// 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 (!alloc_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;} intget_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 );		/* fall through */	case 3: set->sig[2] = v.sig[4] | (((long)v.sig[5]) << 32 );		/* fall through */	case 2: set->sig[1] = v.sig[2] | (((long)v.sig[3]) << 32 );		/* fall through */	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); /* * 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(ptr, len)))		return NULL; 	return ptr;}EXPORT_SYMBOL_GPL(compat_alloc_user_space);