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