Merge tag 's390-4.20-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

Pull s390 updates from Martin Schwidefsky:

 - Improved access control for the zcrypt driver, multiple device nodes
   can now be created with different access control lists

 - Extend the pkey API to provide random protected keys, this is useful
   for encrypted swap device with ephemeral protected keys

 - Add support for virtually mapped kernel stacks

 - Rework the early boot code, this moves the memory detection into the
   boot code that runs prior to decompression.

 - Add KASAN support

 - Bug fixes and cleanups

* tag 's390-4.20-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (83 commits)
  s390/pkey: move pckmo subfunction available checks away from module init
  s390/kasan: support preemptible kernel build
  s390/pkey: Load pkey kernel module automatically
  s390/perf: Return error when debug_register fails
  s390/sthyi: Fix machine name validity indication
  s390/zcrypt: fix broken zcrypt_send_cprb in-kernel api function
  s390/vmalloc: fix VMALLOC_START calculation
  s390/mem_detect: add missing include
  s390/dumpstack: print psw mask and address again
  s390/crypto: Enhance paes cipher to accept variable length key material
  s390/pkey: Introduce new API for transforming key blobs
  s390/pkey: Introduce new API for random protected key verification
  s390/pkey: Add sysfs attributes to emit secure key blobs
  s390/pkey: Add sysfs attributes to emit protected key blobs
  s390/pkey: Define protected key blob format
  s390/pkey: Introduce new API for random protected key generation
  s390/zcrypt: add ap_adapter_mask sysfs attribute
  s390/zcrypt: provide apfs failure code on type 86 error reply
  s390/zcrypt: zcrypt device driver cleanup
  s390/kasan: add support for mem= kernel parameter
  ...

7 files changed, 486 insertions, 95 deletions

diff --git a/arch/s390/mm/Makefile b/arch/s390/mm/Makefile
index 33fe418506bc..f5880bfd1b0c 100644
--- a/arch/s390/mm/Makefile
+++ b/arch/s390/mm/Makefile
@@ -4,10 +4,12 @@
 #
 
 obj-y		:= init.o fault.o extmem.o mmap.o vmem.o maccess.o
-obj-y		+= page-states.o gup.o pageattr.o mem_detect.o
-obj-y		+= pgtable.o pgalloc.o
+obj-y		+= page-states.o gup.o pageattr.o pgtable.o pgalloc.o
 
 obj-$(CONFIG_CMM)		+= cmm.o
 obj-$(CONFIG_HUGETLB_PAGE)	+= hugetlbpage.o
 obj-$(CONFIG_S390_PTDUMP)	+= dump_pagetables.o
 obj-$(CONFIG_PGSTE)		+= gmap.o
+
+KASAN_SANITIZE_kasan_init.o	:= n
+obj-$(CONFIG_KASAN)		+= kasan_init.o
diff --git a/arch/s390/mm/dump_pagetables.c b/arch/s390/mm/dump_pagetables.c
index 7cdea2ec51e9..363f6470d742 100644
--- a/arch/s390/mm/dump_pagetables.c
+++ b/arch/s390/mm/dump_pagetables.c
@@ -3,6 +3,8 @@
 #include <linux/debugfs.h>
 #include <linux/sched.h>
 #include <linux/mm.h>
+#include <linux/kasan.h>
+#include <asm/kasan.h>
 #include <asm/sections.h>
 #include <asm/pgtable.h>
 
@@ -17,18 +19,26 @@ enum address_markers_idx {
 	IDENTITY_NR = 0,
 	KERNEL_START_NR,
 	KERNEL_END_NR,
+#ifdef CONFIG_KASAN
+	KASAN_SHADOW_START_NR,
+	KASAN_SHADOW_END_NR,
+#endif
 	VMEMMAP_NR,
 	VMALLOC_NR,
 	MODULES_NR,
 };
 
 static struct addr_marker address_markers[] = {
-	[IDENTITY_NR]	  = {0, "Identity Mapping"},
-	[KERNEL_START_NR] = {(unsigned long)_stext, "Kernel Image Start"},
-	[KERNEL_END_NR]	  = {(unsigned long)_end, "Kernel Image End"},
-	[VMEMMAP_NR]	  = {0, "vmemmap Area"},
-	[VMALLOC_NR]	  = {0, "vmalloc Area"},
-	[MODULES_NR]	  = {0, "Modules Area"},
+	[IDENTITY_NR]		= {0, "Identity Mapping"},
+	[KERNEL_START_NR]	= {(unsigned long)_stext, "Kernel Image Start"},
+	[KERNEL_END_NR]		= {(unsigned long)_end, "Kernel Image End"},
+#ifdef CONFIG_KASAN
+	[KASAN_SHADOW_START_NR]	= {KASAN_SHADOW_START, "Kasan Shadow Start"},
+	[KASAN_SHADOW_END_NR]	= {KASAN_SHADOW_END, "Kasan Shadow End"},
+#endif
+	[VMEMMAP_NR]		= {0, "vmemmap Area"},
+	[VMALLOC_NR]		= {0, "vmalloc Area"},
+	[MODULES_NR]		= {0, "Modules Area"},
 	{ -1, NULL }
 };
 
@@ -80,7 +90,7 @@ static void note_page(struct seq_file *m, struct pg_state *st,
 	} else if (prot != cur || level != st->level ||
 		   st->current_address >= st->marker[1].start_address) {
 		/* Print the actual finished series */
-		seq_printf(m, "0x%0*lx-0x%0*lx",
+		seq_printf(m, "0x%0*lx-0x%0*lx ",
 			   width, st->start_address,
 			   width, st->current_address);
 		delta = (st->current_address - st->start_address) >> 10;
@@ -90,7 +100,7 @@ static void note_page(struct seq_file *m, struct pg_state *st,
 		}
 		seq_printf(m, "%9lu%c ", delta, *unit);
 		print_prot(m, st->current_prot, st->level);
-		if (st->current_address >= st->marker[1].start_address) {
+		while (st->current_address >= st->marker[1].start_address) {
 			st->marker++;
 			seq_printf(m, "---[ %s ]---\n", st->marker->name);
 		}
@@ -100,6 +110,17 @@ static void note_page(struct seq_file *m, struct pg_state *st,
 	}
 }
 
+#ifdef CONFIG_KASAN
+static void note_kasan_zero_page(struct seq_file *m, struct pg_state *st)
+{
+	unsigned int prot;
+
+	prot = pte_val(*kasan_zero_pte) &
+		(_PAGE_PROTECT | _PAGE_INVALID | _PAGE_NOEXEC);
+	note_page(m, st, prot, 4);
+}
+#endif
+
 /*
  * The actual page table walker functions. In order to keep the
  * implementation of print_prot() short, we only check and pass
@@ -132,6 +153,13 @@ static void walk_pmd_level(struct seq_file *m, struct pg_state *st,
 	pmd_t *pmd;
 	int i;
 
+#ifdef CONFIG_KASAN
+	if ((pud_val(*pud) & PAGE_MASK) == __pa(kasan_zero_pmd)) {
+		note_kasan_zero_page(m, st);
+		return;
+	}
+#endif
+
 	for (i = 0; i < PTRS_PER_PMD && addr < max_addr; i++) {
 		st->current_address = addr;
 		pmd = pmd_offset(pud, addr);
@@ -156,6 +184,13 @@ static void walk_pud_level(struct seq_file *m, struct pg_state *st,
 	pud_t *pud;
 	int i;
 
+#ifdef CONFIG_KASAN
+	if ((p4d_val(*p4d) & PAGE_MASK) == __pa(kasan_zero_pud)) {
+		note_kasan_zero_page(m, st);
+		return;
+	}
+#endif
+
 	for (i = 0; i < PTRS_PER_PUD && addr < max_addr; i++) {
 		st->current_address = addr;
 		pud = pud_offset(p4d, addr);
@@ -179,6 +214,13 @@ static void walk_p4d_level(struct seq_file *m, struct pg_state *st,
 	p4d_t *p4d;
 	int i;
 
+#ifdef CONFIG_KASAN
+	if ((pgd_val(*pgd) & PAGE_MASK) == __pa(kasan_zero_p4d)) {
+		note_kasan_zero_page(m, st);
+		return;
+	}
+#endif
+
 	for (i = 0; i < PTRS_PER_P4D && addr < max_addr; i++) {
 		st->current_address = addr;
 		p4d = p4d_offset(pgd, addr);
diff --git a/arch/s390/mm/fault.c b/arch/s390/mm/fault.c
index 72af23bacbb5..2b8f32f56e0c 100644
--- a/arch/s390/mm/fault.c
+++ b/arch/s390/mm/fault.c
@@ -636,17 +636,19 @@ struct pfault_refbk {
 	u64 reserved;
 } __attribute__ ((packed, aligned(8)));
 
+static struct pfault_refbk pfault_init_refbk = {
+	.refdiagc = 0x258,
+	.reffcode = 0,
+	.refdwlen = 5,
+	.refversn = 2,
+	.refgaddr = __LC_LPP,
+	.refselmk = 1ULL << 48,
+	.refcmpmk = 1ULL << 48,
+	.reserved = __PF_RES_FIELD
+};
+
 int pfault_init(void)
 {
-	struct pfault_refbk refbk = {
-		.refdiagc = 0x258,
-		.reffcode = 0,
-		.refdwlen = 5,
-		.refversn = 2,
-		.refgaddr = __LC_LPP,
-		.refselmk = 1ULL << 48,
-		.refcmpmk = 1ULL << 48,
-		.reserved = __PF_RES_FIELD };
         int rc;
 
 	if (pfault_disable)
@@ -658,18 +660,20 @@ int pfault_init(void)
 		"1:	la	%0,8\n"
 		"2:\n"
 		EX_TABLE(0b,1b)
-		: "=d" (rc) : "a" (&refbk), "m" (refbk) : "cc");
+		: "=d" (rc)
+		: "a" (&pfault_init_refbk), "m" (pfault_init_refbk) : "cc");
         return rc;
 }
 
+static struct pfault_refbk pfault_fini_refbk = {
+	.refdiagc = 0x258,
+	.reffcode = 1,
+	.refdwlen = 5,
+	.refversn = 2,
+};
+
 void pfault_fini(void)
 {
-	struct pfault_refbk refbk = {
-		.refdiagc = 0x258,
-		.reffcode = 1,
-		.refdwlen = 5,
-		.refversn = 2,
-	};
 
 	if (pfault_disable)
 		return;
@@ -678,7 +682,7 @@ void pfault_fini(void)
 		"	diag	%0,0,0x258\n"
 		"0:	nopr	%%r7\n"
 		EX_TABLE(0b,0b)
-		: : "a" (&refbk), "m" (refbk) : "cc");
+		: : "a" (&pfault_fini_refbk), "m" (pfault_fini_refbk) : "cc");
 }
 
 static DEFINE_SPINLOCK(pfault_lock);
diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c
index 3fa3e5323612..92d7a153e72a 100644
--- a/arch/s390/mm/init.c
+++ b/arch/s390/mm/init.c
@@ -42,6 +42,7 @@
 #include <asm/ctl_reg.h>
 #include <asm/sclp.h>
 #include <asm/set_memory.h>
+#include <asm/kasan.h>
 
 pgd_t swapper_pg_dir[PTRS_PER_PGD] __section(.bss..swapper_pg_dir);
 
@@ -98,8 +99,9 @@ void __init paging_init(void)
 	S390_lowcore.user_asce = S390_lowcore.kernel_asce;
 	crst_table_init((unsigned long *) init_mm.pgd, pgd_type);
 	vmem_map_init();
+	kasan_copy_shadow(init_mm.pgd);
 
-        /* enable virtual mapping in kernel mode */
+	/* enable virtual mapping in kernel mode */
 	__ctl_load(S390_lowcore.kernel_asce, 1, 1);
 	__ctl_load(S390_lowcore.kernel_asce, 7, 7);
 	__ctl_load(S390_lowcore.kernel_asce, 13, 13);
@@ -107,6 +109,7 @@ void __init paging_init(void)
 	psw_bits(psw).dat = 1;
 	psw_bits(psw).as = PSW_BITS_AS_HOME;
 	__load_psw_mask(psw.mask);
+	kasan_free_early_identity();
 
 	sparse_memory_present_with_active_regions(MAX_NUMNODES);
 	sparse_init();
diff --git a/arch/s390/mm/kasan_init.c b/arch/s390/mm/kasan_init.c
new file mode 100644
index 000000000000..acb9645b762b
--- /dev/null
+++ b/arch/s390/mm/kasan_init.c
@@ -0,0 +1,387 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/kasan.h>
+#include <linux/sched/task.h>
+#include <linux/memblock.h>
+#include <asm/pgalloc.h>
+#include <asm/pgtable.h>
+#include <asm/kasan.h>
+#include <asm/mem_detect.h>
+#include <asm/processor.h>
+#include <asm/sclp.h>
+#include <asm/facility.h>
+#include <asm/sections.h>
+#include <asm/setup.h>
+
+static unsigned long segment_pos __initdata;
+static unsigned long segment_low __initdata;
+static unsigned long pgalloc_pos __initdata;
+static unsigned long pgalloc_low __initdata;
+static unsigned long pgalloc_freeable __initdata;
+static bool has_edat __initdata;
+static bool has_nx __initdata;
+
+#define __sha(x) ((unsigned long)kasan_mem_to_shadow((void *)x))
+
+static pgd_t early_pg_dir[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE);
+
+static void __init kasan_early_panic(const char *reason)
+{
+	sclp_early_printk("The Linux kernel failed to boot with the KernelAddressSanitizer:\n");
+	sclp_early_printk(reason);
+	disabled_wait(0);
+}
+
+static void * __init kasan_early_alloc_segment(void)
+{
+	segment_pos -= _SEGMENT_SIZE;
+
+	if (segment_pos < segment_low)
+		kasan_early_panic("out of memory during initialisation\n");
+
+	return (void *)segment_pos;
+}
+
+static void * __init kasan_early_alloc_pages(unsigned int order)
+{
+	pgalloc_pos -= (PAGE_SIZE << order);
+
+	if (pgalloc_pos < pgalloc_low)
+		kasan_early_panic("out of memory during initialisation\n");
+
+	return (void *)pgalloc_pos;
+}
+
+static void * __init kasan_early_crst_alloc(unsigned long val)
+{
+	unsigned long *table;
+
+	table = kasan_early_alloc_pages(CRST_ALLOC_ORDER);
+	if (table)
+		crst_table_init(table, val);
+	return table;
+}
+
+static pte_t * __init kasan_early_pte_alloc(void)
+{
+	static void *pte_leftover;
+	pte_t *pte;
+
+	BUILD_BUG_ON(_PAGE_TABLE_SIZE * 2 != PAGE_SIZE);
+
+	if (!pte_leftover) {
+		pte_leftover = kasan_early_alloc_pages(0);
+		pte = pte_leftover + _PAGE_TABLE_SIZE;
+	} else {
+		pte = pte_leftover;
+		pte_leftover = NULL;
+	}
+	memset64((u64 *)pte, _PAGE_INVALID, PTRS_PER_PTE);
+	return pte;
+}
+
+enum populate_mode {
+	POPULATE_ONE2ONE,
+	POPULATE_MAP,
+	POPULATE_ZERO_SHADOW
+};
+static void __init kasan_early_vmemmap_populate(unsigned long address,
+						unsigned long end,
+						enum populate_mode mode)
+{
+	unsigned long pgt_prot_zero, pgt_prot, sgt_prot;
+	pgd_t *pg_dir;
+	p4d_t *p4_dir;
+	pud_t *pu_dir;
+	pmd_t *pm_dir;
+	pte_t *pt_dir;
+
+	pgt_prot_zero = pgprot_val(PAGE_KERNEL_RO);
+	if (!has_nx)
+		pgt_prot_zero &= ~_PAGE_NOEXEC;
+	pgt_prot = pgprot_val(PAGE_KERNEL_EXEC);
+	sgt_prot = pgprot_val(SEGMENT_KERNEL_EXEC);
+
+	while (address < end) {
+		pg_dir = pgd_offset_k(address);
+		if (pgd_none(*pg_dir)) {
+			if (mode == POPULATE_ZERO_SHADOW &&
+			    IS_ALIGNED(address, PGDIR_SIZE) &&
+			    end - address >= PGDIR_SIZE) {
+				pgd_populate(&init_mm, pg_dir, kasan_zero_p4d);
+				address = (address + PGDIR_SIZE) & PGDIR_MASK;
+				continue;
+			}
+			p4_dir = kasan_early_crst_alloc(_REGION2_ENTRY_EMPTY);
+			pgd_populate(&init_mm, pg_dir, p4_dir);
+		}
+
+		p4_dir = p4d_offset(pg_dir, address);
+		if (p4d_none(*p4_dir)) {
+			if (mode == POPULATE_ZERO_SHADOW &&
+			    IS_ALIGNED(address, P4D_SIZE) &&
+			    end - address >= P4D_SIZE) {
+				p4d_populate(&init_mm, p4_dir, kasan_zero_pud);
+				address = (address + P4D_SIZE) & P4D_MASK;
+				continue;
+			}
+			pu_dir = kasan_early_crst_alloc(_REGION3_ENTRY_EMPTY);
+			p4d_populate(&init_mm, p4_dir, pu_dir);
+		}
+
+		pu_dir = pud_offset(p4_dir, address);
+		if (pud_none(*pu_dir)) {
+			if (mode == POPULATE_ZERO_SHADOW &&
+			    IS_ALIGNED(address, PUD_SIZE) &&
+			    end - address >= PUD_SIZE) {
+				pud_populate(&init_mm, pu_dir, kasan_zero_pmd);
+				address = (address + PUD_SIZE) & PUD_MASK;
+				continue;
+			}
+			pm_dir = kasan_early_crst_alloc(_SEGMENT_ENTRY_EMPTY);
+			pud_populate(&init_mm, pu_dir, pm_dir);
+		}
+
+		pm_dir = pmd_offset(pu_dir, address);
+		if (pmd_none(*pm_dir)) {
+			if (mode == POPULATE_ZERO_SHADOW &&
+			    IS_ALIGNED(address, PMD_SIZE) &&
+			    end - address >= PMD_SIZE) {
+				pmd_populate(&init_mm, pm_dir, kasan_zero_pte);
+				address = (address + PMD_SIZE) & PMD_MASK;
+				continue;
+			}
+			/* the first megabyte of 1:1 is mapped with 4k pages */
+			if (has_edat && address && end - address >= PMD_SIZE &&
+			    mode != POPULATE_ZERO_SHADOW) {
+				void *page;
+
+				if (mode == POPULATE_ONE2ONE) {
+					page = (void *)address;
+				} else {
+					page = kasan_early_alloc_segment();
+					memset(page, 0, _SEGMENT_SIZE);
+				}
+				pmd_val(*pm_dir) = __pa(page) | sgt_prot;
+				address = (address + PMD_SIZE) & PMD_MASK;
+				continue;
+			}
+
+			pt_dir = kasan_early_pte_alloc();
+			pmd_populate(&init_mm, pm_dir, pt_dir);
+		} else if (pmd_large(*pm_dir)) {
+			address = (address + PMD_SIZE) & PMD_MASK;
+			continue;
+		}
+
+		pt_dir = pte_offset_kernel(pm_dir, address);
+		if (pte_none(*pt_dir)) {
+			void *page;
+
+			switch (mode) {
+			case POPULATE_ONE2ONE:
+				page = (void *)address;
+				pte_val(*pt_dir) = __pa(page) | pgt_prot;
+				break;
+			case POPULATE_MAP:
+				page = kasan_early_alloc_pages(0);
+				memset(page, 0, PAGE_SIZE);
+				pte_val(*pt_dir) = __pa(page) | pgt_prot;
+				break;
+			case POPULATE_ZERO_SHADOW:
+				page = kasan_zero_page;
+				pte_val(*pt_dir) = __pa(page) | pgt_prot_zero;
+				break;
+			}
+		}
+		address += PAGE_SIZE;
+	}
+}
+
+static void __init kasan_set_pgd(pgd_t *pgd, unsigned long asce_type)
+{
+	unsigned long asce_bits;
+
+	asce_bits = asce_type | _ASCE_TABLE_LENGTH;
+	S390_lowcore.kernel_asce = (__pa(pgd) & PAGE_MASK) | asce_bits;
+	S390_lowcore.user_asce = S390_lowcore.kernel_asce;
+
+	__ctl_load(S390_lowcore.kernel_asce, 1, 1);
+	__ctl_load(S390_lowcore.kernel_asce, 7, 7);
+	__ctl_load(S390_lowcore.kernel_asce, 13, 13);
+}
+
+static void __init kasan_enable_dat(void)
+{
+	psw_t psw;
+
+	psw.mask = __extract_psw();
+	psw_bits(psw).dat = 1;
+	psw_bits(psw).as = PSW_BITS_AS_HOME;
+	__load_psw_mask(psw.mask);
+}
+
+static void __init kasan_early_detect_facilities(void)
+{
+	__stfle(S390_lowcore.stfle_fac_list,
+		ARRAY_SIZE(S390_lowcore.stfle_fac_list));
+	if (test_facility(8)) {
+		has_edat = true;
+		__ctl_set_bit(0, 23);
+	}
+	if (!noexec_disabled && test_facility(130)) {
+		has_nx = true;
+		__ctl_set_bit(0, 20);
+	}
+}
+
+static unsigned long __init get_mem_detect_end(void)
+{
+	unsigned long start;
+	unsigned long end;
+
+	if (mem_detect.count) {
+		__get_mem_detect_block(mem_detect.count - 1, &start, &end);
+		return end;
+	}
+	return 0;
+}
+
+void __init kasan_early_init(void)
+{
+	unsigned long untracked_mem_end;
+	unsigned long shadow_alloc_size;
+	unsigned long initrd_end;
+	unsigned long asce_type;
+	unsigned long memsize;
+	unsigned long vmax;
+	unsigned long pgt_prot = pgprot_val(PAGE_KERNEL_RO);
+	pte_t pte_z;
+	pmd_t pmd_z = __pmd(__pa(kasan_zero_pte) | _SEGMENT_ENTRY);
+	pud_t pud_z = __pud(__pa(kasan_zero_pmd) | _REGION3_ENTRY);
+	p4d_t p4d_z = __p4d(__pa(kasan_zero_pud) | _REGION2_ENTRY);
+
+	kasan_early_detect_facilities();
+	if (!has_nx)
+		pgt_prot &= ~_PAGE_NOEXEC;
+	pte_z = __pte(__pa(kasan_zero_page) | pgt_prot);
+
+	memsize = get_mem_detect_end();
+	if (!memsize)
+		kasan_early_panic("cannot detect physical memory size\n");
+	/* respect mem= cmdline parameter */
+	if (memory_end_set && memsize > memory_end)
+		memsize = memory_end;
+	memsize = min(memsize, KASAN_SHADOW_START);
+
+	if (IS_ENABLED(CONFIG_KASAN_S390_4_LEVEL_PAGING)) {
+		/* 4 level paging */
+		BUILD_BUG_ON(!IS_ALIGNED(KASAN_SHADOW_START, P4D_SIZE));
+		BUILD_BUG_ON(!IS_ALIGNED(KASAN_SHADOW_END, P4D_SIZE));
+		crst_table_init((unsigned long *)early_pg_dir,
+				_REGION2_ENTRY_EMPTY);
+		untracked_mem_end = vmax = _REGION1_SIZE;
+		asce_type = _ASCE_TYPE_REGION2;
+	} else {
+		/* 3 level paging */
+		BUILD_BUG_ON(!IS_ALIGNED(KASAN_SHADOW_START, PUD_SIZE));
+		BUILD_BUG_ON(!IS_ALIGNED(KASAN_SHADOW_END, PUD_SIZE));
+		crst_table_init((unsigned long *)early_pg_dir,
+				_REGION3_ENTRY_EMPTY);
+		untracked_mem_end = vmax = _REGION2_SIZE;
+		asce_type = _ASCE_TYPE_REGION3;
+	}
+
+	/* init kasan zero shadow */
+	crst_table_init((unsigned long *)kasan_zero_p4d, p4d_val(p4d_z));
+	crst_table_init((unsigned long *)kasan_zero_pud, pud_val(pud_z));
+	crst_table_init((unsigned long *)kasan_zero_pmd, pmd_val(pmd_z));
+	memset64((u64 *)kasan_zero_pte, pte_val(pte_z), PTRS_PER_PTE);
+
+	shadow_alloc_size = memsize >> KASAN_SHADOW_SCALE_SHIFT;
+	pgalloc_low = round_up((unsigned long)_end, _SEGMENT_SIZE);
+	if (IS_ENABLED(CONFIG_BLK_DEV_INITRD)) {
+		initrd_end =
+		    round_up(INITRD_START + INITRD_SIZE, _SEGMENT_SIZE);
+		pgalloc_low = max(pgalloc_low, initrd_end);
+	}
+
+	if (pgalloc_low + shadow_alloc_size > memsize)
+		kasan_early_panic("out of memory during initialisation\n");
+
+	if (has_edat) {
+		segment_pos = round_down(memsize, _SEGMENT_SIZE);
+		segment_low = segment_pos - shadow_alloc_size;
+		pgalloc_pos = segment_low;
+	} else {
+		pgalloc_pos = memsize;
+	}
+	init_mm.pgd = early_pg_dir;
+	/*
+	 * Current memory layout:
+	 * +- 0 -------------+	 +- shadow start -+
+	 * | 1:1 ram mapping |	/| 1/8 ram	  |
+	 * +- end of ram ----+ / +----------------+
+	 * | ... gap ...     |/  |	kasan	  |
+	 * +- shadow start --+	 |	zero	  |
+	 * | 1/8 addr space  |	 |	page	  |
+	 * +- shadow end    -+	 |	mapping	  |
+	 * | ... gap ...     |\  |    (untracked) |
+	 * +- modules vaddr -+ \ +----------------+
+	 * | 2Gb	     |	\|	unmapped  | allocated per module
+	 * +-----------------+	 +- shadow end ---+
+	 */
+	/* populate kasan shadow (for identity mapping and zero page mapping) */
+	kasan_early_vmemmap_populate(__sha(0), __sha(memsize), POPULATE_MAP);
+	if (IS_ENABLED(CONFIG_MODULES))
+		untracked_mem_end = vmax - MODULES_LEN;
+	kasan_early_vmemmap_populate(__sha(max_physmem_end),
+				     __sha(untracked_mem_end),
+				     POPULATE_ZERO_SHADOW);
+	/* memory allocated for identity mapping structs will be freed later */
+	pgalloc_freeable = pgalloc_pos;
+	/* populate identity mapping */
+	kasan_early_vmemmap_populate(0, memsize, POPULATE_ONE2ONE);
+	kasan_set_pgd(early_pg_dir, asce_type);
+	kasan_enable_dat();
+	/* enable kasan */
+	init_task.kasan_depth = 0;
+	memblock_reserve(pgalloc_pos, memsize - pgalloc_pos);
+	sclp_early_printk("KernelAddressSanitizer initialized\n");
+}
+
+void __init kasan_copy_shadow(pgd_t *pg_dir)
+{
+	/*
+	 * At this point we are still running on early pages setup early_pg_dir,
+	 * while swapper_pg_dir has just been initialized with identity mapping.
+	 * Carry over shadow memory region from early_pg_dir to swapper_pg_dir.
+	 */
+
+	pgd_t *pg_dir_src;
+	pgd_t *pg_dir_dst;
+	p4d_t *p4_dir_src;
+	p4d_t *p4_dir_dst;
+	pud_t *pu_dir_src;
+	pud_t *pu_dir_dst;
+
+	pg_dir_src = pgd_offset_raw(early_pg_dir, KASAN_SHADOW_START);
+	pg_dir_dst = pgd_offset_raw(pg_dir, KASAN_SHADOW_START);
+	p4_dir_src = p4d_offset(pg_dir_src, KASAN_SHADOW_START);
+	p4_dir_dst = p4d_offset(pg_dir_dst, KASAN_SHADOW_START);
+	if (!p4d_folded(*p4_dir_src)) {
+		/* 4 level paging */
+		memcpy(p4_dir_dst, p4_dir_src,
+		       (KASAN_SHADOW_SIZE >> P4D_SHIFT) * sizeof(p4d_t));
+		return;
+	}
+	/* 3 level paging */
+	pu_dir_src = pud_offset(p4_dir_src, KASAN_SHADOW_START);
+	pu_dir_dst = pud_offset(p4_dir_dst, KASAN_SHADOW_START);
+	memcpy(pu_dir_dst, pu_dir_src,
+	       (KASAN_SHADOW_SIZE >> PUD_SHIFT) * sizeof(pud_t));
+}
+
+void __init kasan_free_early_identity(void)
+{
+	memblock_free(pgalloc_pos, pgalloc_freeable - pgalloc_pos);
+}
diff --git a/arch/s390/mm/maccess.c b/arch/s390/mm/maccess.c
index 7be06475809b..97b3ee53852b 100644
--- a/arch/s390/mm/maccess.c
+++ b/arch/s390/mm/maccess.c
@@ -89,10 +89,8 @@ static int __memcpy_real(void *dest, void *src, size_t count)
 	return rc;
 }
 
-/*
- * Copy memory in real mode (kernel to kernel)
- */
-int memcpy_real(void *dest, void *src, size_t count)
+static unsigned long _memcpy_real(unsigned long dest, unsigned long src,
+				  unsigned long count)
 {
 	int irqs_disabled, rc;
 	unsigned long flags;
@@ -103,7 +101,7 @@ int memcpy_real(void *dest, void *src, size_t count)
 	irqs_disabled = arch_irqs_disabled_flags(flags);
 	if (!irqs_disabled)
 		trace_hardirqs_off();
-	rc = __memcpy_real(dest, src, count);
+	rc = __memcpy_real((void *) dest, (void *) src, (size_t) count);
 	if (!irqs_disabled)
 		trace_hardirqs_on();
 	__arch_local_irq_ssm(flags);
@@ -111,6 +109,23 @@ int memcpy_real(void *dest, void *src, size_t count)
 }
 
 /*
+ * Copy memory in real mode (kernel to kernel)
+ */
+int memcpy_real(void *dest, void *src, size_t count)
+{
+	if (S390_lowcore.nodat_stack != 0)
+		return CALL_ON_STACK(_memcpy_real, S390_lowcore.nodat_stack,
+				     3, dest, src, count);
+	/*
+	 * This is a really early memcpy_real call, the stacks are
+	 * not set up yet. Just call _memcpy_real on the early boot
+	 * stack
+	 */
+	return _memcpy_real((unsigned long) dest,(unsigned long) src,
+			    (unsigned long) count);
+}
+
+/*
  * Copy memory in absolute mode (kernel to kernel)
  */
 void memcpy_absolute(void *dest, void *src, size_t count)
diff --git a/arch/s390/mm/mem_detect.c b/arch/s390/mm/mem_detect.c
deleted file mode 100644
index 21f6c82c8296..000000000000
--- a/arch/s390/mm/mem_detect.c
+++ /dev/null
@@ -1,62 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * Copyright IBM Corp. 2008, 2009
- *
- * Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>
- */
-
-#include <linux/kernel.h>
-#include <linux/memblock.h>
-#include <linux/init.h>
-#include <linux/debugfs.h>
-#include <linux/seq_file.h>
-#include <asm/ipl.h>
-#include <asm/sclp.h>
-#include <asm/setup.h>
-
-#define CHUNK_READ_WRITE 0
-#define CHUNK_READ_ONLY  1
-
-static inline void memblock_physmem_add(phys_addr_t start, phys_addr_t size)
-{
-	memblock_dbg("memblock_physmem_add: [%#016llx-%#016llx]\n",
-		     start, start + size - 1);
-	memblock_add_range(&memblock.memory, start, size, 0, 0);
-	memblock_add_range(&memblock.physmem, start, size, 0, 0);
-}
-
-void __init detect_memory_memblock(void)
-{
-	unsigned long memsize, rnmax, rzm, addr, size;
-	int type;
-
-	rzm = sclp.rzm;
-	rnmax = sclp.rnmax;
-	memsize = rzm * rnmax;
-	if (!rzm)
-		rzm = 1UL << 17;
-	max_physmem_end = memsize;
-	addr = 0;
-	/* keep memblock lists close to the kernel */
-	memblock_set_bottom_up(true);
-	do {
-		size = 0;
-		/* assume lowcore is writable */
-		type = addr ? tprot(addr) : CHUNK_READ_WRITE;
-		do {
-			size += rzm;
-			if (max_physmem_end && addr + size >= max_physmem_end)
-				break;
-		} while (type == tprot(addr + size));
-		if (type == CHUNK_READ_WRITE || type == CHUNK_READ_ONLY) {
-			if (max_physmem_end && (addr + size > max_physmem_end))
-				size = max_physmem_end - addr;
-			memblock_physmem_add(addr, size);
-		}
-		addr += size;
-	} while (addr < max_physmem_end);
-	memblock_set_bottom_up(false);
-	if (!max_physmem_end)
-		max_physmem_end = memblock_end_of_DRAM();
-	memblock_dump_all();
-}