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Subject[PATCH v3] intel_txt: add support for S3 memory integrity protection within Intel(R) TXT launched kernel
<compared with v2, this patch adds a check of array size in tboot.c, and a note 
to specify which c/s of tboot supports this kind of MACing in intel_txt.txt>

v3: Based on a complexity analysis and tradeoff, we moved all MAC'ing into
tboot.

This patch adds support for S3 memory integrity protection within an Intel(R)
TXT launched kernel, for all kernel and userspace memory. All RAM used by the
kernel and userspace, as indicated by memory ranges of type E820_RAM and
E820_RESERVED_KERN in the e820 table, will be integrity protected.

The MAINTAINERS file is also updated to reflect the maintainers of the
TXT-related code.

Signed-off-by: Shane Wang <shane.wang@intel.com>
Signed-off-by: Joseph Cihula <joseph.cihula@intel.com>

Documentation/intel_txt.txt | 16 +++++++++-------
MAINTAINERS | 11 +++++++++++
arch/x86/include/asm/e820.h | 7 ++++++-
arch/x86/kernel/tboot.c | 20 +++++++++++---------
4 files changed, 37 insertions(+), 17 deletions(-)

diff -r d2911aa1461d Documentation/intel_txt.txt
--- a/Documentation/intel_txt.txt Thu Mar 04 09:37:53 2010 -0500
+++ b/Documentation/intel_txt.txt Wed Mar 10 08:18:48 2010 -0500
@@ -161,13 +161,15 @@ o In order to put a system into any of
has been restored, it will restore the TPM PCRs and then
transfer control back to the kernel's S3 resume vector.
In order to preserve system integrity across S3, the kernel
- provides tboot with a set of memory ranges (kernel
- code/data/bss, S3 resume code, and AP trampoline) that tboot
- will calculate a MAC (message authentication code) over and then
- seal with the TPM. On resume and once the measured environment
- has been re-established, tboot will re-calculate the MAC and
- verify it against the sealed value. Tboot's policy determines
- what happens if the verification fails.
+ provides tboot with a set of memory ranges (RAM and RESERVED_KERN
+ in the e820 table, but not any memory that BIOS might alter over
+ the S3 transition) that tboot will calculate a MAC (message
+ authentication code) over and then seal with the TPM. On resume
+ and once the measured environment has been re-established, tboot
+ will re-calculate the MAC and verify it against the sealed value.
+ Tboot's policy determines what happens if the verification fails.
+ Note that the c/s 194 of tboot which has the new MAC code supports
+ this.

That's pretty much it for TXT support.

diff -r d2911aa1461d MAINTAINERS
--- a/MAINTAINERS Thu Mar 04 09:37:53 2010 -0500
+++ b/MAINTAINERS Wed Mar 10 08:18:48 2010 -0500
@@ -2891,6 +2891,17 @@ F: Documentation/networking/README.ipw22
F: Documentation/networking/README.ipw2200
F: drivers/net/wireless/ipw2x00/ipw2200.*

+INTEL(R) TRUSTED EXECUTION TECHNOLOGY (TXT)
+M: Joseph Cihula <joseph.cihula@intel.com>
+M: Shane Wang <shane.wang@intel.com>
+L: tboot-devel@lists.sourceforge.net
+W: http://tboot.sourceforge.net
+T: Mercurial http://www.bughost.org/repos.hg/tboot.hg
+S: Supported
+F: Documentation/intel_txt.txt
+F: include/linux/tboot.h
+F: arch/x86/kernel/tboot.c
+
INTEL WIRELESS WIMAX CONNECTION 2400
M: Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
M: linux-wimax@intel.com
diff -r d2911aa1461d arch/x86/include/asm/e820.h
--- a/arch/x86/include/asm/e820.h Thu Mar 04 09:37:53 2010 -0500
+++ b/arch/x86/include/asm/e820.h Wed Mar 10 08:18:48 2010 -0500
@@ -45,7 +45,12 @@
#define E820_NVS 4
#define E820_UNUSABLE 5

-/* reserved RAM used by kernel itself */
+/*
+ * reserved RAM used by kernel itself
+ * if CONFIG_INTEL_TXT is enabled, memory of this type will be
+ * included in the S3 integrity calculation and so should not include
+ * any memory that BIOS might alter over the S3 transition
+ */
#define E820_RESERVED_KERN 128

#ifndef __ASSEMBLY__
diff -r d2911aa1461d arch/x86/kernel/tboot.c
--- a/arch/x86/kernel/tboot.c Thu Mar 04 09:37:53 2010 -0500
+++ b/arch/x86/kernel/tboot.c Wed Mar 10 08:18:48 2010 -0500
@@ -130,6 +130,9 @@ static void add_mac_region(phys_addr_t s
struct tboot_mac_region *mr;
phys_addr_t end = start + size;

+ if (tboot->num_mac_regions >= MAX_TB_MAC_REGIONS)
+ panic("tboot: Too many MAC regions\n");
+
if (start && size) {
mr = &tboot->mac_regions[tboot->num_mac_regions++];
mr->start = round_down(start, PAGE_SIZE);
@@ -139,18 +142,17 @@ static void add_mac_region(phys_addr_t s

static void __init tboot_setup_sleep(void)
{
+ int i;
+
tboot->num_mac_regions = 0;

- /* S3 resume code */
- add_mac_region(acpi_wakeup_address, WAKEUP_SIZE);
+ for (i = 0; i < e820.nr_map; i++) {
+ if ((e820.map[i].type != E820_RAM)
+ && (e820.map[i].type != E820_RESERVED_KERN))
+ continue;

-#ifdef CONFIG_X86_TRAMPOLINE
- /* AP trampoline code */
- add_mac_region(virt_to_phys(trampoline_base), TRAMPOLINE_SIZE);
-#endif
-
- /* kernel code + data + bss */
- add_mac_region(virt_to_phys(_text), _end - _text);
+ add_mac_region(e820.map[i].addr, e820.map[i].size);
+ }

tboot->acpi_sinfo.kernel_s3_resume_vector = acpi_wakeup_address;
}
v3: Based on a complexity analysis and tradeoff, we moved all MAC'ing into
tboot.

This patch adds support for S3 memory integrity protection within an Intel(R)
TXT launched kernel, for all kernel and userspace memory. All RAM used by the
kernel and userspace, as indicated by memory ranges of type E820_RAM and
E820_RESERVED_KERN in the e820 table, will be integrity protected.

The MAINTAINERS file is also updated to reflect the maintainers of the
TXT-related code.

Signed-off-by: Shane Wang <shane.wang@intel.com>
Signed-off-by: Joseph Cihula <joseph.cihula@intel.com>

diff -r d2911aa1461d Documentation/intel_txt.txt
--- a/Documentation/intel_txt.txt Thu Mar 04 09:37:53 2010 -0500
+++ b/Documentation/intel_txt.txt Wed Mar 10 08:18:48 2010 -0500
@@ -161,13 +161,15 @@ o In order to put a system into any of
has been restored, it will restore the TPM PCRs and then
transfer control back to the kernel's S3 resume vector.
In order to preserve system integrity across S3, the kernel
- provides tboot with a set of memory ranges (kernel
- code/data/bss, S3 resume code, and AP trampoline) that tboot
- will calculate a MAC (message authentication code) over and then
- seal with the TPM. On resume and once the measured environment
- has been re-established, tboot will re-calculate the MAC and
- verify it against the sealed value. Tboot's policy determines
- what happens if the verification fails.
+ provides tboot with a set of memory ranges (RAM and RESERVED_KERN
+ in the e820 table, but not any memory that BIOS might alter over
+ the S3 transition) that tboot will calculate a MAC (message
+ authentication code) over and then seal with the TPM. On resume
+ and once the measured environment has been re-established, tboot
+ will re-calculate the MAC and verify it against the sealed value.
+ Tboot's policy determines what happens if the verification fails.
+ Note that the c/s 194 of tboot which has the new MAC code supports
+ this.

That's pretty much it for TXT support.

diff -r d2911aa1461d MAINTAINERS
--- a/MAINTAINERS Thu Mar 04 09:37:53 2010 -0500
+++ b/MAINTAINERS Wed Mar 10 08:18:48 2010 -0500
@@ -2891,6 +2891,17 @@ F: Documentation/networking/README.ipw22
F: Documentation/networking/README.ipw2200
F: drivers/net/wireless/ipw2x00/ipw2200.*

+INTEL(R) TRUSTED EXECUTION TECHNOLOGY (TXT)
+M: Joseph Cihula <joseph.cihula@intel.com>
+M: Shane Wang <shane.wang@intel.com>
+L: tboot-devel@lists.sourceforge.net
+W: http://tboot.sourceforge.net
+T: Mercurial http://www.bughost.org/repos.hg/tboot.hg
+S: Supported
+F: Documentation/intel_txt.txt
+F: include/linux/tboot.h
+F: arch/x86/kernel/tboot.c
+
INTEL WIRELESS WIMAX CONNECTION 2400
M: Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
M: linux-wimax@intel.com
diff -r d2911aa1461d arch/x86/include/asm/e820.h
--- a/arch/x86/include/asm/e820.h Thu Mar 04 09:37:53 2010 -0500
+++ b/arch/x86/include/asm/e820.h Wed Mar 10 08:18:48 2010 -0500
@@ -45,7 +45,12 @@
#define E820_NVS 4
#define E820_UNUSABLE 5

-/* reserved RAM used by kernel itself */
+/*
+ * reserved RAM used by kernel itself
+ * if CONFIG_INTEL_TXT is enabled, memory of this type will be
+ * included in the S3 integrity calculation and so should not include
+ * any memory that BIOS might alter over the S3 transition
+ */
#define E820_RESERVED_KERN 128

#ifndef __ASSEMBLY__
diff -r d2911aa1461d arch/x86/kernel/tboot.c
--- a/arch/x86/kernel/tboot.c Thu Mar 04 09:37:53 2010 -0500
+++ b/arch/x86/kernel/tboot.c Wed Mar 10 08:18:48 2010 -0500
@@ -130,6 +130,9 @@ static void add_mac_region(phys_addr_t s
struct tboot_mac_region *mr;
phys_addr_t end = start + size;

+ if (tboot->num_mac_regions >= MAX_TB_MAC_REGIONS)
+ panic("tboot: Too many MAC regions\n");
+
if (start && size) {
mr = &tboot->mac_regions[tboot->num_mac_regions++];
mr->start = round_down(start, PAGE_SIZE);
@@ -139,18 +142,17 @@ static void add_mac_region(phys_addr_t s

static void __init tboot_setup_sleep(void)
{
+ int i;
+
tboot->num_mac_regions = 0;

- /* S3 resume code */
- add_mac_region(acpi_wakeup_address, WAKEUP_SIZE);
+ for (i = 0; i < e820.nr_map; i++) {
+ if ((e820.map[i].type != E820_RAM)
+ && (e820.map[i].type != E820_RESERVED_KERN))
+ continue;

-#ifdef CONFIG_X86_TRAMPOLINE
- /* AP trampoline code */
- add_mac_region(virt_to_phys(trampoline_base), TRAMPOLINE_SIZE);
-#endif
-
- /* kernel code + data + bss */
- add_mac_region(virt_to_phys(_text), _end - _text);
+ add_mac_region(e820.map[i].addr, e820.map[i].size);
+ }

tboot->acpi_sinfo.kernel_s3_resume_vector = acpi_wakeup_address;
}
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