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