src/afs/LINUX/osi_module.c

   1 /*
   2  * Copyright 2000, International Business Machines Corporation and others.
   3  * All Rights Reserved.
   4  *
   5  * This software has been released under the terms of the IBM Public
   6  * License.  For details, see the LICENSE file in the top-level source
   7  * directory or online at http://www.openafs.org/dl/license10.html
   8  */
   9
  10 /*
  11  * Linux module support routines.
  12  *
  13  */
  14 #include <afsconfig.h>
  15 #include "afs/param.h"
  16
  17 RCSID("$Header$");
  18
  19 #include "afs/sysincludes.h"
  20 #include "afsincludes.h"
  21 #include "h/unistd.h" /* For syscall numbers. */
  22 #include "h/mm.h"
  23
  24 #include <linux/module.h>
  25 #include <linux/slab.h>
  26 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,4,0)
  27 #include <linux/init.h>
  28 #include <linux/sched.h>
  29 #endif
  30 #if !defined(EXPORTED_SYS_CALL_TABLE) && defined(HAVE_KERNEL_LINUX_SYSCALL_H)
  31 #include <linux/syscall.h>
  32 #endif
  33
  34
  35 #ifdef AFS_SPARC64_LINUX24_ENV
  36 #define __NR_setgroups32      82 /* This number is not exported for some bizarre reason. */
  37 #endif
  38
  39 asmlinkage int (*sys_settimeofdayp)(struct timeval *tv, struct timezone *tz);
  40 asmlinkage long (*sys_setgroupsp)(int gidsetsize, gid_t *grouplist);
  41
  42 #ifdef EXPORTED_SYS_CALL_TABLE
  43 #ifdef AFS_SPARC64_LINUX20_ENV
  44 extern unsigned int sys_call_table[];  /* changed to uint because SPARC64 has syscaltable of 32bit items */
  45 #else
  46 extern void * sys_call_table[]; /* safer for other linuces */
  47 #endif
  48 #else /* EXPORTED_SYS_CALL_TABLE */
  49 #ifdef AFS_SPARC64_LINUX20_ENV
  50 static unsigned int *sys_call_table;  /* changed to uint because SPARC64 has syscaltable of 32bit items */
  51 #else
  52 static void ** sys_call_table; /* safer for other linuces */
  53 #endif
  54 #endif
  55 extern struct file_system_type afs_file_system;
  56
  57 static long get_page_offset(void);
  58
  59 #if defined(AFS_LINUX24_ENV)
  60 DECLARE_MUTEX(afs_global_lock);
  61 #else
  62 struct semaphore afs_global_lock = MUTEX;
  63 #endif
  64 int afs_global_owner = 0;
  65 unsigned long afs_linux_page_offset = 0; /* contains the PAGE_OFFSET value */
  66
  67 /* Since sys_ni_syscall is not exported, I need to cache it in order to restore
  68  * it.
  69  */
  70 #ifdef AFS_SPARC64_LINUX20_ENV
  71 static unsigned int afs_ni_syscall = 0;
  72 #else
  73 static void* afs_ni_syscall = 0;
  74 #endif
  75
  76 #ifdef AFS_SPARC64_LINUX20_ENV
  77 static unsigned int afs_ni_syscall32 = 0;
  78 asmlinkage int (*sys32_setgroupsp)(int gidsetsize, __kernel_gid_t32 *grouplist);
  79 #if defined(__NR_setgroups32)
  80 asmlinkage int (*sys32_setgroups32p)(int gidsetsize, __kernel_gid_t32 *grouplist);
  81 #endif
  82 #ifdef EXPORTED_SYS_CALL_TABLE
  83 extern unsigned int sys_call_table32[];
  84 #else
  85 static unsigned int *sys_call_table32;
  86 #endif
  87
  88 asmlinkage int afs_syscall32(long syscall, long parm1, long parm2, long parm3,
  89                              long parm4, long parm5)
  90 {
  91 __asm__ __volatile__ ("srl %o4, 0, %o4\n\t"
  92                       "mov %o7, %i7\n\t"
  93                       "call afs_syscall\n\t"
  94                       "srl %o5, 0, %o5\n\t"
  95                       "ret\n\t"
  96                       "nop");
  97 }
  98 #endif
  99
 100 #ifdef AFS_IA64_LINUX20_ENV
 101
 102 asmlinkage long
 103 afs_syscall_stub(int r0, int r1, long r2, long r3, long r4, long gp)
 104 {
 105 __asm__ __volatile__ ("alloc r42 = ar.pfs, 8, 3, 6, 0\n\t"
 106                       "mov r41 = b0\n\t"                /* save rp */
 107                       "mov out0 = in0\n\t"
 108                       "mov out1 = in1\n\t"
 109                       "mov out2 = in2\n\t"
 110                       "mov out3 = in3\n\t"
 111                       "mov out4 = in4\n\t"
 112                       "mov out5 = gp\n\t"                       /* save gp */
 113                       ";;\n"
 114                       ".L1:    mov r3 = ip\n\t"
 115                       ";;\n\t"
 116                       "addl r15=.fptr_afs_syscall-.L1,r3\n\t"
 117                       ";;\n\t"
 118                       "ld8 r15=[r15]\n\t"
 119                       ";;\n\t"
 120                       "ld8 r16=[r15],8\n\t"
 121                       ";;\n\t"
 122                       "ld8 gp=[r15]\n\t"
 123                       "mov b6=r16\n\t"
 124                       "br.call.sptk.many b0 = b6\n\t"
 125                       ";;\n\t"
 126                       "mov ar.pfs = r42\n\t"
 127                       "mov b0 = r41\n\t"
 128                       "mov gp = r48\n\t"                /* restore gp */
 129                       "br.ret.sptk.many b0\n"
 130                       ".fptr_afs_syscall:\n\t"
 131                       "data8 @fptr(afs_syscall)");
 132 }
 133
 134 asmlinkage long
 135 afs_xsetgroups_stub(int r0, int r1, long r2, long r3, long r4, long gp)
 136 {
 137 __asm__ __volatile__ ("alloc r42 = ar.pfs, 8, 3, 6, 0\n\t"
 138                       "mov r41 = b0\n\t"                /* save rp */
 139                       "mov out0 = in0\n\t"
 140                       "mov out1 = in1\n\t"
 141                       "mov out2 = in2\n\t"
 142                       "mov out3 = in3\n\t"
 143                       "mov out4 = in4\n\t"
 144                       "mov out5 = gp\n\t"                       /* save gp */
 145                       ";;\n"
 146                       ".L2:    mov r3 = ip\n\t"
 147                       ";;\n\t"
 148                       "addl r15=.fptr_afs_xsetgroups - .L2,r3\n\t"
 149                       ";;\n\t"
 150                       "ld8 r15=[r15]\n\t"
 151                       ";;\n\t"
 152                       "ld8 r16=[r15],8\n\t"
 153                       ";;\n\t"
 154                       "ld8 gp=[r15]\n\t"
 155                       "mov b6=r16\n\t"
 156                       "br.call.sptk.many b0 = b6\n\t"
 157                       ";;\n\t"
 158                       "mov ar.pfs = r42\n\t"
 159                       "mov b0 = r41\n\t"
 160                       "mov gp = r48\n\t"                /* restore gp */
 161                       "br.ret.sptk.many b0\n"
 162                       ".fptr_afs_xsetgroups:\n\t"
 163                       "data8 @fptr(afs_xsetgroups)");
 164 }
 165
 166 struct fptr
 167 {
 168         void *ip;
 169         unsigned long gp;
 170 };
 171
 172 #endif /* AFS_IA64_LINUX20_ENV */
 173
 174 #ifdef AFS_LINUX24_ENV
 175 asmlinkage int (*sys_setgroups32p)(int gidsetsize, __kernel_gid32_t *grouplist);
 176 #endif
 177
 178 #ifdef AFS_SPARC64_LINUX20_ENV
 179 #define POINTER2SYSCALL (unsigned int)(unsigned long)
 180 #define SYSCALL2POINTER (void *)(long)
 181 #else
 182 #define POINTER2SYSCALL (void *)
 183 #define SYSCALL2POINTER (void *)
 184 #endif
 185
 186 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,4,0)
 187 int __init afs_init(void)
 188 #else
 189 int init_module(void)
 190 #endif
 191 {
 192 #if defined(AFS_IA64_LINUX20_ENV)
 193     unsigned long kernel_gp;
 194     static struct fptr sys_settimeofday, sys_setgroups;
 195 #endif
 196     extern int afs_syscall();
 197     extern long afs_xsetgroups();
 198 #if defined(__NR_setgroups32)
 199     extern int afs_xsetgroups32();
 200 #endif
 201 #ifdef AFS_SPARC64_LINUX20_ENV
 202     extern int afs32_xsetgroups();
 203 #if defined(__NR_setgroups32)
 204     extern int afs32_xsetgroups32();
 205 #endif
 206 #endif
 207
 208 #ifndef EXPORTED_SYS_CALL_TABLE
 209     unsigned long *ptr;
 210     unsigned long offset;
 211     unsigned long datalen;
 212     int ret;
 213     unsigned long token;
 214     char      *mod_name;
 215     unsigned long    mod_start;
 216     unsigned long    mod_end;
 217     char      *sec_name;
 218     unsigned long    sec_start;
 219     unsigned long    sec_end;
 220     char      *sym_name;
 221     unsigned long    sym_start;
 222     unsigned long    sym_end;
 223 #endif
 224
 225     RWLOCK_INIT(&afs_xosi, "afs_xosi");
 226
 227     /* obtain PAGE_OFFSET value */
 228     afs_linux_page_offset = get_page_offset();
 229
 230 #ifndef AFS_S390_LINUX22_ENV
 231     if (afs_linux_page_offset == 0) {
 232         /* couldn't obtain page offset so can't continue */
 233         printf("afs: Unable to obtain PAGE_OFFSET. Exiting..");
 234         return -EIO;
 235     }
 236 #endif
 237 #ifndef EXPORTED_SYS_CALL_TABLE
 238     sys_call_table=0;
 239
 240 #ifdef EXPORTED_KALLSYMS_SYMBOL
 241     ret=1;
 242     token=0;
 243     while (ret) {
 244       sym_start=0;
 245       ret=kallsyms_symbol_to_address("sys_call_table", &token, &mod_name,
 246                                      &mod_start, &mod_end, &sec_name, &sec_start, &sec_end,
 247                                      &sym_name, &sym_start, &sym_end);
 248       if (ret && !strcmp(mod_name, "kernel"))
 249         break;
 250     }
 251     if (ret && sym_start) {
 252       sys_call_table=sym_start;
 253     }
 254 #else
 255 #ifdef EXPORTED_KALLSYMS_ADDRESS
 256     ret=kallsyms_address_to_symbol((unsigned long)&init_mm, &mod_name,
 257                                    &mod_start, &mod_end, &sec_name, &sec_start, &sec_end,
 258                                    &sym_name, &sym_start, &sym_end);
 259     ptr=(unsigned long *)sec_start;
 260     datalen=(sec_end-sec_start)/sizeof(unsigned long);
 261 #else
 262 #if defined(AFS_IA64_LINUX20_ENV)
 263     ptr = (unsigned long *) (&sys_close - 0x180000);
 264     datalen=0x180000/sizeof(ptr);
 265 #else
 266     ptr=(unsigned long *)&init_mm;
 267     datalen=16384;
 268 #endif
 269 #endif
 270     for (offset=0;offset <datalen;ptr++,offset++) {
 271 #if defined(AFS_IA64_LINUX20_ENV)
 272         unsigned long close_ip=(unsigned long) ((struct fptr *)&sys_close)->ip;
 273         unsigned long chdir_ip=(unsigned long) ((struct fptr *)&sys_chdir)->ip;
 274         unsigned long write_ip=(unsigned long) ((struct fptr *)&sys_write)->ip;
 275         if (ptr[0] == close_ip &&
 276             ptr[__NR_chdir - __NR_close] == chdir_ip &&
 277             ptr[__NR_write - __NR_close] == write_ip) {
 278             sys_call_table=(void *) &(ptr[ -1 * (__NR_close-1024)]);
 279             break;
 280         }
 281 #else
 282 #if defined(EXPORTED_SYS_WAIT4) && defined(EXPORTED_SYS_CLOSE)
 283         if (ptr[0] == (unsigned long)&sys_close &&
 284             ptr[__NR_wait4 - __NR_close] == (unsigned long)&sys_wait4) {
 285             sys_call_table=ptr - __NR_close;
 286             break;
 287         }
 288 #else
 289 #if defined(EXPORTED_SYS_CHDIR) && defined(EXPORTED_SYS_CLOSE)
 290         if (ptr[0] == (unsigned long)&sys_close &&
 291             ptr[__NR_chdir - __NR_close] == (unsigned long)&sys_chdir) {
 292             sys_call_table=ptr - __NR_close;
 293             break;
 294         }
 295 #else
 296         if (ptr[0] == (unsigned long)&sys_exit &&
 297             ptr[__NR_open - __NR_exit] == (unsigned long)&sys_open) {
 298             sys_call_table=ptr - __NR_exit;
 299             break;
 300         }
 301 #endif
 302 #endif
 303 #endif
 304     }
 305 #ifdef EXPORTED_KALLSYMS_ADDRESS
 306     ret=kallsyms_address_to_symbol((unsigned long)sys_call_table, &mod_name,
 307                                    &mod_start, &mod_end, &sec_name, &sec_start, &sec_end,
 308                                    &sym_name, &sym_start, &sym_end);
 309     if (ret && strcmp(sym_name, "sys_call_table"))
 310       sys_call_table=0;
 311 #endif
 312 #endif
 313     if (!sys_call_table) {
 314       printf("Failed to find address of sys_call_table\n");
 315       return -EIO;
 316     }
 317     printf("Found sys_call_table at %x\n", sys_call_table);
 318 # ifdef AFS_SPARC64_LINUX20_ENV
 319     error cant support this yet.
 320 #endif
 321 #endif /* EXPORTED_SYS_CALL_TABLE */
 322
 323     /* Initialize pointers to kernel syscalls. */
 324 #if defined(AFS_IA64_LINUX20_ENV)
 325     kernel_gp = ((struct fptr *)printk)->gp;
 326
 327     sys_settimeofdayp = (void *) &sys_settimeofday;
 328
 329     ((struct fptr *)sys_settimeofdayp)->ip =
 330                 SYSCALL2POINTER sys_call_table[__NR_settimeofday - 1024];
 331     ((struct fptr *)sys_settimeofdayp)->gp = kernel_gp;
 332
 333 #else /* !AFS_IA64_LINUX20_ENV */
 334     sys_settimeofdayp = SYSCALL2POINTER sys_call_table[__NR_settimeofday];
 335 #endif /* AFS_IA64_LINUX20_ENV */
 336
 337     /* setup AFS entry point. */
 338     if (
 339 #if defined(AFS_IA64_LINUX20_ENV)
 340         SYSCALL2POINTER sys_call_table[__NR_afs_syscall - 1024]
 341 #else
 342         SYSCALL2POINTER sys_call_table[__NR_afs_syscall]
 343 #endif
 344         == afs_syscall) {
 345         printf("AFS syscall entry point already in use!\n");
 346         return -EBUSY;
 347     }
 348
 349 #if defined(AFS_IA64_LINUX20_ENV)
 350     afs_ni_syscall = sys_call_table[__NR_afs_syscall - 1024];
 351     sys_call_table[__NR_afs_syscall - 1024] = POINTER2SYSCALL ((struct fptr *)afs_syscall_stub)->ip;
 352 #else /* AFS_IA64_LINUX20_ENV */
 353     afs_ni_syscall = sys_call_table[__NR_afs_syscall];
 354     sys_call_table[__NR_afs_syscall] = POINTER2SYSCALL afs_syscall;
 355 # ifdef AFS_SPARC64_LINUX20_ENV
 356     afs_ni_syscall32 = sys_call_table32[__NR_afs_syscall];
 357     sys_call_table32[__NR_afs_syscall] = POINTER2SYSCALL afs_syscall32;
 358 # endif
 359 #endif /* AFS_IA64_LINUX20_ENV */
 360
 361     osi_Init();
 362     register_filesystem(&afs_file_system);
 363
 364     /* Intercept setgroups calls */
 365 #if defined(AFS_IA64_LINUX20_ENV)
 366     sys_setgroupsp = (void *) &sys_setgroups;
 367
 368     ((struct fptr *)sys_setgroupsp)->ip =
 369                 SYSCALL2POINTER sys_call_table[__NR_setgroups - 1024];
 370     ((struct fptr *)sys_setgroupsp)->gp = kernel_gp;
 371
 372     sys_call_table[__NR_setgroups - 1024] = POINTER2SYSCALL ((struct fptr *)afs_xsetgroups_stub)->ip;
 373 #else /* AFS_IA64_LINUX20_ENV */
 374     sys_setgroupsp = SYSCALL2POINTER sys_call_table[__NR_setgroups];
 375     sys_call_table[__NR_setgroups] = POINTER2SYSCALL afs_xsetgroups;
 376 # ifdef AFS_SPARC64_LINUX20_ENV
 377     sys32_setgroupsp = SYSCALL2POINTER sys_call_table32[__NR_setgroups];
 378     sys_call_table32[__NR_setgroups] = POINTER2SYSCALL afs32_xsetgroups;
 379 # endif
 380 # if defined(__NR_setgroups32)
 381     sys_setgroups32p = SYSCALL2POINTER sys_call_table[__NR_setgroups32];
 382     sys_call_table[__NR_setgroups32] = POINTER2SYSCALL afs_xsetgroups32;
 383 # ifdef AFS_SPARC64_LINUX20_ENV
 384     sys32_setgroups32p = SYSCALL2POINTER sys_call_table32[__NR_setgroups32];
 385     sys_call_table32[__NR_setgroups32] = POINTER2SYSCALL afs32_xsetgroups32;
 386 # endif
 387 # endif
 388 #endif /* AFS_IA64_LINUX20_ENV */
 389
 390     osi_sysctl_init();
 391
 392     return 0;
 393 }
 394
 395 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,4,0)
 396 void __exit afs_cleanup(void)
 397 #else
 398 void cleanup_module(void)
 399 #endif
 400 {
 401     struct task_struct *t;
 402
 403     osi_sysctl_clean();
 404
 405 #if defined(AFS_IA64_LINUX20_ENV)
 406     sys_call_table[__NR_setgroups - 1024] = POINTER2SYSCALL ((struct fptr *) sys_setgroupsp)->ip;
 407     sys_call_table[__NR_afs_syscall - 1024] = afs_ni_syscall;
 408 #else /* AFS_IA64_LINUX20_ENV */
 409     sys_call_table[__NR_setgroups] = POINTER2SYSCALL sys_setgroupsp;
 410     sys_call_table[__NR_afs_syscall] = afs_ni_syscall;
 411 # ifdef AFS_SPARC64_LINUX20_ENV
 412     sys_call_table32[__NR_setgroups] = POINTER2SYSCALL sys32_setgroupsp;
 413     sys_call_table32[__NR_afs_syscall] = afs_ni_syscall32;
 414 # endif
 415 # if defined(__NR_setgroups32)
 416     sys_call_table[__NR_setgroups32] = POINTER2SYSCALL sys_setgroups32p;
 417 # ifdef AFS_SPARC64_LINUX20_ENV
 418     sys_call_table32[__NR_setgroups32] = POINTER2SYSCALL sys32_setgroups32p;
 419 # endif
 420 # endif
 421 #endif /* AFS_IA64_LINUX20_ENV */
 422     unregister_filesystem(&afs_file_system);
 423
 424     osi_linux_free_inode_pages(); /* Invalidate all pages using AFS inodes. */
 425     osi_linux_free_afs_memory();
 426
 427     return;
 428 }
 429
 430 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,4,0)
 431 module_init(afs_init);
 432 module_exit(afs_cleanup);
 433 #endif
 434
 435
 436 static long get_page_offset(void)
 437 {
 438 #if defined(AFS_PPC_LINUX22_ENV) || defined(AFS_SPARC64_LINUX20_ENV) || defined(AFS_SPARC_LINUX20_ENV) || defined(AFS_ALPHA_LINUX20_ENV) || defined(AFS_S390_LINUX22_ENV) || defined(AFS_IA64_LINUX20_ENV) || defined(AFS_PARISC_LINUX24_ENV) || defined(AFS_AMD64_LINUX20_ENV)
 439     return PAGE_OFFSET;
 440 #else
 441     struct task_struct *p, *q;
 442
 443     /* search backward thru the circular list */
 444 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,4,0)
 445     read_lock(&tasklist_lock);
 446 #endif
 447     /* search backward thru the circular list */
 448 #ifdef DEFINED_PREV_TASK
 449     for(q = current; p = q; q = prev_task(p)) {
 450 #else
 451     for(p = current; p; p = p->prev_task) {
 452 #endif
 453             if (p->pid == 1) {
 454 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,4,0)
 455                     read_unlock(&tasklist_lock);
 456 #endif
 457                     return p->addr_limit.seg;
 458             }
 459     }
 460
 461 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,4,0)
 462     read_unlock(&tasklist_lock);
 463 #endif
 464   return 0;
 465 #endif
 466 }