[PATCH 00/12][RFC v3] Backport several fixes from 64bits to 32bits hibernation

[PATCH 00/12][RFC v3] Backport several fixes from 64bits to 32bits hibernation

[Chen Yu]

Currently there are mainly three bugs in 32bits system when doing
hibernation:
1. The page copy code is not running in safe page, which might
   cause hang during resume.
2. There's no text mapping for the final jump address
   of the original kernel, which might cause the system jumping
   into illegal address and causes system hang during resume.
3. The restore kernel switches to its own kernel page table(swapper_pg_dir)
   rather than the original kernel page table after all the pages
   been copied back, which might cause invalid virtual-physical
   mapping issue during resume.

To solve these problems:

1. Copy the code core_restore_code to a safe page, to avoid the instruction
   code been overwritten when image kernel pages are being copied.
2. Set up temporary text mapping for the image kernel's jump address,
   so that after all the pages have been copied back, the system could
   jump to this address.
3. Switch to the original kernel page table during resume.

Furthermore, MD5 hash check for e820 map is also backported from 64bits
system.

In order to make this patch set more readable, these fixes are splitted
into several sub patches.

Chen Yu (1):
  PM / hibernate: Check the success of generating md5 digest before
    hibernation

Zhimin Gu (11):
  x86, hibernate: Fix nosave_regions setup for hibernation
  x86/asm/power: Create stack frames in hibernate_asm_32.S
  x86, hibernate: Extract the common code of 64/32 bit system
  x86, hibernate: Enable CONFIG_ARCH_HIBERNATION_HEADER set on 32bit
    system
  x86, hibernate: Rename temp_level4_pgt to temp_pgt
  x86, hibernate: Use temp_pgt as the temporary page table
  x86, hibernate: Use the page size macro instead of constant value
  x86, hibernate: Switch to original page table after resumed
  x86, hibernate: Switch to relocated restore code during resume on
    32bit system
  x86, hibernate: Set up temporary text mapping for 32bit system
  x86, hibernate: Adjust in_suspend after resumed on 32bit system

 arch/x86/Kconfig                  |   2 +-
 arch/x86/include/asm/suspend.h    |   8 +
 arch/x86/include/asm/suspend_32.h |   4 +
 arch/x86/kernel/setup.c           |   2 +-
 arch/x86/power/Makefile           |   2 +-
 arch/x86/power/hibernate.c        | 249 ++++++++++++++++++++++++++++++
 arch/x86/power/hibernate_32.c     |  52 +++++--
 arch/x86/power/hibernate_64.c     | 224 +--------------------------
 arch/x86/power/hibernate_asm_32.S |  37 ++++-
 arch/x86/power/hibernate_asm_64.S |   2 +-
 10 files changed, 335 insertions(+), 247 deletions(-)
 create mode 100644 arch/x86/power/hibernate.c

-- 
2.17.1

[PATCH 01/12][RFC v3] x86, hibernate: Fix nosave_regions setup for hibernation

[Chen Yu]

From: Zhimin Gu <kookoo.gu@intel.com>

On 32bit systems, nosave_regions(non RAM areas) located between
max_low_pfn and max_pfn are not excluded from hibernation snapshot
currently, which may result in a machine check exception when
trying to access these unsafe regions during hibernation:

[  612.800453] Disabling lock debugging due to kernel taint
[  612.805786] mce: [Hardware Error]: CPU 0: Machine Check Exception: 5 Bank 6: fe00000000801136
[  612.814344] mce: [Hardware Error]: RIP !INEXACT! 60:<00000000d90be566> {swsusp_save+0x436/0x560}
[  612.823167] mce: [Hardware Error]: TSC 1f5939fe276 ADDR dd000000 MISC 30e0000086
[  612.830677] mce: [Hardware Error]: PROCESSOR 0:306c3 TIME 1529487426 SOCKET 0 APIC 0 microcode 24
[  612.839581] mce: [Hardware Error]: Run the above through 'mcelog --ascii'
[  612.846394] mce: [Hardware Error]: Machine check: Processor context corrupt
[  612.853380] Kernel panic - not syncing: Fatal machine check
[  612.858978] Kernel Offset: 0x18000000 from 0xc1000000 (relocation range: 0xc0000000-0xf7ffdfff)

This is because on 32bit systems, pages above max_low_pfn are regarded
as high memeory, and accessing unsafe pages might cause expected MCE.
On the problematic 32bit system, there are reserved memory above low
memory, which triggered the MCE:

e820 memory mapping:
[    0.000000] BIOS-e820: [mem 0x0000000000000000-0x000000000009d7ff] usable
[    0.000000] BIOS-e820: [mem 0x000000000009d800-0x000000000009ffff] reserved
[    0.000000] BIOS-e820: [mem 0x00000000000e0000-0x00000000000fffff] reserved
[    0.000000] BIOS-e820: [mem 0x0000000000100000-0x00000000d160cfff] usable
[    0.000000] BIOS-e820: [mem 0x00000000d160d000-0x00000000d1613fff] ACPI NVS
[    0.000000] BIOS-e820: [mem 0x00000000d1614000-0x00000000d1a44fff] usable
[    0.000000] BIOS-e820: [mem 0x00000000d1a45000-0x00000000d1ecffff] reserved
[    0.000000] BIOS-e820: [mem 0x00000000d1ed0000-0x00000000d7eeafff] usable
[    0.000000] BIOS-e820: [mem 0x00000000d7eeb000-0x00000000d7ffffff] reserved
[    0.000000] BIOS-e820: [mem 0x00000000d8000000-0x00000000d875ffff] usable
[    0.000000] BIOS-e820: [mem 0x00000000d8760000-0x00000000d87fffff] reserved
[    0.000000] BIOS-e820: [mem 0x00000000d8800000-0x00000000d8fadfff] usable
[    0.000000] BIOS-e820: [mem 0x00000000d8fae000-0x00000000d8ffffff] ACPI data
[    0.000000] BIOS-e820: [mem 0x00000000d9000000-0x00000000da71bfff] usable
[    0.000000] BIOS-e820: [mem 0x00000000da71c000-0x00000000da7fffff] ACPI NVS
[    0.000000] BIOS-e820: [mem 0x00000000da800000-0x00000000dbb8bfff] usable
[    0.000000] BIOS-e820: [mem 0x00000000dbb8c000-0x00000000dbffffff] reserved
[    0.000000] BIOS-e820: [mem 0x00000000dd000000-0x00000000df1fffff] reserved
[    0.000000] BIOS-e820: [mem 0x00000000f8000000-0x00000000fbffffff] reserved
[    0.000000] BIOS-e820: [mem 0x00000000fec00000-0x00000000fec00fff] reserved
[    0.000000] BIOS-e820: [mem 0x00000000fed00000-0x00000000fed03fff] reserved
[    0.000000] BIOS-e820: [mem 0x00000000fed1c000-0x00000000fed1ffff] reserved
[    0.000000] BIOS-e820: [mem 0x00000000fee00000-0x00000000fee00fff] reserved
[    0.000000] BIOS-e820: [mem 0x00000000ff000000-0x00000000ffffffff] reserved
[    0.000000] BIOS-e820: [mem 0x0000000100000000-0x000000041edfffff] usable

Fix this problem by changing pfn limit from max_low_pfn to max_pfn.
This fix does not impact 64bit system because on 64bit max_low_pfn
is the same as max_pfn.

Acked-by: Pavel Machek <pavel@ucw.cz>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Zhimin Gu <kookoo.gu@intel.com>
Signed-off-by: Chen Yu <yu.c.chen@intel.com>
---
 arch/x86/kernel/setup.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index b4866badb235..90ecc108bc8a 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -1251,7 +1251,7 @@ void __init setup_arch(char **cmdline_p)
 	x86_init.hyper.guest_late_init();
 
 	e820__reserve_resources();
-	e820__register_nosave_regions(max_low_pfn);
+	e820__register_nosave_regions(max_pfn);
 
 	x86_init.resources.reserve_resources();
 
-- 
2.17.1

[PATCH 02/12][RFC v3] PM / hibernate: Check the success of generating md5 digest before hibernation

[Chen Yu]

Currently if get_e820_md5() fails, then it will hibernate nevertheless.
Actually the error code should be propagated to upper caller so that
the hibernation could be aware of the result and terminates the process
if md5 digest fails.

Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Signed-off-by: Chen Yu <yu.c.chen@intel.com>
---
 arch/x86/power/hibernate_64.c | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/arch/x86/power/hibernate_64.c b/arch/x86/power/hibernate_64.c
index f8e3b668d20b..e0de959ad02d 100644
--- a/arch/x86/power/hibernate_64.c
+++ b/arch/x86/power/hibernate_64.c
@@ -265,9 +265,9 @@ static int get_e820_md5(struct e820_table *table, void *buf)
 	return ret;
 }
 
-static void hibernation_e820_save(void *buf)
+static int hibernation_e820_save(void *buf)
 {
-	get_e820_md5(e820_table_firmware, buf);
+	return get_e820_md5(e820_table_firmware, buf);
 }
 
 static bool hibernation_e820_mismatch(void *buf)
@@ -287,8 +287,9 @@ static bool hibernation_e820_mismatch(void *buf)
 	return memcmp(result, buf, MD5_DIGEST_SIZE) ? true : false;
 }
 #else
-static void hibernation_e820_save(void *buf)
+static int hibernation_e820_save(void *buf)
 {
+	return 0;
 }
 
 static bool hibernation_e820_mismatch(void *buf)
@@ -333,9 +334,7 @@ int arch_hibernation_header_save(void *addr, unsigned int max_size)
 
 	rdr->magic = RESTORE_MAGIC;
 
-	hibernation_e820_save(rdr->e820_digest);
-
-	return 0;
+	return hibernation_e820_save(rdr->e820_digest);
 }
 
 /**
-- 
2.17.1

[PATCH 03/12][RFC v3] x86-32/asm/power: Create stack frames in hibernate_asm_32.S

[Chen Yu]

From: Zhimin Gu <kookoo.gu@intel.com>

Backport
Commit ef0f3ed5a4ac (x86/asm/power: Create stack frames
in hibernate_asm_64.S)
and
Commit 4ce827b4cc58 (x86/power/64: Fix hibernation return
address corruption)

And also prepare for relocated code and jump address
mapping.

Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Signed-off-by: Zhimin Gu <kookoo.gu@intel.com>
Signed-off-by: Chen Yu <yu.c.chen@intel.com>
---
 arch/x86/include/asm/suspend_32.h | 4 ++++
 arch/x86/power/hibernate_asm_32.S | 9 +++++++++
 2 files changed, 13 insertions(+)

diff --git a/arch/x86/include/asm/suspend_32.h b/arch/x86/include/asm/suspend_32.h
index 8be6afb58471..fdbd9d7b7bca 100644
--- a/arch/x86/include/asm/suspend_32.h
+++ b/arch/x86/include/asm/suspend_32.h
@@ -32,4 +32,8 @@ struct saved_context {
 	unsigned long return_address;
 } __attribute__((packed));
 
+/* routines for saving/restoring kernel state */
+extern char core_restore_code[];
+extern char restore_registers[];
+
 #endif /* _ASM_X86_SUSPEND_32_H */
diff --git a/arch/x86/power/hibernate_asm_32.S b/arch/x86/power/hibernate_asm_32.S
index 6e56815e13a0..671d38d0d931 100644
--- a/arch/x86/power/hibernate_asm_32.S
+++ b/arch/x86/power/hibernate_asm_32.S
@@ -12,6 +12,7 @@
 #include <asm/page_types.h>
 #include <asm/asm-offsets.h>
 #include <asm/processor-flags.h>
+#include <asm/frame.h>
 
 .text
 
@@ -24,8 +25,11 @@ ENTRY(swsusp_arch_suspend)
 	pushfl
 	popl saved_context_eflags
 
+	FRAME_BEGIN
 	call swsusp_save
+	FRAME_END
 	ret
+ENDPROC(swsusp_arch_suspend)
 
 ENTRY(restore_image)
 	movl	mmu_cr4_features, %ecx
@@ -58,6 +62,10 @@ copy_loop:
 	.p2align 4,,7
 
 done:
+
+	/* code below belongs to the image kernel */
+	.align PAGE_SIZE
+ENTRY(restore_registers)
 	/* go back to the original page tables */
 	movl	$swapper_pg_dir, %eax
 	subl	$__PAGE_OFFSET, %eax
@@ -83,3 +91,4 @@ done:
 	xorl	%eax, %eax
 
 	ret
+ENDPROC(restore_registers)
-- 
2.17.1

[PATCH 04/12][RFC v3] x86, hibernate: Extract the common code of 64/32 bit system

[Chen Yu]

From: Zhimin Gu <kookoo.gu@intel.com>

Reduce the hibernation code duplication between x86-32 and x86-64
by extracting the common code into hibernate.c.

No functional change.

Acked-by: Pavel Machek <pavel@ucw.cz>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Zhimin Gu <kookoo.gu@intel.com>
Signed-off-by: Chen Yu <yu.c.chen@intel.com>
---
 arch/x86/include/asm/suspend.h |   8 ++
 arch/x86/power/Makefile        |   2 +-
 arch/x86/power/hibernate.c     | 249 +++++++++++++++++++++++++++++++++
 arch/x86/power/hibernate_32.c  |  15 +-
 arch/x86/power/hibernate_64.c  | 221 -----------------------------
 5 files changed, 259 insertions(+), 236 deletions(-)
 create mode 100644 arch/x86/power/hibernate.c

diff --git a/arch/x86/include/asm/suspend.h b/arch/x86/include/asm/suspend.h
index ecffe81ff65c..40b02558749f 100644
--- a/arch/x86/include/asm/suspend.h
+++ b/arch/x86/include/asm/suspend.h
@@ -4,3 +4,11 @@
 #else
 # include <asm/suspend_64.h>
 #endif
+extern unsigned long restore_jump_address __visible;
+extern unsigned long jump_address_phys;
+extern unsigned long restore_cr3 __visible;
+extern unsigned long temp_level4_pgt __visible;
+extern unsigned long relocated_restore_code __visible;
+extern int relocate_restore_code(void);
+/* Defined in hibernate_asm_32/64.S */
+extern asmlinkage __visible int restore_image(void);
diff --git a/arch/x86/power/Makefile b/arch/x86/power/Makefile
index a4701389562c..37923d715741 100644
--- a/arch/x86/power/Makefile
+++ b/arch/x86/power/Makefile
@@ -7,4 +7,4 @@ nostackp := $(call cc-option, -fno-stack-protector)
 CFLAGS_cpu.o	:= $(nostackp)
 
 obj-$(CONFIG_PM_SLEEP)		+= cpu.o
-obj-$(CONFIG_HIBERNATION)	+= hibernate_$(BITS).o hibernate_asm_$(BITS).o
+obj-$(CONFIG_HIBERNATION)	+= hibernate_$(BITS).o hibernate_asm_$(BITS).o hibernate.o
diff --git a/arch/x86/power/hibernate.c b/arch/x86/power/hibernate.c
new file mode 100644
index 000000000000..fbde8f0e8fe0
--- /dev/null
+++ b/arch/x86/power/hibernate.c
@@ -0,0 +1,249 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Hibernation support for x86
+ *
+ * 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>
+ */
+
+#include <linux/gfp.h>
+#include <linux/smp.h>
+#include <linux/suspend.h>
+#include <linux/scatterlist.h>
+#include <linux/kdebug.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>
+
+/*
+ * 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 __visible;
+unsigned long jump_address_phys;
+
+/*
+ * Value of the cr3 register from before the hibernation (this value is passed
+ * in the image header).
+ */
+unsigned long restore_cr3 __visible;
+unsigned long temp_level4_pgt __visible;
+unsigned long relocated_restore_code __visible;
+
+#ifdef CONFIG_X86_64
+#define RESTORE_MAGIC	0x23456789ABCDEF01UL
+#else
+#define RESTORE_MAGIC	0x12345678UL
+#endif
+
+/**
+ *	pfn_is_nosave - check if given pfn is in the 'nosave' section
+ */
+int pfn_is_nosave(unsigned long pfn)
+{
+	unsigned long nosave_begin_pfn;
+	unsigned long nosave_end_pfn;
+
+	nosave_begin_pfn = __pa_symbol(&__nosave_begin) >> PAGE_SHIFT;
+	nosave_end_pfn = PAGE_ALIGN(__pa_symbol(&__nosave_end)) >> PAGE_SHIFT;
+
+	return pfn >= nosave_begin_pfn && pfn < nosave_end_pfn;
+}
+
+int relocate_restore_code(void)
+{
+	pgd_t *pgd;
+	p4d_t *p4d;
+	pud_t *pud;
+	pmd_t *pmd;
+	pte_t *pte;
+
+	relocated_restore_code = get_safe_page(GFP_ATOMIC);
+	if (!relocated_restore_code)
+		return -ENOMEM;
+
+	memcpy((void *)relocated_restore_code, core_restore_code, PAGE_SIZE);
+
+	/* Make the page containing the relocated code executable */
+	pgd = (pgd_t *)__va(read_cr3_pa()) +
+		pgd_index(relocated_restore_code);
+	p4d = p4d_offset(pgd, relocated_restore_code);
+	if (p4d_large(*p4d)) {
+		set_p4d(p4d, __p4d(p4d_val(*p4d) & ~_PAGE_NX));
+		goto out;
+	}
+	pud = pud_offset(p4d, relocated_restore_code);
+	if (pud_large(*pud)) {
+		set_pud(pud, __pud(pud_val(*pud) & ~_PAGE_NX));
+		goto out;
+	}
+	pmd = pmd_offset(pud, relocated_restore_code);
+	if (pmd_large(*pmd)) {
+		set_pmd(pmd, __pmd(pmd_val(*pmd) & ~_PAGE_NX));
+		goto out;
+	}
+	pte = pte_offset_kernel(pmd, relocated_restore_code);
+	set_pte(pte, __pte(pte_val(*pte) & ~_PAGE_NX));
+out:
+	__flush_tlb_all();
+	return 0;
+}
+
+#define MD5_DIGEST_SIZE 16
+
+struct restore_data_record {
+	unsigned long jump_address;
+	unsigned long jump_address_phys;
+	unsigned long cr3;
+	unsigned long magic;
+	u8 e820_digest[MD5_DIGEST_SIZE];
+};
+
+#if IS_BUILTIN(CONFIG_CRYPTO_MD5)
+/**
+ * get_e820_md5 - calculate md5 according to given e820 table
+ *
+ * @table: the e820 table to be calculated
+ * @buf: the md5 result to be stored to
+ */
+static int get_e820_md5(struct e820_table *table, void *buf)
+{
+	struct crypto_shash *tfm;
+	struct shash_desc *desc;
+	int size;
+	int ret = 0;
+
+	tfm = crypto_alloc_shash("md5", 0, 0);
+	if (IS_ERR(tfm))
+		return -ENOMEM;
+
+	desc = kmalloc(sizeof(struct shash_desc) + crypto_shash_descsize(tfm),
+		       GFP_KERNEL);
+	if (!desc) {
+		ret = -ENOMEM;
+		goto free_tfm;
+	}
+
+	desc->tfm = tfm;
+	desc->flags = 0;
+
+	size = offsetof(struct e820_table, entries) +
+		sizeof(struct e820_entry) * table->nr_entries;
+
+	if (crypto_shash_digest(desc, (u8 *)table, size, buf))
+		ret = -EINVAL;
+
+	kzfree(desc);
+
+free_tfm:
+	crypto_free_shash(tfm);
+	return ret;
+}
+
+static int hibernation_e820_save(void *buf)
+{
+	return get_e820_md5(e820_table_firmware, buf);
+}
+
+static bool hibernation_e820_mismatch(void *buf)
+{
+	int ret;
+	u8 result[MD5_DIGEST_SIZE];
+
+	memset(result, 0, MD5_DIGEST_SIZE);
+	/* If there is no digest in suspend kernel, let it go. */
+	if (!memcmp(result, buf, MD5_DIGEST_SIZE))
+		return false;
+
+	ret = get_e820_md5(e820_table_firmware, result);
+	if (ret)
+		return true;
+
+	return memcmp(result, buf, MD5_DIGEST_SIZE) ? true : false;
+}
+#else
+static int hibernation_e820_save(void *buf)
+{
+	return 0;
+}
+
+static bool hibernation_e820_mismatch(void *buf)
+{
+	/* If md5 is not builtin for restore kernel, let it go. */
+	return false;
+}
+#endif
+
+/**
+ *	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 = (unsigned long)restore_registers;
+	rdr->jump_address_phys = __pa_symbol(restore_registers);
+
+	/*
+	 * The restore code fixes up CR3 and CR4 in the following sequence:
+	 *
+	 * [in hibernation asm]
+	 * 1. CR3 <= temporary page tables
+	 * 2. CR4 <= mmu_cr4_features (from the kernel that restores us)
+	 * 3. CR3 <= rdr->cr3
+	 * 4. CR4 <= mmu_cr4_features (from us, i.e. the image kernel)
+	 * [in restore_processor_state()]
+	 * 5. CR4 <= saved CR4
+	 * 6. CR3 <= saved CR3
+	 *
+	 * Our mmu_cr4_features has CR4.PCIDE=0, and toggling
+	 * CR4.PCIDE while CR3's PCID bits are nonzero is illegal, so
+	 * rdr->cr3 needs to point to valid page tables but must not
+	 * have any of the PCID bits set.
+	 */
+	rdr->cr3 = restore_cr3 & ~CR3_PCID_MASK;
+
+	rdr->magic = RESTORE_MAGIC;
+
+	return hibernation_e820_save(rdr->e820_digest);
+}
+
+/**
+ *	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;
+	jump_address_phys = rdr->jump_address_phys;
+	restore_cr3 = rdr->cr3;
+
+	if (rdr->magic != RESTORE_MAGIC) {
+		pr_crit("Unrecognized hibernate image header format!\n");
+		return -EINVAL;
+	}
+
+	if (hibernation_e820_mismatch(rdr->e820_digest)) {
+		pr_crit("Hibernate inconsistent memory map detected!\n");
+		return -ENODEV;
+	}
+
+	return 0;
+}
diff --git a/arch/x86/power/hibernate_32.c b/arch/x86/power/hibernate_32.c
index afc4ed7b1578..f82fbd279d08 100644
--- a/arch/x86/power/hibernate_32.c
+++ b/arch/x86/power/hibernate_32.c
@@ -14,9 +14,7 @@
 #include <asm/pgtable.h>
 #include <asm/mmzone.h>
 #include <asm/sections.h>
-
-/* Defined in hibernate_asm_32.S */
-extern int restore_image(void);
+#include <asm/suspend.h>
 
 /* Pointer to the temporary resume page tables */
 pgd_t *resume_pg_dir;
@@ -162,14 +160,3 @@ asmlinkage int swsusp_arch_resume(void)
 	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);
-}
diff --git a/arch/x86/power/hibernate_64.c b/arch/x86/power/hibernate_64.c
index e0de959ad02d..8bc2eb0dc464 100644
--- a/arch/x86/power/hibernate_64.c
+++ b/arch/x86/power/hibernate_64.c
@@ -26,26 +26,6 @@
 #include <asm/suspend.h>
 #include <asm/tlbflush.h>
 
-/* Defined in hibernate_asm_64.S */
-extern asmlinkage __visible int restore_image(void);
-
-/*
- * 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 __visible;
-unsigned long jump_address_phys;
-
-/*
- * Value of the cr3 register from before the hibernation (this value is passed
- * in the image header).
- */
-unsigned long restore_cr3 __visible;
-
-unsigned long temp_level4_pgt __visible;
-
-unsigned long relocated_restore_code __visible;
-
 static int set_up_temporary_text_mapping(pgd_t *pgd)
 {
 	pmd_t *pmd;
@@ -145,45 +125,6 @@ static int set_up_temporary_mappings(void)
 	return 0;
 }
 
-static int relocate_restore_code(void)
-{
-	pgd_t *pgd;
-	p4d_t *p4d;
-	pud_t *pud;
-	pmd_t *pmd;
-	pte_t *pte;
-
-	relocated_restore_code = get_safe_page(GFP_ATOMIC);
-	if (!relocated_restore_code)
-		return -ENOMEM;
-
-	memcpy((void *)relocated_restore_code, core_restore_code, PAGE_SIZE);
-
-	/* Make the page containing the relocated code executable */
-	pgd = (pgd_t *)__va(read_cr3_pa()) +
-		pgd_index(relocated_restore_code);
-	p4d = p4d_offset(pgd, relocated_restore_code);
-	if (p4d_large(*p4d)) {
-		set_p4d(p4d, __p4d(p4d_val(*p4d) & ~_PAGE_NX));
-		goto out;
-	}
-	pud = pud_offset(p4d, relocated_restore_code);
-	if (pud_large(*pud)) {
-		set_pud(pud, __pud(pud_val(*pud) & ~_PAGE_NX));
-		goto out;
-	}
-	pmd = pmd_offset(pud, relocated_restore_code);
-	if (pmd_large(*pmd)) {
-		set_pmd(pmd, __pmd(pmd_val(*pmd) & ~_PAGE_NX));
-		goto out;
-	}
-	pte = pte_offset_kernel(pmd, relocated_restore_code);
-	set_pte(pte, __pte(pte_val(*pte) & ~_PAGE_NX));
-out:
-	__flush_tlb_all();
-	return 0;
-}
-
 asmlinkage int swsusp_arch_resume(void)
 {
 	int error;
@@ -200,165 +141,3 @@ asmlinkage int swsusp_arch_resume(void)
 	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);
-}
-
-#define MD5_DIGEST_SIZE 16
-
-struct restore_data_record {
-	unsigned long jump_address;
-	unsigned long jump_address_phys;
-	unsigned long cr3;
-	unsigned long magic;
-	u8 e820_digest[MD5_DIGEST_SIZE];
-};
-
-#define RESTORE_MAGIC	0x23456789ABCDEF01UL
-
-#if IS_BUILTIN(CONFIG_CRYPTO_MD5)
-/**
- * get_e820_md5 - calculate md5 according to given e820 table
- *
- * @table: the e820 table to be calculated
- * @buf: the md5 result to be stored to
- */
-static int get_e820_md5(struct e820_table *table, void *buf)
-{
-	struct crypto_shash *tfm;
-	struct shash_desc *desc;
-	int size;
-	int ret = 0;
-
-	tfm = crypto_alloc_shash("md5", 0, 0);
-	if (IS_ERR(tfm))
-		return -ENOMEM;
-
-	desc = kmalloc(sizeof(struct shash_desc) + crypto_shash_descsize(tfm),
-		       GFP_KERNEL);
-	if (!desc) {
-		ret = -ENOMEM;
-		goto free_tfm;
-	}
-
-	desc->tfm = tfm;
-	desc->flags = 0;
-
-	size = offsetof(struct e820_table, entries) +
-		sizeof(struct e820_entry) * table->nr_entries;
-
-	if (crypto_shash_digest(desc, (u8 *)table, size, buf))
-		ret = -EINVAL;
-
-	kzfree(desc);
-
-free_tfm:
-	crypto_free_shash(tfm);
-	return ret;
-}
-
-static int hibernation_e820_save(void *buf)
-{
-	return get_e820_md5(e820_table_firmware, buf);
-}
-
-static bool hibernation_e820_mismatch(void *buf)
-{
-	int ret;
-	u8 result[MD5_DIGEST_SIZE];
-
-	memset(result, 0, MD5_DIGEST_SIZE);
-	/* If there is no digest in suspend kernel, let it go. */
-	if (!memcmp(result, buf, MD5_DIGEST_SIZE))
-		return false;
-
-	ret = get_e820_md5(e820_table_firmware, result);
-	if (ret)
-		return true;
-
-	return memcmp(result, buf, MD5_DIGEST_SIZE) ? true : false;
-}
-#else
-static int hibernation_e820_save(void *buf)
-{
-	return 0;
-}
-
-static bool hibernation_e820_mismatch(void *buf)
-{
-	/* If md5 is not builtin for restore kernel, let it go. */
-	return false;
-}
-#endif
-
-/**
- *	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 = (unsigned long)restore_registers;
-	rdr->jump_address_phys = __pa_symbol(restore_registers);
-
-	/*
-	 * The restore code fixes up CR3 and CR4 in the following sequence:
-	 *
-	 * [in hibernation asm]
-	 * 1. CR3 <= temporary page tables
-	 * 2. CR4 <= mmu_cr4_features (from the kernel that restores us)
-	 * 3. CR3 <= rdr->cr3
-	 * 4. CR4 <= mmu_cr4_features (from us, i.e. the image kernel)
-	 * [in restore_processor_state()]
-	 * 5. CR4 <= saved CR4
-	 * 6. CR3 <= saved CR3
-	 *
-	 * Our mmu_cr4_features has CR4.PCIDE=0, and toggling
-	 * CR4.PCIDE while CR3's PCID bits are nonzero is illegal, so
-	 * rdr->cr3 needs to point to valid page tables but must not
-	 * have any of the PCID bits set.
-	 */
-	rdr->cr3 = restore_cr3 & ~CR3_PCID_MASK;
-
-	rdr->magic = RESTORE_MAGIC;
-
-	return hibernation_e820_save(rdr->e820_digest);
-}
-
-/**
- *	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;
-	jump_address_phys = rdr->jump_address_phys;
-	restore_cr3 = rdr->cr3;
-
-	if (rdr->magic != RESTORE_MAGIC) {
-		pr_crit("Unrecognized hibernate image header format!\n");
-		return -EINVAL;
-	}
-
-	if (hibernation_e820_mismatch(rdr->e820_digest)) {
-		pr_crit("Hibernate inconsistent memory map detected!\n");
-		return -ENODEV;
-	}
-
-	return 0;
-}
-- 
2.17.1

[PATCH 05/12][RFC v3] x86-32, hibernate: Enable CONFIG_ARCH_HIBERNATION_HEADER set on 32bit system

[Chen Yu]

From: Zhimin Gu <kookoo.gu@intel.com>

Enable CONFIG_ARCH_HIBERNATION_HEADER for 32bit system so that
md5 check is enabled and prepare for relocated code executing
and jump address mapping.

Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Signed-off-by: Zhimin Gu <kookoo.gu@intel.com>
Signed-off-by: Chen Yu <yu.c.chen@intel.com>
---
 arch/x86/Kconfig | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 1a0be022f91d..e8de5de1057f 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -2422,7 +2422,7 @@ menu "Power management and ACPI options"
 
 config ARCH_HIBERNATION_HEADER
 	def_bool y
-	depends on X86_64 && HIBERNATION
+	depends on HIBERNATION
 
 source "kernel/power/Kconfig"
 
-- 
2.17.1

[PATCH 06/12][RFC v3] x86, hibernate: Rename temp_level4_pgt to temp_pgt

[Chen Yu]

From: Zhimin Gu <kookoo.gu@intel.com>

As 32bit system is not using 4-level page, rename it
to temp_pgt so that it can be reused for both 32bit
and 64bit hibernation.

No functional change.

Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Signed-off-by: Zhimin Gu <kookoo.gu@intel.com>
Signed-off-by: Chen Yu <yu.c.chen@intel.com>
---
 arch/x86/include/asm/suspend.h    | 2 +-
 arch/x86/power/hibernate.c        | 2 +-
 arch/x86/power/hibernate_64.c     | 2 +-
 arch/x86/power/hibernate_asm_64.S | 2 +-
 4 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/x86/include/asm/suspend.h b/arch/x86/include/asm/suspend.h
index 40b02558749f..a892494ca5e4 100644
--- a/arch/x86/include/asm/suspend.h
+++ b/arch/x86/include/asm/suspend.h
@@ -7,7 +7,7 @@
 extern unsigned long restore_jump_address __visible;
 extern unsigned long jump_address_phys;
 extern unsigned long restore_cr3 __visible;
-extern unsigned long temp_level4_pgt __visible;
+extern unsigned long temp_pgt __visible;
 extern unsigned long relocated_restore_code __visible;
 extern int relocate_restore_code(void);
 /* Defined in hibernate_asm_32/64.S */
diff --git a/arch/x86/power/hibernate.c b/arch/x86/power/hibernate.c
index fbde8f0e8fe0..b0e586ae947e 100644
--- a/arch/x86/power/hibernate.c
+++ b/arch/x86/power/hibernate.c
@@ -37,7 +37,7 @@ unsigned long jump_address_phys;
  * in the image header).
  */
 unsigned long restore_cr3 __visible;
-unsigned long temp_level4_pgt __visible;
+unsigned long temp_pgt __visible;
 unsigned long relocated_restore_code __visible;
 
 #ifdef CONFIG_X86_64
diff --git a/arch/x86/power/hibernate_64.c b/arch/x86/power/hibernate_64.c
index 8bc2eb0dc464..239f424ccb29 100644
--- a/arch/x86/power/hibernate_64.c
+++ b/arch/x86/power/hibernate_64.c
@@ -121,7 +121,7 @@ static int set_up_temporary_mappings(void)
 			return result;
 	}
 
-	temp_level4_pgt = __pa(pgd);
+	temp_pgt = __pa(pgd);
 	return 0;
 }
 
diff --git a/arch/x86/power/hibernate_asm_64.S b/arch/x86/power/hibernate_asm_64.S
index fd369a6e9ff8..3008baa2fa95 100644
--- a/arch/x86/power/hibernate_asm_64.S
+++ b/arch/x86/power/hibernate_asm_64.S
@@ -59,7 +59,7 @@ ENTRY(restore_image)
 	movq	restore_cr3(%rip), %r9
 
 	/* prepare to switch to temporary page tables */
-	movq	temp_level4_pgt(%rip), %rax
+	movq	temp_pgt(%rip), %rax
 	movq	mmu_cr4_features(%rip), %rbx
 
 	/* prepare to copy image data to their original locations */
-- 
2.17.1

[PATCH 07/12][RFC v3] x86-32, hibernate: Use temp_pgt as the temporary page table

[Chen Yu]

From: Zhimin Gu <kookoo.gu@intel.com>

This is to reuse the temp_pgt for both 32bit and 64bit
system.

No functional change.

Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Signed-off-by: Zhimin Gu <kookoo.gu@intel.com>
Signed-off-by: Chen Yu <yu.c.chen@intel.com>
---
 arch/x86/power/hibernate_32.c     | 2 ++
 arch/x86/power/hibernate_asm_32.S | 3 +--
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/arch/x86/power/hibernate_32.c b/arch/x86/power/hibernate_32.c
index f82fbd279d08..a44bdada4e4e 100644
--- a/arch/x86/power/hibernate_32.c
+++ b/arch/x86/power/hibernate_32.c
@@ -156,6 +156,8 @@ asmlinkage int swsusp_arch_resume(void)
 	if (error)
 		return error;
 
+	temp_pgt = __pa(resume_pg_dir);
+
 	/* We have got enough memory and from now on we cannot recover */
 	restore_image();
 	return 0;
diff --git a/arch/x86/power/hibernate_asm_32.S b/arch/x86/power/hibernate_asm_32.S
index 671d38d0d931..f0627cf30a36 100644
--- a/arch/x86/power/hibernate_asm_32.S
+++ b/arch/x86/power/hibernate_asm_32.S
@@ -33,8 +33,7 @@ ENDPROC(swsusp_arch_suspend)
 
 ENTRY(restore_image)
 	movl	mmu_cr4_features, %ecx
-	movl	resume_pg_dir, %eax
-	subl	$__PAGE_OFFSET, %eax
+	movl	temp_pgt, %eax
 	movl	%eax, %cr3
 
 	jecxz	1f	# cr4 Pentium and higher, skip if zero
-- 
2.17.1

[PATCH 08/12][RFC v3] x86-32, hibernate: Use the page size macro instead of constant value

[Chen Yu]

From: Zhimin Gu <kookoo.gu@intel.com>

Convert the hard code into PAGE_SIZE for better scalability.

No functional change.

Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Signed-off-by: Zhimin Gu <kookoo.gu@intel.com>
Signed-off-by: Chen Yu <yu.c.chen@intel.com>
---
 arch/x86/power/hibernate_asm_32.S | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/power/hibernate_asm_32.S b/arch/x86/power/hibernate_asm_32.S
index f0627cf30a36..f5103ae96582 100644
--- a/arch/x86/power/hibernate_asm_32.S
+++ b/arch/x86/power/hibernate_asm_32.S
@@ -52,7 +52,7 @@ copy_loop:
 	movl	pbe_address(%edx), %esi
 	movl	pbe_orig_address(%edx), %edi
 
-	movl	$1024, %ecx
+	movl	$(PAGE_SIZE >> 2), %ecx
 	rep
 	movsl
 
-- 
2.17.1

[PATCH 09/12][RFC v3] x86-32, hibernate: Switch to original page table after resumed

[Chen Yu]

From: Zhimin Gu <kookoo.gu@intel.com>

After all the pages are restored to previous address, the page
table switches back to current swapper_pg_dir. However the
swapper_pg_dir currently in used might not be consistent with
previous page table, which might cause issue after resumed.

Fix this issue by switching to original page table after resumed.

Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Signed-off-by: Zhimin Gu <kookoo.gu@intel.com>
Signed-off-by: Chen Yu <yu.c.chen@intel.com>
---
 arch/x86/power/hibernate_asm_32.S | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/arch/x86/power/hibernate_asm_32.S b/arch/x86/power/hibernate_asm_32.S
index f5103ae96582..6b2b94937113 100644
--- a/arch/x86/power/hibernate_asm_32.S
+++ b/arch/x86/power/hibernate_asm_32.S
@@ -25,6 +25,10 @@ ENTRY(swsusp_arch_suspend)
 	pushfl
 	popl saved_context_eflags
 
+	/* save cr3 */
+	movl	%cr3, %eax
+	movl	%eax, restore_cr3
+
 	FRAME_BEGIN
 	call swsusp_save
 	FRAME_END
@@ -32,6 +36,8 @@ ENTRY(swsusp_arch_suspend)
 ENDPROC(swsusp_arch_suspend)
 
 ENTRY(restore_image)
+	movl	restore_cr3, %ebp
+
 	movl	mmu_cr4_features, %ecx
 	movl	temp_pgt, %eax
 	movl	%eax, %cr3
@@ -66,9 +72,7 @@ done:
 	.align PAGE_SIZE
 ENTRY(restore_registers)
 	/* go back to the original page tables */
-	movl	$swapper_pg_dir, %eax
-	subl	$__PAGE_OFFSET, %eax
-	movl	%eax, %cr3
+	movl	%ebp, %cr3
 	movl	mmu_cr4_features, %ecx
 	jecxz	1f	# cr4 Pentium and higher, skip if zero
 	movl	%ecx, %cr4;  # turn PGE back on
-- 
2.17.1

[PATCH 10/12][RFC v3] x86-32, hibernate: Switch to relocated restore code during resume on 32bit system

[Chen Yu]

From: Zhimin Gu <kookoo.gu@intel.com>

Code should be executed in a safe page during page
restoring, as the page where instruction is running
during resume might be scribbled and causes issues.

Backport the code from 64 bit system to fix this bug.

Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Signed-off-by: Zhimin Gu <kookoo.gu@intel.com>
Signed-off-by: Chen Yu <yu.c.chen@intel.com>
---
 arch/x86/power/hibernate_32.c     | 4 ++++
 arch/x86/power/hibernate_asm_32.S | 7 +++++++
 2 files changed, 11 insertions(+)

diff --git a/arch/x86/power/hibernate_32.c b/arch/x86/power/hibernate_32.c
index a44bdada4e4e..a9861095fbb8 100644
--- a/arch/x86/power/hibernate_32.c
+++ b/arch/x86/power/hibernate_32.c
@@ -158,6 +158,10 @@ asmlinkage int swsusp_arch_resume(void)
 
 	temp_pgt = __pa(resume_pg_dir);
 
+	error = relocate_restore_code();
+	if (error)
+		return error;
+
 	/* We have got enough memory and from now on we cannot recover */
 	restore_image();
 	return 0;
diff --git a/arch/x86/power/hibernate_asm_32.S b/arch/x86/power/hibernate_asm_32.S
index 6b2b94937113..e9adda6b6b02 100644
--- a/arch/x86/power/hibernate_asm_32.S
+++ b/arch/x86/power/hibernate_asm_32.S
@@ -39,6 +39,13 @@ ENTRY(restore_image)
 	movl	restore_cr3, %ebp
 
 	movl	mmu_cr4_features, %ecx
+
+	/* jump to relocated restore code */
+	movl	relocated_restore_code, %eax
+	jmpl	*%eax
+
+/* code below has been relocated to a safe page */
+ENTRY(core_restore_code)
 	movl	temp_pgt, %eax
 	movl	%eax, %cr3
 
-- 
2.17.1

[PATCH 11/12][RFC v3] x86-32, hibernate: Set up temporary text mapping for 32bit system

[Chen Yu]

From: Zhimin Gu <kookoo.gu@intel.com>

Set up the temporary text mapping for the final jump address
so that the system could jump to the right address after all
the pages have been copied back to their original address.

Back-port from 64bit system.

Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Signed-off-by: Zhimin Gu <kookoo.gu@intel.com>
Signed-off-by: Chen Yu <yu.c.chen@intel.com>
---
 arch/x86/power/hibernate_32.c     | 31 +++++++++++++++++++++++++++++++
 arch/x86/power/hibernate_asm_32.S |  3 +++
 2 files changed, 34 insertions(+)

diff --git a/arch/x86/power/hibernate_32.c b/arch/x86/power/hibernate_32.c
index a9861095fbb8..15695e30f982 100644
--- a/arch/x86/power/hibernate_32.c
+++ b/arch/x86/power/hibernate_32.c
@@ -143,6 +143,32 @@ static inline void resume_init_first_level_page_table(pgd_t *pg_dir)
 #endif
 }
 
+static int set_up_temporary_text_mapping(pgd_t *pgd_base)
+{
+	pgd_t *pgd;
+	pmd_t *pmd;
+	pte_t *pte;
+
+	pgd = pgd_base + pgd_index(restore_jump_address);
+
+	pmd = resume_one_md_table_init(pgd);
+	if (!pmd)
+		return -ENOMEM;
+
+	if (boot_cpu_has(X86_FEATURE_PSE)) {
+		set_pmd(pmd + pmd_index(restore_jump_address),
+		__pmd((jump_address_phys & PMD_MASK) | pgprot_val(PAGE_KERNEL_LARGE_EXEC)));
+	} else {
+		pte = resume_one_page_table_init(pmd);
+		if (!pte)
+			return -ENOMEM;
+		set_pte(pte + pte_index(restore_jump_address),
+		__pte((jump_address_phys & PAGE_MASK) | pgprot_val(PAGE_KERNEL_EXEC)));
+	}
+
+	return 0;
+}
+
 asmlinkage int swsusp_arch_resume(void)
 {
 	int error;
@@ -152,6 +178,11 @@ asmlinkage int swsusp_arch_resume(void)
 		return -ENOMEM;
 
 	resume_init_first_level_page_table(resume_pg_dir);
+
+	error = set_up_temporary_text_mapping(resume_pg_dir);
+	if (error)
+		return error;
+
 	error = resume_physical_mapping_init(resume_pg_dir);
 	if (error)
 		return error;
diff --git a/arch/x86/power/hibernate_asm_32.S b/arch/x86/power/hibernate_asm_32.S
index e9adda6b6b02..01f653fae7bd 100644
--- a/arch/x86/power/hibernate_asm_32.S
+++ b/arch/x86/power/hibernate_asm_32.S
@@ -36,6 +36,8 @@ ENTRY(swsusp_arch_suspend)
 ENDPROC(swsusp_arch_suspend)
 
 ENTRY(restore_image)
+	/* prepare to jump to the image kernel */
+	movl	restore_jump_address, %ebx
 	movl	restore_cr3, %ebp
 
 	movl	mmu_cr4_features, %ecx
@@ -74,6 +76,7 @@ copy_loop:
 	.p2align 4,,7
 
 done:
+	jmpl	*%ebx
 
 	/* code below belongs to the image kernel */
 	.align PAGE_SIZE
-- 
2.17.1

[PATCH 12/12][RFC v3] x86-32, hibernate: Adjust in_suspend after resumed on 32bit system

[Chen Yu]

From: Zhimin Gu <kookoo.gu@intel.com>

Update the in_suspend variable to reflect the actual hibernation
status. Back-port from 64bit system.

Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Signed-off-by: Zhimin Gu <kookoo.gu@intel.com>
Signed-off-by: Chen Yu <yu.c.chen@intel.com>
---
 arch/x86/power/hibernate_asm_32.S | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/x86/power/hibernate_asm_32.S b/arch/x86/power/hibernate_asm_32.S
index 01f653fae7bd..6fe383002125 100644
--- a/arch/x86/power/hibernate_asm_32.S
+++ b/arch/x86/power/hibernate_asm_32.S
@@ -103,5 +103,8 @@ ENTRY(restore_registers)
 
 	xorl	%eax, %eax
 
+	/* tell the hibernation core that we've just restored the memory */
+	movl	%eax, in_suspend
+
 	ret
 ENDPROC(restore_registers)
-- 
2.17.1

Re: [PATCH 01/12][RFC v3] x86, hibernate: Fix nosave_regions setup for hibernation

[Rafael J. Wysocki]

On Wed, Sep 19, 2018 at 9:30 AM Chen Yu <yu.c.chen@intel.com> wrote:
>
> From: Zhimin Gu <kookoo.gu@intel.com>
>
> On 32bit systems, nosave_regions(non RAM areas) located between
> max_low_pfn and max_pfn are not excluded from hibernation snapshot
> currently, which may result in a machine check exception when
> trying to access these unsafe regions during hibernation:
>
> [  612.800453] Disabling lock debugging due to kernel taint
> [  612.805786] mce: [Hardware Error]: CPU 0: Machine Check Exception: 5 Bank 6: fe00000000801136
> [  612.814344] mce: [Hardware Error]: RIP !INEXACT! 60:<00000000d90be566> {swsusp_save+0x436/0x560}
> [  612.823167] mce: [Hardware Error]: TSC 1f5939fe276 ADDR dd000000 MISC 30e0000086
> [  612.830677] mce: [Hardware Error]: PROCESSOR 0:306c3 TIME 1529487426 SOCKET 0 APIC 0 microcode 24
> [  612.839581] mce: [Hardware Error]: Run the above through 'mcelog --ascii'
> [  612.846394] mce: [Hardware Error]: Machine check: Processor context corrupt
> [  612.853380] Kernel panic - not syncing: Fatal machine check
> [  612.858978] Kernel Offset: 0x18000000 from 0xc1000000 (relocation range: 0xc0000000-0xf7ffdfff)
>
> This is because on 32bit systems, pages above max_low_pfn are regarded
> as high memeory, and accessing unsafe pages might cause expected MCE.
> On the problematic 32bit system, there are reserved memory above low
> memory, which triggered the MCE:
>
> e820 memory mapping:
> [    0.000000] BIOS-e820: [mem 0x0000000000000000-0x000000000009d7ff] usable
> [    0.000000] BIOS-e820: [mem 0x000000000009d800-0x000000000009ffff] reserved
> [    0.000000] BIOS-e820: [mem 0x00000000000e0000-0x00000000000fffff] reserved
> [    0.000000] BIOS-e820: [mem 0x0000000000100000-0x00000000d160cfff] usable
> [    0.000000] BIOS-e820: [mem 0x00000000d160d000-0x00000000d1613fff] ACPI NVS
> [    0.000000] BIOS-e820: [mem 0x00000000d1614000-0x00000000d1a44fff] usable
> [    0.000000] BIOS-e820: [mem 0x00000000d1a45000-0x00000000d1ecffff] reserved
> [    0.000000] BIOS-e820: [mem 0x00000000d1ed0000-0x00000000d7eeafff] usable
> [    0.000000] BIOS-e820: [mem 0x00000000d7eeb000-0x00000000d7ffffff] reserved
> [    0.000000] BIOS-e820: [mem 0x00000000d8000000-0x00000000d875ffff] usable
> [    0.000000] BIOS-e820: [mem 0x00000000d8760000-0x00000000d87fffff] reserved
> [    0.000000] BIOS-e820: [mem 0x00000000d8800000-0x00000000d8fadfff] usable
> [    0.000000] BIOS-e820: [mem 0x00000000d8fae000-0x00000000d8ffffff] ACPI data
> [    0.000000] BIOS-e820: [mem 0x00000000d9000000-0x00000000da71bfff] usable
> [    0.000000] BIOS-e820: [mem 0x00000000da71c000-0x00000000da7fffff] ACPI NVS
> [    0.000000] BIOS-e820: [mem 0x00000000da800000-0x00000000dbb8bfff] usable
> [    0.000000] BIOS-e820: [mem 0x00000000dbb8c000-0x00000000dbffffff] reserved
> [    0.000000] BIOS-e820: [mem 0x00000000dd000000-0x00000000df1fffff] reserved
> [    0.000000] BIOS-e820: [mem 0x00000000f8000000-0x00000000fbffffff] reserved
> [    0.000000] BIOS-e820: [mem 0x00000000fec00000-0x00000000fec00fff] reserved
> [    0.000000] BIOS-e820: [mem 0x00000000fed00000-0x00000000fed03fff] reserved
> [    0.000000] BIOS-e820: [mem 0x00000000fed1c000-0x00000000fed1ffff] reserved
> [    0.000000] BIOS-e820: [mem 0x00000000fee00000-0x00000000fee00fff] reserved
> [    0.000000] BIOS-e820: [mem 0x00000000ff000000-0x00000000ffffffff] reserved
> [    0.000000] BIOS-e820: [mem 0x0000000100000000-0x000000041edfffff] usable
>
> Fix this problem by changing pfn limit from max_low_pfn to max_pfn.
> This fix does not impact 64bit system because on 64bit max_low_pfn
> is the same as max_pfn.
>
> Acked-by: Pavel Machek <pavel@ucw.cz>
> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Signed-off-by: Zhimin Gu <kookoo.gu@intel.com>
> Signed-off-by: Chen Yu <yu.c.chen@intel.com>
> ---
>  arch/x86/kernel/setup.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
> index b4866badb235..90ecc108bc8a 100644
> --- a/arch/x86/kernel/setup.c
> +++ b/arch/x86/kernel/setup.c
> @@ -1251,7 +1251,7 @@ void __init setup_arch(char **cmdline_p)
>         x86_init.hyper.guest_late_init();
>
>         e820__reserve_resources();
> -       e820__register_nosave_regions(max_low_pfn);
> +       e820__register_nosave_regions(max_pfn);
>
>         x86_init.resources.reserve_resources();
>
> --

Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Re: [PATCH 02/12][RFC v3] PM / hibernate: Check the success of generating md5 digest before hibernation

[Rafael J. Wysocki]

On Wed, Sep 19, 2018 at 9:31 AM Chen Yu <yu.c.chen@intel.com> wrote:
>
> Currently if get_e820_md5() fails, then it will hibernate nevertheless.
> Actually the error code should be propagated to upper caller so that
> the hibernation could be aware of the result and terminates the process
> if md5 digest fails.
>
> Suggested-by: Thomas Gleixner <tglx@linutronix.de>
> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
> Signed-off-by: Chen Yu <yu.c.chen@intel.com>
> ---
>  arch/x86/power/hibernate_64.c | 11 +++++------
>  1 file changed, 5 insertions(+), 6 deletions(-)
>
> diff --git a/arch/x86/power/hibernate_64.c b/arch/x86/power/hibernate_64.c
> index f8e3b668d20b..e0de959ad02d 100644
> --- a/arch/x86/power/hibernate_64.c
> +++ b/arch/x86/power/hibernate_64.c
> @@ -265,9 +265,9 @@ static int get_e820_md5(struct e820_table *table, void *buf)
>         return ret;
>  }
>
> -static void hibernation_e820_save(void *buf)
> +static int hibernation_e820_save(void *buf)
>  {
> -       get_e820_md5(e820_table_firmware, buf);
> +       return get_e820_md5(e820_table_firmware, buf);
>  }
>
>  static bool hibernation_e820_mismatch(void *buf)
> @@ -287,8 +287,9 @@ static bool hibernation_e820_mismatch(void *buf)
>         return memcmp(result, buf, MD5_DIGEST_SIZE) ? true : false;
>  }
>  #else
> -static void hibernation_e820_save(void *buf)
> +static int hibernation_e820_save(void *buf)
>  {
> +       return 0;
>  }
>
>  static bool hibernation_e820_mismatch(void *buf)
> @@ -333,9 +334,7 @@ int arch_hibernation_header_save(void *addr, unsigned int max_size)
>
>         rdr->magic = RESTORE_MAGIC;
>
> -       hibernation_e820_save(rdr->e820_digest);
> -
> -       return 0;
> +       return hibernation_e820_save(rdr->e820_digest);
>  }
>
>  /**
> --

Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Re: [PATCH 03/12][RFC v3] x86-32/asm/power: Create stack frames in hibernate_asm_32.S

[Rafael J. Wysocki]

On Wed, Sep 19, 2018 at 9:31 AM Chen Yu <yu.c.chen@intel.com> wrote:
>
> From: Zhimin Gu <kookoo.gu@intel.com>
>
> Backport
> Commit ef0f3ed5a4ac (x86/asm/power: Create stack frames
> in hibernate_asm_64.S)
> and
> Commit 4ce827b4cc58 (x86/power/64: Fix hibernation return
> address corruption)
>
> And also prepare for relocated code and jump address
> mapping.

I don't like the changelog.

It should explain the technical reasons for making the changes in the
first place and then mention that analogous changes were made for
64-bit before and by which commits.

Thanks,
Rafael

Re: [PATCH 03/12][RFC v3] x86-32/asm/power: Create stack frames in hibernate_asm_32.S

[Yu Chen]

On Wed, Sep 19, 2018 at 10:41:16AM +0200, Rafael J. Wysocki wrote:
> On Wed, Sep 19, 2018 at 9:31 AM Chen Yu <yu.c.chen@intel.com> wrote:
> >
> > From: Zhimin Gu <kookoo.gu@intel.com>
> >
> > Backport
> > Commit ef0f3ed5a4ac (x86/asm/power: Create stack frames
> > in hibernate_asm_64.S)
> > and
> > Commit 4ce827b4cc58 (x86/power/64: Fix hibernation return
> > address corruption)
> >
> > And also prepare for relocated code and jump address
> > mapping.
> 
> I don't like the changelog.
> 
> It should explain the technical reasons for making the changes in the
> first place and then mention that analogous changes were made for
> 64-bit before and by which commits.
>
Ok, will change it in next version.

Thanks,
Yu
> Thanks,
> Rafael

Re: [PATCH 04/12][RFC v3] x86, hibernate: Extract the common code of 64/32 bit system

[Rafael J. Wysocki]

On Wed, Sep 19, 2018 at 9:32 AM Chen Yu <yu.c.chen@intel.com> wrote:
>
> From: Zhimin Gu <kookoo.gu@intel.com>
>
> Reduce the hibernation code duplication between x86-32 and x86-64
> by extracting the common code into hibernate.c.
>
> No functional change.
>
> Acked-by: Pavel Machek <pavel@ucw.cz>
> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Signed-off-by: Zhimin Gu <kookoo.gu@intel.com>
> Signed-off-by: Chen Yu <yu.c.chen@intel.com>
> ---
>  arch/x86/include/asm/suspend.h |   8 ++
>  arch/x86/power/Makefile        |   2 +-
>  arch/x86/power/hibernate.c     | 249 +++++++++++++++++++++++++++++++++
>  arch/x86/power/hibernate_32.c  |  15 +-
>  arch/x86/power/hibernate_64.c  | 221 -----------------------------
>  5 files changed, 259 insertions(+), 236 deletions(-)
>  create mode 100644 arch/x86/power/hibernate.c
>
> diff --git a/arch/x86/include/asm/suspend.h b/arch/x86/include/asm/suspend.h
> index ecffe81ff65c..40b02558749f 100644
> --- a/arch/x86/include/asm/suspend.h
> +++ b/arch/x86/include/asm/suspend.h
> @@ -4,3 +4,11 @@
>  #else
>  # include <asm/suspend_64.h>
>  #endif
> +extern unsigned long restore_jump_address __visible;
> +extern unsigned long jump_address_phys;
> +extern unsigned long restore_cr3 __visible;
> +extern unsigned long temp_level4_pgt __visible;
> +extern unsigned long relocated_restore_code __visible;
> +extern int relocate_restore_code(void);
> +/* Defined in hibernate_asm_32/64.S */
> +extern asmlinkage __visible int restore_image(void);
> diff --git a/arch/x86/power/Makefile b/arch/x86/power/Makefile
> index a4701389562c..37923d715741 100644
> --- a/arch/x86/power/Makefile
> +++ b/arch/x86/power/Makefile
> @@ -7,4 +7,4 @@ nostackp := $(call cc-option, -fno-stack-protector)
>  CFLAGS_cpu.o   := $(nostackp)
>
>  obj-$(CONFIG_PM_SLEEP)         += cpu.o
> -obj-$(CONFIG_HIBERNATION)      += hibernate_$(BITS).o hibernate_asm_$(BITS).o
> +obj-$(CONFIG_HIBERNATION)      += hibernate_$(BITS).o hibernate_asm_$(BITS).o hibernate.o
> diff --git a/arch/x86/power/hibernate.c b/arch/x86/power/hibernate.c
> new file mode 100644
> index 000000000000..fbde8f0e8fe0
> --- /dev/null
> +++ b/arch/x86/power/hibernate.c
> @@ -0,0 +1,249 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Hibernation support for x86
> + *
> + * 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>

I don't think this "copyright" information has any legal bearing any
more at this point.

I would just write it as

 * Authors:
 *  2007 Rafael J. Wysocki <rjw@sisk.pl>
 *  2002 Pavel Machek <pavel@ucw.cz>
 *  2001 Patrick Mochel <mochel@osdl.org>

as a matter of credits to the people who originally developed this code.

> + */
> +
> +#include <linux/gfp.h>
> +#include <linux/smp.h>
> +#include <linux/suspend.h>
> +#include <linux/scatterlist.h>
> +#include <linux/kdebug.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>
> +
> +/*
> + * 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 __visible;
> +unsigned long jump_address_phys;
> +
> +/*
> + * Value of the cr3 register from before the hibernation (this value is passed
> + * in the image header).
> + */
> +unsigned long restore_cr3 __visible;
> +unsigned long temp_level4_pgt __visible;
> +unsigned long relocated_restore_code __visible;
> +
> +#ifdef CONFIG_X86_64
> +#define RESTORE_MAGIC  0x23456789ABCDEF01UL
> +#else
> +#define RESTORE_MAGIC  0x12345678UL
> +#endif
> +
> +/**
> + *     pfn_is_nosave - check if given pfn is in the 'nosave' section
> + */
> +int pfn_is_nosave(unsigned long pfn)
> +{
> +       unsigned long nosave_begin_pfn;
> +       unsigned long nosave_end_pfn;
> +
> +       nosave_begin_pfn = __pa_symbol(&__nosave_begin) >> PAGE_SHIFT;
> +       nosave_end_pfn = PAGE_ALIGN(__pa_symbol(&__nosave_end)) >> PAGE_SHIFT;
> +
> +       return pfn >= nosave_begin_pfn && pfn < nosave_end_pfn;
> +}
> +

Since the majority of the code below in this new file is only going to
be used on 64-bit to start with, I will put it under #ifdef
CONFIG_X86_64 at this point and remove the #ifdef in one of the
subsequent patches when 32-bit actually starts to use it.

Thanks,
Rafael

Re: [PATCH 04/12][RFC v3] x86, hibernate: Extract the common code of 64/32 bit system

[Rafael J. Wysocki]

On Wed, Sep 19, 2018 at 11:03 AM Rafael J. Wysocki <rafael@kernel.org> wrote:
>
> On Wed, Sep 19, 2018 at 9:32 AM Chen Yu <yu.c.chen@intel.com> wrote:
> >
> > From: Zhimin Gu <kookoo.gu@intel.com>
> >
> > Reduce the hibernation code duplication between x86-32 and x86-64
> > by extracting the common code into hibernate.c.
> >
> > No functional change.
> >
> > Acked-by: Pavel Machek <pavel@ucw.cz>
> > Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
> > Cc: Thomas Gleixner <tglx@linutronix.de>
> > Signed-off-by: Zhimin Gu <kookoo.gu@intel.com>
> > Signed-off-by: Chen Yu <yu.c.chen@intel.com>
> > ---
> >  arch/x86/include/asm/suspend.h |   8 ++
> >  arch/x86/power/Makefile        |   2 +-
> >  arch/x86/power/hibernate.c     | 249 +++++++++++++++++++++++++++++++++
> >  arch/x86/power/hibernate_32.c  |  15 +-
> >  arch/x86/power/hibernate_64.c  | 221 -----------------------------
> >  5 files changed, 259 insertions(+), 236 deletions(-)
> >  create mode 100644 arch/x86/power/hibernate.c
> >
> > diff --git a/arch/x86/include/asm/suspend.h b/arch/x86/include/asm/suspend.h
> > index ecffe81ff65c..40b02558749f 100644
> > --- a/arch/x86/include/asm/suspend.h
> > +++ b/arch/x86/include/asm/suspend.h
> > @@ -4,3 +4,11 @@
> >  #else
> >  # include <asm/suspend_64.h>
> >  #endif
> > +extern unsigned long restore_jump_address __visible;
> > +extern unsigned long jump_address_phys;
> > +extern unsigned long restore_cr3 __visible;
> > +extern unsigned long temp_level4_pgt __visible;
> > +extern unsigned long relocated_restore_code __visible;
> > +extern int relocate_restore_code(void);
> > +/* Defined in hibernate_asm_32/64.S */
> > +extern asmlinkage __visible int restore_image(void);
> > diff --git a/arch/x86/power/Makefile b/arch/x86/power/Makefile
> > index a4701389562c..37923d715741 100644
> > --- a/arch/x86/power/Makefile
> > +++ b/arch/x86/power/Makefile
> > @@ -7,4 +7,4 @@ nostackp := $(call cc-option, -fno-stack-protector)
> >  CFLAGS_cpu.o   := $(nostackp)
> >
> >  obj-$(CONFIG_PM_SLEEP)         += cpu.o
> > -obj-$(CONFIG_HIBERNATION)      += hibernate_$(BITS).o hibernate_asm_$(BITS).o
> > +obj-$(CONFIG_HIBERNATION)      += hibernate_$(BITS).o hibernate_asm_$(BITS).o hibernate.o
> > diff --git a/arch/x86/power/hibernate.c b/arch/x86/power/hibernate.c
> > new file mode 100644
> > index 000000000000..fbde8f0e8fe0
> > --- /dev/null
> > +++ b/arch/x86/power/hibernate.c
> > @@ -0,0 +1,249 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Hibernation support for x86
> > + *
> > + * 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>
>
> I don't think this "copyright" information has any legal bearing any
> more at this point.
>
> I would just write it as
>
>  * Authors:
>  *  2007 Rafael J. Wysocki <rjw@sisk.pl>
>  *  2002 Pavel Machek <pavel@ucw.cz>
>  *  2001 Patrick Mochel <mochel@osdl.org>
>
> as a matter of credits to the people who originally developed this code.
>
> > + */
> > +
> > +#include <linux/gfp.h>
> > +#include <linux/smp.h>
> > +#include <linux/suspend.h>
> > +#include <linux/scatterlist.h>
> > +#include <linux/kdebug.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>
> > +
> > +/*
> > + * 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 __visible;
> > +unsigned long jump_address_phys;
> > +
> > +/*
> > + * Value of the cr3 register from before the hibernation (this value is passed
> > + * in the image header).
> > + */
> > +unsigned long restore_cr3 __visible;
> > +unsigned long temp_level4_pgt __visible;
> > +unsigned long relocated_restore_code __visible;
> > +
> > +#ifdef CONFIG_X86_64
> > +#define RESTORE_MAGIC  0x23456789ABCDEF01UL
> > +#else
> > +#define RESTORE_MAGIC  0x12345678UL
> > +#endif
> > +
> > +/**
> > + *     pfn_is_nosave - check if given pfn is in the 'nosave' section
> > + */
> > +int pfn_is_nosave(unsigned long pfn)
> > +{
> > +       unsigned long nosave_begin_pfn;
> > +       unsigned long nosave_end_pfn;
> > +
> > +       nosave_begin_pfn = __pa_symbol(&__nosave_begin) >> PAGE_SHIFT;
> > +       nosave_end_pfn = PAGE_ALIGN(__pa_symbol(&__nosave_end)) >> PAGE_SHIFT;
> > +
> > +       return pfn >= nosave_begin_pfn && pfn < nosave_end_pfn;
> > +}
> > +
>
> Since the majority of the code below in this new file is only going to
> be used on 64-bit to start with, I will put it under #ifdef

I should have said "I would put it under #ifdef" here, sorry for the
possible confusion.

> CONFIG_X86_64 at this point and remove the #ifdef in one of the
> subsequent patches when 32-bit actually starts to use it.

Thanks,
Rafael

Re: [PATCH 05/12][RFC v3] x86-32, hibernate: Enable CONFIG_ARCH_HIBERNATION_HEADER set on 32bit system

[Rafael J. Wysocki]

On Wed, Sep 19, 2018 at 9:32 AM Chen Yu <yu.c.chen@intel.com> wrote:
>
> From: Zhimin Gu <kookoo.gu@intel.com>
>
> Enable CONFIG_ARCH_HIBERNATION_HEADER for 32bit system so that
> md5 check is enabled and prepare for relocated code executing
> and jump address mapping.
>
> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
> Signed-off-by: Zhimin Gu <kookoo.gu@intel.com>
> Signed-off-by: Chen Yu <yu.c.chen@intel.com>
> ---
>  arch/x86/Kconfig | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
> index 1a0be022f91d..e8de5de1057f 100644
> --- a/arch/x86/Kconfig
> +++ b/arch/x86/Kconfig
> @@ -2422,7 +2422,7 @@ menu "Power management and ACPI options"
>
>  config ARCH_HIBERNATION_HEADER
>         def_bool y
> -       depends on X86_64 && HIBERNATION
> +       depends on HIBERNATION
>
>  source "kernel/power/Kconfig"
>
> --

In this patch, in addition to the above, I would start moving the code
in hibernate.c that you want to be common in the end out of #ifdef
CONFIG_X86_64 blocks.

To start with, that would be the checksum handling code and the parts
of arch_hibernation_header_save/restore() that refer to it and the
"magic" value.

I would continue doing that in the subsequent patches to make it
easier to follow which pieces of code start to be used on 32-bit after
each patch.  The impact of each patch would be more clear this way
IMO.

Thanks,
Rafael

Re: [PATCH 04/12][RFC v3] x86, hibernate: Extract the common code of 64/32 bit system

[Ingo Molnar]

* Rafael J. Wysocki <rafael@kernel.org> wrote:

> > index 000000000000..fbde8f0e8fe0
> > --- /dev/null
> > +++ b/arch/x86/power/hibernate.c
> > @@ -0,0 +1,249 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Hibernation support for x86
> > + *
> > + * 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>
> 
> I don't think this "copyright" information has any legal bearing any
> more at this point.

I think that's wrong in general, and it's routine for corporate legal
departments to insist on specific boilerplate copyright notices when
OSS code is contributed.

Copying code and then removing copyright notices is frowned upon
independently as well.

While you can probably talk for your own copyright notice, I'm not sure
it's true of the two other historic copyright notices that were copied.

So I think it's best practice to preserve all copyright notices as-is.

Thanks,

	Ingo

Re: [PATCH 04/12][RFC v3] x86, hibernate: Extract the common code of 64/32 bit system

[Rafael J. Wysocki]

On Wed, Sep 19, 2018 at 12:34 PM Ingo Molnar <mingo@kernel.org> wrote:
>
>
> * Rafael J. Wysocki <rafael@kernel.org> wrote:
>
> > > index 000000000000..fbde8f0e8fe0
> > > --- /dev/null
> > > +++ b/arch/x86/power/hibernate.c
> > > @@ -0,0 +1,249 @@
> > > +// SPDX-License-Identifier: GPL-2.0
> > > +/*
> > > + * Hibernation support for x86
> > > + *
> > > + * 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>
> >
> > I don't think this "copyright" information has any legal bearing any
> > more at this point.
>
> I think that's wrong in general, and it's routine for corporate legal
> departments to insist on specific boilerplate copyright notices when
> OSS code is contributed.
>
> Copying code and then removing copyright notices is frowned upon
> independently as well.
>
> While you can probably talk for your own copyright notice, I'm not sure
> it's true of the two other historic copyright notices that were copied.
>
> So I think it's best practice to preserve all copyright notices as-is.

OK, let's retain them, then.

Thanks,
Rafael

Re: [PATCH 01/12][RFC v3] x86, hibernate: Fix nosave_regions setup for hibernation

[Pavel Machek]

On Wed 2018-09-19 15:37:15, Chen Yu wrote:
> From: Zhimin Gu <kookoo.gu@intel.com>
> 
> On 32bit systems, nosave_regions(non RAM areas) located between
> max_low_pfn and max_pfn are not excluded from hibernation snapshot
> currently, which may result in a machine check exception when
> trying to access these unsafe regions during hibernation:
> 
> [  612.800453] Disabling lock debugging due to kernel taint
> [  612.805786] mce: [Hardware Error]: CPU 0: Machine Check Exception: 5 Bank 6: fe00000000801136
> [  612.814344] mce: [Hardware Error]: RIP !INEXACT! 60:<00000000d90be566> {swsusp_save+0x436/0x560}
> [  612.823167] mce: [Hardware Error]: TSC 1f5939fe276 ADDR dd000000 MISC 30e0000086
> [  612.830677] mce: [Hardware Error]: PROCESSOR 0:306c3 TIME 1529487426 SOCKET 0 APIC 0 microcode 24
> [  612.839581] mce: [Hardware Error]: Run the above through 'mcelog --ascii'
> [  612.846394] mce: [Hardware Error]: Machine check: Processor context corrupt
> [  612.853380] Kernel panic - not syncing: Fatal machine check
> [  612.858978] Kernel Offset: 0x18000000 from 0xc1000000 (relocation range: 0xc0000000-0xf7ffdfff)
> 
> This is because on 32bit systems, pages above max_low_pfn are regarded
> as high memeory, and accessing unsafe pages might cause expected MCE.
> On the problematic 32bit system, there are reserved memory above low
> memory, which triggered the MCE:
> 
> Fix this problem by changing pfn limit from max_low_pfn to max_pfn.
> This fix does not impact 64bit system because on 64bit max_low_pfn
> is the same as max_pfn.
> 
> Acked-by: Pavel Machek <pavel@ucw.cz>

Thanks.

I think this is nasty enough to add Cc: stable.
									Pavel
-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

Re: [PATCH 02/12][RFC v3] PM / hibernate: Check the success of generating md5 digest before hibernation

[Pavel Machek]

On Wed 2018-09-19 15:38:17, Chen Yu wrote:
> Currently if get_e820_md5() fails, then it will hibernate nevertheless.
> Actually the error code should be propagated to upper caller so that
> the hibernation could be aware of the result and terminates the process
> if md5 digest fails.
> 
> Suggested-by: Thomas Gleixner <tglx@linutronix.de>
> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
> Signed-off-by: Chen Yu <yu.c.chen@intel.com>

Acked-by: Pavel Machek <pavel@ucw.cz>

> ---
>  arch/x86/power/hibernate_64.c | 11 +++++------
>  1 file changed, 5 insertions(+), 6 deletions(-)


-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

Re: [PATCH 04/12][RFC v3] x86, hibernate: Extract the common code of 64/32 bit system

[Pavel Machek]

On Wed 2018-09-19 12:36:40, Rafael J. Wysocki wrote:
> On Wed, Sep 19, 2018 at 12:34 PM Ingo Molnar <mingo@kernel.org> wrote:
> >
> >
> > * Rafael J. Wysocki <rafael@kernel.org> wrote:
> >
> > > > index 000000000000..fbde8f0e8fe0
> > > > --- /dev/null
> > > > +++ b/arch/x86/power/hibernate.c
> > > > @@ -0,0 +1,249 @@
> > > > +// SPDX-License-Identifier: GPL-2.0
> > > > +/*
> > > > + * Hibernation support for x86
> > > > + *
> > > > + * 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>
> > >
> > > I don't think this "copyright" information has any legal bearing any
> > > more at this point.
> >
> > I think that's wrong in general, and it's routine for corporate legal
> > departments to insist on specific boilerplate copyright notices when
> > OSS code is contributed.
> >
> > Copying code and then removing copyright notices is frowned upon
> > independently as well.
> >
> > While you can probably talk for your own copyright notice, I'm not sure
> > it's true of the two other historic copyright notices that were copied.
> >
> > So I think it's best practice to preserve all copyright notices as-is.
> 
> OK, let's retain them, then.

Thank you, I was about to make same comment as Ingo.

									Pavel
-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

Re: [PATCH 07/12][RFC v3] x86-32, hibernate: Use temp_pgt as the temporary page table

[Pavel Machek]

On Wed 2018-09-19 15:42:48, Chen Yu wrote:
> From: Zhimin Gu <kookoo.gu@intel.com>
> 
> This is to reuse the temp_pgt for both 32bit and 64bit
> system.
> 
> No functional change.
> 
> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
> Signed-off-by: Zhimin Gu <kookoo.gu@intel.com>
> Signed-off-by: Chen Yu <yu.c.chen@intel.com>

Acked-by: Pavel Machek <pavel@ucw.cz>

Re: [PATCH 06/12][RFC v3] x86, hibernate: Rename temp_level4_pgt to temp_pgt

[Pavel Machek]

On Wed 2018-09-19 15:42:39, Chen Yu wrote:
> From: Zhimin Gu <kookoo.gu@intel.com>
> 
> As 32bit system is not using 4-level page, rename it
> to temp_pgt so that it can be reused for both 32bit
> and 64bit hibernation.
> 
> No functional change.
> 
> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
> Signed-off-by: Zhimin Gu <kookoo.gu@intel.com>
> Signed-off-by: Chen Yu <yu.c.chen@intel.com>

Acked-by: Pavel Machek <pavel@ucw.cz>

Re: [PATCH 08/12][RFC v3] x86-32, hibernate: Use the page size macro instead of constant value

[Pavel Machek]

On Wed 2018-09-19 15:42:57, Chen Yu wrote:
> From: Zhimin Gu <kookoo.gu@intel.com>
> 
> Convert the hard code into PAGE_SIZE for better scalability.
> 
> No functional change.
> 
> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
> Signed-off-by: Zhimin Gu <kookoo.gu@intel.com>
> Signed-off-by: Chen Yu <yu.c.chen@intel.com>

Acked-by: Pavel Machek <pavel@ucw.cz>

Re: [PATCH 09/12][RFC v3] x86-32, hibernate: Switch to original page table after resumed

[Pavel Machek]

On Wed 2018-09-19 15:43:05, Chen Yu wrote:
> From: Zhimin Gu <kookoo.gu@intel.com>
> 
> After all the pages are restored to previous address, the page
> table switches back to current swapper_pg_dir. However the
> swapper_pg_dir currently in used might not be consistent with
> previous page table, which might cause issue after resumed.
> 
> Fix this issue by switching to original page table after resumed.

"after resume".

Acked-by: Pavel Machek <pavel@ucw.cz>

Re: [PATCH 10/12][RFC v3] x86-32, hibernate: Switch to relocated restore code during resume on 32bit system

[Pavel Machek]

On Wed 2018-09-19 15:43:12, Chen Yu wrote:
> From: Zhimin Gu <kookoo.gu@intel.com>
> 
> Code should be executed in a safe page during page
> restoring, as the page where instruction is running
> during resume might be scribbled and causes issues.
> 
> Backport the code from 64 bit system to fix this bug.

On 32 bit, we only suspend resuming by same kernel that did the suspend.

64 bit does not have that restriction. So 32 bit code should not be actually
bugy.

> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
> Signed-off-by: Zhimin Gu <kookoo.gu@intel.com>
> Signed-off-by: Chen Yu <yu.c.chen@intel.com>

But we'd like to remove that restriction in future, so:

Acked-by: Pavel Machek <pavel@ucw.cz>

Re: [PATCH 11/12][RFC v3] x86-32, hibernate: Set up temporary text mapping for 32bit system

[Pavel Machek]

On Wed 2018-09-19 15:43:22, Chen Yu wrote:
> From: Zhimin Gu <kookoo.gu@intel.com>
> 
> Set up the temporary text mapping for the final jump address
> so that the system could jump to the right address after all
> the pages have been copied back to their original address.
> 
> Back-port from 64bit system.
> 
> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
> Signed-off-by: Zhimin Gu <kookoo.gu@intel.com>
> Signed-off-by: Chen Yu <yu.c.chen@intel.com>

Acked-by: Pavel Machek <pavel@ucw.cz>

Re: [PATCH 12/12][RFC v3] x86-32, hibernate: Adjust in_suspend after resumed on 32bit system

[Pavel Machek]

On Wed 2018-09-19 15:43:42, Chen Yu wrote:
> From: Zhimin Gu <kookoo.gu@intel.com>
> 
> Update the in_suspend variable to reflect the actual hibernation
> status. Back-port from 64bit system.
> 
> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
> Signed-off-by: Zhimin Gu <kookoo.gu@intel.com>
> Signed-off-by: Chen Yu <yu.c.chen@intel.com>

Acked-by: Pavel Machek <pavel@ucw.cz>