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
  35 static int load_aout32_binary(struct linux_binprm *, struct pt_regs * regs);
  36 static int load_aout32_library(struct file*);
  37 static int aout32_core_dump(long signr, struct pt_regs * regs, struct file *file);
  38
  39 static struct linux_binfmt aout32_format = {
  40         NULL, THIS_MODULE, load_aout32_binary, load_aout32_library, aout32_core_dump,
  41         PAGE_SIZE
  42 };
  43
  44 static void set_brk(unsigned long start, unsigned long end)
  45 {
  46         start = PAGE_ALIGN(start);
  47         end = PAGE_ALIGN(end);
  48         if (end <= start)
  49                 return;
  50         down_write(&current->mm->mmap_sem);
  51         do_brk(start, end - start);
  52         up_write(&current->mm->mmap_sem);
  53 }
  54
  55 /*
  56  * These are the only things you should do on a core-file: use only these
  57  * macros to write out all the necessary info.
  58  */
  59
  60 static int dump_write(struct file *file, const void *addr, int nr)
  61 {
  62         return file->f_op->write(file, addr, nr, &file->f_pos) == nr;
  63 }
  64
  65 #define DUMP_WRITE(addr, nr)    \
  66         if (!dump_write(file, (void *)(addr), (nr))) \
  67                 goto end_coredump;
  68
  69 #define DUMP_SEEK(offset) \
  70 if (file->f_op->llseek) { \
  71         if (file->f_op->llseek(file,(offset),0) != (offset)) \
  72                 goto end_coredump; \
  73 } else file->f_pos = (offset)
  74
  75 /*
  76  * Routine writes a core dump image in the current directory.
  77  * Currently only a stub-function.
  78  *
  79  * Note that setuid/setgid files won't make a core-dump if the uid/gid
  80  * changed due to the set[u|g]id. It's enforced by the "current->mm->dumpable"
  81  * field, which also makes sure the core-dumps won't be recursive if the
  82  * dumping of the process results in another error..
  83  */
  84
  85 static int aout32_core_dump(long signr, struct pt_regs *regs, struct file *file)
  86 {
  87         mm_segment_t fs;
  88         int has_dumped = 0;
  89         unsigned long dump_start, dump_size;
  90         struct user dump;
  91 #       define START_DATA(u)    (u.u_tsize)
  92 #       define START_STACK(u)   ((regs->u_regs[UREG_FP]) & ~(PAGE_SIZE - 1))
  93
  94         fs = get_fs();
  95         set_fs(KERNEL_DS);
  96         has_dumped = 1;
  97         current->flags |= PF_DUMPCORE;
  98         strncpy(dump.u_comm, current->comm, sizeof(dump.u_comm));
  99         dump.signal = signr;
 100         dump_thread(regs, &dump);
 101
 102 /* If the size of the dump file exceeds the rlimit, then see what would happen
 103    if we wrote the stack, but not the data area.  */
 104         if ((dump.u_dsize+dump.u_ssize) >
 105             current->signal->rlim[RLIMIT_CORE].rlim_cur)
 106                 dump.u_dsize = 0;
 107
 108 /* Make sure we have enough room to write the stack and data areas. */
 109         if ((dump.u_ssize) >
 110             current->signal->rlim[RLIMIT_CORE].rlim_cur)
 111                 dump.u_ssize = 0;
 112
 113 /* make sure we actually have a data and stack area to dump */
 114         set_fs(USER_DS);
 115         if (!access_ok(VERIFY_READ, (void __user *) START_DATA(dump), dump.u_dsize))
 116                 dump.u_dsize = 0;
 117         if (!access_ok(VERIFY_READ, (void __user *) START_STACK(dump), dump.u_ssize))
 118                 dump.u_ssize = 0;
 119
 120         set_fs(KERNEL_DS);
 121 /* struct user */
 122         DUMP_WRITE(&dump,sizeof(dump));
 123 /* now we start writing out the user space info */
 124         set_fs(USER_DS);
 125 /* Dump the data area */
 126         if (dump.u_dsize != 0) {
 127                 dump_start = START_DATA(dump);
 128                 dump_size = dump.u_dsize;
 129                 DUMP_WRITE(dump_start,dump_size);
 130         }
 131 /* Now prepare to dump the stack area */
 132         if (dump.u_ssize != 0) {
 133                 dump_start = START_STACK(dump);
 134                 dump_size = dump.u_ssize;
 135                 DUMP_WRITE(dump_start,dump_size);
 136         }
 137 /* Finally dump the task struct.  Not be used by gdb, but could be useful */
 138         set_fs(KERNEL_DS);
 139         DUMP_WRITE(current,sizeof(*current));
 140 end_coredump:
 141         set_fs(fs);
 142         return has_dumped;
 143 }
 144
 145 /*
 146  * create_aout32_tables() parses the env- and arg-strings in new user
 147  * memory and creates the pointer tables from them, and puts their
 148  * addresses on the "stack", returning the new stack pointer value.
 149  */
 150
 151 static u32 __user *create_aout32_tables(char __user *p, struct linux_binprm *bprm)
 152 {
 153         u32 __user *argv;
 154         u32 __user *envp;
 155         u32 __user *sp;
 156         int argc = bprm->argc;
 157         int envc = bprm->envc;
 158
 159         sp = (u32 __user *)((-(unsigned long)sizeof(char *))&(unsigned long)p);
 160
 161         /* This imposes the proper stack alignment for a new process. */
 162         sp = (u32 __user *) (((unsigned long) sp) & ~7);
 163         if ((envc+argc+3)&1)
 164                 --sp;
 165
 166         sp -= envc+1;
 167         envp = sp;
 168         sp -= argc+1;
 169         argv = sp;
 170         put_user(argc,--sp);
 171         current->mm->arg_start = (unsigned long) p;
 172         while (argc-->0) {
 173                 char c;
 174                 put_user(((u32)(unsigned long)(p)),argv++);
 175                 do {
 176                         get_user(c,p++);
 177                 } while (c);
 178         }
 179         put_user(NULL,argv);
 180         current->mm->arg_end = current->mm->env_start = (unsigned long) p;
 181         while (envc-->0) {
 182                 char c;
 183                 put_user(((u32)(unsigned long)(p)),envp++);
 184                 do {
 185                         get_user(c,p++);
 186                 } while (c);
 187         }
 188         put_user(NULL,envp);
 189         current->mm->env_end = (unsigned long) p;
 190         return sp;
 191 }
 192
 193 /*
 194  * These are the functions used to load a.out style executables and shared
 195  * libraries.  There is no binary dependent code anywhere else.
 196  */
 197
 198 static int load_aout32_binary(struct linux_binprm * bprm, struct pt_regs * regs)
 199 {
 200         struct exec ex;
 201         unsigned long error;
 202         unsigned long fd_offset;
 203         unsigned long rlim;
 204         unsigned long orig_thr_flags;
 205         int retval;
 206
 207         ex = *((struct exec *) bprm->buf);              /* exec-header */
 208         if ((N_MAGIC(ex) != ZMAGIC && N_MAGIC(ex) != OMAGIC &&
 209              N_MAGIC(ex) != QMAGIC && N_MAGIC(ex) != NMAGIC) ||
 210             N_TRSIZE(ex) || N_DRSIZE(ex) ||
 211             bprm->file->f_dentry->d_inode->i_size < ex.a_text+ex.a_data+N_SYMSIZE(ex)+N_TXTOFF(ex)) {
 212                 return -ENOEXEC;
 213         }
 214
 215         fd_offset = N_TXTOFF(ex);
 216
 217         /* Check initial limits. This avoids letting people circumvent
 218          * size limits imposed on them by creating programs with large
 219          * arrays in the data or bss.
 220          */
 221         rlim = current->signal->rlim[RLIMIT_DATA].rlim_cur;
 222         if (rlim >= RLIM_INFINITY)
 223                 rlim = ~0;
 224         if (ex.a_data + ex.a_bss > rlim)
 225                 return -ENOMEM;
 226
 227         /* Flush all traces of the currently running executable */
 228         retval = flush_old_exec(bprm);
 229         if (retval)
 230                 return retval;
 231
 232         /* OK, This is the point of no return */
 233         set_personality(PER_SUNOS);
 234
 235         current->mm->end_code = ex.a_text +
 236                 (current->mm->start_code = N_TXTADDR(ex));
 237         current->mm->end_data = ex.a_data +
 238                 (current->mm->start_data = N_DATADDR(ex));
 239         current->mm->brk = ex.a_bss +
 240                 (current->mm->start_brk = N_BSSADDR(ex));
 241
 242         current->mm->mmap = NULL;
 243         compute_creds(bprm);
 244         current->flags &= ~PF_FORKNOEXEC;
 245         if (N_MAGIC(ex) == NMAGIC) {
 246                 loff_t pos = fd_offset;
 247                 /* Fuck me plenty... */
 248                 down_write(&current->mm->mmap_sem);
 249                 error = do_brk(N_TXTADDR(ex), ex.a_text);
 250                 up_write(&current->mm->mmap_sem);
 251                 bprm->file->f_op->read(bprm->file, (char __user *)N_TXTADDR(ex),
 252                           ex.a_text, &pos);
 253                 down_write(&current->mm->mmap_sem);
 254                 error = do_brk(N_DATADDR(ex), ex.a_data);
 255                 up_write(&current->mm->mmap_sem);
 256                 bprm->file->f_op->read(bprm->file, (char __user *)N_DATADDR(ex),
 257                           ex.a_data, &pos);
 258                 goto beyond_if;
 259         }
 260
 261         if (N_MAGIC(ex) == OMAGIC) {
 262                 loff_t pos = fd_offset;
 263                 down_write(&current->mm->mmap_sem);
 264                 do_brk(N_TXTADDR(ex) & PAGE_MASK,
 265                         ex.a_text+ex.a_data + PAGE_SIZE - 1);
 266                 up_write(&current->mm->mmap_sem);
 267                 bprm->file->f_op->read(bprm->file, (char __user *)N_TXTADDR(ex),
 268                           ex.a_text+ex.a_data, &pos);
 269         } else {
 270                 static unsigned long error_time;
 271                 if ((ex.a_text & 0xfff || ex.a_data & 0xfff) &&
 272                     (N_MAGIC(ex) != NMAGIC) && (jiffies-error_time) > 5*HZ)
 273                 {
 274                         printk(KERN_NOTICE "executable not page aligned\n");
 275                         error_time = jiffies;
 276                 }
 277
 278                 if (!bprm->file->f_op->mmap) {
 279                         loff_t pos = fd_offset;
 280                         down_write(&current->mm->mmap_sem);
 281                         do_brk(0, ex.a_text+ex.a_data);
 282                         up_write(&current->mm->mmap_sem);
 283                         bprm->file->f_op->read(bprm->file,
 284                                   (char __user *)N_TXTADDR(ex),
 285                                   ex.a_text+ex.a_data, &pos);
 286                         goto beyond_if;
 287                 }
 288
 289                 down_write(&current->mm->mmap_sem);
 290                 error = do_mmap(bprm->file, N_TXTADDR(ex), ex.a_text,
 291                         PROT_READ | PROT_EXEC,
 292                         MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE,
 293                         fd_offset);
 294                 up_write(&current->mm->mmap_sem);
 295
 296                 if (error != N_TXTADDR(ex)) {
 297                         send_sig(SIGKILL, current, 0);
 298                         return error;
 299                 }
 300
 301                 down_write(&current->mm->mmap_sem);
 302                 error = do_mmap(bprm->file, N_DATADDR(ex), ex.a_data,
 303                                 PROT_READ | PROT_WRITE | PROT_EXEC,
 304                                 MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE,
 305                                 fd_offset + ex.a_text);
 306                 up_write(&current->mm->mmap_sem);
 307                 if (error != N_DATADDR(ex)) {
 308                         send_sig(SIGKILL, current, 0);
 309                         return error;
 310                 }
 311         }
 312 beyond_if:
 313         set_binfmt(&aout32_format);
 314
 315         set_brk(current->mm->start_brk, current->mm->brk);
 316
 317         /* Make sure STACK_TOP returns the right thing.  */
 318         orig_thr_flags = current_thread_info()->flags;
 319         current_thread_info()->flags |= _TIF_32BIT;
 320
 321         retval = setup_arg_pages(bprm, STACK_TOP, EXSTACK_DEFAULT);
 322         if (retval < 0) {
 323                 current_thread_info()->flags = orig_thr_flags;
 324
 325                 /* Someone check-me: is this error path enough? */
 326                 send_sig(SIGKILL, current, 0);
 327                 return retval;
 328         }
 329
 330         current->mm->start_stack =
 331                 (unsigned long) create_aout32_tables((char __user *)bprm->p, bprm);
 332         if (!(orig_thr_flags & _TIF_32BIT)) {
 333                 unsigned long pgd_cache = get_pgd_cache(current->mm->pgd);
 334
 335                 __asm__ __volatile__("stxa\t%0, [%1] %2\n\t"
 336                                      "membar #Sync"
 337                                      : /* no outputs */
 338                                      : "r" (pgd_cache),
 339                                        "r" (TSB_REG), "i" (ASI_DMMU));
 340         }
 341         start_thread32(regs, ex.a_entry, current->mm->start_stack);
 342         if (current->ptrace & PT_PTRACED)
 343                 send_sig(SIGTRAP, current, 0);
 344         return 0;
 345 }
 346
 347 /* N.B. Move to .h file and use code in fs/binfmt_aout.c? */
 348 static int load_aout32_library(struct file *file)
 349 {
 350         struct inode * inode;
 351         unsigned long bss, start_addr, len;
 352         unsigned long error;
 353         int retval;
 354         struct exec ex;
 355
 356         inode = file->f_dentry->d_inode;
 357
 358         retval = -ENOEXEC;
 359         error = kernel_read(file, 0, (char *) &ex, sizeof(ex));
 360         if (error != sizeof(ex))
 361                 goto out;
 362
 363         /* We come in here for the regular a.out style of shared libraries */
 364         if ((N_MAGIC(ex) != ZMAGIC && N_MAGIC(ex) != QMAGIC) || N_TRSIZE(ex) ||
 365             N_DRSIZE(ex) || ((ex.a_entry & 0xfff) && N_MAGIC(ex) == ZMAGIC) ||
 366             inode->i_size < ex.a_text+ex.a_data+N_SYMSIZE(ex)+N_TXTOFF(ex)) {
 367                 goto out;
 368         }
 369
 370         if (N_MAGIC(ex) == ZMAGIC && N_TXTOFF(ex) &&
 371             (N_TXTOFF(ex) < inode->i_sb->s_blocksize)) {
 372                 printk("N_TXTOFF < BLOCK_SIZE. Please convert library\n");
 373                 goto out;
 374         }
 375
 376         if (N_FLAGS(ex))
 377                 goto out;
 378
 379         /* For  QMAGIC, the starting address is 0x20 into the page.  We mask
 380            this off to get the starting address for the page */
 381
 382         start_addr =  ex.a_entry & 0xfffff000;
 383
 384         /* Now use mmap to map the library into memory. */
 385         down_write(&current->mm->mmap_sem);
 386         error = do_mmap(file, start_addr, ex.a_text + ex.a_data,
 387                         PROT_READ | PROT_WRITE | PROT_EXEC,
 388                         MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE,
 389                         N_TXTOFF(ex));
 390         up_write(&current->mm->mmap_sem);
 391         retval = error;
 392         if (error != start_addr)
 393                 goto out;
 394
 395         len = PAGE_ALIGN(ex.a_text + ex.a_data);
 396         bss = ex.a_text + ex.a_data + ex.a_bss;
 397         if (bss > len) {
 398                 down_write(&current->mm->mmap_sem);
 399                 error = do_brk(start_addr + len, bss - len);
 400                 up_write(&current->mm->mmap_sem);
 401                 retval = error;
 402                 if (error != start_addr + len)
 403                         goto out;
 404         }
 405         retval = 0;
 406 out:
 407         return retval;
 408 }
 409
 410 static int __init init_aout32_binfmt(void)
 411 {
 412         return register_binfmt(&aout32_format);
 413 }
 414
 415 static void __exit exit_aout32_binfmt(void)
 416 {
 417         unregister_binfmt(&aout32_format);
 418 }
 419
 420 module_init(init_aout32_binfmt);
 421 module_exit(exit_aout32_binfmt);