git.oblomov.eu Git - linux-2.6/blob - 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(0,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(0,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_path.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         current->mm->free_area_cache = current->mm->mmap_base;
 243         current->mm->cached_hole_size = 0;
 244
 245         current->mm->mmap = NULL;
 246         compute_creds(bprm);
 247         current->flags &= ~PF_FORKNOEXEC;
 248         if (N_MAGIC(ex) == NMAGIC) {
 249                 loff_t pos = fd_offset;
 250                 /* Fuck me plenty... */
 251                 down_write(&current->mm->mmap_sem);
 252                 error = do_brk(N_TXTADDR(ex), ex.a_text);
 253                 up_write(&current->mm->mmap_sem);
 254                 bprm->file->f_op->read(bprm->file, (char __user *)N_TXTADDR(ex),
 255                           ex.a_text, &pos);
 256                 down_write(&current->mm->mmap_sem);
 257                 error = do_brk(N_DATADDR(ex), ex.a_data);
 258                 up_write(&current->mm->mmap_sem);
 259                 bprm->file->f_op->read(bprm->file, (char __user *)N_DATADDR(ex),
 260                           ex.a_data, &pos);
 261                 goto beyond_if;
 262         }
 263
 264         if (N_MAGIC(ex) == OMAGIC) {
 265                 loff_t pos = fd_offset;
 266                 down_write(&current->mm->mmap_sem);
 267                 do_brk(N_TXTADDR(ex) & PAGE_MASK,
 268                         ex.a_text+ex.a_data + PAGE_SIZE - 1);
 269                 up_write(&current->mm->mmap_sem);
 270                 bprm->file->f_op->read(bprm->file, (char __user *)N_TXTADDR(ex),
 271                           ex.a_text+ex.a_data, &pos);
 272         } else {
 273                 static unsigned long error_time;
 274                 if ((ex.a_text & 0xfff || ex.a_data & 0xfff) &&
 275                     (N_MAGIC(ex) != NMAGIC) && (jiffies-error_time) > 5*HZ)
 276                 {
 277                         printk(KERN_NOTICE "executable not page aligned\n");
 278                         error_time = jiffies;
 279                 }
 280
 281                 if (!bprm->file->f_op->mmap) {
 282                         loff_t pos = fd_offset;
 283                         down_write(&current->mm->mmap_sem);
 284                         do_brk(0, ex.a_text+ex.a_data);
 285                         up_write(&current->mm->mmap_sem);
 286                         bprm->file->f_op->read(bprm->file,
 287                                   (char __user *)N_TXTADDR(ex),
 288                                   ex.a_text+ex.a_data, &pos);
 289                         goto beyond_if;
 290                 }
 291
 292                 down_write(&current->mm->mmap_sem);
 293                 error = do_mmap(bprm->file, N_TXTADDR(ex), ex.a_text,
 294                         PROT_READ | PROT_EXEC,
 295                         MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE,
 296                         fd_offset);
 297                 up_write(&current->mm->mmap_sem);
 298
 299                 if (error != N_TXTADDR(ex)) {
 300                         send_sig(SIGKILL, current, 0);
 301                         return error;
 302                 }
 303
 304                 down_write(&current->mm->mmap_sem);
 305                 error = do_mmap(bprm->file, N_DATADDR(ex), ex.a_data,
 306                                 PROT_READ | PROT_WRITE | PROT_EXEC,
 307                                 MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE,
 308                                 fd_offset + ex.a_text);
 309                 up_write(&current->mm->mmap_sem);
 310                 if (error != N_DATADDR(ex)) {
 311                         send_sig(SIGKILL, current, 0);
 312                         return error;
 313                 }
 314         }
 315 beyond_if:
 316         set_binfmt(&aout32_format);
 317
 318         set_brk(current->mm->start_brk, current->mm->brk);
 319
 320         /* Make sure STACK_TOP returns the right thing.  */
 321         orig_thr_flags = current_thread_info()->flags;
 322         current_thread_info()->flags |= _TIF_32BIT;
 323
 324         retval = setup_arg_pages(bprm, STACK_TOP, EXSTACK_DEFAULT);
 325         if (retval < 0) {
 326                 current_thread_info()->flags = orig_thr_flags;
 327
 328                 /* Someone check-me: is this error path enough? */
 329                 send_sig(SIGKILL, current, 0);
 330                 return retval;
 331         }
 332
 333         current->mm->start_stack =
 334                 (unsigned long) create_aout32_tables((char __user *)bprm->p, bprm);
 335         tsb_context_switch(current->mm);
 336
 337         start_thread32(regs, ex.a_entry, current->mm->start_stack);
 338         if (current->ptrace & PT_PTRACED)
 339                 send_sig(SIGTRAP, current, 0);
 340         return 0;
 341 }
 342
 343 /* N.B. Move to .h file and use code in fs/binfmt_aout.c? */
 344 static int load_aout32_library(struct file *file)
 345 {
 346         struct inode * inode;
 347         unsigned long bss, start_addr, len;
 348         unsigned long error;
 349         int retval;
 350         struct exec ex;
 351
 352         inode = file->f_path.dentry->d_inode;
 353
 354         retval = -ENOEXEC;
 355         error = kernel_read(file, 0, (char *) &ex, sizeof(ex));
 356         if (error != sizeof(ex))
 357                 goto out;
 358
 359         /* We come in here for the regular a.out style of shared libraries */
 360         if ((N_MAGIC(ex) != ZMAGIC && N_MAGIC(ex) != QMAGIC) || N_TRSIZE(ex) ||
 361             N_DRSIZE(ex) || ((ex.a_entry & 0xfff) && N_MAGIC(ex) == ZMAGIC) ||
 362             inode->i_size < ex.a_text+ex.a_data+N_SYMSIZE(ex)+N_TXTOFF(ex)) {
 363                 goto out;
 364         }
 365
 366         if (N_MAGIC(ex) == ZMAGIC && N_TXTOFF(ex) &&
 367             (N_TXTOFF(ex) < inode->i_sb->s_blocksize)) {
 368                 printk("N_TXTOFF < BLOCK_SIZE. Please convert library\n");
 369                 goto out;
 370         }
 371
 372         if (N_FLAGS(ex))
 373                 goto out;
 374
 375         /* For  QMAGIC, the starting address is 0x20 into the page.  We mask
 376            this off to get the starting address for the page */
 377
 378         start_addr =  ex.a_entry & 0xfffff000;
 379
 380         /* Now use mmap to map the library into memory. */
 381         down_write(&current->mm->mmap_sem);
 382         error = do_mmap(file, start_addr, ex.a_text + ex.a_data,
 383                         PROT_READ | PROT_WRITE | PROT_EXEC,
 384                         MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE,
 385                         N_TXTOFF(ex));
 386         up_write(&current->mm->mmap_sem);
 387         retval = error;
 388         if (error != start_addr)
 389                 goto out;
 390
 391         len = PAGE_ALIGN(ex.a_text + ex.a_data);
 392         bss = ex.a_text + ex.a_data + ex.a_bss;
 393         if (bss > len) {
 394                 down_write(&current->mm->mmap_sem);
 395                 error = do_brk(start_addr + len, bss - len);
 396                 up_write(&current->mm->mmap_sem);
 397                 retval = error;
 398                 if (error != start_addr + len)
 399                         goto out;
 400         }
 401         retval = 0;
 402 out:
 403         return retval;
 404 }
 405
 406 static int __init init_aout32_binfmt(void)
 407 {
 408         return register_binfmt(&aout32_format);
 409 }
 410
 411 static void __exit exit_aout32_binfmt(void)
 412 {
 413         unregister_binfmt(&aout32_format);
 414 }
 415
 416 module_init(init_aout32_binfmt);
 417 module_exit(exit_aout32_binfmt);