diff options
Diffstat (limited to 'sysdeps/unix/sysv/linux/alpha/clone.S')
| -rw-r--r-- | sysdeps/unix/sysv/linux/alpha/clone.S | 143 |
1 files changed, 143 insertions, 0 deletions
diff --git a/sysdeps/unix/sysv/linux/alpha/clone.S b/sysdeps/unix/sysv/linux/alpha/clone.S new file mode 100644 index 0000000000..c5c3300c47 --- /dev/null +++ b/sysdeps/unix/sysv/linux/alpha/clone.S @@ -0,0 +1,143 @@ +/* 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) |