1 files changed, 80 insertions, 87 deletions

diff --git a/arch/x86/power/hibernate_64.c b/arch/x86/power/hibernate_64.c
index a0fde91c16cf..a595953f1d6d 100644
--- a/arch/x86/power/hibernate_64.c
+++ b/arch/x86/power/hibernate_64.c
@@ -1,8 +1,7 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * Hibernation support for x86-64
  *
- * Distribute under GPLv2
- *
  * Copyright (c) 2007 Rafael J. Wysocki <rjw@sisk.pl>
  * Copyright (c) 2002 Pavel Machek <pavel@ucw.cz>
  * Copyright (c) 2001 Patrick Mochel <mochel@osdl.org>
@@ -11,35 +10,79 @@
 #include <linux/gfp.h>
 #include <linux/smp.h>
 #include <linux/suspend.h>
+#include <linux/scatterlist.h>
+#include <linux/kdebug.h>
+#include <linux/pgtable.h>
+
+#include <crypto/hash.h>
 
+#include <asm/e820/api.h>
 #include <asm/init.h>
 #include <asm/proto.h>
 #include <asm/page.h>
-#include <asm/pgtable.h>
 #include <asm/mtrr.h>
+#include <asm/sections.h>
 #include <asm/suspend.h>
+#include <asm/tlbflush.h>
 
-/* References to section boundaries */
-extern const void __nosave_begin, __nosave_end;
-
-/* Defined in hibernate_asm_64.S */
-extern int restore_image(void);
+static int set_up_temporary_text_mapping(pgd_t *pgd)
+{
+	pmd_t *pmd;
+	pud_t *pud;
+	p4d_t *p4d = NULL;
+	pgprot_t pgtable_prot = __pgprot(_KERNPG_TABLE);
+	pgprot_t pmd_text_prot = __pgprot(__PAGE_KERNEL_LARGE_EXEC);
+
+	/* Filter out unsupported __PAGE_KERNEL* bits: */
+	pgprot_val(pmd_text_prot) &= __default_kernel_pte_mask;
+	pgprot_val(pgtable_prot)  &= __default_kernel_pte_mask;
+
+	/*
+	 * The new mapping only has to cover the page containing the image
+	 * kernel's entry point (jump_address_phys), because the switch over to
+	 * it is carried out by relocated code running from a page allocated
+	 * specifically for this purpose and covered by the identity mapping, so
+	 * the temporary kernel text mapping is only needed for the final jump.
+	 * Moreover, in that mapping the virtual address of the image kernel's
+	 * entry point must be the same as its virtual address in the image
+	 * kernel (restore_jump_address), so the image kernel's
+	 * restore_registers() code doesn't find itself in a different area of
+	 * the virtual address space after switching over to the original page
+	 * tables used by the image kernel.
+	 */
+
+	if (pgtable_l5_enabled()) {
+		p4d = (p4d_t *)get_safe_page(GFP_ATOMIC);
+		if (!p4d)
+			return -ENOMEM;
+	}
 
-/*
- * Address to jump to in the last phase of restore in order to get to the image
- * kernel's text (this value is passed in the image header).
- */
-unsigned long restore_jump_address;
+	pud = (pud_t *)get_safe_page(GFP_ATOMIC);
+	if (!pud)
+		return -ENOMEM;
 
-/*
- * Value of the cr3 register from before the hibernation (this value is passed
- * in the image header).
- */
-unsigned long restore_cr3;
+	pmd = (pmd_t *)get_safe_page(GFP_ATOMIC);
+	if (!pmd)
+		return -ENOMEM;
 
-pgd_t *temp_level4_pgt;
+	set_pmd(pmd + pmd_index(restore_jump_address),
+		__pmd((jump_address_phys & PMD_MASK) | pgprot_val(pmd_text_prot)));
+	set_pud(pud + pud_index(restore_jump_address),
+		__pud(__pa(pmd) | pgprot_val(pgtable_prot)));
+	if (p4d) {
+		p4d_t new_p4d = __p4d(__pa(pud) | pgprot_val(pgtable_prot));
+		pgd_t new_pgd = __pgd(__pa(p4d) | pgprot_val(pgtable_prot));
+
+		set_p4d(p4d + p4d_index(restore_jump_address), new_p4d);
+		set_pgd(pgd + pgd_index(restore_jump_address), new_pgd);
+	} else {
+		/* No p4d for 4-level paging: point the pgd to the pud page table */
+		pgd_t new_pgd = __pgd(__pa(pud) | pgprot_val(pgtable_prot));
+		set_pgd(pgd + pgd_index(restore_jump_address), new_pgd);
+	}
 
-void *relocated_restore_code;
+	return 0;
+}
 
 static void *alloc_pgt_page(void *context)
 {
@@ -50,100 +93,50 @@ static int set_up_temporary_mappings(void)
 {
 	struct x86_mapping_info info = {
 		.alloc_pgt_page	= alloc_pgt_page,
-		.pmd_flag	= __PAGE_KERNEL_LARGE_EXEC,
-		.kernel_mapping = true,
+		.page_flag	= __PAGE_KERNEL_LARGE_EXEC,
+		.offset		= __PAGE_OFFSET,
 	};
 	unsigned long mstart, mend;
+	pgd_t *pgd;
 	int result;
 	int i;
 
-	temp_level4_pgt = (pgd_t *)get_safe_page(GFP_ATOMIC);
-	if (!temp_level4_pgt)
+	pgd = (pgd_t *)get_safe_page(GFP_ATOMIC);
+	if (!pgd)
 		return -ENOMEM;
 
-	/* It is safe to reuse the original kernel mapping */
-	set_pgd(temp_level4_pgt + pgd_index(__START_KERNEL_map),
-		init_level4_pgt[pgd_index(__START_KERNEL_map)]);
+	/* Prepare a temporary mapping for the kernel text */
+	result = set_up_temporary_text_mapping(pgd);
+	if (result)
+		return result;
 
 	/* Set up the direct mapping from scratch */
 	for (i = 0; i < nr_pfn_mapped; i++) {
 		mstart = pfn_mapped[i].start << PAGE_SHIFT;
 		mend   = pfn_mapped[i].end << PAGE_SHIFT;
 
-		result = kernel_ident_mapping_init(&info, temp_level4_pgt,
-						   mstart, mend);
-
+		result = kernel_ident_mapping_init(&info, pgd, mstart, mend);
 		if (result)
 			return result;
 	}
 
+	temp_pgt = __pa(pgd);
 	return 0;
 }
 
-int swsusp_arch_resume(void)
+asmlinkage int swsusp_arch_resume(void)
 {
 	int error;
 
 	/* We have got enough memory and from now on we cannot recover */
-	if ((error = set_up_temporary_mappings()))
+	error = set_up_temporary_mappings();
+	if (error)
 		return error;
 
-	relocated_restore_code = (void *)get_safe_page(GFP_ATOMIC);
-	if (!relocated_restore_code)
-		return -ENOMEM;
-	memcpy(relocated_restore_code, &core_restore_code,
-	       &restore_registers - &core_restore_code);
+	error = relocate_restore_code();
+	if (error)
+		return error;
 
 	restore_image();
 	return 0;
 }
-
-/*
- *	pfn_is_nosave - check if given pfn is in the 'nosave' section
- */
-
-int pfn_is_nosave(unsigned long pfn)
-{
-	unsigned long nosave_begin_pfn = __pa_symbol(&__nosave_begin) >> PAGE_SHIFT;
-	unsigned long nosave_end_pfn = PAGE_ALIGN(__pa_symbol(&__nosave_end)) >> PAGE_SHIFT;
-	return (pfn >= nosave_begin_pfn) && (pfn < nosave_end_pfn);
-}
-
-struct restore_data_record {
-	unsigned long jump_address;
-	unsigned long cr3;
-	unsigned long magic;
-};
-
-#define RESTORE_MAGIC	0x0123456789ABCDEFUL
-
-/**
- *	arch_hibernation_header_save - populate the architecture specific part
- *		of a hibernation image header
- *	@addr: address to save the data at
- */
-int arch_hibernation_header_save(void *addr, unsigned int max_size)
-{
-	struct restore_data_record *rdr = addr;
-
-	if (max_size < sizeof(struct restore_data_record))
-		return -EOVERFLOW;
-	rdr->jump_address = restore_jump_address;
-	rdr->cr3 = restore_cr3;
-	rdr->magic = RESTORE_MAGIC;
-	return 0;
-}
-
-/**
- *	arch_hibernation_header_restore - read the architecture specific data
- *		from the hibernation image header
- *	@addr: address to read the data from
- */
-int arch_hibernation_header_restore(void *addr)
-{
-	struct restore_data_record *rdr = addr;
-
-	restore_jump_address = rdr->jump_address;
-	restore_cr3 = rdr->cr3;
-	return (rdr->magic == RESTORE_MAGIC) ? 0 : -EINVAL;
-}