Revision ea164d73a7a0b2b2be3a1d8c2a8a4dab8999fa9c authored by Andrea Arcangeli on 28 November 2005, 21:44:15 UTC, committed by Linus Torvalds on 28 November 2005, 22:42:26 UTC
With Andrew Morton <akpm@osdl.org>

The slab scanning code tries to balance the scanning rate of slabs versus the
scanning rate of LRU pages.  To do this, it retains state concerning how many
slabs have been scanned - if a particular slab shrinker didn't scan enough
objects, we remember that for next time, and scan more objects on the next
pass.

The problem with this is that with (say) a huge number of GFP_NOIO
direct-reclaim attempts, the number of objects which are to be scanned when we
finally get a GFP_KERNEL request can be huge.  Because some shrinker handlers
just bail out if !__GFP_FS.

So the patch clamps the number of objects-to-be-scanned to 2* the total number
of objects in the slab cache.

Signed-off-by: Andrea Arcangeli <andrea@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
1 parent 154f484
Raw File
compat.c
/*
 *  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/futex.h>	/* for FUTEX_WAIT */
#include <linux/syscalls.h>
#include <linux/unistd.h>
#include <linux/security.h>

#include <asm/uaccess.h>
#include <asm/bug.h>

int get_compat_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;
}

int put_compat_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 long compat_nanosleep_restart(struct restart_block *restart)
{
	unsigned long expire = restart->arg0, now = jiffies;
	struct compat_timespec __user *rmtp;

	/* Did it expire while we handled signals? */
	if (!time_after(expire, now))
		return 0;

	expire = schedule_timeout_interruptible(expire - now);
	if (expire == 0)
		return 0;

	rmtp = (struct compat_timespec __user *)restart->arg1;
	if (rmtp) {
		struct compat_timespec ct;
		struct timespec t;

		jiffies_to_timespec(expire, &t);
		ct.tv_sec = t.tv_sec;
		ct.tv_nsec = t.tv_nsec;
		if (copy_to_user(rmtp, &ct, sizeof(ct)))
			return -EFAULT;
	}
	/* The 'restart' block is already filled in */
	return -ERESTART_RESTARTBLOCK;
}

asmlinkage long compat_sys_nanosleep(struct compat_timespec __user *rqtp,
		struct compat_timespec __user *rmtp)
{
	struct timespec t;
	struct restart_block *restart;
	unsigned long expire;

	if (get_compat_timespec(&t, rqtp))
		return -EFAULT;

	if ((t.tv_nsec >= 1000000000L) || (t.tv_nsec < 0) || (t.tv_sec < 0))
		return -EINVAL;

	expire = timespec_to_jiffies(&t) + (t.tv_sec || t.tv_nsec);
	expire = schedule_timeout_interruptible(expire);
	if (expire == 0)
		return 0;

	if (rmtp) {
		jiffies_to_timespec(expire, &t);
		if (put_compat_timespec(&t, rmtp))
			return -EFAULT;
	}
	restart = &current_thread_info()->restart_block;
	restart->fn = compat_nanosleep_restart;
	restart->arg0 = jiffies + expire;
	restart->arg1 = (unsigned long) rmtp;
	return -ERESTART_RESTARTBLOCK;
}

static inline long get_compat_itimerval(struct itimerval *o,
		struct compat_itimerval __user *i)
{
	return (!access_ok(VERIFY_READ, i, sizeof(*i)) ||
		(__get_user(o->it_interval.tv_sec, &i->it_interval.tv_sec) |
		 __get_user(o->it_interval.tv_usec, &i->it_interval.tv_usec) |
		 __get_user(o->it_value.tv_sec, &i->it_value.tv_sec) |
		 __get_user(o->it_value.tv_usec, &i->it_value.tv_usec)));
}

static inline long put_compat_itimerval(struct compat_itimerval __user *o,
		struct itimerval *i)
{
	return (!access_ok(VERIFY_WRITE, o, sizeof(*o)) ||
		(__put_user(i->it_interval.tv_sec, &o->it_interval.tv_sec) |
		 __put_user(i->it_interval.tv_usec, &o->it_interval.tv_usec) |
		 __put_user(i->it_value.tv_sec, &o->it_value.tv_sec) |
		 __put_user(i->it_value.tv_usec, &o->it_value.tv_usec)));
}

asmlinkage long compat_sys_getitimer(int which,
		struct compat_itimerval __user *it)
{
	struct itimerval kit;
	int error;

	error = do_getitimer(which, &kit);
	if (!error && put_compat_itimerval(it, &kit))
		error = -EFAULT;
	return error;
}

asmlinkage long compat_sys_setitimer(int which,
		struct compat_itimerval __user *in,
		struct compat_itimerval __user *out)
{
	struct itimerval kin, kout;
	int error;

	if (in) {
		if (get_compat_itimerval(&kin, in))
			return -EFAULT;
	} else
		memset(&kin, 0, sizeof(kin));

	error = do_setitimer(which, &kin, out ? &kout : NULL);
	if (error || !out)
		return error;
	if (put_compat_itimerval(out, &kout))
		return -EFAULT;
	return 0;
}

asmlinkage long compat_sys_times(struct compat_tms __user *tbuf)
{
	/*
	 *	In the SMP world we might just be unlucky and have one of
	 *	the times increment as we use it. Since the value is an
	 *	atomically safe type this is just fine. Conceptually its
	 *	as if the syscall took an instant longer to occur.
	 */
	if (tbuf) {
		struct compat_tms tmp;
		struct task_struct *tsk = current;
		struct task_struct *t;
		cputime_t utime, stime, cutime, cstime;

		read_lock(&tasklist_lock);
		utime = tsk->signal->utime;
		stime = tsk->signal->stime;
		t = tsk;
		do {
			utime = cputime_add(utime, t->utime);
			stime = cputime_add(stime, t->stime);
			t = next_thread(t);
		} while (t != tsk);

		/*
		 * While we have tasklist_lock read-locked, no dying thread
		 * can be updating current->signal->[us]time.  Instead,
		 * we got their counts included in the live thread loop.
		 * However, another thread can come in right now and
		 * do a wait call that updates current->signal->c[us]time.
		 * To make sure we always see that pair updated atomically,
		 * we take the siglock around fetching them.
		 */
		spin_lock_irq(&tsk->sighand->siglock);
		cutime = tsk->signal->cutime;
		cstime = tsk->signal->cstime;
		spin_unlock_irq(&tsk->sighand->siglock);
		read_unlock(&tasklist_lock);

		tmp.tms_utime = compat_jiffies_to_clock_t(cputime_to_jiffies(utime));
		tmp.tms_stime = compat_jiffies_to_clock_t(cputime_to_jiffies(stime));
		tmp.tms_cutime = compat_jiffies_to_clock_t(cputime_to_jiffies(cutime));
		tmp.tms_cstime = compat_jiffies_to_clock_t(cputime_to_jiffies(cstime));
		if (copy_to_user(tbuf, &tmp, sizeof(tmp)))
			return -EFAULT;
	}
	return compat_jiffies_to_clock_t(jiffies);
}

/*
 * Assumption: old_sigset_t and compat_old_sigset_t are both
 * types that can be passed to put_user()/get_user().
 */

asmlinkage long compat_sys_sigpending(compat_old_sigset_t __user *set)
{
	old_sigset_t s;
	long ret;
	mm_segment_t old_fs = get_fs();

	set_fs(KERNEL_DS);
	ret = sys_sigpending((old_sigset_t __user *) &s);
	set_fs(old_fs);
	if (ret == 0)
		ret = put_user(s, set);
	return ret;
}

asmlinkage long compat_sys_sigprocmask(int how, compat_old_sigset_t __user *set,
		compat_old_sigset_t __user *oset)
{
	old_sigset_t s;
	long ret;
	mm_segment_t old_fs;

	if (set && get_user(s, set))
		return -EFAULT;
	old_fs = get_fs();
	set_fs(KERNEL_DS);
	ret = sys_sigprocmask(how,
			      set ? (old_sigset_t __user *) &s : NULL,
			      oset ? (old_sigset_t __user *) &s : NULL);
	set_fs(old_fs);
	if (ret == 0)
		if (oset)
			ret = put_user(s, oset);
	return ret;
}

#ifdef CONFIG_FUTEX
asmlinkage long compat_sys_futex(u32 __user *uaddr, int op, int val,
		struct compat_timespec __user *utime, u32 __user *uaddr2,
		int val3)
{
	struct timespec t;
	unsigned long timeout = MAX_SCHEDULE_TIMEOUT;
	int val2 = 0;

	if ((op == FUTEX_WAIT) && utime) {
		if (get_compat_timespec(&t, utime))
			return -EFAULT;
		timeout = timespec_to_jiffies(&t) + 1;
	}
	if (op >= FUTEX_REQUEUE)
		val2 = (int) (unsigned long) utime;

	return do_futex((unsigned long)uaddr, op, val, timeout,
			(unsigned long)uaddr2, val2, val3);
}
#endif

asmlinkage long compat_sys_setrlimit(unsigned int resource,
		struct compat_rlimit __user *rlim)
{
	struct rlimit r;
	int ret;
	mm_segment_t old_fs = get_fs ();

	if (resource >= RLIM_NLIMITS) 
		return -EINVAL;	

	if (!access_ok(VERIFY_READ, rlim, sizeof(*rlim)) ||
	    __get_user(r.rlim_cur, &rlim->rlim_cur) ||
	    __get_user(r.rlim_max, &rlim->rlim_max))
		return -EFAULT;

	if (r.rlim_cur == COMPAT_RLIM_INFINITY)
		r.rlim_cur = RLIM_INFINITY;
	if (r.rlim_max == COMPAT_RLIM_INFINITY)
		r.rlim_max = RLIM_INFINITY;
	set_fs(KERNEL_DS);
	ret = sys_setrlimit(resource, (struct rlimit __user *) &r);
	set_fs(old_fs);
	return ret;
}

#ifdef COMPAT_RLIM_OLD_INFINITY

asmlinkage long compat_sys_old_getrlimit(unsigned int resource,
		struct compat_rlimit __user *rlim)
{
	struct rlimit r;
	int ret;
	mm_segment_t old_fs = get_fs();

	set_fs(KERNEL_DS);
	ret = sys_old_getrlimit(resource, &r);
	set_fs(old_fs);

	if (!ret) {
		if (r.rlim_cur > COMPAT_RLIM_OLD_INFINITY)
			r.rlim_cur = COMPAT_RLIM_INFINITY;
		if (r.rlim_max > COMPAT_RLIM_OLD_INFINITY)
			r.rlim_max = COMPAT_RLIM_INFINITY;

		if (!access_ok(VERIFY_WRITE, rlim, sizeof(*rlim)) ||
		    __put_user(r.rlim_cur, &rlim->rlim_cur) ||
		    __put_user(r.rlim_max, &rlim->rlim_max))
			return -EFAULT;
	}
	return ret;
}

#endif

asmlinkage long compat_sys_getrlimit (unsigned int resource,
		struct compat_rlimit __user *rlim)
{
	struct rlimit r;
	int ret;
	mm_segment_t old_fs = get_fs();

	set_fs(KERNEL_DS);
	ret = sys_getrlimit(resource, (struct rlimit __user *) &r);
	set_fs(old_fs);
	if (!ret) {
		if (r.rlim_cur > COMPAT_RLIM_INFINITY)
			r.rlim_cur = COMPAT_RLIM_INFINITY;
		if (r.rlim_max > COMPAT_RLIM_INFINITY)
			r.rlim_max = COMPAT_RLIM_INFINITY;

		if (!access_ok(VERIFY_WRITE, rlim, sizeof(*rlim)) ||
		    __put_user(r.rlim_cur, &rlim->rlim_cur) ||
		    __put_user(r.rlim_max, &rlim->rlim_max))
			return -EFAULT;
	}
	return ret;
}

int put_compat_rusage(const struct rusage *r, struct compat_rusage __user *ru)
{
	if (!access_ok(VERIFY_WRITE, ru, sizeof(*ru)) ||
	    __put_user(r->ru_utime.tv_sec, &ru->ru_utime.tv_sec) ||
	    __put_user(r->ru_utime.tv_usec, &ru->ru_utime.tv_usec) ||
	    __put_user(r->ru_stime.tv_sec, &ru->ru_stime.tv_sec) ||
	    __put_user(r->ru_stime.tv_usec, &ru->ru_stime.tv_usec) ||
	    __put_user(r->ru_maxrss, &ru->ru_maxrss) ||
	    __put_user(r->ru_ixrss, &ru->ru_ixrss) ||
	    __put_user(r->ru_idrss, &ru->ru_idrss) ||
	    __put_user(r->ru_isrss, &ru->ru_isrss) ||
	    __put_user(r->ru_minflt, &ru->ru_minflt) ||
	    __put_user(r->ru_majflt, &ru->ru_majflt) ||
	    __put_user(r->ru_nswap, &ru->ru_nswap) ||
	    __put_user(r->ru_inblock, &ru->ru_inblock) ||
	    __put_user(r->ru_oublock, &ru->ru_oublock) ||
	    __put_user(r->ru_msgsnd, &ru->ru_msgsnd) ||
	    __put_user(r->ru_msgrcv, &ru->ru_msgrcv) ||
	    __put_user(r->ru_nsignals, &ru->ru_nsignals) ||
	    __put_user(r->ru_nvcsw, &ru->ru_nvcsw) ||
	    __put_user(r->ru_nivcsw, &ru->ru_nivcsw))
		return -EFAULT;
	return 0;
}

asmlinkage long compat_sys_getrusage(int who, struct compat_rusage __user *ru)
{
	struct rusage r;
	int ret;
	mm_segment_t old_fs = get_fs();

	set_fs(KERNEL_DS);
	ret = sys_getrusage(who, (struct rusage __user *) &r);
	set_fs(old_fs);

	if (ret)
		return ret;

	if (put_compat_rusage(&r, ru))
		return -EFAULT;

	return 0;
}

asmlinkage long
compat_sys_wait4(compat_pid_t pid, compat_uint_t __user *stat_addr, int options,
	struct compat_rusage __user *ru)
{
	if (!ru) {
		return sys_wait4(pid, stat_addr, options, NULL);
	} else {
		struct rusage r;
		int ret;
		unsigned int status;
		mm_segment_t old_fs = get_fs();

		set_fs (KERNEL_DS);
		ret = sys_wait4(pid,
				(stat_addr ?
				 (unsigned int __user *) &status : NULL),
				options, (struct rusage __user *) &r);
		set_fs (old_fs);

		if (ret > 0) {
			if (put_compat_rusage(&r, ru))
				return -EFAULT;
			if (stat_addr && put_user(status, stat_addr))
				return -EFAULT;
		}
		return ret;
	}
}

asmlinkage long compat_sys_waitid(int which, compat_pid_t pid,
		struct compat_siginfo __user *uinfo, int options,
		struct compat_rusage __user *uru)
{
	siginfo_t info;
	struct rusage ru;
	long ret;
	mm_segment_t old_fs = get_fs();

	memset(&info, 0, sizeof(info));

	set_fs(KERNEL_DS);
	ret = sys_waitid(which, pid, (siginfo_t __user *)&info, options,
			 uru ? (struct rusage __user *)&ru : NULL);
	set_fs(old_fs);

	if ((ret < 0) || (info.si_signo == 0))
		return ret;

	if (uru) {
		ret = put_compat_rusage(&ru, uru);
		if (ret)
			return ret;
	}

	BUG_ON(info.si_code & __SI_MASK);
	info.si_code |= __SI_CHLD;
	return copy_siginfo_to_user32(uinfo, &info);
}

static int compat_get_user_cpu_mask(compat_ulong_t __user *user_mask_ptr,
				    unsigned len, cpumask_t *new_mask)
{
	unsigned long *k;

	if (len < sizeof(cpumask_t))
		memset(new_mask, 0, sizeof(cpumask_t));
	else if (len > sizeof(cpumask_t))
		len = sizeof(cpumask_t);

	k = cpus_addr(*new_mask);
	return compat_get_bitmap(k, user_mask_ptr, len * 8);
}

asmlinkage long compat_sys_sched_setaffinity(compat_pid_t pid,
					     unsigned int len,
					     compat_ulong_t __user *user_mask_ptr)
{
	cpumask_t new_mask;
	int retval;

	retval = compat_get_user_cpu_mask(user_mask_ptr, len, &new_mask);
	if (retval)
		return retval;

	return sched_setaffinity(pid, new_mask);
}

asmlinkage long compat_sys_sched_getaffinity(compat_pid_t pid, unsigned int len,
					     compat_ulong_t __user *user_mask_ptr)
{
	int ret;
	cpumask_t mask;
	unsigned long *k;
	unsigned int min_length = sizeof(cpumask_t);

	if (NR_CPUS <= BITS_PER_COMPAT_LONG)
		min_length = sizeof(compat_ulong_t);

	if (len < min_length)
		return -EINVAL;

	ret = sched_getaffinity(pid, &mask);
	if (ret < 0)
		return ret;

	k = cpus_addr(mask);
	ret = compat_put_bitmap(user_mask_ptr, k, min_length * 8);
	if (ret)
		return ret;

	return min_length;
}

static int get_compat_itimerspec(struct itimerspec *dst, 
				 struct compat_itimerspec __user *src)
{ 
	if (get_compat_timespec(&dst->it_interval, &src->it_interval) ||
	    get_compat_timespec(&dst->it_value, &src->it_value))
		return -EFAULT;
	return 0;
} 

static int put_compat_itimerspec(struct compat_itimerspec __user *dst, 
				 struct itimerspec *src)
{ 
	if (put_compat_timespec(&src->it_interval, &dst->it_interval) ||
	    put_compat_timespec(&src->it_value, &dst->it_value))
		return -EFAULT;
	return 0;
} 

long compat_sys_timer_settime(timer_t timer_id, int flags,
			  struct compat_itimerspec __user *new, 
			  struct compat_itimerspec __user *old)
{ 
	long err;
	mm_segment_t oldfs;
	struct itimerspec newts, oldts;

	if (!new)
		return -EINVAL;
	if (get_compat_itimerspec(&newts, new))
		return -EFAULT;	
	oldfs = get_fs();
	set_fs(KERNEL_DS);
	err = sys_timer_settime(timer_id, flags,
				(struct itimerspec __user *) &newts,
				(struct itimerspec __user *) &oldts);
	set_fs(oldfs); 
	if (!err && old && put_compat_itimerspec(old, &oldts))
		return -EFAULT;
	return err;
} 

long compat_sys_timer_gettime(timer_t timer_id,
		struct compat_itimerspec __user *setting)
{ 
	long err;
	mm_segment_t oldfs;
	struct itimerspec ts; 

	oldfs = get_fs();
	set_fs(KERNEL_DS);
	err = sys_timer_gettime(timer_id,
				(struct itimerspec __user *) &ts); 
	set_fs(oldfs); 
	if (!err && put_compat_itimerspec(setting, &ts))
		return -EFAULT;
	return err;
} 

long compat_sys_clock_settime(clockid_t which_clock,
		struct compat_timespec __user *tp)
{
	long err;
	mm_segment_t oldfs;
	struct timespec ts; 

	if (get_compat_timespec(&ts, tp))
		return -EFAULT; 
	oldfs = get_fs();
	set_fs(KERNEL_DS);	
	err = sys_clock_settime(which_clock,
				(struct timespec __user *) &ts);
	set_fs(oldfs);
	return err;
} 

long compat_sys_clock_gettime(clockid_t which_clock,
		struct compat_timespec __user *tp)
{
	long err;
	mm_segment_t oldfs;
	struct timespec ts; 

	oldfs = get_fs();
	set_fs(KERNEL_DS);
	err = sys_clock_gettime(which_clock,
				(struct timespec __user *) &ts);
	set_fs(oldfs);
	if (!err && put_compat_timespec(&ts, tp))
		return -EFAULT; 
	return err;
} 

long compat_sys_clock_getres(clockid_t which_clock,
		struct compat_timespec __user *tp)
{
	long err;
	mm_segment_t oldfs;
	struct timespec ts; 

	oldfs = get_fs();
	set_fs(KERNEL_DS);
	err = sys_clock_getres(which_clock,
			       (struct timespec __user *) &ts);
	set_fs(oldfs);
	if (!err && tp && put_compat_timespec(&ts, tp))
		return -EFAULT; 
	return err;
} 

long compat_sys_clock_nanosleep(clockid_t which_clock, int flags,
			    struct compat_timespec __user *rqtp,
			    struct compat_timespec __user *rmtp)
{
	long err;
	mm_segment_t oldfs;
	struct timespec in, out; 

	if (get_compat_timespec(&in, rqtp)) 
		return -EFAULT;

	oldfs = get_fs();
	set_fs(KERNEL_DS);
	err = sys_clock_nanosleep(which_clock, flags,
				  (struct timespec __user *) &in,
				  (struct timespec __user *) &out);
	set_fs(oldfs);
	if ((err == -ERESTART_RESTARTBLOCK) && rmtp &&
	    put_compat_timespec(&out, rmtp))
		return -EFAULT;
	return err;	
} 

/*
 * 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;
}

/* timer_create is architecture specific because it needs sigevent conversion */

long compat_get_bitmap(unsigned long *mask, compat_ulong_t __user *umask,
		       unsigned long bitmap_size)
{
	int i, j;
	unsigned long m;
	compat_ulong_t um;
	unsigned long nr_compat_longs;

	/* align bitmap up to nearest compat_long_t boundary */
	bitmap_size = ALIGN(bitmap_size, BITS_PER_COMPAT_LONG);

	if (!access_ok(VERIFY_READ, umask, bitmap_size / 8))
		return -EFAULT;

	nr_compat_longs = BITS_TO_COMPAT_LONGS(bitmap_size);

	for (i = 0; i < BITS_TO_LONGS(bitmap_size); i++) {
		m = 0;

		for (j = 0; j < sizeof(m)/sizeof(um); j++) {
			/*
			 * We dont want to read past the end of the userspace
			 * bitmap. We must however ensure the end of the
			 * kernel bitmap is zeroed.
			 */
			if (nr_compat_longs-- > 0) {
				if (__get_user(um, umask))
					return -EFAULT;
			} else {
				um = 0;
			}

			umask++;
			m |= (long)um << (j * BITS_PER_COMPAT_LONG);
		}
		*mask++ = m;
	}

	return 0;
}

long compat_put_bitmap(compat_ulong_t __user *umask, unsigned long *mask,
		       unsigned long bitmap_size)
{
	int i, j;
	unsigned long m;
	compat_ulong_t um;
	unsigned long nr_compat_longs;

	/* align bitmap up to nearest compat_long_t boundary */
	bitmap_size = ALIGN(bitmap_size, BITS_PER_COMPAT_LONG);

	if (!access_ok(VERIFY_WRITE, umask, bitmap_size / 8))
		return -EFAULT;

	nr_compat_longs = BITS_TO_COMPAT_LONGS(bitmap_size);

	for (i = 0; i < BITS_TO_LONGS(bitmap_size); i++) {
		m = *mask++;

		for (j = 0; j < sizeof(m)/sizeof(um); j++) {
			um = m;

			/*
			 * We dont want to write past the end of the userspace
			 * bitmap.
			 */
			if (nr_compat_longs-- > 0) {
				if (__put_user(um, umask))
					return -EFAULT;
			}

			umask++;
			m >>= 4*sizeof(um);
			m >>= 4*sizeof(um);
		}
	}

	return 0;
}

void
sigset_from_compat (sigset_t *set, compat_sigset_t *compat)
{
	switch (_NSIG_WORDS) {
#if defined (__COMPAT_ENDIAN_SWAP__)
	case 4: set->sig[3] = compat->sig[7] | (((long)compat->sig[6]) << 32 );
	case 3: set->sig[2] = compat->sig[5] | (((long)compat->sig[4]) << 32 );
	case 2: set->sig[1] = compat->sig[3] | (((long)compat->sig[2]) << 32 );
	case 1: set->sig[0] = compat->sig[1] | (((long)compat->sig[0]) << 32 );
#else
	case 4: set->sig[3] = compat->sig[6] | (((long)compat->sig[7]) << 32 );
	case 3: set->sig[2] = compat->sig[4] | (((long)compat->sig[5]) << 32 );
	case 2: set->sig[1] = compat->sig[2] | (((long)compat->sig[3]) << 32 );
	case 1: set->sig[0] = compat->sig[0] | (((long)compat->sig[1]) << 32 );
#endif
	}
}

asmlinkage long
compat_sys_rt_sigtimedwait (compat_sigset_t __user *uthese,
		struct compat_siginfo __user *uinfo,
		struct compat_timespec __user *uts, compat_size_t sigsetsize)
{
	compat_sigset_t s32;
	sigset_t s;
	int sig;
	struct timespec t;
	siginfo_t info;
	long ret, timeout = 0;

	if (sigsetsize != sizeof(sigset_t))
		return -EINVAL;

	if (copy_from_user(&s32, uthese, sizeof(compat_sigset_t)))
		return -EFAULT;
	sigset_from_compat(&s, &s32);
	sigdelsetmask(&s,sigmask(SIGKILL)|sigmask(SIGSTOP));
	signotset(&s);

	if (uts) {
		if (get_compat_timespec (&t, uts))
			return -EFAULT;
		if (t.tv_nsec >= 1000000000L || t.tv_nsec < 0
				|| t.tv_sec < 0)
			return -EINVAL;
	}

	spin_lock_irq(&current->sighand->siglock);
	sig = dequeue_signal(current, &s, &info);
	if (!sig) {
		timeout = MAX_SCHEDULE_TIMEOUT;
		if (uts)
			timeout = timespec_to_jiffies(&t)
				+(t.tv_sec || t.tv_nsec);
		if (timeout) {
			current->real_blocked = current->blocked;
			sigandsets(&current->blocked, &current->blocked, &s);

			recalc_sigpending();
			spin_unlock_irq(&current->sighand->siglock);

			timeout = schedule_timeout_interruptible(timeout);

			spin_lock_irq(&current->sighand->siglock);
			sig = dequeue_signal(current, &s, &info);
			current->blocked = current->real_blocked;
			siginitset(&current->real_blocked, 0);
			recalc_sigpending();
		}
	}
	spin_unlock_irq(&current->sighand->siglock);

	if (sig) {
		ret = sig;
		if (uinfo) {
			if (copy_siginfo_to_user32(uinfo, &info))
				ret = -EFAULT;
		}
	}else {
		ret = timeout?-EINTR:-EAGAIN;
	}
	return ret;

}

#ifdef __ARCH_WANT_COMPAT_SYS_TIME

/* compat_time_t is a 32 bit "long" and needs to get converted. */

asmlinkage long compat_sys_time(compat_time_t __user * tloc)
{
	compat_time_t i;
	struct timeval tv;

	do_gettimeofday(&tv);
	i = tv.tv_sec;

	if (tloc) {
		if (put_user(i,tloc))
			i = -EFAULT;
	}
	return i;
}

asmlinkage long compat_sys_stime(compat_time_t __user *tptr)
{
	struct timespec tv;
	int err;

	if (get_user(tv.tv_sec, tptr))
		return -EFAULT;

	tv.tv_nsec = 0;

	err = security_settime(&tv, NULL);
	if (err)
		return err;

	do_settimeofday(&tv);
	return 0;
}

#endif /* __ARCH_WANT_COMPAT_SYS_TIME */
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