| yuezonghe | 824eb0c | 2024-06-27 02:32:26 -0700 | [diff] [blame^] | 1 | /* Copyright (C) 1996-2000,02,03,04,2005 Free Software Foundation, Inc. |
| 2 | This file is part of the GNU C Library. |
| 3 | Contributed by Richard Henderson (rth@tamu.edu) |
| 4 | |
| 5 | The GNU C Library is free software; you can redistribute it and/or |
| 6 | modify it under the terms of the GNU Lesser General Public |
| 7 | License as published by the Free Software Foundation; either |
| 8 | version 2.1 of the License, or (at your option) any later version. |
| 9 | |
| 10 | The GNU C Library is distributed in the hope that it will be useful, |
| 11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 13 | Lesser General Public License for more details. |
| 14 | |
| 15 | You should have received a copy of the GNU Lesser General Public |
| 16 | License along with the GNU C Library; if not, write to the Free |
| 17 | Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA |
| 18 | 02111-1307 USA. */ |
| 19 | |
| 20 | /* clone() is even more special than fork() as it mucks with stacks |
| 21 | and invokes a function in the right context after its all over. |
| 22 | |
| 23 | Hacked up for uClibc by Erik Andersen <andersen@codepoet.org> |
| 24 | */ |
| 25 | |
| 26 | #define _ERRNO_H 1 |
| 27 | #include <bits/errno.h> |
| 28 | #include <sys/syscall.h> |
| 29 | |
| 30 | /* int clone(int (*fn)(void *arg), void *child_stack, int flags, void *arg, |
| 31 | pid_t *ptid, struct user_desc *tls, pid_t *ctid); */ |
| 32 | |
| 33 | #define LINKAGE 4 |
| 34 | #define PTR_SIZE 4 |
| 35 | #define PARMS LINKAGE /* no space for saved regs */ |
| 36 | #define FUNC PARMS |
| 37 | #define STACK FUNC+4 |
| 38 | #define FLAGS STACK+PTR_SIZE |
| 39 | #define ARG FLAGS+4 |
| 40 | #define PTID ARG+PTR_SIZE |
| 41 | #define TLS PTID+PTR_SIZE |
| 42 | #define CTID TLS+PTR_SIZE |
| 43 | |
| 44 | .text |
| 45 | .global clone |
| 46 | .type clone,%function |
| 47 | clone: |
| 48 | /* Sanity check arguments. */ |
| 49 | movl $-EINVAL,%eax |
| 50 | |
| 51 | /* no NULL function pointers */ |
| 52 | movl FUNC(%esp),%ecx |
| 53 | #ifdef __PIC__ |
| 54 | jecxz __error |
| 55 | #else |
| 56 | testl %ecx,%ecx |
| 57 | jz __error |
| 58 | #endif |
| 59 | |
| 60 | /* no NULL stack pointers */ |
| 61 | movl STACK(%esp),%ecx |
| 62 | #ifdef __PIC__ |
| 63 | jecxz __error |
| 64 | #else |
| 65 | testl %ecx,%ecx |
| 66 | jz __error |
| 67 | #endif |
| 68 | |
| 69 | /* Insert the argument onto the new stack. Make sure the new |
| 70 | thread is started with an alignment of (mod 16). */ |
| 71 | andl $0xfffffff0, %ecx |
| 72 | subl $28,%ecx |
| 73 | movl ARG(%esp),%eax /* no negative argument counts */ |
| 74 | movl %eax,12(%ecx) |
| 75 | |
| 76 | /* Save the function pointer as the zeroth argument. |
| 77 | It will be popped off in the child in the ebx frobbing below. */ |
| 78 | movl FUNC(%esp),%eax |
| 79 | movl %eax,8(%ecx) |
| 80 | /* Don't leak any information. */ |
| 81 | movl $0,4(%ecx) |
| 82 | #ifndef RESET_PID |
| 83 | movl $0,(%ecx) |
| 84 | #endif |
| 85 | |
| 86 | |
| 87 | /* Do the system call */ |
| 88 | pushl %ebx |
| 89 | pushl %esi |
| 90 | pushl %edi |
| 91 | movl TLS+12(%esp),%esi |
| 92 | movl PTID+12(%esp),%edx |
| 93 | movl FLAGS+12(%esp),%ebx |
| 94 | movl CTID+12(%esp),%edi |
| 95 | movl $__NR_clone,%eax |
| 96 | #ifdef RESET_PID |
| 97 | /* Remember the flag value. */ |
| 98 | movl %ebx, (%ecx) |
| 99 | #endif |
| 100 | int $0x80 |
| 101 | popl %edi |
| 102 | popl %esi |
| 103 | popl %ebx |
| 104 | |
| 105 | test %eax,%eax |
| 106 | jl __error |
| 107 | jz .Lthread_start |
| 108 | ret |
| 109 | |
| 110 | .Lthread_start: |
| 111 | /* Note: %esi is zero. */ |
| 112 | movl %esi,%ebp /* terminate the stack frame */ |
| 113 | call *%ebx |
| 114 | #ifdef __PIC__ |
| 115 | call .Lhere |
| 116 | .Lhere: |
| 117 | popl %ebx |
| 118 | addl $_GLOBAL_OFFSET_TABLE_+[.-.Lhere], %ebx |
| 119 | #endif |
| 120 | movl %eax, %ebx |
| 121 | movl $__NR_exit, %eax |
| 122 | int $0x80 |
| 123 | |
| 124 | /* Need to indirect jump to syscall error |
| 125 | * or we end up with TEXTREL's |
| 126 | */ |
| 127 | __error: |
| 128 | jmp __syscall_error |
| 129 | |
| 130 | .size clone,.-clone |
| 131 | weak_alias(clone, __clone) |