Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6
[muen/linux.git] / arch / x86 / ia32 / ia32_aout.c
1 /*
2  *  a.out loader for x86-64
3  *
4  *  Copyright (C) 1991, 1992, 1996  Linus Torvalds
5  *  Hacked together by Andi Kleen
6  */
7
8 #include <linux/module.h>
9
10 #include <linux/time.h>
11 #include <linux/kernel.h>
12 #include <linux/mm.h>
13 #include <linux/mman.h>
14 #include <linux/a.out.h>
15 #include <linux/errno.h>
16 #include <linux/signal.h>
17 #include <linux/string.h>
18 #include <linux/fs.h>
19 #include <linux/file.h>
20 #include <linux/stat.h>
21 #include <linux/fcntl.h>
22 #include <linux/ptrace.h>
23 #include <linux/user.h>
24 #include <linux/binfmts.h>
25 #include <linux/personality.h>
26 #include <linux/init.h>
27 #include <linux/jiffies.h>
28 #include <linux/perf_event.h>
29 #include <linux/sched/task_stack.h>
30
31 #include <linux/uaccess.h>
32 #include <asm/pgalloc.h>
33 #include <asm/cacheflush.h>
34 #include <asm/user32.h>
35 #include <asm/ia32.h>
36
37 #undef WARN_OLD
38
39 static int load_aout_binary(struct linux_binprm *);
40 static int load_aout_library(struct file *);
41
42 #ifdef CONFIG_COREDUMP
43 static int aout_core_dump(struct coredump_params *);
44
45 static unsigned long get_dr(int n)
46 {
47         struct perf_event *bp = current->thread.ptrace_bps[n];
48         return bp ? bp->hw.info.address : 0;
49 }
50
51 /*
52  * fill in the user structure for a core dump..
53  */
54 static void fill_dump(struct pt_regs *regs, struct user32 *dump)
55 {
56         u32 fs, gs;
57         memset(dump, 0, sizeof(*dump));
58
59 /* changed the size calculations - should hopefully work better. lbt */
60         dump->magic = CMAGIC;
61         dump->start_code = 0;
62         dump->start_stack = regs->sp & ~(PAGE_SIZE - 1);
63         dump->u_tsize = ((unsigned long) current->mm->end_code) >> PAGE_SHIFT;
64         dump->u_dsize = ((unsigned long)
65                          (current->mm->brk + (PAGE_SIZE-1))) >> PAGE_SHIFT;
66         dump->u_dsize -= dump->u_tsize;
67         dump->u_debugreg[0] = get_dr(0);
68         dump->u_debugreg[1] = get_dr(1);
69         dump->u_debugreg[2] = get_dr(2);
70         dump->u_debugreg[3] = get_dr(3);
71         dump->u_debugreg[6] = current->thread.debugreg6;
72         dump->u_debugreg[7] = current->thread.ptrace_dr7;
73
74         if (dump->start_stack < 0xc0000000) {
75                 unsigned long tmp;
76
77                 tmp = (unsigned long) (0xc0000000 - dump->start_stack);
78                 dump->u_ssize = tmp >> PAGE_SHIFT;
79         }
80
81         dump->regs.ebx = regs->bx;
82         dump->regs.ecx = regs->cx;
83         dump->regs.edx = regs->dx;
84         dump->regs.esi = regs->si;
85         dump->regs.edi = regs->di;
86         dump->regs.ebp = regs->bp;
87         dump->regs.eax = regs->ax;
88         dump->regs.ds = current->thread.ds;
89         dump->regs.es = current->thread.es;
90         savesegment(fs, fs);
91         dump->regs.fs = fs;
92         savesegment(gs, gs);
93         dump->regs.gs = gs;
94         dump->regs.orig_eax = regs->orig_ax;
95         dump->regs.eip = regs->ip;
96         dump->regs.cs = regs->cs;
97         dump->regs.eflags = regs->flags;
98         dump->regs.esp = regs->sp;
99         dump->regs.ss = regs->ss;
100
101 #if 1 /* FIXME */
102         dump->u_fpvalid = 0;
103 #else
104         dump->u_fpvalid = dump_fpu(regs, &dump->i387);
105 #endif
106 }
107
108 #endif
109
110 static struct linux_binfmt aout_format = {
111         .module         = THIS_MODULE,
112         .load_binary    = load_aout_binary,
113         .load_shlib     = load_aout_library,
114 #ifdef CONFIG_COREDUMP
115         .core_dump      = aout_core_dump,
116 #endif
117         .min_coredump   = PAGE_SIZE
118 };
119
120 static int set_brk(unsigned long start, unsigned long end)
121 {
122         start = PAGE_ALIGN(start);
123         end = PAGE_ALIGN(end);
124         if (end <= start)
125                 return 0;
126         return vm_brk(start, end - start);
127 }
128
129 #ifdef CONFIG_COREDUMP
130 /*
131  * These are the only things you should do on a core-file: use only these
132  * macros to write out all the necessary info.
133  */
134
135 #include <linux/coredump.h>
136
137 #define START_DATA(u)   (u.u_tsize << PAGE_SHIFT)
138 #define START_STACK(u)  (u.start_stack)
139
140 /*
141  * Routine writes a core dump image in the current directory.
142  * Currently only a stub-function.
143  *
144  * Note that setuid/setgid files won't make a core-dump if the uid/gid
145  * changed due to the set[u|g]id. It's enforced by the "current->mm->dumpable"
146  * field, which also makes sure the core-dumps won't be recursive if the
147  * dumping of the process results in another error..
148  */
149
150 static int aout_core_dump(struct coredump_params *cprm)
151 {
152         mm_segment_t fs;
153         int has_dumped = 0;
154         unsigned long dump_start, dump_size;
155         struct user32 dump;
156
157         fs = get_fs();
158         set_fs(KERNEL_DS);
159         has_dumped = 1;
160
161         fill_dump(cprm->regs, &dump);
162
163         strncpy(dump.u_comm, current->comm, sizeof(current->comm));
164         dump.u_ar0 = offsetof(struct user32, regs);
165         dump.signal = cprm->siginfo->si_signo;
166
167         /*
168          * If the size of the dump file exceeds the rlimit, then see
169          * what would happen if we wrote the stack, but not the data
170          * area.
171          */
172         if ((dump.u_dsize + dump.u_ssize + 1) * PAGE_SIZE > cprm->limit)
173                 dump.u_dsize = 0;
174
175         /* Make sure we have enough room to write the stack and data areas. */
176         if ((dump.u_ssize + 1) * PAGE_SIZE > cprm->limit)
177                 dump.u_ssize = 0;
178
179         /* make sure we actually have a data and stack area to dump */
180         set_fs(USER_DS);
181         if (!access_ok((void *) (unsigned long)START_DATA(dump),
182                        dump.u_dsize << PAGE_SHIFT))
183                 dump.u_dsize = 0;
184         if (!access_ok((void *) (unsigned long)START_STACK(dump),
185                        dump.u_ssize << PAGE_SHIFT))
186                 dump.u_ssize = 0;
187
188         set_fs(KERNEL_DS);
189         /* struct user */
190         if (!dump_emit(cprm, &dump, sizeof(dump)))
191                 goto end_coredump;
192         /* Now dump all of the user data.  Include malloced stuff as well */
193         if (!dump_skip(cprm, PAGE_SIZE - sizeof(dump)))
194                 goto end_coredump;
195         /* now we start writing out the user space info */
196         set_fs(USER_DS);
197         /* Dump the data area */
198         if (dump.u_dsize != 0) {
199                 dump_start = START_DATA(dump);
200                 dump_size = dump.u_dsize << PAGE_SHIFT;
201                 if (!dump_emit(cprm, (void *)dump_start, dump_size))
202                         goto end_coredump;
203         }
204         /* Now prepare to dump the stack area */
205         if (dump.u_ssize != 0) {
206                 dump_start = START_STACK(dump);
207                 dump_size = dump.u_ssize << PAGE_SHIFT;
208                 if (!dump_emit(cprm, (void *)dump_start, dump_size))
209                         goto end_coredump;
210         }
211 end_coredump:
212         set_fs(fs);
213         return has_dumped;
214 }
215 #endif
216
217 /*
218  * create_aout_tables() parses the env- and arg-strings in new user
219  * memory and creates the pointer tables from them, and puts their
220  * addresses on the "stack", returning the new stack pointer value.
221  */
222 static u32 __user *create_aout_tables(char __user *p, struct linux_binprm *bprm)
223 {
224         u32 __user *argv, *envp, *sp;
225         int argc = bprm->argc, envc = bprm->envc;
226
227         sp = (u32 __user *) ((-(unsigned long)sizeof(u32)) & (unsigned long) p);
228         sp -= envc+1;
229         envp = sp;
230         sp -= argc+1;
231         argv = sp;
232         put_user((unsigned long) envp, --sp);
233         put_user((unsigned long) argv, --sp);
234         put_user(argc, --sp);
235         current->mm->arg_start = (unsigned long) p;
236         while (argc-- > 0) {
237                 char c;
238
239                 put_user((u32)(unsigned long)p, argv++);
240                 do {
241                         get_user(c, p++);
242                 } while (c);
243         }
244         put_user(0, argv);
245         current->mm->arg_end = current->mm->env_start = (unsigned long) p;
246         while (envc-- > 0) {
247                 char c;
248
249                 put_user((u32)(unsigned long)p, envp++);
250                 do {
251                         get_user(c, p++);
252                 } while (c);
253         }
254         put_user(0, envp);
255         current->mm->env_end = (unsigned long) p;
256         return sp;
257 }
258
259 /*
260  * These are the functions used to load a.out style executables and shared
261  * libraries.  There is no binary dependent code anywhere else.
262  */
263 static int load_aout_binary(struct linux_binprm *bprm)
264 {
265         unsigned long error, fd_offset, rlim;
266         struct pt_regs *regs = current_pt_regs();
267         struct exec ex;
268         int retval;
269
270         ex = *((struct exec *) bprm->buf);              /* exec-header */
271         if ((N_MAGIC(ex) != ZMAGIC && N_MAGIC(ex) != OMAGIC &&
272              N_MAGIC(ex) != QMAGIC && N_MAGIC(ex) != NMAGIC) ||
273             N_TRSIZE(ex) || N_DRSIZE(ex) ||
274             i_size_read(file_inode(bprm->file)) <
275             ex.a_text+ex.a_data+N_SYMSIZE(ex)+N_TXTOFF(ex)) {
276                 return -ENOEXEC;
277         }
278
279         fd_offset = N_TXTOFF(ex);
280
281         /* Check initial limits. This avoids letting people circumvent
282          * size limits imposed on them by creating programs with large
283          * arrays in the data or bss.
284          */
285         rlim = rlimit(RLIMIT_DATA);
286         if (rlim >= RLIM_INFINITY)
287                 rlim = ~0;
288         if (ex.a_data + ex.a_bss > rlim)
289                 return -ENOMEM;
290
291         /* Flush all traces of the currently running executable */
292         retval = flush_old_exec(bprm);
293         if (retval)
294                 return retval;
295
296         /* OK, This is the point of no return */
297         set_personality(PER_LINUX);
298         set_personality_ia32(false);
299
300         setup_new_exec(bprm);
301
302         regs->cs = __USER32_CS;
303         regs->r8 = regs->r9 = regs->r10 = regs->r11 = regs->r12 =
304                 regs->r13 = regs->r14 = regs->r15 = 0;
305
306         current->mm->end_code = ex.a_text +
307                 (current->mm->start_code = N_TXTADDR(ex));
308         current->mm->end_data = ex.a_data +
309                 (current->mm->start_data = N_DATADDR(ex));
310         current->mm->brk = ex.a_bss +
311                 (current->mm->start_brk = N_BSSADDR(ex));
312
313         retval = setup_arg_pages(bprm, IA32_STACK_TOP, EXSTACK_DEFAULT);
314         if (retval < 0)
315                 return retval;
316
317         install_exec_creds(bprm);
318
319         if (N_MAGIC(ex) == OMAGIC) {
320                 unsigned long text_addr, map_size;
321
322                 text_addr = N_TXTADDR(ex);
323                 map_size = ex.a_text+ex.a_data;
324
325                 error = vm_brk(text_addr & PAGE_MASK, map_size);
326
327                 if (error)
328                         return error;
329
330                 error = read_code(bprm->file, text_addr, 32,
331                                   ex.a_text + ex.a_data);
332                 if ((signed long)error < 0)
333                         return error;
334         } else {
335 #ifdef WARN_OLD
336                 static unsigned long error_time, error_time2;
337                 if ((ex.a_text & 0xfff || ex.a_data & 0xfff) &&
338                     (N_MAGIC(ex) != NMAGIC) &&
339                                 time_after(jiffies, error_time2 + 5*HZ)) {
340                         printk(KERN_NOTICE "executable not page aligned\n");
341                         error_time2 = jiffies;
342                 }
343
344                 if ((fd_offset & ~PAGE_MASK) != 0 &&
345                             time_after(jiffies, error_time + 5*HZ)) {
346                         printk(KERN_WARNING
347                                "fd_offset is not page aligned. Please convert "
348                                "program: %pD\n",
349                                bprm->file);
350                         error_time = jiffies;
351                 }
352 #endif
353
354                 if (!bprm->file->f_op->mmap || (fd_offset & ~PAGE_MASK) != 0) {
355                         error = vm_brk(N_TXTADDR(ex), ex.a_text+ex.a_data);
356                         if (error)
357                                 return error;
358
359                         read_code(bprm->file, N_TXTADDR(ex), fd_offset,
360                                         ex.a_text+ex.a_data);
361                         goto beyond_if;
362                 }
363
364                 error = vm_mmap(bprm->file, N_TXTADDR(ex), ex.a_text,
365                                 PROT_READ | PROT_EXEC,
366                                 MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE |
367                                 MAP_EXECUTABLE | MAP_32BIT,
368                                 fd_offset);
369
370                 if (error != N_TXTADDR(ex))
371                         return error;
372
373                 error = vm_mmap(bprm->file, N_DATADDR(ex), ex.a_data,
374                                 PROT_READ | PROT_WRITE | PROT_EXEC,
375                                 MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE |
376                                 MAP_EXECUTABLE | MAP_32BIT,
377                                 fd_offset + ex.a_text);
378                 if (error != N_DATADDR(ex))
379                         return error;
380         }
381
382 beyond_if:
383         error = set_brk(current->mm->start_brk, current->mm->brk);
384         if (error)
385                 return error;
386
387         set_binfmt(&aout_format);
388
389         current->mm->start_stack =
390                 (unsigned long)create_aout_tables((char __user *)bprm->p, bprm);
391         /* start thread */
392         loadsegment(fs, 0);
393         loadsegment(ds, __USER32_DS);
394         loadsegment(es, __USER32_DS);
395         load_gs_index(0);
396         (regs)->ip = ex.a_entry;
397         (regs)->sp = current->mm->start_stack;
398         (regs)->flags = 0x200;
399         (regs)->cs = __USER32_CS;
400         (regs)->ss = __USER32_DS;
401         regs->r8 = regs->r9 = regs->r10 = regs->r11 =
402         regs->r12 = regs->r13 = regs->r14 = regs->r15 = 0;
403         set_fs(USER_DS);
404         return 0;
405 }
406
407 static int load_aout_library(struct file *file)
408 {
409         unsigned long bss, start_addr, len, error;
410         int retval;
411         struct exec ex;
412         loff_t pos = 0;
413
414         retval = -ENOEXEC;
415         error = kernel_read(file, &ex, sizeof(ex), &pos);
416         if (error != sizeof(ex))
417                 goto out;
418
419         /* We come in here for the regular a.out style of shared libraries */
420         if ((N_MAGIC(ex) != ZMAGIC && N_MAGIC(ex) != QMAGIC) || N_TRSIZE(ex) ||
421             N_DRSIZE(ex) || ((ex.a_entry & 0xfff) && N_MAGIC(ex) == ZMAGIC) ||
422             i_size_read(file_inode(file)) <
423             ex.a_text+ex.a_data+N_SYMSIZE(ex)+N_TXTOFF(ex)) {
424                 goto out;
425         }
426
427         if (N_FLAGS(ex))
428                 goto out;
429
430         /* For  QMAGIC, the starting address is 0x20 into the page.  We mask
431            this off to get the starting address for the page */
432
433         start_addr =  ex.a_entry & 0xfffff000;
434
435         if ((N_TXTOFF(ex) & ~PAGE_MASK) != 0) {
436 #ifdef WARN_OLD
437                 static unsigned long error_time;
438                 if (time_after(jiffies, error_time + 5*HZ)) {
439                         printk(KERN_WARNING
440                                "N_TXTOFF is not page aligned. Please convert "
441                                "library: %pD\n",
442                                file);
443                         error_time = jiffies;
444                 }
445 #endif
446                 retval = vm_brk(start_addr, ex.a_text + ex.a_data + ex.a_bss);
447                 if (retval)
448                         goto out;
449
450                 read_code(file, start_addr, N_TXTOFF(ex),
451                           ex.a_text + ex.a_data);
452                 retval = 0;
453                 goto out;
454         }
455         /* Now use mmap to map the library into memory. */
456         error = vm_mmap(file, start_addr, ex.a_text + ex.a_data,
457                         PROT_READ | PROT_WRITE | PROT_EXEC,
458                         MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE | MAP_32BIT,
459                         N_TXTOFF(ex));
460         retval = error;
461         if (error != start_addr)
462                 goto out;
463
464         len = PAGE_ALIGN(ex.a_text + ex.a_data);
465         bss = ex.a_text + ex.a_data + ex.a_bss;
466         if (bss > len) {
467                 retval = vm_brk(start_addr + len, bss - len);
468                 if (retval)
469                         goto out;
470         }
471         retval = 0;
472 out:
473         return retval;
474 }
475
476 static int __init init_aout_binfmt(void)
477 {
478         register_binfmt(&aout_format);
479         return 0;
480 }
481
482 static void __exit exit_aout_binfmt(void)
483 {
484         unregister_binfmt(&aout_format);
485 }
486
487 module_init(init_aout_binfmt);
488 module_exit(exit_aout_binfmt);
489 MODULE_LICENSE("GPL");