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         .module         = THIS_MODULE,
  42         .load_binary    = load_aout32_binary,
  43         .load_shlib     = load_aout32_library,
  44         .core_dump      = aout32_core_dump,
  45         .min_coredump   = PAGE_SIZE,
  46 };
  47
  48 static void set_brk(unsigned long start, unsigned long end)
  49 {
  50         start = PAGE_ALIGN(start);
  51         end = PAGE_ALIGN(end);
  52         if (end <= start)
  53                 return;
  54         down_write(&current->mm->mmap_sem);
  55         do_brk(start, end - start);
  56         up_write(&current->mm->mmap_sem);
  57 }
  58
  59 /*
  60  * These are the only things you should do on a core-file: use only these
  61  * macros to write out all the necessary info.
  62  */
  63
  64 static int dump_write(struct file *file, const void *addr, int nr)
  65 {
  66         return file->f_op->write(file, addr, nr, &file->f_pos) == nr;
  67 }
  68
  69 #define DUMP_WRITE(addr, nr)    \
  70         if (!dump_write(file, (void *)(addr), (nr))) \
  71                 goto end_coredump;
  72
  73 #define DUMP_SEEK(offset) \
  74 if (file->f_op->llseek) { \
  75         if (file->f_op->llseek(file,(offset),0) != (offset)) \
  76                 goto end_coredump; \
  77 } else file->f_pos = (offset)
  78
  79 /*
  80  * Routine writes a core dump image in the current directory.
  81  * Currently only a stub-function.
  82  *
  83  * Note that setuid/setgid files won't make a core-dump if the uid/gid
  84  * changed due to the set[u|g]id. It's enforced by the "current->mm->dumpable"
  85  * field, which also makes sure the core-dumps won't be recursive if the
  86  * dumping of the process results in another error..
  87  */
  88
  89 static int aout32_core_dump(long signr, struct pt_regs *regs, struct file *file)
  90 {
  91         mm_segment_t fs;
  92         int has_dumped = 0;
  93         unsigned long dump_start, dump_size;
  94         struct user dump;
  95 #       define START_DATA(u)    (u.u_tsize)
  96 #       define START_STACK(u)   ((regs->u_regs[UREG_FP]) & ~(PAGE_SIZE - 1))
  97
  98         fs = get_fs();
  99         set_fs(KERNEL_DS);
 100         has_dumped = 1;
 101         current->flags |= PF_DUMPCORE;
 102         strncpy(dump.u_comm, current->comm, sizeof(dump.u_comm));
 103         dump.signal = signr;
 104         dump_thread(regs, &dump);
 105
 106 /* If the size of the dump file exceeds the rlimit, then see what would happen
 107    if we wrote the stack, but not the data area.  */
 108         if ((dump.u_dsize+dump.u_ssize) >
 109             current->signal->rlim[RLIMIT_CORE].rlim_cur)
 110                 dump.u_dsize = 0;
 111
 112 /* Make sure we have enough room to write the stack and data areas. */
 113         if ((dump.u_ssize) >
 114             current->signal->rlim[RLIMIT_CORE].rlim_cur)
 115                 dump.u_ssize = 0;
 116
 117 /* make sure we actually have a data and stack area to dump */
 118         set_fs(USER_DS);
 119         if (!access_ok(VERIFY_READ, (void __user *) START_DATA(dump), dump.u_dsize))
 120                 dump.u_dsize = 0;
 121         if (!access_ok(VERIFY_READ, (void __user *) START_STACK(dump), dump.u_ssize))
 122                 dump.u_ssize = 0;
 123
 124         set_fs(KERNEL_DS);
 125 /* struct user */
 126         DUMP_WRITE(&dump,sizeof(dump));
 127 /* now we start writing out the user space info */
 128         set_fs(USER_DS);
 129 /* Dump the data area */
 130         if (dump.u_dsize != 0) {
 131                 dump_start = START_DATA(dump);
 132                 dump_size = dump.u_dsize;
 133                 DUMP_WRITE(dump_start,dump_size);
 134         }
 135 /* Now prepare to dump the stack area */
 136         if (dump.u_ssize != 0) {
 137                 dump_start = START_STACK(dump);
 138                 dump_size = dump.u_ssize;
 139                 DUMP_WRITE(dump_start,dump_size);
 140         }
 141 /* Finally dump the task struct.  Not be used by gdb, but could be useful */
 142         set_fs(KERNEL_DS);
 143         DUMP_WRITE(current,sizeof(*current));
 144 end_coredump:
 145         set_fs(fs);
 146         return has_dumped;
 147 }
 148
 149 /*
 150  * create_aout32_tables() parses the env- and arg-strings in new user
 151  * memory and creates the pointer tables from them, and puts their
 152  * addresses on the "stack", returning the new stack pointer value.
 153  */
 154
 155 static u32 __user *create_aout32_tables(char __user *p, struct linux_binprm *bprm)
 156 {
 157         u32 __user *argv;
 158         u32 __user *envp;
 159         u32 __user *sp;
 160         int argc = bprm->argc;
 161         int envc = bprm->envc;
 162
 163         sp = (u32 __user *)((-(unsigned long)sizeof(char *))&(unsigned long)p);
 164
 165         /* This imposes the proper stack alignment for a new process. */
 166         sp = (u32 __user *) (((unsigned long) sp) & ~7);
 167         if ((envc+argc+3)&1)
 168                 --sp;
 169
 170         sp -= envc+1;
 171         envp = sp;
 172         sp -= argc+1;
 173         argv = sp;
 174         put_user(argc,--sp);
 175         current->mm->arg_start = (unsigned long) p;
 176         while (argc-->0) {
 177                 char c;
 178                 put_user(((u32)(unsigned long)(p)),argv++);
 179                 do {
 180                         get_user(c,p++);
 181                 } while (c);
 182         }
 183         put_user(0,argv);
 184         current->mm->arg_end = current->mm->env_start = (unsigned long) p;
 185         while (envc-->0) {
 186                 char c;
 187                 put_user(((u32)(unsigned long)(p)),envp++);
 188                 do {
 189                         get_user(c,p++);
 190                 } while (c);
 191         }
 192         put_user(0,envp);
 193         current->mm->env_end = (unsigned long) p;
 194         return sp;
 195 }
 196
 197 /*
 198  * These are the functions used to load a.out style executables and shared
 199  * libraries.  There is no binary dependent code anywhere else.
 200  */
 201
 202 static int load_aout32_binary(struct linux_binprm * bprm, struct pt_regs * regs)
 203 {
 204         struct exec ex;
 205         unsigned long error;
 206         unsigned long fd_offset;
 207         unsigned long rlim;
 208         unsigned long orig_thr_flags;
 209         int retval;
 210
 211         ex = *((struct exec *) bprm->buf);              /* exec-header */
 212         if ((N_MAGIC(ex) != ZMAGIC && N_MAGIC(ex) != OMAGIC &&
 213              N_MAGIC(ex) != QMAGIC && N_MAGIC(ex) != NMAGIC) ||
 214             N_TRSIZE(ex) || N_DRSIZE(ex) ||
 215             bprm->file->f_path.dentry->d_inode->i_size < ex.a_text+ex.a_data+N_SYMSIZE(ex)+N_TXTOFF(ex)) {
 216                 return -ENOEXEC;
 217         }
 218
 219         fd_offset = N_TXTOFF(ex);
 220
 221         /* Check initial limits. This avoids letting people circumvent
 222          * size limits imposed on them by creating programs with large
 223          * arrays in the data or bss.
 224          */
 225         rlim = current->signal->rlim[RLIMIT_DATA].rlim_cur;
 226         if (rlim >= RLIM_INFINITY)
 227                 rlim = ~0;
 228         if (ex.a_data + ex.a_bss > rlim)
 229                 return -ENOMEM;
 230
 231         /* Flush all traces of the currently running executable */
 232         retval = flush_old_exec(bprm);
 233         if (retval)
 234                 return retval;
 235
 236         /* OK, This is the point of no return */
 237         set_personality(PER_SUNOS);
 238
 239         current->mm->end_code = ex.a_text +
 240                 (current->mm->start_code = N_TXTADDR(ex));
 241         current->mm->end_data = ex.a_data +
 242                 (current->mm->start_data = N_DATADDR(ex));
 243         current->mm->brk = ex.a_bss +
 244                 (current->mm->start_brk = N_BSSADDR(ex));
 245         current->mm->free_area_cache = current->mm->mmap_base;
 246         current->mm->cached_hole_size = 0;
 247
 248         current->mm->mmap = NULL;
 249         compute_creds(bprm);
 250         current->flags &= ~PF_FORKNOEXEC;
 251         if (N_MAGIC(ex) == NMAGIC) {
 252                 loff_t pos = fd_offset;
 253                 /* Fuck me plenty... */
 254                 down_write(&current->mm->mmap_sem);
 255                 error = do_brk(N_TXTADDR(ex), ex.a_text);
 256                 up_write(&current->mm->mmap_sem);
 257                 bprm->file->f_op->read(bprm->file, (char __user *)N_TXTADDR(ex),
 258                           ex.a_text, &pos);
 259                 down_write(&current->mm->mmap_sem);
 260                 error = do_brk(N_DATADDR(ex), ex.a_data);
 261                 up_write(&current->mm->mmap_sem);
 262                 bprm->file->f_op->read(bprm->file, (char __user *)N_DATADDR(ex),
 263                           ex.a_data, &pos);
 264                 goto beyond_if;
 265         }
 266
 267         if (N_MAGIC(ex) == OMAGIC) {
 268                 loff_t pos = fd_offset;
 269                 down_write(&current->mm->mmap_sem);
 270                 do_brk(N_TXTADDR(ex) & PAGE_MASK,
 271                         ex.a_text+ex.a_data + PAGE_SIZE - 1);
 272                 up_write(&current->mm->mmap_sem);
 273                 bprm->file->f_op->read(bprm->file, (char __user *)N_TXTADDR(ex),
 274                           ex.a_text+ex.a_data, &pos);
 275         } else {
 276                 static unsigned long error_time;
 277                 if ((ex.a_text & 0xfff || ex.a_data & 0xfff) &&
 278                     (N_MAGIC(ex) != NMAGIC) && (jiffies-error_time) > 5*HZ)
 279                 {
 280                         printk(KERN_NOTICE "executable not page aligned\n");
 281                         error_time = jiffies;
 282                 }
 283
 284                 if (!bprm->file->f_op->mmap) {
 285                         loff_t pos = fd_offset;
 286                         down_write(&current->mm->mmap_sem);
 287                         do_brk(0, ex.a_text+ex.a_data);
 288                         up_write(&current->mm->mmap_sem);
 289                         bprm->file->f_op->read(bprm->file,
 290                                   (char __user *)N_TXTADDR(ex),
 291                                   ex.a_text+ex.a_data, &pos);
 292                         goto beyond_if;
 293                 }
 294
 295                 down_write(&current->mm->mmap_sem);
 296                 error = do_mmap(bprm->file, N_TXTADDR(ex), ex.a_text,
 297                         PROT_READ | PROT_EXEC,
 298                         MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE,
 299                         fd_offset);
 300                 up_write(&current->mm->mmap_sem);
 301
 302                 if (error != N_TXTADDR(ex)) {
 303                         send_sig(SIGKILL, current, 0);
 304                         return error;
 305                 }
 306
 307                 down_write(&current->mm->mmap_sem);
 308                 error = do_mmap(bprm->file, N_DATADDR(ex), ex.a_data,
 309                                 PROT_READ | PROT_WRITE | PROT_EXEC,
 310                                 MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE,
 311                                 fd_offset + ex.a_text);
 312                 up_write(&current->mm->mmap_sem);
 313                 if (error != N_DATADDR(ex)) {
 314                         send_sig(SIGKILL, current, 0);
 315                         return error;
 316                 }
 317         }
 318 beyond_if:
 319         set_binfmt(&aout32_format);
 320
 321         set_brk(current->mm->start_brk, current->mm->brk);
 322
 323         /* Make sure STACK_TOP returns the right thing.  */
 324         orig_thr_flags = current_thread_info()->flags;
 325         current_thread_info()->flags |= _TIF_32BIT;
 326
 327         retval = setup_arg_pages(bprm, STACK_TOP, EXSTACK_DEFAULT);
 328         if (retval < 0) {
 329                 current_thread_info()->flags = orig_thr_flags;
 330
 331                 /* Someone check-me: is this error path enough? */
 332                 send_sig(SIGKILL, current, 0);
 333                 return retval;
 334         }
 335
 336         current->mm->start_stack =
 337                 (unsigned long) create_aout32_tables((char __user *)bprm->p, bprm);
 338         tsb_context_switch(current->mm);
 339
 340         start_thread32(regs, ex.a_entry, current->mm->start_stack);
 341         if (current->ptrace & PT_PTRACED)
 342                 send_sig(SIGTRAP, current, 0);
 343         return 0;
 344 }
 345
 346 /* N.B. Move to .h file and use code in fs/binfmt_aout.c? */
 347 static int load_aout32_library(struct file *file)
 348 {
 349         struct inode * inode;
 350         unsigned long bss, start_addr, len;
 351         unsigned long error;
 352         int retval;
 353         struct exec ex;
 354
 355         inode = file->f_path.dentry->d_inode;
 356
 357         retval = -ENOEXEC;
 358         error = kernel_read(file, 0, (char *) &ex, sizeof(ex));
 359         if (error != sizeof(ex))
 360                 goto out;
 361
 362         /* We come in here for the regular a.out style of shared libraries */
 363         if ((N_MAGIC(ex) != ZMAGIC && N_MAGIC(ex) != QMAGIC) || N_TRSIZE(ex) ||
 364             N_DRSIZE(ex) || ((ex.a_entry & 0xfff) && N_MAGIC(ex) == ZMAGIC) ||
 365             inode->i_size < ex.a_text+ex.a_data+N_SYMSIZE(ex)+N_TXTOFF(ex)) {
 366                 goto out;
 367         }
 368
 369         if (N_MAGIC(ex) == ZMAGIC && N_TXTOFF(ex) &&
 370             (N_TXTOFF(ex) < inode->i_sb->s_blocksize)) {
 371                 printk("N_TXTOFF < BLOCK_SIZE. Please convert library\n");
 372                 goto out;
 373         }
 374
 375         if (N_FLAGS(ex))
 376                 goto out;
 377
 378         /* For  QMAGIC, the starting address is 0x20 into the page.  We mask
 379            this off to get the starting address for the page */
 380
 381         start_addr =  ex.a_entry & 0xfffff000;
 382
 383         /* Now use mmap to map the library into memory. */
 384         down_write(&current->mm->mmap_sem);
 385         error = do_mmap(file, start_addr, ex.a_text + ex.a_data,
 386                         PROT_READ | PROT_WRITE | PROT_EXEC,
 387                         MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE,
 388                         N_TXTOFF(ex));
 389         up_write(&current->mm->mmap_sem);
 390         retval = error;
 391         if (error != start_addr)
 392                 goto out;
 393
 394         len = PAGE_ALIGN(ex.a_text + ex.a_data);
 395         bss = ex.a_text + ex.a_data + ex.a_bss;
 396         if (bss > len) {
 397                 down_write(&current->mm->mmap_sem);
 398                 error = do_brk(start_addr + len, bss - len);
 399                 up_write(&current->mm->mmap_sem);
 400                 retval = error;
 401                 if (error != start_addr + len)
 402                         goto out;
 403         }
 404         retval = 0;
 405 out:
 406         return retval;
 407 }
 408
 409 static int __init init_aout32_binfmt(void)
 410 {
 411         return register_binfmt(&aout32_format);
 412 }
 413
 414 static void __exit exit_aout32_binfmt(void)
 415 {
 416         unregister_binfmt(&aout32_format);
 417 }
 418
 419 module_init(init_aout32_binfmt);
 420 module_exit(exit_aout32_binfmt);