projects / thirdparty / glibc.git / blame
| Commit | Line | Data |
|---|---|---|
| 267ca16a UD |
1 | /* Copyright (C) 1996 Free Software Foundation, Inc. |
| 2 | Contributed by Richard Henderson (rth@tamu.edu) | |
| 3 | ||
| 4 | The GNU C Library is free software; you can redistribute it and/or | |
| 5 | modify it under the terms of the GNU Library General Public License as | |
| 6 | published by the Free Software Foundation; either version 2 of the | |
| 7 | License, or (at your option) any later version. | |
| 8 | ||
| 9 | The GNU C Library is distributed in the hope that it will be useful, | |
| 10 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
| 12 | Library General Public License for more details. | |
| 13 | ||
| 14 | You should have received a copy of the GNU Library General Public | |
| 15 | License along with the GNU C Library; see the file COPYING.LIB. If | |
| 16 | not, write to the Free Software Foundation, Inc., 675 Mass Ave, | |
| 17 | Cambridge, MA 02139, USA. */ | |
| 18 | ||
| 19 | /* clone() is even more special than fork() as it mucks with stacks | |
| 20 | and invokes a function in the right context after its all over. */ | |
| 21 | ||
| 22 | #include <sysdep.h> | |
| 23 | #include <errnos.h> | |
| 24 | ||
| 25 | /* int clone(int (*fn)(), void *child_stack, int flags, int nargs, ...) */ | |
| 26 | ||
| 27 | .text | |
| 28 | ENTRY(__clone) | |
| 29 | /* Sanity check arguments. */ | |
| 30 | movl $-EINVAL,%eax | |
| 31 | movl 4(%esp),%ecx /* no NULL function pointers */ | |
| 32 | testl %ecx,%ecx | |
| 33 | jz syscall_error | |
| 34 | movl 8(%esp),%ecx /* no NULL stack pointers */ | |
| 35 | testl %ecx,%ecx | |
| 36 | jz syscall_error | |
| 37 | movl 16(%esp),%edx /* no negative argument counts */ | |
| 38 | testl %edx,%edx | |
| 39 | js syscall_error | |
| 40 | ||
| 41 | /* Allocate space on the new stack and copy args over */ | |
| 42 | movl %edx,%eax | |
| 43 | negl %eax | |
| 44 | lea -4(%ecx,%eax,4),%ecx | |
| 45 | jz 2f | |
| 46 | 1: movl 16(%esp,%edx,4),%eax | |
| 47 | movl %eax,0(%ecx,%edx,4) | |
| 48 | dec %edx | |
| 49 | jnz 1b | |
| 50 | 2: | |
| 51 | /* Save the function pointer as the zeroth argument. | |
| 52 | It will be popped off in the child in the ebx frobbing below. */ | |
| 53 | movl 4(%esp),%eax | |
| 54 | movl %eax,0(%ecx) | |
| 55 | ||
| 56 | /* Do the system call */ | |
| 57 | pushl %ebx | |
| 58 | movl 16(%esp),%ebx | |
| 59 | movl $SYS_ify(clone),%eax | |
| 60 | int $0x80 | |
| 61 | popl %ebx | |
| 62 | ||
| 63 | test %eax,%eax | |
| 64 | jl syscall_error | |
| 65 | jz thread_start | |
| 66 | ||
| 67 | ret | |
| cccda09f | 68 | .size __clone,.-__clone |
| 267ca16a UD |
69 | |
| 70 | SYSCALL_ERROR_HANDLER | |
| 71 | ||
| 72 | thread_start: | |
| 73 | subl %ebp,%ebp /* terminate the stack frame */ | |
| 74 | call *%ebx | |
| 706074a5 | 75 | pushl %eax |
| 267ca16a UD |
76 | #ifdef PIC |
| 77 | call _exit@PLT | |
| 78 | #else | |
| 79 | call _exit | |
| 80 | #endif | |
| 81 | ||
| 82 | weak_alias(__clone, clone) |