[SPARC]: Fix length parameter verification in sys_getdomainname().
[linux-2.6] / arch / sparc / kernel / sys_sparc.c
1 /* $Id: sys_sparc.c,v 1.70 2001/04/14 01:12:02 davem Exp $
2  * linux/arch/sparc/kernel/sys_sparc.c
3  *
4  * This file contains various random system calls that
5  * have a non-standard calling sequence on the Linux/sparc
6  * platform.
7  */
8
9 #include <linux/errno.h>
10 #include <linux/types.h>
11 #include <linux/sched.h>
12 #include <linux/mm.h>
13 #include <linux/fs.h>
14 #include <linux/file.h>
15 #include <linux/sem.h>
16 #include <linux/msg.h>
17 #include <linux/shm.h>
18 #include <linux/stat.h>
19 #include <linux/syscalls.h>
20 #include <linux/mman.h>
21 #include <linux/utsname.h>
22 #include <linux/smp.h>
23 #include <linux/smp_lock.h>
24
25 #include <asm/uaccess.h>
26 #include <asm/ipc.h>
27
28 /* #define DEBUG_UNIMP_SYSCALL */
29
30 /* XXX Make this per-binary type, this way we can detect the type of
31  * XXX a binary.  Every Sparc executable calls this very early on.
32  */
33 asmlinkage unsigned long sys_getpagesize(void)
34 {
35         return PAGE_SIZE; /* Possibly older binaries want 8192 on sun4's? */
36 }
37
38 #define COLOUR_ALIGN(addr)      (((addr)+SHMLBA-1)&~(SHMLBA-1))
39
40 unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr, unsigned long len, unsigned long pgoff, unsigned long flags)
41 {
42         struct vm_area_struct * vmm;
43
44         if (flags & MAP_FIXED) {
45                 /* We do not accept a shared mapping if it would violate
46                  * cache aliasing constraints.
47                  */
48                 if ((flags & MAP_SHARED) && (addr & (SHMLBA - 1)))
49                         return -EINVAL;
50                 return addr;
51         }
52
53         /* See asm-sparc/uaccess.h */
54         if (len > TASK_SIZE - PAGE_SIZE)
55                 return -ENOMEM;
56         if (ARCH_SUN4C_SUN4 && len > 0x20000000)
57                 return -ENOMEM;
58         if (!addr)
59                 addr = TASK_UNMAPPED_BASE;
60
61         if (flags & MAP_SHARED)
62                 addr = COLOUR_ALIGN(addr);
63         else
64                 addr = PAGE_ALIGN(addr);
65
66         for (vmm = find_vma(current->mm, addr); ; vmm = vmm->vm_next) {
67                 /* At this point:  (!vmm || addr < vmm->vm_end). */
68                 if (ARCH_SUN4C_SUN4 && addr < 0xe0000000 && 0x20000000 - len < addr) {
69                         addr = PAGE_OFFSET;
70                         vmm = find_vma(current->mm, PAGE_OFFSET);
71                 }
72                 if (TASK_SIZE - PAGE_SIZE - len < addr)
73                         return -ENOMEM;
74                 if (!vmm || addr + len <= vmm->vm_start)
75                         return addr;
76                 addr = vmm->vm_end;
77                 if (flags & MAP_SHARED)
78                         addr = COLOUR_ALIGN(addr);
79         }
80 }
81
82 asmlinkage unsigned long sparc_brk(unsigned long brk)
83 {
84         if(ARCH_SUN4C_SUN4) {
85                 if ((brk & 0xe0000000) != (current->mm->brk & 0xe0000000))
86                         return current->mm->brk;
87         }
88         return sys_brk(brk);
89 }
90
91 /*
92  * sys_pipe() is the normal C calling standard for creating
93  * a pipe. It's not the way unix traditionally does this, though.
94  */
95 asmlinkage int sparc_pipe(struct pt_regs *regs)
96 {
97         int fd[2];
98         int error;
99
100         error = do_pipe(fd);
101         if (error)
102                 goto out;
103         regs->u_regs[UREG_I1] = fd[1];
104         error = fd[0];
105 out:
106         return error;
107 }
108
109 /*
110  * sys_ipc() is the de-multiplexer for the SysV IPC calls..
111  *
112  * This is really horribly ugly.
113  */
114
115 asmlinkage int sys_ipc (uint call, int first, int second, int third, void __user *ptr, long fifth)
116 {
117         int version, err;
118
119         version = call >> 16; /* hack for backward compatibility */
120         call &= 0xffff;
121
122         if (call <= SEMCTL)
123                 switch (call) {
124                 case SEMOP:
125                         err = sys_semtimedop (first, (struct sembuf __user *)ptr, second, NULL);
126                         goto out;
127                 case SEMTIMEDOP:
128                         err = sys_semtimedop (first, (struct sembuf __user *)ptr, second, (const struct timespec __user *) fifth);
129                         goto out;
130                 case SEMGET:
131                         err = sys_semget (first, second, third);
132                         goto out;
133                 case SEMCTL: {
134                         union semun fourth;
135                         err = -EINVAL;
136                         if (!ptr)
137                                 goto out;
138                         err = -EFAULT;
139                         if (get_user(fourth.__pad,
140                                      (void __user * __user *)ptr))
141                                 goto out;
142                         err = sys_semctl (first, second, third, fourth);
143                         goto out;
144                         }
145                 default:
146                         err = -ENOSYS;
147                         goto out;
148                 }
149         if (call <= MSGCTL) 
150                 switch (call) {
151                 case MSGSND:
152                         err = sys_msgsnd (first, (struct msgbuf __user *) ptr, 
153                                           second, third);
154                         goto out;
155                 case MSGRCV:
156                         switch (version) {
157                         case 0: {
158                                 struct ipc_kludge tmp;
159                                 err = -EINVAL;
160                                 if (!ptr)
161                                         goto out;
162                                 err = -EFAULT;
163                                 if (copy_from_user(&tmp, (struct ipc_kludge __user *) ptr, sizeof (tmp)))
164                                         goto out;
165                                 err = sys_msgrcv (first, tmp.msgp, second, tmp.msgtyp, third);
166                                 goto out;
167                                 }
168                         case 1: default:
169                                 err = sys_msgrcv (first,
170                                                   (struct msgbuf __user *) ptr,
171                                                   second, fifth, third);
172                                 goto out;
173                         }
174                 case MSGGET:
175                         err = sys_msgget ((key_t) first, second);
176                         goto out;
177                 case MSGCTL:
178                         err = sys_msgctl (first, second, (struct msqid_ds __user *) ptr);
179                         goto out;
180                 default:
181                         err = -ENOSYS;
182                         goto out;
183                 }
184         if (call <= SHMCTL) 
185                 switch (call) {
186                 case SHMAT:
187                         switch (version) {
188                         case 0: default: {
189                                 ulong raddr;
190                                 err = do_shmat (first, (char __user *) ptr, second, &raddr);
191                                 if (err)
192                                         goto out;
193                                 err = -EFAULT;
194                                 if (put_user (raddr, (ulong __user *) third))
195                                         goto out;
196                                 err = 0;
197                                 goto out;
198                                 }
199                         case 1: /* iBCS2 emulator entry point */
200                                 err = -EINVAL;
201                                 goto out;
202                         }
203                 case SHMDT: 
204                         err = sys_shmdt ((char __user *)ptr);
205                         goto out;
206                 case SHMGET:
207                         err = sys_shmget (first, second, third);
208                         goto out;
209                 case SHMCTL:
210                         err = sys_shmctl (first, second, (struct shmid_ds __user *) ptr);
211                         goto out;
212                 default:
213                         err = -ENOSYS;
214                         goto out;
215                 }
216         else
217                 err = -ENOSYS;
218 out:
219         return err;
220 }
221
222 /* Linux version of mmap */
223 static unsigned long do_mmap2(unsigned long addr, unsigned long len,
224         unsigned long prot, unsigned long flags, unsigned long fd,
225         unsigned long pgoff)
226 {
227         struct file * file = NULL;
228         unsigned long retval = -EBADF;
229
230         if (!(flags & MAP_ANONYMOUS)) {
231                 file = fget(fd);
232                 if (!file)
233                         goto out;
234         }
235
236         retval = -EINVAL;
237         len = PAGE_ALIGN(len);
238         if (ARCH_SUN4C_SUN4 &&
239             (len > 0x20000000 ||
240              ((flags & MAP_FIXED) &&
241               addr < 0xe0000000 && addr + len > 0x20000000)))
242                 goto out_putf;
243
244         /* See asm-sparc/uaccess.h */
245         if (len > TASK_SIZE - PAGE_SIZE || addr + len > TASK_SIZE - PAGE_SIZE)
246                 goto out_putf;
247
248         flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE);
249
250         down_write(&current->mm->mmap_sem);
251         retval = do_mmap_pgoff(file, addr, len, prot, flags, pgoff);
252         up_write(&current->mm->mmap_sem);
253
254 out_putf:
255         if (file)
256                 fput(file);
257 out:
258         return retval;
259 }
260
261 asmlinkage unsigned long sys_mmap2(unsigned long addr, unsigned long len,
262         unsigned long prot, unsigned long flags, unsigned long fd,
263         unsigned long pgoff)
264 {
265         /* Make sure the shift for mmap2 is constant (12), no matter what PAGE_SIZE
266            we have. */
267         return do_mmap2(addr, len, prot, flags, fd, pgoff >> (PAGE_SHIFT - 12));
268 }
269
270 asmlinkage unsigned long sys_mmap(unsigned long addr, unsigned long len,
271         unsigned long prot, unsigned long flags, unsigned long fd,
272         unsigned long off)
273 {
274         return do_mmap2(addr, len, prot, flags, fd, off >> PAGE_SHIFT);
275 }
276
277 long sparc_remap_file_pages(unsigned long start, unsigned long size,
278                            unsigned long prot, unsigned long pgoff,
279                            unsigned long flags)
280 {
281         /* This works on an existing mmap so we don't need to validate
282          * the range as that was done at the original mmap call.
283          */
284         return sys_remap_file_pages(start, size, prot,
285                                     (pgoff >> (PAGE_SHIFT - 12)), flags);
286 }
287
288 extern unsigned long do_mremap(unsigned long addr,
289         unsigned long old_len, unsigned long new_len,
290         unsigned long flags, unsigned long new_addr);
291                 
292 asmlinkage unsigned long sparc_mremap(unsigned long addr,
293         unsigned long old_len, unsigned long new_len,
294         unsigned long flags, unsigned long new_addr)
295 {
296         struct vm_area_struct *vma;
297         unsigned long ret = -EINVAL;
298         if (ARCH_SUN4C_SUN4) {
299                 if (old_len > 0x20000000 || new_len > 0x20000000)
300                         goto out;
301                 if (addr < 0xe0000000 && addr + old_len > 0x20000000)
302                         goto out;
303         }
304         if (old_len > TASK_SIZE - PAGE_SIZE ||
305             new_len > TASK_SIZE - PAGE_SIZE)
306                 goto out;
307         down_write(&current->mm->mmap_sem);
308         if (flags & MREMAP_FIXED) {
309                 if (ARCH_SUN4C_SUN4 &&
310                     new_addr < 0xe0000000 &&
311                     new_addr + new_len > 0x20000000)
312                         goto out_sem;
313                 if (new_addr + new_len > TASK_SIZE - PAGE_SIZE)
314                         goto out_sem;
315         } else if ((ARCH_SUN4C_SUN4 && addr < 0xe0000000 &&
316                     addr + new_len > 0x20000000) ||
317                    addr + new_len > TASK_SIZE - PAGE_SIZE) {
318                 unsigned long map_flags = 0;
319                 struct file *file = NULL;
320
321                 ret = -ENOMEM;
322                 if (!(flags & MREMAP_MAYMOVE))
323                         goto out_sem;
324
325                 vma = find_vma(current->mm, addr);
326                 if (vma) {
327                         if (vma->vm_flags & VM_SHARED)
328                                 map_flags |= MAP_SHARED;
329                         file = vma->vm_file;
330                 }
331
332                 new_addr = get_unmapped_area(file, addr, new_len,
333                                      vma ? vma->vm_pgoff : 0,
334                                      map_flags);
335                 ret = new_addr;
336                 if (new_addr & ~PAGE_MASK)
337                         goto out_sem;
338                 flags |= MREMAP_FIXED;
339         }
340         ret = do_mremap(addr, old_len, new_len, flags, new_addr);
341 out_sem:
342         up_write(&current->mm->mmap_sem);
343 out:
344         return ret;       
345 }
346
347 /* we come to here via sys_nis_syscall so it can setup the regs argument */
348 asmlinkage unsigned long
349 c_sys_nis_syscall (struct pt_regs *regs)
350 {
351         static int count = 0;
352
353         if (count++ > 5)
354                 return -ENOSYS;
355         printk ("%s[%d]: Unimplemented SPARC system call %d\n",
356                 current->comm, current->pid, (int)regs->u_regs[1]);
357 #ifdef DEBUG_UNIMP_SYSCALL      
358         show_regs (regs);
359 #endif
360         return -ENOSYS;
361 }
362
363 /* #define DEBUG_SPARC_BREAKPOINT */
364
365 asmlinkage void
366 sparc_breakpoint (struct pt_regs *regs)
367 {
368         siginfo_t info;
369
370         lock_kernel();
371 #ifdef DEBUG_SPARC_BREAKPOINT
372         printk ("TRAP: Entering kernel PC=%x, nPC=%x\n", regs->pc, regs->npc);
373 #endif
374         info.si_signo = SIGTRAP;
375         info.si_errno = 0;
376         info.si_code = TRAP_BRKPT;
377         info.si_addr = (void __user *)regs->pc;
378         info.si_trapno = 0;
379         force_sig_info(SIGTRAP, &info, current);
380
381 #ifdef DEBUG_SPARC_BREAKPOINT
382         printk ("TRAP: Returning to space: PC=%x nPC=%x\n", regs->pc, regs->npc);
383 #endif
384         unlock_kernel();
385 }
386
387 asmlinkage int
388 sparc_sigaction (int sig, const struct old_sigaction __user *act,
389                  struct old_sigaction __user *oact)
390 {
391         struct k_sigaction new_ka, old_ka;
392         int ret;
393
394         if (sig < 0) {
395                 current->thread.new_signal = 1;
396                 sig = -sig;
397         }
398
399         if (act) {
400                 unsigned long mask;
401
402                 if (!access_ok(VERIFY_READ, act, sizeof(*act)) ||
403                     __get_user(new_ka.sa.sa_handler, &act->sa_handler) ||
404                     __get_user(new_ka.sa.sa_restorer, &act->sa_restorer))
405                         return -EFAULT;
406                 __get_user(new_ka.sa.sa_flags, &act->sa_flags);
407                 __get_user(mask, &act->sa_mask);
408                 siginitset(&new_ka.sa.sa_mask, mask);
409                 new_ka.ka_restorer = NULL;
410         }
411
412         ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
413
414         if (!ret && oact) {
415                 /* In the clone() case we could copy half consistent
416                  * state to the user, however this could sleep and
417                  * deadlock us if we held the signal lock on SMP.  So for
418                  * now I take the easy way out and do no locking.
419                  */
420                 if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) ||
421                     __put_user(old_ka.sa.sa_handler, &oact->sa_handler) ||
422                     __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer))
423                         return -EFAULT;
424                 __put_user(old_ka.sa.sa_flags, &oact->sa_flags);
425                 __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask);
426         }
427
428         return ret;
429 }
430
431 asmlinkage long
432 sys_rt_sigaction(int sig,
433                  const struct sigaction __user *act,
434                  struct sigaction __user *oact,
435                  void __user *restorer,
436                  size_t sigsetsize)
437 {
438         struct k_sigaction new_ka, old_ka;
439         int ret;
440
441         /* XXX: Don't preclude handling different sized sigset_t's.  */
442         if (sigsetsize != sizeof(sigset_t))
443                 return -EINVAL;
444
445         /* All tasks which use RT signals (effectively) use
446          * new style signals.
447          */
448         current->thread.new_signal = 1;
449
450         if (act) {
451                 new_ka.ka_restorer = restorer;
452                 if (copy_from_user(&new_ka.sa, act, sizeof(*act)))
453                         return -EFAULT;
454         }
455
456         ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
457
458         if (!ret && oact) {
459                 if (copy_to_user(oact, &old_ka.sa, sizeof(*oact)))
460                         return -EFAULT;
461         }
462
463         return ret;
464 }
465
466 asmlinkage int sys_getdomainname(char __user *name, int len)
467 {
468         int nlen, err;
469         
470         if (len < 0 || len > __NEW_UTS_LEN)
471                 return -EINVAL;
472
473         down_read(&uts_sem);
474         
475         nlen = strlen(system_utsname.domainname) + 1;
476         if (nlen < len)
477                 len = nlen;
478
479         err = -EFAULT;
480         if (!copy_to_user(name, system_utsname.domainname, len))
481                 err = 0;
482
483         up_read(&uts_sem);
484         return err;
485 }