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compat.c
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compat.c
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/*
* 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_itimerspec(struct itimerspec *dst,
const struct compat_itimerspec __user *src)
{
if (__compat_get_timespec(&dst->it_interval, &src->it_interval) ||
__compat_get_timespec(&dst->it_value, &src->it_value))
return -EFAULT;
return 0;
}
int put_compat_itimerspec(struct compat_itimerspec __user *dst,
const struct itimerspec *src)
{
if (__compat_put_timespec(&src->it_interval, &dst->it_interval) ||
__compat_put_timespec(&src->it_value, &dst->it_value))
return -EFAULT;
return 0;
}
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;
}
void
sigset_from_compat(sigset_t *set, const compat_sigset_t *compat)
{
switch (_NSIG_WORDS) {
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 );
}
}
EXPORT_SYMBOL_GPL(sigset_from_compat);
void
sigset_to_compat(compat_sigset_t *compat, const sigset_t *set)
{
switch (_NSIG_WORDS) {
case 4: compat->sig[7] = (set->sig[3] >> 32); compat->sig[6] = set->sig[3];
case 3: compat->sig[5] = (set->sig[2] >> 32); compat->sig[4] = set->sig[2];
case 2: compat->sig[3] = (set->sig[1] >> 32); compat->sig[2] = set->sig[1];
case 1: compat->sig[1] = (set->sig[0] >> 32); compat->sig[0] = set->sig[0];
}
}
#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
COMPAT_SYSCALL_DEFINE2(sched_rr_get_interval,
compat_pid_t, pid,
struct compat_timespec __user *, interval)
{
struct timespec t;
int ret;
mm_segment_t old_fs = get_fs();
set_fs(KERNEL_DS);
ret = sys_sched_rr_get_interval(pid, (struct timespec __user *)&t);
set_fs(old_fs);
if (compat_put_timespec(&t, interval))
return -EFAULT;
return ret;
}
/*
* 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);