1 /* 2 * linux/kernel/compat.c 3 * 4 * Kernel compatibililty routines for e.g. 32 bit syscall support 5 * on 64 bit kernels. 6 * 7 * Copyright (C) 2002-2003 Stephen Rothwell, IBM Corporation 8 * 9 * This program is free software; you can redistribute it and/or modify 10 * it under the terms of the GNU General Public License version 2 as 11 * published by the Free Software Foundation. 12 */ 13 14 #include <linux/linkage.h> 15 #include <linux/compat.h> 16 #include <linux/errno.h> 17 #include <linux/time.h> 18 #include <linux/signal.h> 19 #include <linux/sched.h> /* for MAX_SCHEDULE_TIMEOUT */ 20 #include <linux/syscalls.h> 21 #include <linux/unistd.h> 22 #include <linux/security.h> 23 #include <linux/export.h> 24 #include <linux/migrate.h> 25 #include <linux/posix-timers.h> 26 #include <linux/times.h> 27 #include <linux/ptrace.h> 28 #include <linux/gfp.h> 29 30 #include <linux/uaccess.h> 31 32 static int __compat_get_timeval(struct timeval *tv, const struct old_timeval32 __user *ctv) 33 { 34 return (!access_ok(ctv, sizeof(*ctv)) || 35 __get_user(tv->tv_sec, &ctv->tv_sec) || 36 __get_user(tv->tv_usec, &ctv->tv_usec)) ? -EFAULT : 0; 37 } 38 39 static int __compat_put_timeval(const struct timeval *tv, struct old_timeval32 __user *ctv) 40 { 41 return (!access_ok(ctv, sizeof(*ctv)) || 42 __put_user(tv->tv_sec, &ctv->tv_sec) || 43 __put_user(tv->tv_usec, &ctv->tv_usec)) ? -EFAULT : 0; 44 } 45 46 static int __compat_get_timespec(struct timespec *ts, const struct old_timespec32 __user *cts) 47 { 48 return (!access_ok(cts, sizeof(*cts)) || 49 __get_user(ts->tv_sec, &cts->tv_sec) || 50 __get_user(ts->tv_nsec, &cts->tv_nsec)) ? -EFAULT : 0; 51 } 52 53 static int __compat_put_timespec(const struct timespec *ts, struct old_timespec32 __user *cts) 54 { 55 return (!access_ok(cts, sizeof(*cts)) || 56 __put_user(ts->tv_sec, &cts->tv_sec) || 57 __put_user(ts->tv_nsec, &cts->tv_nsec)) ? -EFAULT : 0; 58 } 59 60 int compat_get_timeval(struct timeval *tv, const void __user *utv) 61 { 62 if (COMPAT_USE_64BIT_TIME) 63 return copy_from_user(tv, utv, sizeof(*tv)) ? -EFAULT : 0; 64 else 65 return __compat_get_timeval(tv, utv); 66 } 67 EXPORT_SYMBOL_GPL(compat_get_timeval); 68 69 int compat_put_timeval(const struct timeval *tv, void __user *utv) 70 { 71 if (COMPAT_USE_64BIT_TIME) 72 return copy_to_user(utv, tv, sizeof(*tv)) ? -EFAULT : 0; 73 else 74 return __compat_put_timeval(tv, utv); 75 } 76 EXPORT_SYMBOL_GPL(compat_put_timeval); 77 78 int compat_get_timespec(struct timespec *ts, const void __user *uts) 79 { 80 if (COMPAT_USE_64BIT_TIME) 81 return copy_from_user(ts, uts, sizeof(*ts)) ? -EFAULT : 0; 82 else 83 return __compat_get_timespec(ts, uts); 84 } 85 EXPORT_SYMBOL_GPL(compat_get_timespec); 86 87 int compat_put_timespec(const struct timespec *ts, void __user *uts) 88 { 89 if (COMPAT_USE_64BIT_TIME) 90 return copy_to_user(uts, ts, sizeof(*ts)) ? -EFAULT : 0; 91 else 92 return __compat_put_timespec(ts, uts); 93 } 94 EXPORT_SYMBOL_GPL(compat_put_timespec); 95 96 int get_compat_itimerval(struct itimerval *o, const struct compat_itimerval __user *i) 97 { 98 struct compat_itimerval v32; 99 100 if (copy_from_user(&v32, i, sizeof(struct compat_itimerval))) 101 return -EFAULT; 102 o->it_interval.tv_sec = v32.it_interval.tv_sec; 103 o->it_interval.tv_usec = v32.it_interval.tv_usec; 104 o->it_value.tv_sec = v32.it_value.tv_sec; 105 o->it_value.tv_usec = v32.it_value.tv_usec; 106 return 0; 107 } 108 109 int put_compat_itimerval(struct compat_itimerval __user *o, const struct itimerval *i) 110 { 111 struct compat_itimerval v32; 112 113 v32.it_interval.tv_sec = i->it_interval.tv_sec; 114 v32.it_interval.tv_usec = i->it_interval.tv_usec; 115 v32.it_value.tv_sec = i->it_value.tv_sec; 116 v32.it_value.tv_usec = i->it_value.tv_usec; 117 return copy_to_user(o, &v32, sizeof(struct compat_itimerval)) ? -EFAULT : 0; 118 } 119 120 #ifdef __ARCH_WANT_SYS_SIGPROCMASK 121 122 /* 123 * sys_sigprocmask SIG_SETMASK sets the first (compat) word of the 124 * blocked set of signals to the supplied signal set 125 */ 126 static inline void compat_sig_setmask(sigset_t *blocked, compat_sigset_word set) 127 { 128 memcpy(blocked->sig, &set, sizeof(set)); 129 } 130 131 COMPAT_SYSCALL_DEFINE3(sigprocmask, int, how, 132 compat_old_sigset_t __user *, nset, 133 compat_old_sigset_t __user *, oset) 134 { 135 old_sigset_t old_set, new_set; 136 sigset_t new_blocked; 137 138 old_set = current->blocked.sig[0]; 139 140 if (nset) { 141 if (get_user(new_set, nset)) 142 return -EFAULT; 143 new_set &= ~(sigmask(SIGKILL) | sigmask(SIGSTOP)); 144 145 new_blocked = current->blocked; 146 147 switch (how) { 148 case SIG_BLOCK: 149 sigaddsetmask(&new_blocked, new_set); 150 break; 151 case SIG_UNBLOCK: 152 sigdelsetmask(&new_blocked, new_set); 153 break; 154 case SIG_SETMASK: 155 compat_sig_setmask(&new_blocked, new_set); 156 break; 157 default: 158 return -EINVAL; 159 } 160 161 set_current_blocked(&new_blocked); 162 } 163 164 if (oset) { 165 if (put_user(old_set, oset)) 166 return -EFAULT; 167 } 168 169 return 0; 170 } 171 172 #endif 173 174 int put_compat_rusage(const struct rusage *r, struct compat_rusage __user *ru) 175 { 176 struct compat_rusage r32; 177 memset(&r32, 0, sizeof(r32)); 178 r32.ru_utime.tv_sec = r->ru_utime.tv_sec; 179 r32.ru_utime.tv_usec = r->ru_utime.tv_usec; 180 r32.ru_stime.tv_sec = r->ru_stime.tv_sec; 181 r32.ru_stime.tv_usec = r->ru_stime.tv_usec; 182 r32.ru_maxrss = r->ru_maxrss; 183 r32.ru_ixrss = r->ru_ixrss; 184 r32.ru_idrss = r->ru_idrss; 185 r32.ru_isrss = r->ru_isrss; 186 r32.ru_minflt = r->ru_minflt; 187 r32.ru_majflt = r->ru_majflt; 188 r32.ru_nswap = r->ru_nswap; 189 r32.ru_inblock = r->ru_inblock; 190 r32.ru_oublock = r->ru_oublock; 191 r32.ru_msgsnd = r->ru_msgsnd; 192 r32.ru_msgrcv = r->ru_msgrcv; 193 r32.ru_nsignals = r->ru_nsignals; 194 r32.ru_nvcsw = r->ru_nvcsw; 195 r32.ru_nivcsw = r->ru_nivcsw; 196 if (copy_to_user(ru, &r32, sizeof(r32))) 197 return -EFAULT; 198 return 0; 199 } 200 201 static int compat_get_user_cpu_mask(compat_ulong_t __user *user_mask_ptr, 202 unsigned len, struct cpumask *new_mask) 203 { 204 unsigned long *k; 205 206 if (len < cpumask_size()) 207 memset(new_mask, 0, cpumask_size()); 208 else if (len > cpumask_size()) 209 len = cpumask_size(); 210 211 k = cpumask_bits(new_mask); 212 return compat_get_bitmap(k, user_mask_ptr, len * 8); 213 } 214 215 COMPAT_SYSCALL_DEFINE3(sched_setaffinity, compat_pid_t, pid, 216 unsigned int, len, 217 compat_ulong_t __user *, user_mask_ptr) 218 { 219 cpumask_var_t new_mask; 220 int retval; 221 222 if (!alloc_cpumask_var(&new_mask, GFP_KERNEL)) 223 return -ENOMEM; 224 225 retval = compat_get_user_cpu_mask(user_mask_ptr, len, new_mask); 226 if (retval) 227 goto out; 228 229 retval = sched_setaffinity(pid, new_mask); 230 out: 231 free_cpumask_var(new_mask); 232 return retval; 233 } 234 235 COMPAT_SYSCALL_DEFINE3(sched_getaffinity, compat_pid_t, pid, unsigned int, len, 236 compat_ulong_t __user *, user_mask_ptr) 237 { 238 int ret; 239 cpumask_var_t mask; 240 241 if ((len * BITS_PER_BYTE) < nr_cpu_ids) 242 return -EINVAL; 243 if (len & (sizeof(compat_ulong_t)-1)) 244 return -EINVAL; 245 246 if (!alloc_cpumask_var(&mask, GFP_KERNEL)) 247 return -ENOMEM; 248 249 ret = sched_getaffinity(pid, mask); 250 if (ret == 0) { 251 unsigned int retlen = min(len, cpumask_size()); 252 253 if (compat_put_bitmap(user_mask_ptr, cpumask_bits(mask), retlen * 8)) 254 ret = -EFAULT; 255 else 256 ret = retlen; 257 } 258 free_cpumask_var(mask); 259 260 return ret; 261 } 262 263 /* 264 * We currently only need the following fields from the sigevent 265 * structure: sigev_value, sigev_signo, sig_notify and (sometimes 266 * sigev_notify_thread_id). The others are handled in user mode. 267 * We also assume that copying sigev_value.sival_int is sufficient 268 * to keep all the bits of sigev_value.sival_ptr intact. 269 */ 270 int get_compat_sigevent(struct sigevent *event, 271 const struct compat_sigevent __user *u_event) 272 { 273 memset(event, 0, sizeof(*event)); 274 return (!access_ok(u_event, sizeof(*u_event)) || 275 __get_user(event->sigev_value.sival_int, 276 &u_event->sigev_value.sival_int) || 277 __get_user(event->sigev_signo, &u_event->sigev_signo) || 278 __get_user(event->sigev_notify, &u_event->sigev_notify) || 279 __get_user(event->sigev_notify_thread_id, 280 &u_event->sigev_notify_thread_id)) 281 ? -EFAULT : 0; 282 } 283 284 long compat_get_bitmap(unsigned long *mask, const compat_ulong_t __user *umask, 285 unsigned long bitmap_size) 286 { 287 unsigned long nr_compat_longs; 288 289 /* align bitmap up to nearest compat_long_t boundary */ 290 bitmap_size = ALIGN(bitmap_size, BITS_PER_COMPAT_LONG); 291 nr_compat_longs = BITS_TO_COMPAT_LONGS(bitmap_size); 292 293 if (!user_access_begin(umask, bitmap_size / 8)) 294 return -EFAULT; 295 296 while (nr_compat_longs > 1) { 297 compat_ulong_t l1, l2; 298 unsafe_get_user(l1, umask++, Efault); 299 unsafe_get_user(l2, umask++, Efault); 300 *mask++ = ((unsigned long)l2 << BITS_PER_COMPAT_LONG) | l1; 301 nr_compat_longs -= 2; 302 } 303 if (nr_compat_longs) 304 unsafe_get_user(*mask, umask++, Efault); 305 user_access_end(); 306 return 0; 307 308 Efault: 309 user_access_end(); 310 return -EFAULT; 311 } 312 313 long compat_put_bitmap(compat_ulong_t __user *umask, unsigned long *mask, 314 unsigned long bitmap_size) 315 { 316 unsigned long nr_compat_longs; 317 318 /* align bitmap up to nearest compat_long_t boundary */ 319 bitmap_size = ALIGN(bitmap_size, BITS_PER_COMPAT_LONG); 320 nr_compat_longs = BITS_TO_COMPAT_LONGS(bitmap_size); 321 322 if (!user_access_begin(umask, bitmap_size / 8)) 323 return -EFAULT; 324 325 while (nr_compat_longs > 1) { 326 unsigned long m = *mask++; 327 unsafe_put_user((compat_ulong_t)m, umask++, Efault); 328 unsafe_put_user(m >> BITS_PER_COMPAT_LONG, umask++, Efault); 329 nr_compat_longs -= 2; 330 } 331 if (nr_compat_longs) 332 unsafe_put_user((compat_ulong_t)*mask, umask++, Efault); 333 user_access_end(); 334 return 0; 335 Efault: 336 user_access_end(); 337 return -EFAULT; 338 } 339 340 int 341 get_compat_sigset(sigset_t *set, const compat_sigset_t __user *compat) 342 { 343 #ifdef __BIG_ENDIAN 344 compat_sigset_t v; 345 if (copy_from_user(&v, compat, sizeof(compat_sigset_t))) 346 return -EFAULT; 347 switch (_NSIG_WORDS) { 348 case 4: set->sig[3] = v.sig[6] | (((long)v.sig[7]) << 32 ); 349 case 3: set->sig[2] = v.sig[4] | (((long)v.sig[5]) << 32 ); 350 case 2: set->sig[1] = v.sig[2] | (((long)v.sig[3]) << 32 ); 351 case 1: set->sig[0] = v.sig[0] | (((long)v.sig[1]) << 32 ); 352 } 353 #else 354 if (copy_from_user(set, compat, sizeof(compat_sigset_t))) 355 return -EFAULT; 356 #endif 357 return 0; 358 } 359 EXPORT_SYMBOL_GPL(get_compat_sigset); 360 361 /* 362 * Allocate user-space memory for the duration of a single system call, 363 * in order to marshall parameters inside a compat thunk. 364 */ 365 void __user *compat_alloc_user_space(unsigned long len) 366 { 367 void __user *ptr; 368 369 /* If len would occupy more than half of the entire compat space... */ 370 if (unlikely(len > (((compat_uptr_t)~0) >> 1))) 371 return NULL; 372 373 ptr = arch_compat_alloc_user_space(len); 374 375 if (unlikely(!access_ok(ptr, len))) 376 return NULL; 377 378 return ptr; 379 } 380 EXPORT_SYMBOL_GPL(compat_alloc_user_space); 381