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 #include <asm/a.out-core.h>
  36
  37 static int load_aout32_binary(struct linux_binprm *, struct pt_regs * regs);
  38 static int load_aout32_library(struct file*);
  39 static int aout32_core_dump(long signr, struct pt_regs *regs, struct file *file, unsigned long limit);
  40
  41 static struct linux_binfmt aout32_format = {
  42         .module         = THIS_MODULE,
  43         .load_binary    = load_aout32_binary,
  44         .load_shlib     = load_aout32_library,
  45         .core_dump      = aout32_core_dump,
  46         .min_coredump   = PAGE_SIZE,
  47 };
  48
  49 static void set_brk(unsigned long start, unsigned long end)
  50 {
  51         start = PAGE_ALIGN(start);
  52         end = PAGE_ALIGN(end);
  53         if (end <= start)
  54                 return;
  55         down_write(&current->mm->mmap_sem);
  56         do_brk(start, end - start);
  57         up_write(&current->mm->mmap_sem);
  58 }
  59
  60 /*
  61  * These are the only things you should do on a core-file: use only these
  62  * macros to write out all the necessary info.
  63  */
  64
  65 static int dump_write(struct file *file, const void *addr, int nr)
  66 {
  67         return file->f_op->write(file, addr, nr, &file->f_pos) == nr;
  68 }
  69
  70 #define DUMP_WRITE(addr, nr)    \
  71         if (!dump_write(file, (void *)(addr), (nr))) \
  72                 goto end_coredump;
  73
  74 #define DUMP_SEEK(offset) \
  75 if (file->f_op->llseek) { \
  76         if (file->f_op->llseek(file,(offset),0) != (offset)) \
  77                 goto end_coredump; \
  78 } else file->f_pos = (offset)
  79
  80 /*
  81  * Routine writes a core dump image in the current directory.
  82  * Currently only a stub-function.
  83  *
  84  * Note that setuid/setgid files won't make a core-dump if the uid/gid
  85  * changed due to the set[u|g]id. It's enforced by the "current->mm->dumpable"
  86  * field, which also makes sure the core-dumps won't be recursive if the
  87  * dumping of the process results in another error..
  88  */
  89
  90 static int aout32_core_dump(long signr, struct pt_regs *regs, struct file *file, unsigned long limit)
  91 {
  92         mm_segment_t fs;
  93         int has_dumped = 0;
  94         unsigned long dump_start, dump_size;
  95         struct user dump;
  96 #       define START_DATA(u)    (u.u_tsize)
  97 #       define START_STACK(u)   ((regs->u_regs[UREG_FP]) & ~(PAGE_SIZE - 1))
  98
  99         fs = get_fs();
 100         set_fs(KERNEL_DS);
 101         has_dumped = 1;
 102         current->flags |= PF_DUMPCORE;
 103         strncpy(dump.u_comm, current->comm, sizeof(dump.u_comm));
 104         dump.signal = signr;
 105         aout_dump_thread(regs, &dump);
 106
 107 /* If the size of the dump file exceeds the rlimit, then see what would happen
 108    if we wrote the stack, but not the data area.  */
 109         if (dump.u_dsize + dump.u_ssize > limit)
 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 > limit)
 114                 dump.u_ssize = 0;
 115
 116 /* make sure we actually have a data and stack area to dump */
 117         set_fs(USER_DS);
 118         if (!access_ok(VERIFY_READ, (void __user *) START_DATA(dump), dump.u_dsize))
 119                 dump.u_dsize = 0;
 120         if (!access_ok(VERIFY_READ, (void __user *) START_STACK(dump), dump.u_ssize))
 121                 dump.u_ssize = 0;
 122
 123         set_fs(KERNEL_DS);
 124 /* struct user */
 125         DUMP_WRITE(&dump,sizeof(dump));
 126 /* now we start writing out the user space info */
 127         set_fs(USER_DS);
 128 /* Dump the data area */
 129         if (dump.u_dsize != 0) {
 130                 dump_start = START_DATA(dump);
 131                 dump_size = dump.u_dsize;
 132                 DUMP_WRITE(dump_start,dump_size);
 133         }
 134 /* Now prepare to dump the stack area */
 135         if (dump.u_ssize != 0) {
 136                 dump_start = START_STACK(dump);
 137                 dump_size = dump.u_ssize;
 138                 DUMP_WRITE(dump_start,dump_size);
 139         }
 140 /* Finally dump the task struct.  Not be used by gdb, but could be useful */
 141         set_fs(KERNEL_DS);
 142         DUMP_WRITE(current,sizeof(*current));
 143 end_coredump:
 144         set_fs(fs);
 145         return has_dumped;
 146 }
 147
 148 /*
 149  * create_aout32_tables() parses the env- and arg-strings in new user
 150  * memory and creates the pointer tables from them, and puts their
 151  * addresses on the "stack", returning the new stack pointer value.
 152  */
 153
 154 static u32 __user *create_aout32_tables(char __user *p, struct linux_binprm *bprm)
 155 {
 156         u32 __user *argv;
 157         u32 __user *envp;
 158         u32 __user *sp;
 159         int argc = bprm->argc;
 160         int envc = bprm->envc;
 161
 162         sp = (u32 __user *)((-(unsigned long)sizeof(char *))&(unsigned long)p);
 163
 164         /* This imposes the proper stack alignment for a new process. */
 165         sp = (u32 __user *) (((unsigned long) sp) & ~7);
 166         if ((envc+argc+3)&1)
 167                 --sp;
 168
 169         sp -= envc+1;
 170         envp = sp;
 171         sp -= argc+1;
 172         argv = sp;
 173         put_user(argc,--sp);
 174         current->mm->arg_start = (unsigned long) p;
 175         while (argc-->0) {
 176                 char c;
 177                 put_user(((u32)(unsigned long)(p)),argv++);
 178                 do {
 179                         get_user(c,p++);
 180                 } while (c);
 181         }
 182         put_user(0,argv);
 183         current->mm->arg_end = current->mm->env_start = (unsigned long) p;
 184         while (envc-->0) {
 185                 char c;
 186                 put_user(((u32)(unsigned long)(p)),envp++);
 187                 do {
 188                         get_user(c,p++);
 189                 } while (c);
 190         }
 191         put_user(0,envp);
 192         current->mm->env_end = (unsigned long) p;
 193         return sp;
 194 }
 195
 196 /*
 197  * These are the functions used to load a.out style executables and shared
 198  * libraries.  There is no binary dependent code anywhere else.
 199  */
 200
 201 static int load_aout32_binary(struct linux_binprm * bprm, struct pt_regs * regs)
 202 {
 203         struct exec ex;
 204         unsigned long error;
 205         unsigned long fd_offset;
 206         unsigned long rlim;
 207         unsigned long orig_thr_flags;
 208         int retval;
 209
 210         ex = *((struct exec *) bprm->buf);              /* exec-header */
 211         if ((N_MAGIC(ex) != ZMAGIC && N_MAGIC(ex) != OMAGIC &&
 212              N_MAGIC(ex) != QMAGIC && N_MAGIC(ex) != NMAGIC) ||
 213             N_TRSIZE(ex) || N_DRSIZE(ex) ||
 214             bprm->file->f_path.dentry->d_inode->i_size < ex.a_text+ex.a_data+N_SYMSIZE(ex)+N_TXTOFF(ex)) {
 215                 return -ENOEXEC;
 216         }
 217
 218         fd_offset = N_TXTOFF(ex);
 219
 220         /* Check initial limits. This avoids letting people circumvent
 221          * size limits imposed on them by creating programs with large
 222          * arrays in the data or bss.
 223          */
 224         rlim = current->signal->rlim[RLIMIT_DATA].rlim_cur;
 225         if (rlim >= RLIM_INFINITY)
 226                 rlim = ~0;
 227         if (ex.a_data + ex.a_bss > rlim)
 228                 return -ENOMEM;
 229
 230         /* Flush all traces of the currently running executable */
 231         retval = flush_old_exec(bprm);
 232         if (retval)
 233                 return retval;
 234
 235         /* OK, This is the point of no return */
 236         set_personality(PER_SUNOS);
 237
 238         current->mm->end_code = ex.a_text +
 239                 (current->mm->start_code = N_TXTADDR(ex));
 240         current->mm->end_data = ex.a_data +
 241                 (current->mm->start_data = N_DATADDR(ex));
 242         current->mm->brk = ex.a_bss +
 243                 (current->mm->start_brk = N_BSSADDR(ex));
 244         current->mm->free_area_cache = current->mm->mmap_base;
 245         current->mm->cached_hole_size = 0;
 246
 247         current->mm->mmap = NULL;
 248         compute_creds(bprm);
 249         current->flags &= ~PF_FORKNOEXEC;
 250         if (N_MAGIC(ex) == NMAGIC) {
 251                 loff_t pos = fd_offset;
 252                 /* Fuck me plenty... */
 253                 down_write(&current->mm->mmap_sem);
 254                 error = do_brk(N_TXTADDR(ex), ex.a_text);
 255                 up_write(&current->mm->mmap_sem);
 256                 bprm->file->f_op->read(bprm->file, (char __user *)N_TXTADDR(ex),
 257                           ex.a_text, &pos);
 258                 down_write(&current->mm->mmap_sem);
 259                 error = do_brk(N_DATADDR(ex), ex.a_data);
 260                 up_write(&current->mm->mmap_sem);
 261                 bprm->file->f_op->read(bprm->file, (char __user *)N_DATADDR(ex),
 262                           ex.a_data, &pos);
 263                 goto beyond_if;
 264         }
 265
 266         if (N_MAGIC(ex) == OMAGIC) {
 267                 loff_t pos = fd_offset;
 268                 down_write(&current->mm->mmap_sem);
 269                 do_brk(N_TXTADDR(ex) & PAGE_MASK,
 270                         ex.a_text+ex.a_data + PAGE_SIZE - 1);
 271                 up_write(&current->mm->mmap_sem);
 272                 bprm->file->f_op->read(bprm->file, (char __user *)N_TXTADDR(ex),
 273                           ex.a_text+ex.a_data, &pos);
 274         } else {
 275                 static unsigned long error_time;
 276                 if ((ex.a_text & 0xfff || ex.a_data & 0xfff) &&
 277                     (N_MAGIC(ex) != NMAGIC) && (jiffies-error_time) > 5*HZ)
 278                 {
 279                         printk(KERN_NOTICE "executable not page aligned\n");
 280                         error_time = jiffies;
 281                 }
 282
 283                 if (!bprm->file->f_op->mmap) {
 284                         loff_t pos = fd_offset;
 285                         down_write(&current->mm->mmap_sem);
 286                         do_brk(0, ex.a_text+ex.a_data);
 287                         up_write(&current->mm->mmap_sem);
 288                         bprm->file->f_op->read(bprm->file,
 289                                   (char __user *)N_TXTADDR(ex),
 290                                   ex.a_text+ex.a_data, &pos);
 291                         goto beyond_if;
 292                 }
 293
 294                 down_write(&current->mm->mmap_sem);
 295                 error = do_mmap(bprm->file, N_TXTADDR(ex), ex.a_text,
 296                         PROT_READ | PROT_EXEC,
 297                         MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE,
 298                         fd_offset);
 299                 up_write(&current->mm->mmap_sem);
 300
 301                 if (error != N_TXTADDR(ex)) {
 302                         send_sig(SIGKILL, current, 0);
 303                         return error;
 304                 }
 305
 306                 down_write(&current->mm->mmap_sem);
 307                 error = do_mmap(bprm->file, N_DATADDR(ex), ex.a_data,
 308                                 PROT_READ | PROT_WRITE | PROT_EXEC,
 309                                 MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE,
 310                                 fd_offset + ex.a_text);
 311                 up_write(&current->mm->mmap_sem);
 312                 if (error != N_DATADDR(ex)) {
 313                         send_sig(SIGKILL, current, 0);
 314                         return error;
 315                 }
 316         }
 317 beyond_if:
 318         set_binfmt(&aout32_format);
 319
 320         set_brk(current->mm->start_brk, current->mm->brk);
 321
 322         /* Make sure STACK_TOP returns the right thing.  */
 323         orig_thr_flags = current_thread_info()->flags;
 324         current_thread_info()->flags |= _TIF_32BIT;
 325
 326         retval = setup_arg_pages(bprm, STACK_TOP, EXSTACK_DEFAULT);
 327         if (retval < 0) {
 328                 current_thread_info()->flags = orig_thr_flags;
 329
 330                 /* Someone check-me: is this error path enough? */
 331                 send_sig(SIGKILL, current, 0);
 332                 return retval;
 333         }
 334
 335         current->mm->start_stack =
 336                 (unsigned long) create_aout32_tables((char __user *)bprm->p, bprm);
 337         tsb_context_switch(current->mm);
 338
 339         start_thread32(regs, ex.a_entry, current->mm->start_stack);
 340         if (current->ptrace & PT_PTRACED)
 341                 send_sig(SIGTRAP, current, 0);
 342         return 0;
 343 }
 344
 345 /* N.B. Move to .h file and use code in fs/binfmt_aout.c? */
 346 static int load_aout32_library(struct file *file)
 347 {
 348         struct inode * inode;
 349         unsigned long bss, start_addr, len;
 350         unsigned long error;
 351         int retval;
 352         struct exec ex;
 353
 354         inode = file->f_path.dentry->d_inode;
 355
 356         retval = -ENOEXEC;
 357         error = kernel_read(file, 0, (char *) &ex, sizeof(ex));
 358         if (error != sizeof(ex))
 359                 goto out;
 360
 361         /* We come in here for the regular a.out style of shared libraries */
 362         if ((N_MAGIC(ex) != ZMAGIC && N_MAGIC(ex) != QMAGIC) || N_TRSIZE(ex) ||
 363             N_DRSIZE(ex) || ((ex.a_entry & 0xfff) && N_MAGIC(ex) == ZMAGIC) ||
 364             inode->i_size < ex.a_text+ex.a_data+N_SYMSIZE(ex)+N_TXTOFF(ex)) {
 365                 goto out;
 366         }
 367
 368         if (N_MAGIC(ex) == ZMAGIC && N_TXTOFF(ex) &&
 369             (N_TXTOFF(ex) < inode->i_sb->s_blocksize)) {
 370                 printk("N_TXTOFF < BLOCK_SIZE. Please convert library\n");
 371                 goto out;
 372         }
 373
 374         if (N_FLAGS(ex))
 375                 goto out;
 376
 377         /* For  QMAGIC, the starting address is 0x20 into the page.  We mask
 378            this off to get the starting address for the page */
 379
 380         start_addr =  ex.a_entry & 0xfffff000;
 381
 382         /* Now use mmap to map the library into memory. */
 383         down_write(&current->mm->mmap_sem);
 384         error = do_mmap(file, start_addr, ex.a_text + ex.a_data,
 385                         PROT_READ | PROT_WRITE | PROT_EXEC,
 386                         MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE,
 387                         N_TXTOFF(ex));
 388         up_write(&current->mm->mmap_sem);
 389         retval = error;
 390         if (error != start_addr)
 391                 goto out;
 392
 393         len = PAGE_ALIGN(ex.a_text + ex.a_data);
 394         bss = ex.a_text + ex.a_data + ex.a_bss;
 395         if (bss > len) {
 396                 down_write(&current->mm->mmap_sem);
 397                 error = do_brk(start_addr + len, bss - len);
 398                 up_write(&current->mm->mmap_sem);
 399                 retval = error;
 400                 if (error != start_addr + len)
 401                         goto out;
 402         }
 403         retval = 0;
 404 out:
 405         return retval;
 406 }
 407
 408 static int __init init_aout32_binfmt(void)
 409 {
 410         return register_binfmt(&aout32_format);
 411 }
 412
 413 static void __exit exit_aout32_binfmt(void)
 414 {
 415         unregister_binfmt(&aout32_format);
 416 }
 417
 418 module_init(init_aout32_binfmt);
 419 module_exit(exit_aout32_binfmt);