Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/kernel/compat.c b/kernel/compat.c
index 8e40efc..a2bc1d6 100644
--- a/kernel/compat.c
+++ b/kernel/compat.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  *  linux/kernel/compat.c
  *
@@ -5,10 +6,6 @@
  *  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>
@@ -20,7 +17,6 @@
 #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>
@@ -30,93 +26,30 @@
 
 #include <linux/uaccess.h>
 
-int compat_get_timex(struct timex *txc, const struct compat_timex __user *utp)
+static int __compat_get_timeval(struct timeval *tv, const struct old_timeval32 __user *ctv)
 {
-	struct compat_timex tx32;
-
-	memset(txc, 0, sizeof(struct timex));
-	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)) ||
+	return (!access_ok(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)
+static int __compat_put_timeval(const struct timeval *tv, struct old_timeval32 __user *ctv)
 {
-	return (!access_ok(VERIFY_WRITE, ctv, sizeof(*ctv)) ||
+	return (!access_ok(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)
+static int __compat_get_timespec(struct timespec *ts, const struct old_timespec32 __user *cts)
 {
-	return (!access_ok(VERIFY_READ, cts, sizeof(*cts)) ||
+	return (!access_ok(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)
+static int __compat_put_timespec(const struct timespec *ts, struct old_timespec32 __user *cts)
 {
-	return (!access_ok(VERIFY_WRITE, cts, sizeof(*cts)) ||
+	return (!access_ok(cts, sizeof(*cts)) ||
 			__put_user(ts->tv_sec, &cts->tv_sec) ||
 			__put_user(ts->tv_nsec, &cts->tv_nsec)) ? -EFAULT : 0;
 }
@@ -335,7 +268,7 @@
 		const struct compat_sigevent __user *u_event)
 {
 	memset(event, 0, sizeof(*event));
-	return (!access_ok(VERIFY_READ, u_event, sizeof(*u_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) ||
@@ -354,10 +287,9 @@
 	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))
+	if (!user_access_begin(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);
@@ -384,10 +316,9 @@
 	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))
+	if (!user_access_begin(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);
@@ -412,8 +343,11 @@
 		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
@@ -438,7 +372,7 @@
 
 	ptr = arch_compat_alloc_user_space(len);
 
-	if (unlikely(!access_ok(VERIFY_WRITE, ptr, len)))
+	if (unlikely(!access_ok(ptr, len)))
 		return NULL;
 
 	return ptr;