text: /*
   *  linux/kernel/compat.c
   *
   *  Kernel compatibililty routines for e.g. 32 bit syscall support
   *  on 64 bit kernels.
   *
   *  Copyright (C) 2002-2003 Stephen Rothwell, IBM Corporation
   *
   *  This program is free software; you can redistribute it and/or modify
   *  it under the terms of the GNU General Public License version 2 as
   *  published by the Free Software Foundation.
   */
  
  #include <linux/linkage.h>
  #include <linux/compat.h>
  #include <linux/errno.h>
  #include <linux/time.h>
  #include <linux/signal.h>
  #include <linux/sched.h>	/* for MAX_SCHEDULE_TIMEOUT */
  #include <linux/syscalls.h>
  #include <linux/unistd.h>
  #include <linux/security.h>
  #include <linux/timex.h>
  #include <linux/export.h>
  #include <linux/migrate.h>
  #include <linux/posix-timers.h>
  #include <linux/times.h>
  #include <linux/ptrace.h>
  #include <linux/gfp.h>
  
  #include <linux/uaccess.h>
  
  int compat_get_timex(struct timex *txc, const struct compat_timex __user *utp)
  {
  	struct compat_timex tx32;
  
  	if (copy_from_user(&tx32, utp, sizeof(struct compat_timex)))
  		return -EFAULT;
  
  	txc->modes = tx32.modes;
  	txc->offset = tx32.offset;
  	txc->freq = tx32.freq;
  	txc->maxerror = tx32.maxerror;
  	txc->esterror = tx32.esterror;
  	txc->status = tx32.status;
  	txc->constant = tx32.constant;
  	txc->precision = tx32.precision;
  	txc->tolerance = tx32.tolerance;
  	txc->time.tv_sec = tx32.time.tv_sec;
  	txc->time.tv_usec = tx32.time.tv_usec;
  	txc->tick = tx32.tick;
  	txc->ppsfreq = tx32.ppsfreq;
  	txc->jitter = tx32.jitter;
  	txc->shift = tx32.shift;
  	txc->stabil = tx32.stabil;
  	txc->jitcnt = tx32.jitcnt;
  	txc->calcnt = tx32.calcnt;
  	txc->errcnt = tx32.errcnt;
  	txc->stbcnt = tx32.stbcnt;
  
  	return 0;
  }
  
  int compat_put_timex(struct compat_timex __user *utp, const struct timex *txc)
  {
  	struct compat_timex tx32;
  
  	memset(&tx32, 0, sizeof(struct compat_timex));
  	tx32.modes = txc->modes;
  	tx32.offset = txc->offset;
  	tx32.freq = txc->freq;
  	tx32.maxerror = txc->maxerror;
  	tx32.esterror = txc->esterror;
  	tx32.status = txc->status;
  	tx32.constant = txc->constant;
  	tx32.precision = txc->precision;
  	tx32.tolerance = txc->tolerance;
  	tx32.time.tv_sec = txc->time.tv_sec;
  	tx32.time.tv_usec = txc->time.tv_usec;
  	tx32.tick = txc->tick;
  	tx32.ppsfreq = txc->ppsfreq;
  	tx32.jitter = txc->jitter;
  	tx32.shift = txc->shift;
  	tx32.stabil = txc->stabil;
  	tx32.jitcnt = txc->jitcnt;
  	tx32.calcnt = txc->calcnt;
  	tx32.errcnt = txc->errcnt;
  	tx32.stbcnt = txc->stbcnt;
  	tx32.tai = txc->tai;
  	if (copy_to_user(utp, &tx32, sizeof(struct compat_timex)))
  		return -EFAULT;
  	return 0;
  }
  
  static int __compat_get_timeval(struct timeval *tv, const struct compat_timeval __user *ctv)
  {
  	return (!access_ok(VERIFY_READ, ctv, sizeof(*ctv)) ||
  			__get_user(tv->tv_sec, &ctv->tv_sec) ||
  			__get_user(tv->tv_usec, &ctv->tv_usec)) ? -EFAULT : 0;
  }
  
  static int __compat_put_timeval(const struct timeval *tv, struct compat_timeval __user *ctv)
  {
  	return (!access_ok(VERIFY_WRITE, ctv, sizeof(*ctv)) ||
  			__put_user(tv->tv_sec, &ctv->tv_sec) ||
  			__put_user(tv->tv_usec, &ctv->tv_usec)) ? -EFAULT : 0;
  }
  
  static int __compat_get_timespec(struct timespec *ts, const struct compat_timespec __user *cts)
  {
  	return (!access_ok(VERIFY_READ, cts, sizeof(*cts)) ||
  			__get_user(ts->tv_sec, &cts->tv_sec) ||
  			__get_user(ts->tv_nsec, &cts->tv_nsec)) ? -EFAULT : 0;
  }
  
  static int __compat_put_timespec(const struct timespec *ts, struct compat_timespec __user *cts)
  {
  	return (!access_ok(VERIFY_WRITE, cts, sizeof(*cts)) ||
  			__put_user(ts->tv_sec, &cts->tv_sec) ||
  			__put_user(ts->tv_nsec, &cts->tv_nsec)) ? -EFAULT : 0;
  }
  
  static int __compat_get_timespec64(struct timespec64 *ts64,
  				   const struct compat_timespec __user *cts)
  {
  	struct compat_timespec ts;
  	int ret;
  
  	ret = copy_from_user(&ts, cts, sizeof(ts));
  	if (ret)
  		return -EFAULT;
  
  	ts64->tv_sec = ts.tv_sec;
  	ts64->tv_nsec = ts.tv_nsec;
  
  	return 0;
  }
  
  static int __compat_put_timespec64(const struct timespec64 *ts64,
  				   struct compat_timespec __user *cts)
  {
  	struct compat_timespec ts = {
  		.tv_sec = ts64->tv_sec,
  		.tv_nsec = ts64->tv_nsec
  	};
  	return copy_to_user(cts, &ts, sizeof(ts)) ? -EFAULT : 0;
  }
  
  int compat_get_timespec64(struct timespec64 *ts, const void __user *uts)
  {
  	if (COMPAT_USE_64BIT_TIME)
  		return copy_from_user(ts, uts, sizeof(*ts)) ? -EFAULT : 0;
  	else
  		return __compat_get_timespec64(ts, uts);
  }
  EXPORT_SYMBOL_GPL(compat_get_timespec64);
  
  int compat_put_timespec64(const struct timespec64 *ts, void __user *uts)
  {
  	if (COMPAT_USE_64BIT_TIME)
  		return copy_to_user(uts, ts, sizeof(*ts)) ? -EFAULT : 0;
  	else
  		return __compat_put_timespec64(ts, uts);
  }
  EXPORT_SYMBOL_GPL(compat_put_timespec64);
  
  int compat_get_timeval(struct timeval *tv, const void __user *utv)
  {
  	if (COMPAT_USE_64BIT_TIME)
  		return copy_from_user(tv, utv, sizeof(*tv)) ? -EFAULT : 0;
  	else
  		return __compat_get_timeval(tv, utv);
  }
  EXPORT_SYMBOL_GPL(compat_get_timeval);
  
  int compat_put_timeval(const struct timeval *tv, void __user *utv)
  {
  	if (COMPAT_USE_64BIT_TIME)
  		return copy_to_user(utv, tv, sizeof(*tv)) ? -EFAULT : 0;
  	else
  		return __compat_put_timeval(tv, utv);
  }
  EXPORT_SYMBOL_GPL(compat_put_timeval);
  
  int compat_get_timespec(struct timespec *ts, const void __user *uts)
  {
  	if (COMPAT_USE_64BIT_TIME)
  		return copy_from_user(ts, uts, sizeof(*ts)) ? -EFAULT : 0;
  	else
  		return __compat_get_timespec(ts, uts);
  }
  EXPORT_SYMBOL_GPL(compat_get_timespec);
  
  int compat_put_timespec(const struct timespec *ts, void __user *uts)
  {
  	if (COMPAT_USE_64BIT_TIME)
  		return copy_to_user(uts, ts, sizeof(*ts)) ? -EFAULT : 0;
  	else
  		return __compat_put_timespec(ts, uts);
  }
  EXPORT_SYMBOL_GPL(compat_put_timespec);
  
  int get_compat_itimerval(struct itimerval *o, const struct compat_itimerval __user *i)
  {
  	struct compat_itimerval v32;
  
  	if (copy_from_user(&v32, i, sizeof(struct compat_itimerval)))
  		return -EFAULT;
  	o->it_interval.tv_sec = v32.it_interval.tv_sec;
  	o->it_interval.tv_usec = v32.it_interval.tv_usec;
  	o->it_value.tv_sec = v32.it_value.tv_sec;
  	o->it_value.tv_usec = v32.it_value.tv_usec;
  	return 0;
  }
  
  int put_compat_itimerval(struct compat_itimerval __user *o, const struct itimerval *i)
  {
  	struct compat_itimerval v32;
  
  	v32.it_interval.tv_sec = i->it_interval.tv_sec;
  	v32.it_interval.tv_usec = i->it_interval.tv_usec;
  	v32.it_value.tv_sec = i->it_value.tv_sec;
  	v32.it_value.tv_usec = i->it_value.tv_usec;
  	return copy_to_user(o, &v32, sizeof(struct compat_itimerval)) ? -EFAULT : 0;
  }
  
  #ifdef __ARCH_WANT_SYS_SIGPROCMASK
  
  /*
   * sys_sigprocmask SIG_SETMASK sets the first (compat) word of the
   * blocked set of signals to the supplied signal set
   */
  static inline void compat_sig_setmask(sigset_t *blocked, compat_sigset_word set)
  {
  	memcpy(blocked->sig, &set, sizeof(set));
  }
  
  COMPAT_SYSCALL_DEFINE3(sigprocmask, int, how,
  		       compat_old_sigset_t __user *, nset,
  		       compat_old_sigset_t __user *, oset)
  {
  	old_sigset_t old_set, new_set;
  	sigset_t new_blocked;
  
  	old_set = current->blocked.sig[0];
  
  	if (nset) {
  		if (get_user(new_set, nset))
  			return -EFAULT;
  		new_set &= ~(sigmask(SIGKILL) | sigmask(SIGSTOP));
  
  		new_blocked = current->blocked;
  
  		switch (how) {
  		case SIG_BLOCK:
  			sigaddsetmask(&new_blocked, new_set);
  			break;
  		case SIG_UNBLOCK:
  			sigdelsetmask(&new_blocked, new_set);
  			break;
  		case SIG_SETMASK:
  			compat_sig_setmask(&new_blocked, new_set);
  			break;
  		default:
  			return -EINVAL;
  		}
  
  		set_current_blocked(&new_blocked);
  	}
  
  	if (oset) {
  		if (put_user(old_set, oset))
  			return -EFAULT;
  	}
  
  	return 0;
  }
  
  #endif
  
  int put_compat_rusage(const struct rusage *r, struct compat_rusage __user *ru)
  {
  	struct compat_rusage r32;
  	memset(&r32, 0, sizeof(r32));
  	r32.ru_utime.tv_sec = r->ru_utime.tv_sec;
  	r32.ru_utime.tv_usec = r->ru_utime.tv_usec;
  	r32.ru_stime.tv_sec = r->ru_stime.tv_sec;
  	r32.ru_stime.tv_usec = r->ru_stime.tv_usec;
  	r32.ru_maxrss = r->ru_maxrss;
  	r32.ru_ixrss = r->ru_ixrss;
  	r32.ru_idrss = r->ru_idrss;
  	r32.ru_isrss = r->ru_isrss;
  	r32.ru_minflt = r->ru_minflt;
  	r32.ru_majflt = r->ru_majflt;
  	r32.ru_nswap = r->ru_nswap;
  	r32.ru_inblock = r->ru_inblock;
  	r32.ru_oublock = r->ru_oublock;
  	r32.ru_msgsnd = r->ru_msgsnd;
  	r32.ru_msgrcv = r->ru_msgrcv;
  	r32.ru_nsignals = r->ru_nsignals;
  	r32.ru_nvcsw = r->ru_nvcsw;
  	r32.ru_nivcsw = r->ru_nivcsw;
  	if (copy_to_user(ru, &r32, sizeof(r32)))
  		return -EFAULT;
  	return 0;
  }
  
  static int compat_get_user_cpu_mask(compat_ulong_t __user *user_mask_ptr,
  				    unsigned len, struct cpumask *new_mask)
  {
  	unsigned long *k;
  
  	if (len < cpumask_size())
  		memset(new_mask, 0, cpumask_size());
  	else if (len > cpumask_size())
  		len = cpumask_size();
  
  	k = cpumask_bits(new_mask);
  	return compat_get_bitmap(k, user_mask_ptr, len * 8);
  }
  
  COMPAT_SYSCALL_DEFINE3(sched_setaffinity, compat_pid_t, pid,
  		       unsigned int, len,
  		       compat_ulong_t __user *, user_mask_ptr)
  {
  	cpumask_var_t new_mask;
  	int retval;
  
  	if (!alloc_cpumask_var(&new_mask, GFP_KERNEL))
  		return -ENOMEM;
  
  	retval = compat_get_user_cpu_mask(user_mask_ptr, len, new_mask);
  	if (retval)
  		goto out;
  
  	retval = sched_setaffinity(pid, new_mask);
  out:
  	free_cpumask_var(new_mask);
  	return retval;
  }
  
  COMPAT_SYSCALL_DEFINE3(sched_getaffinity, compat_pid_t,  pid, unsigned int, len,
  		       compat_ulong_t __user *, user_mask_ptr)
  {
  	int ret;
  	cpumask_var_t mask;
  
  	if ((len * BITS_PER_BYTE) < nr_cpu_ids)
  		return -EINVAL;
  	if (len & (sizeof(compat_ulong_t)-1))
  		return -EINVAL;
  
  	if (!alloc_cpumask_var(&mask, GFP_KERNEL))
  		return -ENOMEM;
  
  	ret = sched_getaffinity(pid, mask);
  	if (ret == 0) {
  		size_t retlen = min_t(size_t, len, cpumask_size());
  
  		if (compat_put_bitmap(user_mask_ptr, cpumask_bits(mask), retlen * 8))
  			ret = -EFAULT;
  		else
  			ret = retlen;
  	}
  	free_cpumask_var(mask);
  
  	return ret;
  }
  
  int get_compat_itimerspec64(struct itimerspec64 *its,
  			const struct compat_itimerspec __user *uits)
  {
  
  	if (__compat_get_timespec64(&its->it_interval, &uits->it_interval) ||
  	    __compat_get_timespec64(&its->it_value, &uits->it_value))
  		return -EFAULT;
  	return 0;
  }
  EXPORT_SYMBOL_GPL(get_compat_itimerspec64);
  
  int put_compat_itimerspec64(const struct itimerspec64 *its,
  			struct compat_itimerspec __user *uits)
  {
  	if (__compat_put_timespec64(&its->it_interval, &uits->it_interval) ||
  	    __compat_put_timespec64(&its->it_value, &uits->it_value))
  		return -EFAULT;
  	return 0;
  }
  EXPORT_SYMBOL_GPL(put_compat_itimerspec64);
  
  /*
   * We currently only need the following fields from the sigevent
   * structure: sigev_value, sigev_signo, sig_notify and (sometimes
   * sigev_notify_thread_id).  The others are handled in user mode.
   * We also assume that copying sigev_value.sival_int is sufficient
   * to keep all the bits of sigev_value.sival_ptr intact.
   */
  int get_compat_sigevent(struct sigevent *event,
  		const struct compat_sigevent __user *u_event)
  {
  	memset(event, 0, sizeof(*event));
  	return (!access_ok(VERIFY_READ, u_event, sizeof(*u_event)) ||
  		__get_user(event->sigev_value.sival_int,
  			&u_event->sigev_value.sival_int) ||
  		__get_user(event->sigev_signo, &u_event->sigev_signo) ||
  		__get_user(event->sigev_notify, &u_event->sigev_notify) ||
  		__get_user(event->sigev_notify_thread_id,
  			&u_event->sigev_notify_thread_id))
  		? -EFAULT : 0;
  }
  
  long compat_get_bitmap(unsigned long *mask, const compat_ulong_t __user *umask,
  		       unsigned long bitmap_size)
  {
  	unsigned long nr_compat_longs;
  
  	/* align bitmap up to nearest compat_long_t boundary */
  	bitmap_size = ALIGN(bitmap_size, BITS_PER_COMPAT_LONG);
  	nr_compat_longs = BITS_TO_COMPAT_LONGS(bitmap_size);
  
  	if (!access_ok(VERIFY_READ, umask, bitmap_size / 8))
  		return -EFAULT;
  
  	user_access_begin();
  	while (nr_compat_longs > 1) {
  		compat_ulong_t l1, l2;
  		unsafe_get_user(l1, umask++, Efault);
  		unsafe_get_user(l2, umask++, Efault);
  		*mask++ = ((unsigned long)l2 << BITS_PER_COMPAT_LONG) | l1;
  		nr_compat_longs -= 2;
  	}
  	if (nr_compat_longs)
  		unsafe_get_user(*mask, umask++, Efault);
  	user_access_end();
  	return 0;
  
  Efault:
  	user_access_end();
  	return -EFAULT;
  }
  
  long compat_put_bitmap(compat_ulong_t __user *umask, unsigned long *mask,
  		       unsigned long bitmap_size)
  {
  	unsigned long nr_compat_longs;
  
  	/* align bitmap up to nearest compat_long_t boundary */
  	bitmap_size = ALIGN(bitmap_size, BITS_PER_COMPAT_LONG);
  	nr_compat_longs = BITS_TO_COMPAT_LONGS(bitmap_size);
  
  	if (!access_ok(VERIFY_WRITE, umask, bitmap_size / 8))
  		return -EFAULT;
  
  	user_access_begin();
  	while (nr_compat_longs > 1) {
  		unsigned long m = *mask++;
  		unsafe_put_user((compat_ulong_t)m, umask++, Efault);
  		unsafe_put_user(m >> BITS_PER_COMPAT_LONG, umask++, Efault);
  		nr_compat_longs -= 2;
  	}
  	if (nr_compat_longs)
  		unsafe_put_user((compat_ulong_t)*mask, umask++, Efault);
  	user_access_end();
  	return 0;
  Efault:
  	user_access_end();
  	return -EFAULT;
  }
  
  int
  get_compat_sigset(sigset_t *set, const compat_sigset_t __user *compat)
  {
  #ifdef __BIG_ENDIAN
  	compat_sigset_t v;
  	if (copy_from_user(&v, compat, sizeof(compat_sigset_t)))
  		return -EFAULT;
  	switch (_NSIG_WORDS) {
  	case 4: set->sig[3] = v.sig[6] | (((long)v.sig[7]) << 32 );
  	case 3: set->sig[2] = v.sig[4] | (((long)v.sig[5]) << 32 );
  	case 2: set->sig[1] = v.sig[2] | (((long)v.sig[3]) << 32 );
  	case 1: set->sig[0] = v.sig[0] | (((long)v.sig[1]) << 32 );
  	}
  #else
  	if (copy_from_user(set, compat, sizeof(compat_sigset_t)))
  		return -EFAULT;
  #endif
  	return 0;
  }
  EXPORT_SYMBOL_GPL(get_compat_sigset);
  
  int
  put_compat_sigset(compat_sigset_t __user *compat, const sigset_t *set,
  		  unsigned int size)
  {
  	/* size <= sizeof(compat_sigset_t) <= sizeof(sigset_t) */
  #ifdef __BIG_ENDIAN
  	compat_sigset_t v;
  	switch (_NSIG_WORDS) {
  	case 4: v.sig[7] = (set->sig[3] >> 32); v.sig[6] = set->sig[3];
  	case 3: v.sig[5] = (set->sig[2] >> 32); v.sig[4] = set->sig[2];
  	case 2: v.sig[3] = (set->sig[1] >> 32); v.sig[2] = set->sig[1];
  	case 1: v.sig[1] = (set->sig[0] >> 32); v.sig[0] = set->sig[0];
  	}
  	return copy_to_user(compat, &v, size) ? -EFAULT : 0;
  #else
  	return copy_to_user(compat, set, size) ? -EFAULT : 0;
  #endif
  }
  
  #ifdef CONFIG_NUMA
  COMPAT_SYSCALL_DEFINE6(move_pages, pid_t, pid, compat_ulong_t, nr_pages,
  		       compat_uptr_t __user *, pages32,
  		       const int __user *, nodes,
  		       int __user *, status,
  		       int, flags)
  {
  	const void __user * __user *pages;
  	int i;
  
  	pages = compat_alloc_user_space(nr_pages * sizeof(void *));
  	for (i = 0; i < nr_pages; i++) {
  		compat_uptr_t p;
  
  		if (get_user(p, pages32 + i) ||
  			put_user(compat_ptr(p), pages + i))
  			return -EFAULT;
  	}
  	return sys_move_pages(pid, nr_pages, pages, nodes, status, flags);
  }
  
  COMPAT_SYSCALL_DEFINE4(migrate_pages, compat_pid_t, pid,
  		       compat_ulong_t, maxnode,
  		       const compat_ulong_t __user *, old_nodes,
  		       const compat_ulong_t __user *, new_nodes)
  {
  	unsigned long __user *old = NULL;
  	unsigned long __user *new = NULL;
  	nodemask_t tmp_mask;
  	unsigned long nr_bits;
  	unsigned long size;
  
  	nr_bits = min_t(unsigned long, maxnode - 1, MAX_NUMNODES);
  	size = ALIGN(nr_bits, BITS_PER_LONG) / 8;
  	if (old_nodes) {
  		if (compat_get_bitmap(nodes_addr(tmp_mask), old_nodes, nr_bits))
  			return -EFAULT;
  		old = compat_alloc_user_space(new_nodes ? size * 2 : size);
  		if (new_nodes)
  			new = old + size / sizeof(unsigned long);
  		if (copy_to_user(old, nodes_addr(tmp_mask), size))
  			return -EFAULT;
  	}
  	if (new_nodes) {
  		if (compat_get_bitmap(nodes_addr(tmp_mask), new_nodes, nr_bits))
  			return -EFAULT;
  		if (new == NULL)
  			new = compat_alloc_user_space(size);
  		if (copy_to_user(new, nodes_addr(tmp_mask), size))
  			return -EFAULT;
  	}
  	return sys_migrate_pages(pid, nr_bits + 1, old, new);
  }
  #endif
  
  /*
   * Allocate user-space memory for the duration of a single system call,
   * in order to marshall parameters inside a compat thunk.
   */
  void __user *compat_alloc_user_space(unsigned long len)
  {
  	void __user *ptr;
  
  	/* If len would occupy more than half of the entire compat space... */
  	if (unlikely(len > (((compat_uptr_t)~0) >> 1)))
  		return NULL;
  
  	ptr = arch_compat_alloc_user_space(len);
  
  	if (unlikely(!access_ok(VERIFY_WRITE, ptr, len)))
  		return NULL;
  
  	return ptr;
  }
  EXPORT_SYMBOL_GPL(compat_alloc_user_space);
  