[linux.git] / kernel / compat.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 *  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
 */

#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/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>

#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 (!zalloc_cpumask_var(&mask, GFP_KERNEL))
		return -ENOMEM;

	ret = sched_getaffinity(pid, mask);
	if (ret == 0) {
		unsigned int retlen = min(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;
}

/*
 * 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(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 (!user_read_access_begin(umask, bitmap_size / 8))
		return -EFAULT;

	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_read_access_end();
	return 0;

Efault:
	user_read_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 (!user_write_access_begin(umask, bitmap_size / 8))
		return -EFAULT;

	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_write_access_end();
	return 0;
Efault:
	user_write_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 );
		fallthrough;
	case 3: set->sig[2] = v.sig[4] | (((long)v.sig[5]) << 32 );
		fallthrough;
	case 2: set->sig[1] = v.sig[2] | (((long)v.sig[3]) << 32 );
		fallthrough;
	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);
Commit	Line	Data
d2912cb1	1	// SPDX-License-Identifier: GPL-2.0-only
1da177e4 LT	2	/*
	3	* linux/kernel/compat.c
	4	*
	5	* Kernel compatibililty routines for e.g. 32 bit syscall support
	6	* on 64 bit kernels.
	7	*
	8	* Copyright (C) 2002-2003 Stephen Rothwell, IBM Corporation
1da177e4 LT	9	*/
	10
	11	#include <linux/linkage.h>
	12	#include <linux/compat.h>
	13	#include <linux/errno.h>
	14	#include <linux/time.h>
	15	#include <linux/signal.h>
	16	#include <linux/sched.h> /* for MAX_SCHEDULE_TIMEOUT */
1da177e4 LT	17	#include <linux/syscalls.h>
	18	#include <linux/unistd.h>
	19	#include <linux/security.h>
6e5fdeed	20	#include <linux/export.h>
1b2db9fb	21	#include <linux/migrate.h>
1711ef38	22	#include <linux/posix-timers.h>
f06febc9	23	#include <linux/times.h>
e3d5a27d	24	#include <linux/ptrace.h>
5a0e3ad6	25	#include <linux/gfp.h>
1da177e4	26
7c0f6ba6	27	#include <linux/uaccess.h>
1da177e4	28
be84cb43 CM	29	#ifdef __ARCH_WANT_SYS_SIGPROCMASK
be84cb43 CM	30
b7dafa0e JK	31	/*
	32	* sys_sigprocmask SIG_SETMASK sets the first (compat) word of the
	33	* blocked set of signals to the supplied signal set
	34	*/
	35	static inline void compat_sig_setmask(sigset_t *blocked, compat_sigset_word set)
1da177e4	36	{
b7dafa0e JK	37	memcpy(blocked->sig, &set, sizeof(set));
b7dafa0e JK	38	}
1da177e4	39
5cf22100 AV	40	COMPAT_SYSCALL_DEFINE3(sigprocmask, int, how,
	41	compat_old_sigset_t __user *, nset,
	42	compat_old_sigset_t __user *, oset)
b7dafa0e JK	43	{
	44	old_sigset_t old_set, new_set;
	45	sigset_t new_blocked;
	46
	47	old_set = current->blocked.sig[0];
	48
	49	if (nset) {
	50	if (get_user(new_set, nset))
	51	return -EFAULT;
	52	new_set &= ~(sigmask(SIGKILL) \| sigmask(SIGSTOP));
	53
	54	new_blocked = current->blocked;
	55
	56	switch (how) {
	57	case SIG_BLOCK:
	58	sigaddsetmask(&new_blocked, new_set);
	59	break;
	60	case SIG_UNBLOCK:
	61	sigdelsetmask(&new_blocked, new_set);
	62	break;
	63	case SIG_SETMASK:
	64	compat_sig_setmask(&new_blocked, new_set);
	65	break;
	66	default:
	67	return -EINVAL;
	68	}
	69
	70	set_current_blocked(&new_blocked);
	71	}
	72
	73	if (oset) {
	74	if (put_user(old_set, oset))
	75	return -EFAULT;
	76	}
	77
	78	return 0;
1da177e4 LT	79	}
1da177e4 LT	80
be84cb43 CM	81	#endif
be84cb43 CM	82
1da177e4 LT	83	int put_compat_rusage(const struct rusage r, struct compat_rusage __user ru)
1da177e4 LT	84	{
7668b679 AV	85	struct compat_rusage r32;
	86	memset(&r32, 0, sizeof(r32));
	87	r32.ru_utime.tv_sec = r->ru_utime.tv_sec;
	88	r32.ru_utime.tv_usec = r->ru_utime.tv_usec;
	89	r32.ru_stime.tv_sec = r->ru_stime.tv_sec;
	90	r32.ru_stime.tv_usec = r->ru_stime.tv_usec;
	91	r32.ru_maxrss = r->ru_maxrss;
	92	r32.ru_ixrss = r->ru_ixrss;
	93	r32.ru_idrss = r->ru_idrss;
	94	r32.ru_isrss = r->ru_isrss;
	95	r32.ru_minflt = r->ru_minflt;
	96	r32.ru_majflt = r->ru_majflt;
	97	r32.ru_nswap = r->ru_nswap;
	98	r32.ru_inblock = r->ru_inblock;
	99	r32.ru_oublock = r->ru_oublock;
	100	r32.ru_msgsnd = r->ru_msgsnd;
	101	r32.ru_msgrcv = r->ru_msgrcv;
	102	r32.ru_nsignals = r->ru_nsignals;
	103	r32.ru_nvcsw = r->ru_nvcsw;
	104	r32.ru_nivcsw = r->ru_nivcsw;
	105	if (copy_to_user(ru, &r32, sizeof(r32)))
1da177e4 LT	106	return -EFAULT;
	107	return 0;
	108	}
	109
1da177e4	110	static int compat_get_user_cpu_mask(compat_ulong_t __user *user_mask_ptr,
a45185d2	111	unsigned len, struct cpumask *new_mask)
1da177e4 LT	112	{
	113	unsigned long *k;
	114
a45185d2 RR	115	if (len < cpumask_size())
	116	memset(new_mask, 0, cpumask_size());
	117	else if (len > cpumask_size())
	118	len = cpumask_size();
1da177e4	119
a45185d2	120	k = cpumask_bits(new_mask);
1da177e4 LT	121	return compat_get_bitmap(k, user_mask_ptr, len * 8);
	122	}
	123
62a6fa97 HC	124	COMPAT_SYSCALL_DEFINE3(sched_setaffinity, compat_pid_t, pid,
	125	unsigned int, len,
	126	compat_ulong_t __user *, user_mask_ptr)
1da177e4	127	{
a45185d2	128	cpumask_var_t new_mask;
1da177e4 LT	129	int retval;
1da177e4 LT	130
a45185d2 RR	131	if (!alloc_cpumask_var(&new_mask, GFP_KERNEL))
	132	return -ENOMEM;
	133
	134	retval = compat_get_user_cpu_mask(user_mask_ptr, len, new_mask);
1da177e4	135	if (retval)
a45185d2	136	goto out;
1da177e4	137
a45185d2 RR	138	retval = sched_setaffinity(pid, new_mask);
	139	out:
	140	free_cpumask_var(new_mask);
	141	return retval;
1da177e4 LT	142	}
1da177e4 LT	143
62a6fa97 HC	144	COMPAT_SYSCALL_DEFINE3(sched_getaffinity, compat_pid_t, pid, unsigned int, len,
62a6fa97 HC	145	compat_ulong_t __user *, user_mask_ptr)
1da177e4 LT	146	{
1da177e4 LT	147	int ret;
a45185d2	148	cpumask_var_t mask;
1da177e4	149
fa9dc265 KM	150	if ((len * BITS_PER_BYTE) < nr_cpu_ids)
	151	return -EINVAL;
	152	if (len & (sizeof(compat_ulong_t)-1))
1da177e4 LT	153	return -EINVAL;
1da177e4 LT	154
6015b1ac	155	if (!zalloc_cpumask_var(&mask, GFP_KERNEL))
a45185d2 RR	156	return -ENOMEM;
	157
	158	ret = sched_getaffinity(pid, mask);
fa9dc265	159	if (ret == 0) {
4de373a1	160	unsigned int retlen = min(len, cpumask_size());
1da177e4	161
fa9dc265 KM	162	if (compat_put_bitmap(user_mask_ptr, cpumask_bits(mask), retlen * 8))
	163	ret = -EFAULT;
	164	else
	165	ret = retlen;
	166	}
a45185d2	167	free_cpumask_var(mask);
fa9dc265	168
a45185d2	169	return ret;
1da177e4 LT	170	}
1da177e4 LT	171
1da177e4 LT	172	/*
	173	* We currently only need the following fields from the sigevent
	174	* structure: sigev_value, sigev_signo, sig_notify and (sometimes
	175	* sigev_notify_thread_id). The others are handled in user mode.
	176	* We also assume that copying sigev_value.sival_int is sufficient
	177	* to keep all the bits of sigev_value.sival_ptr intact.
	178	*/
	179	int get_compat_sigevent(struct sigevent *event,
	180	const struct compat_sigevent __user *u_event)
	181	{
51410d3c	182	memset(event, 0, sizeof(*event));
96d4f267	183	return (!access_ok(u_event, sizeof(*u_event)) \|\|
1da177e4 LT	184	__get_user(event->sigev_value.sival_int,
	185	&u_event->sigev_value.sival_int) \|\|
	186	__get_user(event->sigev_signo, &u_event->sigev_signo) \|\|
	187	__get_user(event->sigev_notify, &u_event->sigev_notify) \|\|
	188	__get_user(event->sigev_notify_thread_id,
	189	&u_event->sigev_notify_thread_id))
	190	? -EFAULT : 0;
	191	}
	192
5fa3839a	193	long compat_get_bitmap(unsigned long mask, const compat_ulong_t __user umask,
1da177e4 LT	194	unsigned long bitmap_size)
1da177e4 LT	195	{
1da177e4 LT	196	unsigned long nr_compat_longs;
	197
	198	/* align bitmap up to nearest compat_long_t boundary */
	199	bitmap_size = ALIGN(bitmap_size, BITS_PER_COMPAT_LONG);
1e1fc133	200	nr_compat_longs = BITS_TO_COMPAT_LONGS(bitmap_size);
1da177e4	201
41cd7805	202	if (!user_read_access_begin(umask, bitmap_size / 8))
1da177e4 LT	203	return -EFAULT;
1da177e4 LT	204
1e1fc133 AV	205	while (nr_compat_longs > 1) {
	206	compat_ulong_t l1, l2;
	207	unsafe_get_user(l1, umask++, Efault);
	208	unsafe_get_user(l2, umask++, Efault);
	209	*mask++ = ((unsigned long)l2 << BITS_PER_COMPAT_LONG) \| l1;
	210	nr_compat_longs -= 2;
1da177e4	211	}
1e1fc133 AV	212	if (nr_compat_longs)
1e1fc133 AV	213	unsafe_get_user(*mask, umask++, Efault);
41cd7805	214	user_read_access_end();
1da177e4	215	return 0;
1e1fc133 AV	216
1e1fc133 AV	217	Efault:
41cd7805	218	user_read_access_end();
1e1fc133	219	return -EFAULT;
1da177e4 LT	220	}
	221
	222	long compat_put_bitmap(compat_ulong_t __user umask, unsigned long mask,
	223	unsigned long bitmap_size)
	224	{
1da177e4 LT	225	unsigned long nr_compat_longs;
	226
	227	/* align bitmap up to nearest compat_long_t boundary */
	228	bitmap_size = ALIGN(bitmap_size, BITS_PER_COMPAT_LONG);
1e1fc133	229	nr_compat_longs = BITS_TO_COMPAT_LONGS(bitmap_size);
1da177e4	230
41cd7805	231	if (!user_write_access_begin(umask, bitmap_size / 8))
1da177e4 LT	232	return -EFAULT;
1da177e4 LT	233
1e1fc133 AV	234	while (nr_compat_longs > 1) {
	235	unsigned long m = *mask++;
	236	unsafe_put_user((compat_ulong_t)m, umask++, Efault);
	237	unsafe_put_user(m >> BITS_PER_COMPAT_LONG, umask++, Efault);
	238	nr_compat_longs -= 2;
1da177e4	239	}
1e1fc133 AV	240	if (nr_compat_longs)
1e1fc133 AV	241	unsafe_put_user((compat_ulong_t)*mask, umask++, Efault);
41cd7805	242	user_write_access_end();
1da177e4	243	return 0;
1e1fc133	244	Efault:
41cd7805	245	user_write_access_end();
1e1fc133	246	return -EFAULT;
1da177e4 LT	247	}
1da177e4 LT	248
3968cf62 AV	249	int
3968cf62 AV	250	get_compat_sigset(sigset_t set, const compat_sigset_t __user compat)
1da177e4	251	{
3968cf62 AV	252	#ifdef __BIG_ENDIAN
	253	compat_sigset_t v;
	254	if (copy_from_user(&v, compat, sizeof(compat_sigset_t)))
	255	return -EFAULT;
1da177e4	256	switch (_NSIG_WORDS) {
3968cf62	257	case 4: set->sig[3] = v.sig[6] \| (((long)v.sig[7]) << 32 );
df561f66	258	fallthrough;
3968cf62	259	case 3: set->sig[2] = v.sig[4] \| (((long)v.sig[5]) << 32 );
df561f66	260	fallthrough;
3968cf62	261	case 2: set->sig[1] = v.sig[2] \| (((long)v.sig[3]) << 32 );
df561f66	262	fallthrough;
3968cf62	263	case 1: set->sig[0] = v.sig[0] \| (((long)v.sig[1]) << 32 );
1da177e4	264	}
3968cf62 AV	265	#else
	266	if (copy_from_user(set, compat, sizeof(compat_sigset_t)))
	267	return -EFAULT;
	268	#endif
	269	return 0;
1da177e4	270	}
3968cf62	271	EXPORT_SYMBOL_GPL(get_compat_sigset);