1 /* 2 * Copyright (C) 2008 The Android Open Source Project 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * * Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * * Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in 12 * the documentation and/or other materials provided with the 13 * distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 16 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 17 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 18 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 19 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS 22 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 25 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29 #include <private/bionic_asm.h> 30 31 // pid_t __bionic_clone(int flags, void* child_stack, pid_t* parent_tid, void* tls, pid_t* child_tid, int (*fn)(void*), void* arg); 32 ENTRY(__bionic_clone) 33 mov ip, sp 34 # save registers to parent stack 35 stmfd sp!, {r4, r5, r6, r7} 36 .cfi_def_cfa_offset 16 37 .cfi_rel_offset r4, 0 38 .cfi_rel_offset r5, 4 39 .cfi_rel_offset r6, 8 40 .cfi_rel_offset r7, 12 41 42 # load extra parameters 43 ldmfd ip, {r4, r5, r6} 44 45 # Push 'fn' and 'arg' onto the child stack. 46 stmdb r1!, {r5, r6} 47 48 # Make the system call. 49 ldr r7, =__NR_clone 50 swi #0 51 52 # Are we the child? 53 movs r0, r0 54 beq 1f 55 56 # In the parent, reload saved registers then either return or set errno. 57 ldmfd sp!, {r4, r5, r6, r7} 58 cmn r0, #(MAX_ERRNO + 1) 59 bxls lr 60 neg r0, r0 61 b __set_errno_internal 62 63 1: # The child. 64 # Setting lr to 0 will make the unwinder stop at __start_thread 65 mov lr, #0 66 # Call __start_thread with the 'fn' and 'arg' we stored on the child stack. 67 pop {r0, r1} 68 b __start_thread 69 END(__bionic_clone) 70 .hidden __bionic_clone 71