1 files changed, 292 insertions, 0 deletions
diff --git a/kernel/compat.c b/kernel/compat.c
new file mode 100644
index 000000000..f9f7a79e0
--- /dev/null
+++ b/kernel/compat.c
@@ -0,0 +1,292 @@
+// 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);
+
+/*
+ * 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);