[PATCH] uml: fork cleanup
[linux-2.6.git] / arch / um / kernel / syscall_kern.c
1 /* 
2  * Copyright (C) 2000 - 2003 Jeff Dike (jdike@addtoit.com)
3  * Licensed under the GPL
4  */
5
6 #include "linux/sched.h"
7 #include "linux/file.h"
8 #include "linux/smp_lock.h"
9 #include "linux/mm.h"
10 #include "linux/utsname.h"
11 #include "linux/msg.h"
12 #include "linux/shm.h"
13 #include "linux/sys.h"
14 #include "linux/syscalls.h"
15 #include "linux/unistd.h"
16 #include "linux/slab.h"
17 #include "linux/utime.h"
18 #include "asm/mman.h"
19 #include "asm/uaccess.h"
20 #include "kern_util.h"
21 #include "user_util.h"
22 #include "sysdep/syscalls.h"
23 #include "mode_kern.h"
24 #include "choose-mode.h"
25
26 /*  Unlocked, I don't care if this is a bit off */
27 int nsyscalls = 0;
28
29 long sys_fork(void)
30 {
31         long ret;
32
33         current->thread.forking = 1;
34         ret = do_fork(SIGCHLD, UPT_SP(&current->thread.regs.regs),
35                       &current->thread.regs, 0, NULL, NULL);
36         current->thread.forking = 0;
37         return(ret);
38 }
39
40 long sys_vfork(void)
41 {
42         long ret;
43
44         current->thread.forking = 1;
45         ret = do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD,
46                       UPT_SP(&current->thread.regs.regs),
47                       &current->thread.regs, 0, NULL, NULL);
48         current->thread.forking = 0;
49         return(ret);
50 }
51
52 /* common code for old and new mmaps */
53 long sys_mmap2(unsigned long addr, unsigned long len,
54                unsigned long prot, unsigned long flags,
55                unsigned long fd, unsigned long pgoff)
56 {
57         long error = -EBADF;
58         struct file * file = NULL;
59
60         flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE);
61         if (!(flags & MAP_ANONYMOUS)) {
62                 file = fget(fd);
63                 if (!file)
64                         goto out;
65         }
66
67         down_write(&current->mm->mmap_sem);
68         error = do_mmap_pgoff(file, addr, len, prot, flags, pgoff);
69         up_write(&current->mm->mmap_sem);
70
71         if (file)
72                 fput(file);
73  out:
74         return error;
75 }
76
77 long old_mmap(unsigned long addr, unsigned long len,
78               unsigned long prot, unsigned long flags,
79               unsigned long fd, unsigned long offset)
80 {
81         long err = -EINVAL;
82         if (offset & ~PAGE_MASK)
83                 goto out;
84
85         err = sys_mmap2(addr, len, prot, flags, fd, offset >> PAGE_SHIFT);
86  out:
87         return err;
88 }
89 /*
90  * sys_pipe() is the normal C calling standard for creating
91  * a pipe. It's not the way unix traditionally does this, though.
92  */
93 long sys_pipe(unsigned long __user * fildes)
94 {
95         int fd[2];
96         long error;
97
98         error = do_pipe(fd);
99         if (!error) {
100                 if (copy_to_user(fildes, fd, sizeof(fd)))
101                         error = -EFAULT;
102         }
103         return error;
104 }
105
106
107 long sys_uname(struct old_utsname * name)
108 {
109         long err;
110         if (!name)
111                 return -EFAULT;
112         down_read(&uts_sem);
113         err=copy_to_user(name, &system_utsname, sizeof (*name));
114         up_read(&uts_sem);
115         return err?-EFAULT:0;
116 }
117
118 long sys_olduname(struct oldold_utsname * name)
119 {
120         long error;
121
122         if (!name)
123                 return -EFAULT;
124         if (!access_ok(VERIFY_WRITE,name,sizeof(struct oldold_utsname)))
125                 return -EFAULT;
126   
127         down_read(&uts_sem);
128         
129         error = __copy_to_user(&name->sysname,&system_utsname.sysname,
130                                __OLD_UTS_LEN);
131         error |= __put_user(0,name->sysname+__OLD_UTS_LEN);
132         error |= __copy_to_user(&name->nodename,&system_utsname.nodename,
133                                 __OLD_UTS_LEN);
134         error |= __put_user(0,name->nodename+__OLD_UTS_LEN);
135         error |= __copy_to_user(&name->release,&system_utsname.release,
136                                 __OLD_UTS_LEN);
137         error |= __put_user(0,name->release+__OLD_UTS_LEN);
138         error |= __copy_to_user(&name->version,&system_utsname.version,
139                                 __OLD_UTS_LEN);
140         error |= __put_user(0,name->version+__OLD_UTS_LEN);
141         error |= __copy_to_user(&name->machine,&system_utsname.machine,
142                                 __OLD_UTS_LEN);
143         error |= __put_user(0,name->machine+__OLD_UTS_LEN);
144         
145         up_read(&uts_sem);
146         
147         error = error ? -EFAULT : 0;
148
149         return error;
150 }
151
152 DEFINE_SPINLOCK(syscall_lock);
153
154 static int syscall_index = 0;
155
156 int next_syscall_index(int limit)
157 {
158         int ret;
159
160         spin_lock(&syscall_lock);
161         ret = syscall_index;
162         if(++syscall_index == limit)
163                 syscall_index = 0;
164         spin_unlock(&syscall_lock);
165         return(ret);
166 }