[PATCH v10 0/7] x86/boot/KASLR: Parse ACPI table and limit kaslr in immovable memory

[PATCH v10 0/7] x86/boot/KASLR: Parse ACPI table and limit kaslr in immovable memory

[Chao Fan]

***Background:
People reported that kaslr may randomly chooses some positions
which are located in movable memory regions. This will break memory
hotplug feature and make the movable memory chosen by KASLR can't be
removed.

***Solutions:
There should be a method to limit kaslr to choosing immovable memory
regions, so there are 2 solutions:
1) Add a kernel parameter to specify the memory regions.
2) Get the information of memory hot-remove, then kaslr will know the
   right regions.
In method 2, information about memory hot-remove is in ACPI
tables, which will be parsed after start_kernel(), kaslr can't get
the information.
In method 1, users should know the regions address and specify in
kernel parameter.

In the earliest time, I tried to dig ACPI tabls to solve this problem.
But I didn't splite the code in 'compressed/' and ACPI code, so the patch
is hard to follow so refused by community.
Somebody suggest to add a kernel parameter to specify the
immovable memory so that limit kaslr in these regions. Then I make
a new patchset. After several versions, Ingo gave a suggestion:
https://www.mail-archive.com/linux-kernel@vger.kernel.org/msg1634024.html
Follow Ingo's suggestion, imitate the ACPI code to parse the acpi
tables, so that the kaslr can get necessary memory information in
ACPI tables.
I think ACPI code is an independent part, so imitate the codes
and functions to 'compressed/' directory, so that kaslr won't
influence the initialization of ACPI.

PATCH 1/7 Introduce cmdline_find_option_arg() to detect if option=arg
          in cmdline
PATCH 2/7 Copy kstrtoull() to compressed period, used to convert memory
          address from string to unsigned long long.
PATCH 3/7 Add efi_get_rsdp_addr() to dig out RSDP from EFI table when
          booting from EFI.
PATCH 4/7 Add bios_get_rsdp_addr() to search RSDP in memory when EFI
          table not found.
PATCH 5/7 Add get_acpi_rsdp() to parse RSDP in cmdline from kexec
PATCH 6/7 Dig out SRAT table from RSDP and walk SRAT table to store
          the immovable memory regions.
PATCH 7/7 Calculate the intersection between memory regions from e820/efi
          memory table and immovable memory regions. Limit KASLR choose
          these regions for randomization.

v1->v2:
 -  Simplify some code.
Follow Baoquan He's suggestion:
 - Reuse the head file of acpi code.

v2->v3:
 - Test in more conditions, so remove the 'RFC' tag.
 - Change some comments.

v3->v4:
Follow Thomas Gleixner's suggetsion:
 - Put the whole efi related function into #define CONFIG_EFI and return
   false in the other stub.

v4->v5:
Follow Dou Liyang's suggestion:
 - Add more comments about some functions based on kernel code.
 - Change some typo in comments.
 - Clean useless variable.
 - Add check for the boundary of array.
 - Add check for 'movable_node' parameter

v5->v6:
Follow Baoquan He's suggestion:
 - Change some log.
 - Add the check for acpi_rsdp
 - Change some code logical to make code clear

v6->v7:
Follow Rafael's suggestion:
 - Add more comments and patch log.
Follow test robot's suggestion:
 - Add "static" tag for function

v7-v8:
Follow Kees Cook's suggestion:
 - Use mem_overlaps() to check memory region.
 - Use #ifdef in the definition of function.

v8-v9:
Follow Boris' suggetion:
 - Change code style.
 - Splite PATCH 1/3 to more path.
 - Introduce some new function
 - Use existing function to rework some code
Follow Masayoshi's suggetion:
 - Make code more readable

v9->v10:
Follow Baoquan's suggestion:
 - Change some log
 - Merge last two patch together.

Any comments will be welcome.

Chao Fan (7):
  x86/boot: Introduce cmdline_find_option_arg()to detect if option=arg
    in cmdline
  x86/boot: Copy kstrtoull() to compressed period
  x86/boot: Add efi_get_rsdp_addr() to dig out RSDP from EFI table
  x86/boot: Add bios_get_rsdp_addr() to search RSDP in memory
  x86/boot: Add get_acpi_rsdp() to parse RSDP in cmdlien from kexec
  x86/boot: Dig out SRAT table from RSDP and find immovable memory
  x86/boot/KASLR: Limit kaslr to choosing the immovable memory

 arch/x86/boot/compressed/Makefile  |   4 +
 arch/x86/boot/compressed/acpitb.c  | 352 +++++++++++++++++++++++++++++
 arch/x86/boot/compressed/cmdline.c |  15 ++
 arch/x86/boot/compressed/kaslr.c   |  81 +++++--
 arch/x86/boot/compressed/misc.c    |  88 ++++++++
 arch/x86/boot/compressed/misc.h    |  20 ++
 6 files changed, 545 insertions(+), 15 deletions(-)
 create mode 100644 arch/x86/boot/compressed/acpitb.c

-- 
2.17.2

[PATCH v10 1/7] x86/boot: Introduce cmdline_find_option_arg()to detect if option=arg in cmdline

[Chao Fan]

Now, there are cmdline_find_option() and cmdline_find_option_bool() in
cmdline.c. Sometimes, when detecting such as whether 'acpi=off' is
in cmdline, we need to cmdline_find_option() first, then compare
the argument. Now splite the operation as a independent function.
Introduce a new function cmdline_find_option_arg() to detect whether
option is in command line and the value is arg.

Signed-off-by: Chao Fan <fanc.fnst@cn.fujitsu.com>
---
 arch/x86/boot/compressed/cmdline.c | 15 +++++++++++++++
 arch/x86/boot/compressed/misc.h    |  1 +
 2 files changed, 16 insertions(+)

diff --git a/arch/x86/boot/compressed/cmdline.c b/arch/x86/boot/compressed/cmdline.c
index af6cda0b7900..61118c69feb8 100644
--- a/arch/x86/boot/compressed/cmdline.c
+++ b/arch/x86/boot/compressed/cmdline.c
@@ -1,5 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0
 #include "misc.h"
+#define STATIC
+#include <linux/decompress/mm.h>
 
 #if CONFIG_EARLY_PRINTK || CONFIG_RANDOMIZE_BASE || CONFIG_X86_5LEVEL
 
@@ -30,5 +32,18 @@ int cmdline_find_option_bool(const char *option)
 {
 	return __cmdline_find_option_bool(get_cmd_line_ptr(), option);
 }
+bool cmdline_find_option_arg(const char *option, const char *arg, int argsize)
+{
+	char *buffer = malloc(argsize+1);
+	bool find = false;
+	int ret;
+
+	ret = cmdline_find_option(option, buffer, argsize+1);
+	if (ret == argsize && !strncmp(buffer, arg, argsize))
+		find = true;
+
+	free(buffer);
+	return find;
+}
 
 #endif
diff --git a/arch/x86/boot/compressed/misc.h b/arch/x86/boot/compressed/misc.h
index a1d5918765f3..008fdc47a29c 100644
--- a/arch/x86/boot/compressed/misc.h
+++ b/arch/x86/boot/compressed/misc.h
@@ -67,6 +67,7 @@ static inline void debug_puthex(const char *s)
 /* cmdline.c */
 int cmdline_find_option(const char *option, char *buffer, int bufsize);
 int cmdline_find_option_bool(const char *option);
+bool cmdline_find_option_arg(const char *option, const char *arg, int argsize);
 #endif
 
 
-- 
2.17.2

Re: [PATCH v10 1/7] x86/boot: Introduce cmdline_find_option_arg()to detect if option=arg in cmdline

[Borislav Petkov]

On Mon, Oct 22, 2018 at 05:37:14PM +0800, Chao Fan wrote:
> Now, there are cmdline_find_option() and cmdline_find_option_bool() in
> cmdline.c. Sometimes, when detecting such as whether 'acpi=off' is
> in cmdline, we need to cmdline_find_option() first, then compare
> the argument. Now splite the operation as a independent function.
> Introduce a new function cmdline_find_option_arg() to detect whether
> option is in command line and the value is arg.

For all future commit messages you write:

Use passive tone in your commit message: no "we", etc.

Also, pls read section "2) Describe your changes" in
Documentation/process/submitting-patches.rst.

> Signed-off-by: Chao Fan <fanc.fnst@cn.fujitsu.com>
> ---
>  arch/x86/boot/compressed/cmdline.c | 15 +++++++++++++++
>  arch/x86/boot/compressed/misc.h    |  1 +
>  2 files changed, 16 insertions(+)
> 
> diff --git a/arch/x86/boot/compressed/cmdline.c b/arch/x86/boot/compressed/cmdline.c
> index af6cda0b7900..61118c69feb8 100644
> --- a/arch/x86/boot/compressed/cmdline.c
> +++ b/arch/x86/boot/compressed/cmdline.c
> @@ -1,5 +1,7 @@
>  // SPDX-License-Identifier: GPL-2.0
>  #include "misc.h"
> +#define STATIC
> +#include <linux/decompress/mm.h>
>  
>  #if CONFIG_EARLY_PRINTK || CONFIG_RANDOMIZE_BASE || CONFIG_X86_5LEVEL
>  
> @@ -30,5 +32,18 @@ int cmdline_find_option_bool(const char *option)
>  {
>  	return __cmdline_find_option_bool(get_cmd_line_ptr(), option);
>  }
> +bool cmdline_find_option_arg(const char *option, const char *arg, int argsize)
> +{
> +	char *buffer = malloc(argsize+1);
> +	bool find = false;
> +	int ret;
> +
> +	ret = cmdline_find_option(option, buffer, argsize+1);
> +	if (ret == argsize && !strncmp(buffer, arg, argsize))
> +		find = true;
> +
> +	free(buffer);
> +	return find;
> +}

I don't think such wrapper is needed. Simply calling
cmdline_find_option() and then examining the buffer - like other call
sites do - is perfectly fine.

Thx.

-- 
Regards/Gruss,
    Boris.

Good mailing practices for 400: avoid top-posting and trim the reply.

Re: [PATCH v10 1/7] x86/boot: Introduce cmdline_find_option_arg()to detect if option=arg in cmdline

[Chao Fan]

On Tue, Nov 06, 2018 at 01:22:53PM +0100, Borislav Petkov wrote:
>On Mon, Oct 22, 2018 at 05:37:14PM +0800, Chao Fan wrote:
>> Now, there are cmdline_find_option() and cmdline_find_option_bool() in
>> cmdline.c. Sometimes, when detecting such as whether 'acpi=off' is
>> in cmdline, we need to cmdline_find_option() first, then compare
>> the argument. Now splite the operation as a independent function.
>> Introduce a new function cmdline_find_option_arg() to detect whether
>> option is in command line and the value is arg.
>
>For all future commit messages you write:
>
>Use passive tone in your commit message: no "we", etc.

Got it.

>
>Also, pls read section "2) Describe your changes" in
>Documentation/process/submitting-patches.rst.
OK.
>
>> Signed-off-by: Chao Fan <fanc.fnst@cn.fujitsu.com>
>> ---
>>  arch/x86/boot/compressed/cmdline.c | 15 +++++++++++++++
>>  arch/x86/boot/compressed/misc.h    |  1 +
>>  2 files changed, 16 insertions(+)
>> 
>> diff --git a/arch/x86/boot/compressed/cmdline.c b/arch/x86/boot/compressed/cmdline.c
>> index af6cda0b7900..61118c69feb8 100644
>> --- a/arch/x86/boot/compressed/cmdline.c
>> +++ b/arch/x86/boot/compressed/cmdline.c
>> @@ -1,5 +1,7 @@
>>  // SPDX-License-Identifier: GPL-2.0
>>  #include "misc.h"
>> +#define STATIC
>> +#include <linux/decompress/mm.h>
>>  
>>  #if CONFIG_EARLY_PRINTK || CONFIG_RANDOMIZE_BASE || CONFIG_X86_5LEVEL
>>  
>> @@ -30,5 +32,18 @@ int cmdline_find_option_bool(const char *option)
>>  {
>>  	return __cmdline_find_option_bool(get_cmd_line_ptr(), option);
>>  }
>> +bool cmdline_find_option_arg(const char *option, const char *arg, int argsize)
>> +{
>> +	char *buffer = malloc(argsize+1);
>> +	bool find = false;
>> +	int ret;
>> +
>> +	ret = cmdline_find_option(option, buffer, argsize+1);
>> +	if (ret == argsize && !strncmp(buffer, arg, argsize))
>> +		find = true;
>> +
>> +	free(buffer);
>> +	return find;
>> +}
>
>I don't think such wrapper is needed. Simply calling
>cmdline_find_option() and then examining the buffer - like other call
>sites do - is perfectly fine.

I will change it.

Thanks,
Chao Fan
>
>Thx.
>
>-- 
>Regards/Gruss,
>    Boris.
>
>Good mailing practices for 400: avoid top-posting and trim the reply.
>
>

[PATCH v10 2/7] x86/boot: Copy kstrtoull() to compressed period

[Chao Fan]

kstrtoull() lives in 'uncompressed' period, used to
convert a string to an unsigned long long.
Copy to 'compressed' so that we can use it to
convert the memory address from sting to unsigned
long long in 'compressed' period.

Signed-off-by: Chao Fan <fanc.fnst@cn.fujitsu.com>
---
 arch/x86/boot/compressed/misc.c | 88 +++++++++++++++++++++++++++++++++
 arch/x86/boot/compressed/misc.h |  4 ++
 2 files changed, 92 insertions(+)

diff --git a/arch/x86/boot/compressed/misc.c b/arch/x86/boot/compressed/misc.c
index 8dd1d5ccae58..5b9b24949337 100644
--- a/arch/x86/boot/compressed/misc.c
+++ b/arch/x86/boot/compressed/misc.c
@@ -426,3 +426,91 @@ void fortify_panic(const char *name)
 {
 	error("detected buffer overflow");
 }
+
+#define KSTRTOX_OVERFLOW        (1U << 31)
+
+static inline char _tolower(const char c)
+{
+	return c | 0x20;
+}
+
+unsigned int
+_parse_integer(const char *s, unsigned int base, unsigned long long *p)
+{
+	unsigned long long res;
+	unsigned int rv;
+
+	res = 0;
+	rv = 0;
+	while (1) {
+		unsigned int c = *s;
+		unsigned int lc = c | 0x20; /* don't tolower() this line */
+		unsigned int val;
+
+		if ('0' <= c && c <= '9')
+			val = c - '0';
+		else if ('a' <= lc && lc <= 'f')
+			val = lc - 'a' + 10;
+		else
+			break;
+
+		if (val >= base)
+			break;
+		/*
+		 * Check for overflow only if we are within range of
+		 * it in the max base we support (16)
+		 */
+		if (unlikely(res & (~0ull << 60))) {
+			if (res > div_u64(ULLONG_MAX - val, base))
+				rv |= KSTRTOX_OVERFLOW;
+		}
+		res = res * base + val;
+		rv++;
+		s++;
+	}
+	*p = res;
+	return rv;
+}
+
+const char *_parse_integer_fixup_radix(const char *s, unsigned int *base)
+{
+	if (*base == 0) {
+		if (s[0] == '0') {
+			if (_tolower(s[1]) == 'x' && isxdigit(s[2]))
+				*base = 16;
+			else
+				*base = 8;
+		} else
+			*base = 10;
+	}
+	if (*base == 16 && s[0] == '0' && _tolower(s[1]) == 'x')
+		s += 2;
+	return s;
+}
+
+static int _kstrtoull(const char *s, unsigned int base, unsigned long long *res)
+{
+	unsigned long long _res;
+	unsigned int rv;
+
+	s = _parse_integer_fixup_radix(s, &base);
+	rv = _parse_integer(s, base, &_res);
+	if (rv & KSTRTOX_OVERFLOW)
+		return -ERANGE;
+	if (rv == 0)
+		return -EINVAL;
+	s += rv;
+	if (*s == '\n')
+		s++;
+	if (*s)
+		return -EINVAL;
+	*res = _res;
+	return 0;
+}
+
+int kstrtoull(const char *s, unsigned int base, unsigned long long *res)
+{
+	if (s[0] == '+')
+		s++;
+	return _kstrtoull(s, base, res);
+}
diff --git a/arch/x86/boot/compressed/misc.h b/arch/x86/boot/compressed/misc.h
index 008fdc47a29c..40378408d980 100644
--- a/arch/x86/boot/compressed/misc.h
+++ b/arch/x86/boot/compressed/misc.h
@@ -63,6 +63,10 @@ static inline void debug_puthex(const char *s)
 
 #endif
 
+#if (defined CONFIG_RANDOMIZE_BASE) && (defined CONFIG_RANDOMIZE_BASE)
+int kstrtoull(const char *s, unsigned int base, unsigned long long *res);
+#endif
+
 #if CONFIG_EARLY_PRINTK || CONFIG_RANDOMIZE_BASE
 /* cmdline.c */
 int cmdline_find_option(const char *option, char *buffer, int bufsize);
-- 
2.17.2

Re: [PATCH v10 2/7] x86/boot: Copy kstrtoull() to compressed period

[Borislav Petkov]

On Mon, Oct 22, 2018 at 05:37:15PM +0800, Chao Fan wrote:
> kstrtoull() lives in 'uncompressed' period, used to
> convert a string to an unsigned long long.
> Copy to 'compressed' so that we can use it to
> convert the memory address from sting to unsigned

sting?

> long long in 'compressed' period.
> 
> Signed-off-by: Chao Fan <fanc.fnst@cn.fujitsu.com>
> ---
>  arch/x86/boot/compressed/misc.c | 88 +++++++++++++++++++++++++++++++++
>  arch/x86/boot/compressed/misc.h |  4 ++
>  2 files changed, 92 insertions(+)

Why do you need to copy things?

You can link that file into compressed/ as lib/kstrtox.c is a library or
include it similar to what arch/x86/boot/compressed/cmdline.c does.

Still better than copying the code.

> diff --git a/arch/x86/boot/compressed/misc.h b/arch/x86/boot/compressed/misc.h
> index 008fdc47a29c..40378408d980 100644
> --- a/arch/x86/boot/compressed/misc.h
> +++ b/arch/x86/boot/compressed/misc.h
> @@ -63,6 +63,10 @@ static inline void debug_puthex(const char *s)
>  
>  #endif
>  
> +#if (defined CONFIG_RANDOMIZE_BASE) && (defined CONFIG_RANDOMIZE_BASE)

CONFIG_RANDOMIZE_BASE twice huh? Once not enough?

:-)

-- 
Regards/Gruss,
    Boris.

Good mailing practices for 400: avoid top-posting and trim the reply.

Re: [PATCH v10 2/7] x86/boot: Copy kstrtoull() to compressed period

[Chao Fan]

On Tue, Nov 06, 2018 at 08:13:03PM +0100, Borislav Petkov wrote:
>On Mon, Oct 22, 2018 at 05:37:15PM +0800, Chao Fan wrote:
>> kstrtoull() lives in 'uncompressed' period, used to
>> convert a string to an unsigned long long.
>> Copy to 'compressed' so that we can use it to
>> convert the memory address from sting to unsigned
>
>sting?

oops, typo, string.
>
>> long long in 'compressed' period.
>> 
>> Signed-off-by: Chao Fan <fanc.fnst@cn.fujitsu.com>
>> ---
>>  arch/x86/boot/compressed/misc.c | 88 +++++++++++++++++++++++++++++++++
>>  arch/x86/boot/compressed/misc.h |  4 ++
>>  2 files changed, 92 insertions(+)
>
>Why do you need to copy things?
>
>You can link that file into compressed/ as lib/kstrtox.c is a library or
>include it similar to what arch/x86/boot/compressed/cmdline.c does.
>
>Still better than copying the code.

I will have a try, thanks for your suggestion.

>
>> diff --git a/arch/x86/boot/compressed/misc.h b/arch/x86/boot/compressed/misc.h
>> index 008fdc47a29c..40378408d980 100644
>> --- a/arch/x86/boot/compressed/misc.h
>> +++ b/arch/x86/boot/compressed/misc.h
>> @@ -63,6 +63,10 @@ static inline void debug_puthex(const char *s)
>>  
>>  #endif
>>  
>> +#if (defined CONFIG_RANDOMIZE_BASE) && (defined CONFIG_RANDOMIZE_BASE)
>
>CONFIG_RANDOMIZE_BASE twice huh? Once not enough?

Sorry for that, the second should be CONFIG_MEMORY_HOTREMOVE.

Thanks,
Chao Fan

>
>:-)
>
>-- 
>Regards/Gruss,
>    Boris.
>
>Good mailing practices for 400: avoid top-posting and trim the reply.
>
>

[PATCH v10 3/7] x86/boot: Add efi_get_rsdp_addr() to dig out RSDP from EFI table

[Chao Fan]

Imitate ACPI code and EFI code to dig RSDP pointer from EFI tables.
Process: boot_param->systab->efi_config_table->RSDP.
Based on efi_init(), efi_config_init(), efi_config_parse_tables().

Used for later patch to dig out SRAT table and get the memory
information. So that we can figure out the immovable memory regions
to avoid KASLR extracts kernel on movable memory, so slove the
conflict between KASLR and movable_node feature.

Signed-off-by: Chao Fan <fanc.fnst@cn.fujitsu.com>
---
 arch/x86/boot/compressed/acpitb.c | 96 +++++++++++++++++++++++++++++++
 1 file changed, 96 insertions(+)
 create mode 100644 arch/x86/boot/compressed/acpitb.c

diff --git a/arch/x86/boot/compressed/acpitb.c b/arch/x86/boot/compressed/acpitb.c
new file mode 100644
index 000000000000..56b54b0e0889
--- /dev/null
+++ b/arch/x86/boot/compressed/acpitb.c
@@ -0,0 +1,96 @@
+// SPDX-License-Identifier: GPL-2.0
+#define BOOT_CTYPE_H
+#include "misc.h"
+#include "error.h"
+
+#include <linux/efi.h>
+#include <asm/efi.h>
+#include <linux/numa.h>
+#include <linux/acpi.h>
+
+/* Search EFI table for RSDP table. */
+static void efi_get_rsdp_addr(acpi_physical_address *rsdp_addr)
+{
+#ifdef CONFIG_EFI
+	efi_system_table_t *systab;
+	bool efi_64 = false;
+	void *config_tables;
+	struct efi_info *e;
+	char *sig;
+	int size;
+	int i;
+
+	e = &boot_params->efi_info;
+	sig = (char *)&e->efi_loader_signature;
+
+	if (!strncmp(sig, EFI64_LOADER_SIGNATURE, 4))
+		efi_64 = true;
+	else if (!strncmp(sig, EFI32_LOADER_SIGNATURE, 4))
+		efi_64 = false;
+	else {
+		debug_putstr("Wrong EFI loader signature.\n");
+		return;
+	}
+
+	/* Get systab from boot params. Based on efi_init(). */
+#ifdef CONFIG_X86_64
+	systab = (efi_system_table_t *)(
+			e->efi_systab | ((__u64)e->efi_systab_hi<<32));
+#else
+	if (e->efi_systab_hi || e->efi_memmap_hi) {
+		debug_putstr("Table located above 4GB. EFI should be disabled.\n");
+		return;
+	}
+	systab = (efi_system_table_t *)e->efi_systab;
+#endif
+
+	if (!systab)
+		return;
+
+	/*
+	 * Get EFI tables from systab. Based on efi_config_init() and
+	 * efi_config_parse_tables(). Only dig out the config_table.
+	 */
+	size = efi_64 ? sizeof(efi_config_table_64_t) :
+			sizeof(efi_config_table_32_t);
+
+	for (i = 0; i < systab->nr_tables; i++) {
+		efi_guid_t guid;
+		unsigned long table;
+
+		config_tables = (void *)(systab->tables + size * i);
+		if (efi_64) {
+			efi_config_table_64_t *tmp_table;
+
+			tmp_table = (efi_config_table_64_t *)config_tables;
+			guid = tmp_table->guid;
+			table = tmp_table->table;
+#ifndef CONFIG_64BIT
+			if (table >> 32) {
+				debug_putstr("Table located above 4G. EFI should be disabled.\n");
+				return;
+			}
+#endif
+		} else {
+			efi_config_table_32_t *tmp_table;
+
+			tmp_table = (efi_config_table_32_t *)config_tables;
+			guid = tmp_table->guid;
+			table = tmp_table->table;
+		}
+
+		/*
+		 * Get RSDP from EFI tables.
+		 * If ACPI20 table found, use it.
+		 * If ACPI20 table not found, but ACPI table found,
+		 * use the ACPI table.
+		 */
+		if (!(efi_guidcmp(guid, ACPI_TABLE_GUID))) {
+			*rsdp_addr = (acpi_physical_address)table;
+		} else if (!(efi_guidcmp(guid, ACPI_20_TABLE_GUID))) {
+			*rsdp_addr = (acpi_physical_address)table;
+			return;
+		}
+	}
+#endif
+}
-- 
2.17.2

[PATCH v10 4/7] x86/boot: Add bios_get_rsdp_addr() to search RSDP in memory

[Chao Fan]

Imitate ACPI code to search RSDP pointer from memory.
Walk memory and check the signature until get the RSDP signature.
Based on acpi_tb_scan_memory_for_rsdp() and acpi_find_root_pointer().
If didn't get RSDP from EFI table, will run this function.

Used for later patch to dig out SRAT table and get the memory
information. So that we can figure out the immovable memory regions
to avoid KASLR extracts kernel on movable memory, so slove the
conflict between KASLR and movable_node feature.

Signed-off-by: Chao Fan <fanc.fnst@cn.fujitsu.com>
---
 arch/x86/boot/compressed/acpitb.c | 106 ++++++++++++++++++++++++++++++
 1 file changed, 106 insertions(+)

diff --git a/arch/x86/boot/compressed/acpitb.c b/arch/x86/boot/compressed/acpitb.c
index 56b54b0e0889..50fa65cf824d 100644
--- a/arch/x86/boot/compressed/acpitb.c
+++ b/arch/x86/boot/compressed/acpitb.c
@@ -94,3 +94,109 @@ static void efi_get_rsdp_addr(acpi_physical_address *rsdp_addr)
 	}
 #endif
 }
+
+static u8 compute_checksum(u8 *buffer, u32 length)
+{
+	u8 sum = 0;
+	u8 *end = buffer + length;
+
+	while (buffer < end)
+		sum = (u8)(sum + *(buffer++));
+
+	return sum;
+}
+
+/*
+ * Used to search a block of memory for the RSDP signature.
+ * Return Pointer to the RSDP if found, otherwise NULL.
+ * Based on acpi_tb_scan_memory_for_rsdp().
+ */
+static u8 *scan_mem_for_rsdp(u8 *start, u32 length)
+{
+	struct acpi_table_rsdp *rsdp;
+	u8 *end;
+	u8 *rover;
+
+	end = start + length;
+
+	/* Search from given start address for the requested length */
+	for (rover = start; rover < end; rover += ACPI_RSDP_SCAN_STEP) {
+		/*
+		 * The RSDP signature and checksum must both be correct
+		 * Note: Sometimes there exists more than one RSDP in memory;
+		 * the valid RSDP has a valid checksum, all others have an
+		 * invalid checksum.
+		 */
+		rsdp = (struct acpi_table_rsdp *)rover;
+
+		/* Nope, BAD Signature */
+		if (!ACPI_VALIDATE_RSDP_SIG(rsdp->signature))
+			continue;
+
+		/* Check the standard checksum */
+		if (compute_checksum((u8 *) rsdp, ACPI_RSDP_CHECKSUM_LENGTH))
+			continue;
+
+		/* Check extended checksum if table version >= 2 */
+		if ((rsdp->revision >= 2) &&
+		    (compute_checksum((u8 *) rsdp, ACPI_RSDP_XCHECKSUM_LENGTH)))
+			continue;
+
+		/* Sig and checksum valid, we have found a real RSDP */
+		return rover;
+	}
+	return NULL;
+}
+
+/*
+ * Used to search RSDP physical address.
+ * Based on acpi_find_root_pointer(). Since only use physical address
+ * in this period, so there is no need to do the memory map jobs.
+ */
+static void bios_get_rsdp_addr(acpi_physical_address *rsdp_addr)
+{
+	struct acpi_table_rsdp *rsdp;
+	u8 *table_ptr;
+	u8 *mem_rover;
+	u32 address;
+
+	/*
+	 * Get the location of the Extended BIOS Data Area (EBDA)
+	 * Since we use physical address directely, so
+	 * acpi_os_map_memory() and acpi_os_unmap_memory() are
+	 * not needed here.
+	 */
+	table_ptr = (u8 *)ACPI_EBDA_PTR_LOCATION;
+	*(u32 *)(void *)&address = *(u16 *)(void *)table_ptr;
+	address <<= 4;
+	table_ptr = (u8 *)address;
+
+	/*
+	 * Search EBDA paragraphs (EBDA is required to be a minimum of
+	 * 1K length)
+	 */
+	if (address > 0x400) {
+		mem_rover = scan_mem_for_rsdp(table_ptr, ACPI_EBDA_WINDOW_SIZE);
+
+		if (mem_rover) {
+			address += (u32)ACPI_PTR_DIFF(mem_rover, table_ptr);
+			*rsdp_addr = (acpi_physical_address)address;
+			return;
+		}
+	}
+
+	table_ptr = (u8 *)ACPI_HI_RSDP_WINDOW_BASE;
+	mem_rover = scan_mem_for_rsdp(table_ptr, ACPI_HI_RSDP_WINDOW_SIZE);
+
+	/*
+	 * Search upper memory: 16-byte boundaries in E0000h-FFFFFh
+	 * Since we use physical address directely, so
+	 * acpi_os_map_memory() and acpi_os_unmap_memory() are
+	 * not needed here.
+	 */
+	if (mem_rover) {
+		address = (u32)(ACPI_HI_RSDP_WINDOW_BASE +
+				ACPI_PTR_DIFF(mem_rover, table_ptr));
+		*rsdp_addr = (acpi_physical_address)address;
+	}
+}
-- 
2.17.2

[PATCH v10 5/7] x86/boot: Add get_acpi_rsdp() to parse RSDP in cmdline from kexec

[Chao Fan]

Imitate setup_acpi_rsdp() for the early_param of "acpi_rsdp".
KEXEC writes the RSDP pointer to cmdline for EFI booting.
So if "acpi_rsdp" found in cmdline, use it directely.

Signed-off-by: Chao Fan <fanc.fnst@cn.fujitsu.com>
---
 arch/x86/boot/compressed/acpitb.c | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/arch/x86/boot/compressed/acpitb.c b/arch/x86/boot/compressed/acpitb.c
index 50fa65cf824d..fa63a584d7ec 100644
--- a/arch/x86/boot/compressed/acpitb.c
+++ b/arch/x86/boot/compressed/acpitb.c
@@ -8,6 +8,9 @@
 #include <linux/numa.h>
 #include <linux/acpi.h>
 
+#define STATIC
+#include <linux/decompress/mm.h>
+
 /* Search EFI table for RSDP table. */
 static void efi_get_rsdp_addr(acpi_physical_address *rsdp_addr)
 {
@@ -200,3 +203,23 @@ static void bios_get_rsdp_addr(acpi_physical_address *rsdp_addr)
 		*rsdp_addr = (acpi_physical_address)address;
 	}
 }
+
+static void get_acpi_rsdp(acpi_physical_address *rsdp_addr)
+{
+#ifdef CONFIG_KEXEC
+	unsigned long long res;
+	int len = 0;
+	char *val;
+
+	val = malloc(19);
+	len = cmdline_find_option("acpi_rsdp", val, 19);
+
+	if (len == -1)
+		return;
+
+	if (len > 0) {
+		val[len] = 0;
+		*rsdp_addr = (acpi_physical_address)kstrtoull(val, 16, &res);
+	}
+#endif
+}
-- 
2.17.2

[PATCH v10 6/7] x86/boot: Dig out SRAT table from RSDP and find immovable memory

[Chao Fan]

To avoid KASLR extracting kernel on movable memory, and slove the
conflict between KASLR and movable_node feature, dig the SRAT tables
from RSDP pointer. Walk the SRAT tables and store the immovable
memory regions in immovable_mem[].

The code is imitated from ACPI code, based on acpi_os_get_root_pointer().
Process: RSDP->RSDT/XSDT->ACPI root table->SRAT.

Signed-off-by: Chao Fan <fanc.fnst@cn.fujitsu.com>
---
 arch/x86/boot/compressed/Makefile |   4 +
 arch/x86/boot/compressed/acpitb.c | 127 ++++++++++++++++++++++++++++++
 arch/x86/boot/compressed/kaslr.c  |   4 -
 arch/x86/boot/compressed/misc.h   |  15 ++++
 4 files changed, 146 insertions(+), 4 deletions(-)

diff --git a/arch/x86/boot/compressed/Makefile b/arch/x86/boot/compressed/Makefile
index 28764dacf018..0f631c5613d7 100644
--- a/arch/x86/boot/compressed/Makefile
+++ b/arch/x86/boot/compressed/Makefile
@@ -83,6 +83,10 @@ ifdef CONFIG_X86_64
 	vmlinux-objs-y += $(obj)/pgtable_64.o
 endif
 
+#if (defined CONFIG_MEMORY_HOTREMOVE) && (defined CONFIG_RANDOMIZE_BASE)
+vmlinux-objs-$(CONFIG_RANDOMIZE_BASE) += $(obj)/acpitb.o
+#endif
+
 $(obj)/eboot.o: KBUILD_CFLAGS += -fshort-wchar -mno-red-zone
 
 vmlinux-objs-$(CONFIG_EFI_STUB) += $(obj)/eboot.o $(obj)/efi_stub_$(BITS).o \
diff --git a/arch/x86/boot/compressed/acpitb.c b/arch/x86/boot/compressed/acpitb.c
index fa63a584d7ec..a9dbd42e5ab9 100644
--- a/arch/x86/boot/compressed/acpitb.c
+++ b/arch/x86/boot/compressed/acpitb.c
@@ -11,6 +11,11 @@
 #define STATIC
 #include <linux/decompress/mm.h>
 
+#ifdef CONFIG_MEMORY_HOTREMOVE
+/* Store the immovable memory regions */
+struct mem_vector immovable_mem[MAX_NUMNODES*2];
+#endif
+
 /* Search EFI table for RSDP table. */
 static void efi_get_rsdp_addr(acpi_physical_address *rsdp_addr)
 {
@@ -223,3 +228,125 @@ static void get_acpi_rsdp(acpi_physical_address *rsdp_addr)
 	}
 #endif
 }
+
+/*
+ * Used to dig RSDP table from EFI table or BIOS.
+ * If RSDP table found in EFI table, use it. Or search BIOS.
+ * Based on acpi_os_get_root_pointer().
+ */
+static acpi_physical_address get_rsdp_addr(void)
+{
+	acpi_physical_address pa = 0;
+
+	get_acpi_rsdp(&pa);
+
+	if (!pa)
+		efi_get_rsdp_addr(&pa);
+
+	if (!pa)
+		bios_get_rsdp_addr(&pa);
+
+	return pa;
+}
+
+static struct acpi_table_header *get_acpi_srat_table(void)
+{
+	acpi_physical_address acpi_table;
+	acpi_physical_address root_table;
+	struct acpi_table_header *header;
+	struct acpi_table_rsdp *rsdp;
+	char *signature;
+	u8 *entry;
+	u32 count;
+	u32 size;
+	int i, j;
+	u32 len;
+
+	rsdp = (struct acpi_table_rsdp *)get_rsdp_addr();
+	if (!rsdp)
+		return NULL;
+
+	/* Get RSDT or XSDT from RSDP. */
+	if (!cmdline_find_option_arg("acpi", "rsdt", 4) &&
+	    rsdp->xsdt_physical_address && rsdp->revision > 1) {
+		root_table = rsdp->xsdt_physical_address;
+		size = ACPI_XSDT_ENTRY_SIZE;
+	} else {
+		root_table = rsdp->rsdt_physical_address;
+		size = ACPI_RSDT_ENTRY_SIZE;
+	}
+
+	/* Get ACPI root table from RSDT or XSDT.*/
+	header = (struct acpi_table_header *)root_table;
+	len = header->length;
+	count = (u32)((len - sizeof(struct acpi_table_header)) / size);
+	entry = ACPI_ADD_PTR(u8, header, sizeof(struct acpi_table_header));
+
+	for (i = 0; i < count; i++) {
+		u64 address64;
+
+		if (size == ACPI_RSDT_ENTRY_SIZE)
+			acpi_table = ((acpi_physical_address)
+				      (*ACPI_CAST_PTR(u32, entry)));
+		else {
+			*(u64 *)(void *)&address64 = *(u64 *)(void *)entry;
+			acpi_table = (acpi_physical_address) address64;
+		}
+
+		if (acpi_table) {
+			header = (struct acpi_table_header *)acpi_table;
+			signature = header->signature;
+
+			if (ACPI_COMPARE_NAME(header->signature, ACPI_SIG_SRAT))
+				return header;
+		}
+		entry += size;
+	}
+	return NULL;
+}
+
+/*
+ * According to ACPI table, filter the immvoable memory regions
+ * and store them in immovable_mem[].
+ */
+void get_immovable_mem(void)
+{
+	struct acpi_table_header *table_header;
+	struct acpi_subtable_header *table;
+	struct acpi_srat_mem_affinity *ma;
+	unsigned long table_end;
+	int i = 0;
+
+	if (!cmdline_find_option_bool("movable_node") ||
+	    cmdline_find_option_arg("acpi", "off", 3))
+		return;
+
+	table_header = get_acpi_srat_table();
+	if (!table_header)
+		return;
+
+	table_end = (unsigned long)table_header + table_header->length;
+
+	table = (struct acpi_subtable_header *)
+		((unsigned long)table_header + sizeof(struct acpi_table_srat));
+
+	while (((unsigned long)table) +
+		       sizeof(struct acpi_subtable_header) < table_end) {
+		if (table->type == ACPI_SRAT_TYPE_MEMORY_AFFINITY) {
+			ma = (struct acpi_srat_mem_affinity *)table;
+			if (!(ma->flags & ACPI_SRAT_MEM_HOT_PLUGGABLE)) {
+				immovable_mem[i].start = ma->base_address;
+				immovable_mem[i].size = ma->length;
+				i++;
+			}
+
+			if (i >= MAX_NUMNODES*2) {
+				debug_putstr("Too many immovable memory regions, aborted.\n");
+				break;
+			}
+		}
+		table = (struct acpi_subtable_header *)
+			((unsigned long)table + table->length);
+	}
+	num_immovable_mem = i;
+}
diff --git a/arch/x86/boot/compressed/kaslr.c b/arch/x86/boot/compressed/kaslr.c
index 9ed9709d9947..b251572e77af 100644
--- a/arch/x86/boot/compressed/kaslr.c
+++ b/arch/x86/boot/compressed/kaslr.c
@@ -87,10 +87,6 @@ static unsigned long get_boot_seed(void)
 #define KASLR_COMPRESSED_BOOT
 #include "../../lib/kaslr.c"
 
-struct mem_vector {
-	unsigned long long start;
-	unsigned long long size;
-};
 
 /* Only supporting at most 4 unusable memmap regions with kaslr */
 #define MAX_MEMMAP_REGIONS	4
diff --git a/arch/x86/boot/compressed/misc.h b/arch/x86/boot/compressed/misc.h
index 40378408d980..83075b9c6eea 100644
--- a/arch/x86/boot/compressed/misc.h
+++ b/arch/x86/boot/compressed/misc.h
@@ -82,6 +82,11 @@ void choose_random_location(unsigned long input,
 			    unsigned long *output,
 			    unsigned long output_size,
 			    unsigned long *virt_addr);
+struct mem_vector {
+	unsigned long long start;
+	unsigned long long size;
+};
+
 /* cpuflags.c */
 bool has_cpuflag(int flag);
 #else
@@ -121,3 +126,13 @@ static inline void console_init(void)
 void set_sev_encryption_mask(void);
 
 #endif
+
+/* acpitb.c */
+#ifdef CONFIG_RANDOMIZE_BASE
+int num_immovable_mem;
+#ifdef CONFIG_MEMORY_HOTREMOVE
+/* Store the amount of immovable memory regions */
+#define ACPI_MAX_TABLES                128
+void get_immovable_mem(void);
+#endif
+#endif
-- 
2.17.2

[PATCH v10 7/7] x86/boot/KASLR: Limit kaslr to choosing the immovable memory

[Chao Fan]

If CONFIG_MEMORY_HOTREMOVE enabled, walk through the SRAT memory
tables and store those immovable memory regions so that KASLR can get
where to choose for randomization.

If the amount of immovable memory regions is not zero, which
means the immovable memory regions existing. Calculate the intersection
between memory regions from e820/efi memory table and immovable memory
regions.

Signed-off-by: Chao Fan <fanc.fnst@cn.fujitsu.com>
---
 arch/x86/boot/compressed/kaslr.c | 77 +++++++++++++++++++++++++++-----
 1 file changed, 66 insertions(+), 11 deletions(-)

diff --git a/arch/x86/boot/compressed/kaslr.c b/arch/x86/boot/compressed/kaslr.c
index b251572e77af..174d2114045e 100644
--- a/arch/x86/boot/compressed/kaslr.c
+++ b/arch/x86/boot/compressed/kaslr.c
@@ -97,6 +97,11 @@ static bool memmap_too_large;
 /* Store memory limit specified by "mem=nn[KMG]" or "memmap=nn[KMG]" */
 static unsigned long long mem_limit = ULLONG_MAX;
 
+#ifdef CONFIG_MEMORY_HOTREMOVE
+/* Store the immovable memory regions */
+extern struct mem_vector immovable_mem[MAX_NUMNODES*2];
+#endif
+
 
 enum mem_avoid_index {
 	MEM_AVOID_ZO_RANGE = 0,
@@ -413,6 +418,11 @@ static void mem_avoid_init(unsigned long input, unsigned long input_size,
 	/* Mark the memmap regions we need to avoid */
 	handle_mem_options();
 
+#ifdef CONFIG_MEMORY_HOTREMOVE
+	/* Mark the immovable regions we need to choose */
+	get_immovable_mem();
+#endif
+
 #ifdef CONFIG_X86_VERBOSE_BOOTUP
 	/* Make sure video RAM can be used. */
 	add_identity_map(0, PMD_SIZE);
@@ -568,9 +578,9 @@ static unsigned long slots_fetch_random(void)
 	return 0;
 }
 
-static void process_mem_region(struct mem_vector *entry,
-			       unsigned long minimum,
-			       unsigned long image_size)
+static void slots_count(struct mem_vector *entry,
+			unsigned long minimum,
+			unsigned long image_size)
 {
 	struct mem_vector region, overlap;
 	unsigned long start_orig, end;
@@ -646,6 +656,57 @@ static void process_mem_region(struct mem_vector *entry,
 	}
 }
 
+static bool process_mem_region(struct mem_vector *region,
+			       unsigned long long minimum,
+			       unsigned long long image_size)
+{
+	int i;
+	/*
+	 * If no immovable memory found, or MEMORY_HOTREMOVE disabled,
+	 * walk all the regions, so use region directely.
+	 */
+	if (num_immovable_mem == 0) {
+		slots_count(region, minimum, image_size);
+
+		if (slot_area_index == MAX_SLOT_AREA) {
+			debug_putstr("Aborted e820/efi memmap scan (slot_areas full)!\n");
+			return 1;
+		}
+		return 0;
+	}
+
+#ifdef CONFIG_MEMORY_HOTREMOVE
+	/*
+	 * If immovable memory found, filter the intersection between
+	 * immovable memory and region to slots_count.
+	 * Otherwise, go on old code.
+	 */
+	for (i = 0; i < num_immovable_mem; i++) {
+		struct mem_vector entry;
+		unsigned long long start, end, entry_end, region_end;
+
+		if (!mem_overlaps(region, &immovable_mem[i]))
+			continue;
+
+		start = immovable_mem[i].start;
+		end = start + immovable_mem[i].size;
+		region_end = region->start + region->size;
+
+		entry.start = clamp(region->start, start, end);
+		entry_end = clamp(region_end, start, end);
+		entry.size = entry_end - entry.start;
+
+		slots_count(&entry, minimum, image_size);
+
+		if (slot_area_index == MAX_SLOT_AREA) {
+			debug_putstr("Aborted e820/efi memmap scan (slot_areas full)!\n");
+			return 1;
+		}
+	}
+	return 0;
+#endif
+}
+
 #ifdef CONFIG_EFI
 /*
  * Returns true if mirror region found (and must have been processed
@@ -711,11 +772,8 @@ process_efi_entries(unsigned long minimum, unsigned long image_size)
 
 		region.start = md->phys_addr;
 		region.size = md->num_pages << EFI_PAGE_SHIFT;
-		process_mem_region(&region, minimum, image_size);
-		if (slot_area_index == MAX_SLOT_AREA) {
-			debug_putstr("Aborted EFI scan (slot_areas full)!\n");
+		if (process_mem_region(&region, minimum, image_size))
 			break;
-		}
 	}
 	return true;
 }
@@ -742,11 +800,8 @@ static void process_e820_entries(unsigned long minimum,
 			continue;
 		region.start = entry->addr;
 		region.size = entry->size;
-		process_mem_region(&region, minimum, image_size);
-		if (slot_area_index == MAX_SLOT_AREA) {
-			debug_putstr("Aborted e820 scan (slot_areas full)!\n");
+		if (process_mem_region(&region, minimum, image_size))
 			break;
-		}
 	}
 }
 
-- 
2.17.2

Re: [PATCH v10 0/7] x86/boot/KASLR: Parse ACPI table and limit kaslr in immovable memory

[Chao Fan]

Hi all,

Sorry for disturbance.
No reply to this version for more than one week,
any comments?

Thanks,
Chao Fan

On Mon, Oct 22, 2018 at 05:37:13PM +0800, Chao Fan wrote:
>***Background:
>People reported that kaslr may randomly chooses some positions
>which are located in movable memory regions. This will break memory
>hotplug feature and make the movable memory chosen by KASLR can't be
>removed.
>
>***Solutions:
>There should be a method to limit kaslr to choosing immovable memory
>regions, so there are 2 solutions:
>1) Add a kernel parameter to specify the memory regions.
>2) Get the information of memory hot-remove, then kaslr will know the
>   right regions.
>In method 2, information about memory hot-remove is in ACPI
>tables, which will be parsed after start_kernel(), kaslr can't get
>the information.
>In method 1, users should know the regions address and specify in
>kernel parameter.
>
>In the earliest time, I tried to dig ACPI tabls to solve this problem.
>But I didn't splite the code in 'compressed/' and ACPI code, so the patch
>is hard to follow so refused by community.
>Somebody suggest to add a kernel parameter to specify the
>immovable memory so that limit kaslr in these regions. Then I make
>a new patchset. After several versions, Ingo gave a suggestion:
>https://www.mail-archive.com/linux-kernel@vger.kernel.org/msg1634024.html
>Follow Ingo's suggestion, imitate the ACPI code to parse the acpi
>tables, so that the kaslr can get necessary memory information in
>ACPI tables.
>I think ACPI code is an independent part, so imitate the codes
>and functions to 'compressed/' directory, so that kaslr won't
>influence the initialization of ACPI.
>
>PATCH 1/7 Introduce cmdline_find_option_arg() to detect if option=arg
>          in cmdline
>PATCH 2/7 Copy kstrtoull() to compressed period, used to convert memory
>          address from string to unsigned long long.
>PATCH 3/7 Add efi_get_rsdp_addr() to dig out RSDP from EFI table when
>          booting from EFI.
>PATCH 4/7 Add bios_get_rsdp_addr() to search RSDP in memory when EFI
>          table not found.
>PATCH 5/7 Add get_acpi_rsdp() to parse RSDP in cmdline from kexec
>PATCH 6/7 Dig out SRAT table from RSDP and walk SRAT table to store
>          the immovable memory regions.
>PATCH 7/7 Calculate the intersection between memory regions from e820/efi
>          memory table and immovable memory regions. Limit KASLR choose
>          these regions for randomization.
>
>v1->v2:
> -  Simplify some code.
>Follow Baoquan He's suggestion:
> - Reuse the head file of acpi code.
>
>v2->v3:
> - Test in more conditions, so remove the 'RFC' tag.
> - Change some comments.
>
>v3->v4:
>Follow Thomas Gleixner's suggetsion:
> - Put the whole efi related function into #define CONFIG_EFI and return
>   false in the other stub.
>
>v4->v5:
>Follow Dou Liyang's suggestion:
> - Add more comments about some functions based on kernel code.
> - Change some typo in comments.
> - Clean useless variable.
> - Add check for the boundary of array.
> - Add check for 'movable_node' parameter
>
>v5->v6:
>Follow Baoquan He's suggestion:
> - Change some log.
> - Add the check for acpi_rsdp
> - Change some code logical to make code clear
>
>v6->v7:
>Follow Rafael's suggestion:
> - Add more comments and patch log.
>Follow test robot's suggestion:
> - Add "static" tag for function
>
>v7-v8:
>Follow Kees Cook's suggestion:
> - Use mem_overlaps() to check memory region.
> - Use #ifdef in the definition of function.
>
>v8-v9:
>Follow Boris' suggetion:
> - Change code style.
> - Splite PATCH 1/3 to more path.
> - Introduce some new function
> - Use existing function to rework some code
>Follow Masayoshi's suggetion:
> - Make code more readable
>
>v9->v10:
>Follow Baoquan's suggestion:
> - Change some log
> - Merge last two patch together.
>
>Any comments will be welcome.
>
>Chao Fan (7):
>  x86/boot: Introduce cmdline_find_option_arg()to detect if option=arg
>    in cmdline
>  x86/boot: Copy kstrtoull() to compressed period
>  x86/boot: Add efi_get_rsdp_addr() to dig out RSDP from EFI table
>  x86/boot: Add bios_get_rsdp_addr() to search RSDP in memory
>  x86/boot: Add get_acpi_rsdp() to parse RSDP in cmdlien from kexec
>  x86/boot: Dig out SRAT table from RSDP and find immovable memory
>  x86/boot/KASLR: Limit kaslr to choosing the immovable memory
>
> arch/x86/boot/compressed/Makefile  |   4 +
> arch/x86/boot/compressed/acpitb.c  | 352 +++++++++++++++++++++++++++++
> arch/x86/boot/compressed/cmdline.c |  15 ++
> arch/x86/boot/compressed/kaslr.c   |  81 +++++--
> arch/x86/boot/compressed/misc.c    |  88 ++++++++
> arch/x86/boot/compressed/misc.h    |  20 ++
> 6 files changed, 545 insertions(+), 15 deletions(-)
> create mode 100644 arch/x86/boot/compressed/acpitb.c
>
>-- 
>2.17.2
>

Re: [PATCH v10 0/7] x86/boot/KASLR: Parse ACPI table and limit kaslr in immovable memory

[Borislav Petkov]

On Wed, Oct 31, 2018 at 03:42:34PM +0800, Chao Fan wrote:
> Hi all,
> 
> Sorry for disturbance.
> No reply to this version for more than one week,
> any comments?

You do realize that we're right in the merge window right now, right?

And people are busy sending pull requests and fixing fallout.

So sending new stuff during the two weeks of the merge window, will
kinda put you on the backburner. Try to remember that next time and be
patient.

Thx.

-- 
Regards/Gruss,
    Boris.

Good mailing practices for 400: avoid top-posting and trim the reply.

Re: [PATCH v10 0/7] x86/boot/KASLR: Parse ACPI table and limit kaslr in immovable memory

[Chao Fan]

On Wed, Oct 31, 2018 at 11:05:37AM +0100, Borislav Petkov wrote:
>On Wed, Oct 31, 2018 at 03:42:34PM +0800, Chao Fan wrote:
>> Hi all,
>> 
>> Sorry for disturbance.
>> No reply to this version for more than one week,
>> any comments?
>
>You do realize that we're right in the merge window right now, right?
>
>And people are busy sending pull requests and fixing fallout.

So sorry for disturbance, I am not so familiar with merge cycle.

>
>So sending new stuff during the two weeks of the merge window, will
>kinda put you on the backburner. Try to remember that next time and be

Thanks for your advise, I got it.

Thanks,
Chao Fan

>patient.
>
>Thx.
>
>-- 
>Regards/Gruss,
>    Boris.
>
>Good mailing practices for 400: avoid top-posting and trim the reply.
>
>