diff options
Diffstat (limited to 'sysdeps/unix/sysv/linux/arm/clone.S')
| -rw-r--r-- | sysdeps/unix/sysv/linux/arm/clone.S | 99 |
1 files changed, 99 insertions, 0 deletions
diff --git a/sysdeps/unix/sysv/linux/arm/clone.S b/sysdeps/unix/sysv/linux/arm/clone.S new file mode 100644 index 0000000000..03fe9ab728 --- /dev/null +++ b/sysdeps/unix/sysv/linux/arm/clone.S @@ -0,0 +1,99 @@ +/* Copyright (C) 1996-2014 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Pat Beirne <patb@corelcomputer.com> + + 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, struct user_desc *tls, pid_t *ctid); */ + + .text +ENTRY(__clone) + @ sanity check args + cmp r0, #0 + ite ne + cmpne r1, #0 + moveq r0, #-EINVAL + beq PLTJMP(syscall_error) + + @ insert the args onto the new stack + str r3, [r1, #-4]! + str r0, [r1, #-4]! + + @ do the system call + @ get flags + mov r0, r2 +#ifdef RESET_PID + mov ip, r2 +#endif + @ new sp is already in r1 + push {r4, r7} + cfi_adjust_cfa_offset (8) + cfi_rel_offset (r4, 0) + cfi_rel_offset (r7, 4) + ldr r2, [sp, #8] + ldr r3, [sp, #12] + ldr r4, [sp, #16] + ldr r7, =SYS_ify(clone) + swi 0x0 + cfi_endproc + cmp r0, #0 + beq 1f + pop {r4, r7} + blt PLTJMP(C_SYMBOL_NAME(__syscall_error)) + RETINSTR(, lr) + + cfi_startproc +PSEUDO_END (__clone) + +1: + .fnstart + .cantunwind +#ifdef RESET_PID + tst ip, #CLONE_THREAD + bne 3f + GET_TLS (lr) + mov r1, r0 + tst ip, #CLONE_VM + ldr r7, =SYS_ify(getpid) + ite ne + movne r0, #-1 + swieq 0x0 + NEGOFF_ADJ_BASE (r1, TID_OFFSET) + str r0, NEGOFF_OFF1 (r1, TID_OFFSET) + str r0, NEGOFF_OFF2 (r1, PID_OFFSET, TID_OFFSET) +3: +#endif + @ pick the function arg and call address off the stack and execute + ldr r0, [sp, #4] + ldr ip, [sp], #8 + BLX (ip) + + @ and we are done, passing the return value through r0 + b PLTJMP(HIDDEN_JUMPTARGET(_exit)) + + .fnend + +weak_alias (__clone, clone) |