ldq t0, 16(sp)
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lda t1, CLONE_THREAD
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and t0, t1, t2
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beq t2, 2f
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1:
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#endif
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/* Load up the arguments. */
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ldq pv, 0(sp)
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ldq a0, 8(sp)
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addq sp, 32, sp
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/* Call the user's function. */
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jsr ra, (pv)
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ldgp gp, 0(ra)
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/* Call _exit rather than doing it inline for breakpoint purposes. */
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mov v0, a0
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#ifdef PIC
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bsr ra, HIDDEN_JUMPTARGET(_exit) !samegp
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#else
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jsr ra, HIDDEN_JUMPTARGET(_exit)
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#endif
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/* Die horribly. */
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halt
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#ifdef RESET_PID
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2:
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rduniq
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lda t1, CLONE_VM
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mov v0, s0
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lda v0, -1
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and t0, t1, t2
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bne t2, 3f
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lda v0, __NR_getxpid
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callsys
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3:
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stl v0, PID_OFFSET(s0)
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stl v0, TID_OFFSET(s0)
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br 1b
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#endif
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cfi_endproc
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.end thread_start
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weak_alias (__clone, clone)
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