Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/powerpc/mm/init-common.c b/arch/powerpc/mm/init-common.c
index 2b656e6..a84da92 100644
--- a/arch/powerpc/mm/init-common.c
+++ b/arch/powerpc/mm/init-common.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  *  PowerPC version
  *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
@@ -11,12 +12,6 @@
  *
  *  Dave Engebretsen <engebret@us.ibm.com>
  *      Rework for PPC64 port.
- *
- *  This program is free software; you can redistribute it and/or
- *  modify it under the terms of the GNU General Public License
- *  as published by the Free Software Foundation; either version
- *  2 of the License, or (at your option) any later version.
- *
  */
 
 #undef DEBUG
@@ -24,23 +19,67 @@
 #include <linux/string.h>
 #include <asm/pgalloc.h>
 #include <asm/pgtable.h>
+#include <asm/kup.h>
 
-static void pgd_ctor(void *addr)
+static bool disable_kuep = !IS_ENABLED(CONFIG_PPC_KUEP);
+static bool disable_kuap = !IS_ENABLED(CONFIG_PPC_KUAP);
+
+static int __init parse_nosmep(char *p)
 {
-	memset(addr, 0, PGD_TABLE_SIZE);
+	disable_kuep = true;
+	pr_warn("Disabling Kernel Userspace Execution Prevention\n");
+	return 0;
+}
+early_param("nosmep", parse_nosmep);
+
+static int __init parse_nosmap(char *p)
+{
+	disable_kuap = true;
+	pr_warn("Disabling Kernel Userspace Access Protection\n");
+	return 0;
+}
+early_param("nosmap", parse_nosmap);
+
+void __ref setup_kup(void)
+{
+	setup_kuep(disable_kuep);
+	setup_kuap(disable_kuap);
 }
 
-static void pud_ctor(void *addr)
-{
-	memset(addr, 0, PUD_TABLE_SIZE);
+#define CTOR(shift) static void ctor_##shift(void *addr) \
+{							\
+	memset(addr, 0, sizeof(void *) << (shift));	\
 }
 
-static void pmd_ctor(void *addr)
+CTOR(0); CTOR(1); CTOR(2); CTOR(3); CTOR(4); CTOR(5); CTOR(6); CTOR(7);
+CTOR(8); CTOR(9); CTOR(10); CTOR(11); CTOR(12); CTOR(13); CTOR(14); CTOR(15);
+
+static inline void (*ctor(int shift))(void *)
 {
-	memset(addr, 0, PMD_TABLE_SIZE);
+	BUILD_BUG_ON(MAX_PGTABLE_INDEX_SIZE != 15);
+
+	switch (shift) {
+	case 0: return ctor_0;
+	case 1: return ctor_1;
+	case 2: return ctor_2;
+	case 3: return ctor_3;
+	case 4: return ctor_4;
+	case 5: return ctor_5;
+	case 6: return ctor_6;
+	case 7: return ctor_7;
+	case 8: return ctor_8;
+	case 9: return ctor_9;
+	case 10: return ctor_10;
+	case 11: return ctor_11;
+	case 12: return ctor_12;
+	case 13: return ctor_13;
+	case 14: return ctor_14;
+	case 15: return ctor_15;
+	}
+	return NULL;
 }
 
-struct kmem_cache *pgtable_cache[MAX_PGTABLE_INDEX_SIZE];
+struct kmem_cache *pgtable_cache[MAX_PGTABLE_INDEX_SIZE + 1];
 EXPORT_SYMBOL_GPL(pgtable_cache);	/* used by kvm_hv module */
 
 /*
@@ -50,7 +89,7 @@
  * everything else.  Caches created by this function are used for all
  * the higher level pagetables, and for hugepage pagetables.
  */
-void pgtable_cache_add(unsigned shift, void (*ctor)(void *))
+void pgtable_cache_add(unsigned int shift)
 {
 	char *name;
 	unsigned long table_size = sizeof(void *) << shift;
@@ -71,19 +110,19 @@
 	 * moment, gcc doesn't seem to recognize is_power_of_2 as a
 	 * constant expression, so so much for that. */
 	BUG_ON(!is_power_of_2(minalign));
-	BUG_ON((shift < 1) || (shift > MAX_PGTABLE_INDEX_SIZE));
+	BUG_ON(shift > MAX_PGTABLE_INDEX_SIZE);
 
 	if (PGT_CACHE(shift))
 		return; /* Already have a cache of this size */
 
 	align = max_t(unsigned long, align, minalign);
 	name = kasprintf(GFP_KERNEL, "pgtable-2^%d", shift);
-	new = kmem_cache_create(name, table_size, align, 0, ctor);
+	new = kmem_cache_create(name, table_size, align, 0, ctor(shift));
 	if (!new)
 		panic("Could not allocate pgtable cache for order %d", shift);
 
 	kfree(name);
-	pgtable_cache[shift - 1] = new;
+	pgtable_cache[shift] = new;
 
 	pr_debug("Allocated pgtable cache for order %d\n", shift);
 }
@@ -91,15 +130,15 @@
 
 void pgtable_cache_init(void)
 {
-	pgtable_cache_add(PGD_INDEX_SIZE, pgd_ctor);
+	pgtable_cache_add(PGD_INDEX_SIZE);
 
-	if (PMD_CACHE_INDEX && !PGT_CACHE(PMD_CACHE_INDEX))
-		pgtable_cache_add(PMD_CACHE_INDEX, pmd_ctor);
+	if (PMD_CACHE_INDEX)
+		pgtable_cache_add(PMD_CACHE_INDEX);
 	/*
 	 * In all current configs, when the PUD index exists it's the
 	 * same size as either the pgd or pmd index except with THP enabled
 	 * on book3s 64
 	 */
-	if (PUD_CACHE_INDEX && !PGT_CACHE(PUD_CACHE_INDEX))
-		pgtable_cache_add(PUD_CACHE_INDEX, pud_ctor);
+	if (PUD_CACHE_INDEX)
+		pgtable_cache_add(PUD_CACHE_INDEX);
 }