a57d7f2b6f137ee88a4829ae9e17fa5565a9eccc
[linux-2.6.git] / arch / sparc64 / kernel / binfmt_aout32.c
1 /*
2  *  linux/fs/binfmt_aout.c
3  *
4  *  Copyright (C) 1991, 1992, 1996  Linus Torvalds
5  *
6  *  Hacked a bit by DaveM to make it work with 32-bit SunOS
7  *  binaries on the sparc64 port.
8  */
9
10 #include <linux/module.h>
11
12 #include <linux/sched.h>
13 #include <linux/kernel.h>
14 #include <linux/mm.h>
15 #include <linux/mman.h>
16 #include <linux/a.out.h>
17 #include <linux/errno.h>
18 #include <linux/signal.h>
19 #include <linux/string.h>
20 #include <linux/fs.h>
21 #include <linux/file.h>
22 #include <linux/stat.h>
23 #include <linux/fcntl.h>
24 #include <linux/ptrace.h>
25 #include <linux/user.h>
26 #include <linux/slab.h>
27 #include <linux/binfmts.h>
28 #include <linux/personality.h>
29 #include <linux/init.h>
30
31 #include <asm/system.h>
32 #include <asm/uaccess.h>
33 #include <asm/pgalloc.h>
34 #include <asm/mmu_context.h>
35
36 static int load_aout32_binary(struct linux_binprm *, struct pt_regs * regs);
37 static int load_aout32_library(struct file*);
38 static int aout32_core_dump(long signr, struct pt_regs * regs, struct file *file);
39
40 static struct linux_binfmt aout32_format = {
41         NULL, THIS_MODULE, load_aout32_binary, load_aout32_library, aout32_core_dump,
42         PAGE_SIZE
43 };
44
45 static void set_brk(unsigned long start, unsigned long end)
46 {
47         start = PAGE_ALIGN(start);
48         end = PAGE_ALIGN(end);
49         if (end <= start)
50                 return;
51         down_write(&current->mm->mmap_sem);
52         do_brk(start, end - start);
53         up_write(&current->mm->mmap_sem);
54 }
55
56 /*
57  * These are the only things you should do on a core-file: use only these
58  * macros to write out all the necessary info.
59  */
60
61 static int dump_write(struct file *file, const void *addr, int nr)
62 {
63         return file->f_op->write(file, addr, nr, &file->f_pos) == nr;
64 }
65
66 #define DUMP_WRITE(addr, nr)    \
67         if (!dump_write(file, (void *)(addr), (nr))) \
68                 goto end_coredump;
69
70 #define DUMP_SEEK(offset) \
71 if (file->f_op->llseek) { \
72         if (file->f_op->llseek(file,(offset),0) != (offset)) \
73                 goto end_coredump; \
74 } else file->f_pos = (offset)
75
76 /*
77  * Routine writes a core dump image in the current directory.
78  * Currently only a stub-function.
79  *
80  * Note that setuid/setgid files won't make a core-dump if the uid/gid
81  * changed due to the set[u|g]id. It's enforced by the "current->mm->dumpable"
82  * field, which also makes sure the core-dumps won't be recursive if the
83  * dumping of the process results in another error..
84  */
85
86 static int aout32_core_dump(long signr, struct pt_regs *regs, struct file *file)
87 {
88         mm_segment_t fs;
89         int has_dumped = 0;
90         unsigned long dump_start, dump_size;
91         struct user dump;
92 #       define START_DATA(u)    (u.u_tsize)
93 #       define START_STACK(u)   ((regs->u_regs[UREG_FP]) & ~(PAGE_SIZE - 1))
94
95         fs = get_fs();
96         set_fs(KERNEL_DS);
97         has_dumped = 1;
98         current->flags |= PF_DUMPCORE;
99         strncpy(dump.u_comm, current->comm, sizeof(dump.u_comm));
100         dump.signal = signr;
101         dump_thread(regs, &dump);
102
103 /* If the size of the dump file exceeds the rlimit, then see what would happen
104    if we wrote the stack, but not the data area.  */
105         if ((dump.u_dsize+dump.u_ssize) >
106             current->signal->rlim[RLIMIT_CORE].rlim_cur)
107                 dump.u_dsize = 0;
108
109 /* Make sure we have enough room to write the stack and data areas. */
110         if ((dump.u_ssize) >
111             current->signal->rlim[RLIMIT_CORE].rlim_cur)
112                 dump.u_ssize = 0;
113
114 /* make sure we actually have a data and stack area to dump */
115         set_fs(USER_DS);
116         if (!access_ok(VERIFY_READ, (void __user *) START_DATA(dump), dump.u_dsize))
117                 dump.u_dsize = 0;
118         if (!access_ok(VERIFY_READ, (void __user *) START_STACK(dump), dump.u_ssize))
119                 dump.u_ssize = 0;
120
121         set_fs(KERNEL_DS);
122 /* struct user */
123         DUMP_WRITE(&dump,sizeof(dump));
124 /* now we start writing out the user space info */
125         set_fs(USER_DS);
126 /* Dump the data area */
127         if (dump.u_dsize != 0) {
128                 dump_start = START_DATA(dump);
129                 dump_size = dump.u_dsize;
130                 DUMP_WRITE(dump_start,dump_size);
131         }
132 /* Now prepare to dump the stack area */
133         if (dump.u_ssize != 0) {
134                 dump_start = START_STACK(dump);
135                 dump_size = dump.u_ssize;
136                 DUMP_WRITE(dump_start,dump_size);
137         }
138 /* Finally dump the task struct.  Not be used by gdb, but could be useful */
139         set_fs(KERNEL_DS);
140         DUMP_WRITE(current,sizeof(*current));
141 end_coredump:
142         set_fs(fs);
143         return has_dumped;
144 }
145
146 /*
147  * create_aout32_tables() parses the env- and arg-strings in new user
148  * memory and creates the pointer tables from them, and puts their
149  * addresses on the "stack", returning the new stack pointer value.
150  */
151
152 static u32 __user *create_aout32_tables(char __user *p, struct linux_binprm *bprm)
153 {
154         u32 __user *argv;
155         u32 __user *envp;
156         u32 __user *sp;
157         int argc = bprm->argc;
158         int envc = bprm->envc;
159
160         sp = (u32 __user *)((-(unsigned long)sizeof(char *))&(unsigned long)p);
161
162         /* This imposes the proper stack alignment for a new process. */
163         sp = (u32 __user *) (((unsigned long) sp) & ~7);
164         if ((envc+argc+3)&1)
165                 --sp;
166
167         sp -= envc+1;
168         envp = sp;
169         sp -= argc+1;
170         argv = sp;
171         put_user(argc,--sp);
172         current->mm->arg_start = (unsigned long) p;
173         while (argc-->0) {
174                 char c;
175                 put_user(((u32)(unsigned long)(p)),argv++);
176                 do {
177                         get_user(c,p++);
178                 } while (c);
179         }
180         put_user(NULL,argv);
181         current->mm->arg_end = current->mm->env_start = (unsigned long) p;
182         while (envc-->0) {
183                 char c;
184                 put_user(((u32)(unsigned long)(p)),envp++);
185                 do {
186                         get_user(c,p++);
187                 } while (c);
188         }
189         put_user(NULL,envp);
190         current->mm->env_end = (unsigned long) p;
191         return sp;
192 }
193
194 /*
195  * These are the functions used to load a.out style executables and shared
196  * libraries.  There is no binary dependent code anywhere else.
197  */
198
199 static int load_aout32_binary(struct linux_binprm * bprm, struct pt_regs * regs)
200 {
201         struct exec ex;
202         unsigned long error;
203         unsigned long fd_offset;
204         unsigned long rlim;
205         unsigned long orig_thr_flags;
206         int retval;
207
208         ex = *((struct exec *) bprm->buf);              /* exec-header */
209         if ((N_MAGIC(ex) != ZMAGIC && N_MAGIC(ex) != OMAGIC &&
210              N_MAGIC(ex) != QMAGIC && N_MAGIC(ex) != NMAGIC) ||
211             N_TRSIZE(ex) || N_DRSIZE(ex) ||
212             bprm->file->f_dentry->d_inode->i_size < ex.a_text+ex.a_data+N_SYMSIZE(ex)+N_TXTOFF(ex)) {
213                 return -ENOEXEC;
214         }
215
216         fd_offset = N_TXTOFF(ex);
217
218         /* Check initial limits. This avoids letting people circumvent
219          * size limits imposed on them by creating programs with large
220          * arrays in the data or bss.
221          */
222         rlim = current->signal->rlim[RLIMIT_DATA].rlim_cur;
223         if (rlim >= RLIM_INFINITY)
224                 rlim = ~0;
225         if (ex.a_data + ex.a_bss > rlim)
226                 return -ENOMEM;
227
228         /* Flush all traces of the currently running executable */
229         retval = flush_old_exec(bprm);
230         if (retval)
231                 return retval;
232
233         /* OK, This is the point of no return */
234         set_personality(PER_SUNOS);
235
236         current->mm->end_code = ex.a_text +
237                 (current->mm->start_code = N_TXTADDR(ex));
238         current->mm->end_data = ex.a_data +
239                 (current->mm->start_data = N_DATADDR(ex));
240         current->mm->brk = ex.a_bss +
241                 (current->mm->start_brk = N_BSSADDR(ex));
242
243         current->mm->mmap = NULL;
244         compute_creds(bprm);
245         current->flags &= ~PF_FORKNOEXEC;
246         if (N_MAGIC(ex) == NMAGIC) {
247                 loff_t pos = fd_offset;
248                 /* Fuck me plenty... */
249                 down_write(&current->mm->mmap_sem);     
250                 error = do_brk(N_TXTADDR(ex), ex.a_text);
251                 up_write(&current->mm->mmap_sem);
252                 bprm->file->f_op->read(bprm->file, (char __user *)N_TXTADDR(ex),
253                           ex.a_text, &pos);
254                 down_write(&current->mm->mmap_sem);
255                 error = do_brk(N_DATADDR(ex), ex.a_data);
256                 up_write(&current->mm->mmap_sem);
257                 bprm->file->f_op->read(bprm->file, (char __user *)N_DATADDR(ex),
258                           ex.a_data, &pos);
259                 goto beyond_if;
260         }
261
262         if (N_MAGIC(ex) == OMAGIC) {
263                 loff_t pos = fd_offset;
264                 down_write(&current->mm->mmap_sem);
265                 do_brk(N_TXTADDR(ex) & PAGE_MASK,
266                         ex.a_text+ex.a_data + PAGE_SIZE - 1);
267                 up_write(&current->mm->mmap_sem);
268                 bprm->file->f_op->read(bprm->file, (char __user *)N_TXTADDR(ex),
269                           ex.a_text+ex.a_data, &pos);
270         } else {
271                 static unsigned long error_time;
272                 if ((ex.a_text & 0xfff || ex.a_data & 0xfff) &&
273                     (N_MAGIC(ex) != NMAGIC) && (jiffies-error_time) > 5*HZ)
274                 {
275                         printk(KERN_NOTICE "executable not page aligned\n");
276                         error_time = jiffies;
277                 }
278
279                 if (!bprm->file->f_op->mmap) {
280                         loff_t pos = fd_offset;
281                         down_write(&current->mm->mmap_sem);
282                         do_brk(0, ex.a_text+ex.a_data);
283                         up_write(&current->mm->mmap_sem);
284                         bprm->file->f_op->read(bprm->file,
285                                   (char __user *)N_TXTADDR(ex),
286                                   ex.a_text+ex.a_data, &pos);
287                         goto beyond_if;
288                 }
289
290                 down_write(&current->mm->mmap_sem);
291                 error = do_mmap(bprm->file, N_TXTADDR(ex), ex.a_text,
292                         PROT_READ | PROT_EXEC,
293                         MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE,
294                         fd_offset);
295                 up_write(&current->mm->mmap_sem);
296
297                 if (error != N_TXTADDR(ex)) {
298                         send_sig(SIGKILL, current, 0);
299                         return error;
300                 }
301
302                 down_write(&current->mm->mmap_sem);
303                 error = do_mmap(bprm->file, N_DATADDR(ex), ex.a_data,
304                                 PROT_READ | PROT_WRITE | PROT_EXEC,
305                                 MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE,
306                                 fd_offset + ex.a_text);
307                 up_write(&current->mm->mmap_sem);
308                 if (error != N_DATADDR(ex)) {
309                         send_sig(SIGKILL, current, 0);
310                         return error;
311                 }
312         }
313 beyond_if:
314         set_binfmt(&aout32_format);
315
316         set_brk(current->mm->start_brk, current->mm->brk);
317
318         /* Make sure STACK_TOP returns the right thing.  */
319         orig_thr_flags = current_thread_info()->flags;
320         current_thread_info()->flags |= _TIF_32BIT;
321
322         retval = setup_arg_pages(bprm, STACK_TOP, EXSTACK_DEFAULT);
323         if (retval < 0) { 
324                 current_thread_info()->flags = orig_thr_flags;
325
326                 /* Someone check-me: is this error path enough? */ 
327                 send_sig(SIGKILL, current, 0); 
328                 return retval;
329         }
330
331         current->mm->start_stack =
332                 (unsigned long) create_aout32_tables((char __user *)bprm->p, bprm);
333         tsb_context_switch(__pa(current->mm->pgd),
334                            current->mm->context.sparc64_tsb);
335
336         start_thread32(regs, ex.a_entry, current->mm->start_stack);
337         if (current->ptrace & PT_PTRACED)
338                 send_sig(SIGTRAP, current, 0);
339         return 0;
340 }
341
342 /* N.B. Move to .h file and use code in fs/binfmt_aout.c? */
343 static int load_aout32_library(struct file *file)
344 {
345         struct inode * inode;
346         unsigned long bss, start_addr, len;
347         unsigned long error;
348         int retval;
349         struct exec ex;
350
351         inode = file->f_dentry->d_inode;
352
353         retval = -ENOEXEC;
354         error = kernel_read(file, 0, (char *) &ex, sizeof(ex));
355         if (error != sizeof(ex))
356                 goto out;
357
358         /* We come in here for the regular a.out style of shared libraries */
359         if ((N_MAGIC(ex) != ZMAGIC && N_MAGIC(ex) != QMAGIC) || N_TRSIZE(ex) ||
360             N_DRSIZE(ex) || ((ex.a_entry & 0xfff) && N_MAGIC(ex) == ZMAGIC) ||
361             inode->i_size < ex.a_text+ex.a_data+N_SYMSIZE(ex)+N_TXTOFF(ex)) {
362                 goto out;
363         }
364
365         if (N_MAGIC(ex) == ZMAGIC && N_TXTOFF(ex) &&
366             (N_TXTOFF(ex) < inode->i_sb->s_blocksize)) {
367                 printk("N_TXTOFF < BLOCK_SIZE. Please convert library\n");
368                 goto out;
369         }
370
371         if (N_FLAGS(ex))
372                 goto out;
373
374         /* For  QMAGIC, the starting address is 0x20 into the page.  We mask
375            this off to get the starting address for the page */
376
377         start_addr =  ex.a_entry & 0xfffff000;
378
379         /* Now use mmap to map the library into memory. */
380         down_write(&current->mm->mmap_sem);
381         error = do_mmap(file, start_addr, ex.a_text + ex.a_data,
382                         PROT_READ | PROT_WRITE | PROT_EXEC,
383                         MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE,
384                         N_TXTOFF(ex));
385         up_write(&current->mm->mmap_sem);
386         retval = error;
387         if (error != start_addr)
388                 goto out;
389
390         len = PAGE_ALIGN(ex.a_text + ex.a_data);
391         bss = ex.a_text + ex.a_data + ex.a_bss;
392         if (bss > len) {
393                 down_write(&current->mm->mmap_sem);
394                 error = do_brk(start_addr + len, bss - len);
395                 up_write(&current->mm->mmap_sem);
396                 retval = error;
397                 if (error != start_addr + len)
398                         goto out;
399         }
400         retval = 0;
401 out:
402         return retval;
403 }
404
405 static int __init init_aout32_binfmt(void)
406 {
407         return register_binfmt(&aout32_format);
408 }
409
410 static void __exit exit_aout32_binfmt(void)
411 {
412         unregister_binfmt(&aout32_format);
413 }
414
415 module_init(init_aout32_binfmt);
416 module_exit(exit_aout32_binfmt);