aboutsummaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
Diffstat
-rw-r--r--Documentation/intel_txt.txt210
-rw-r--r--Documentation/x86/zero-page.txt1
-rw-r--r--arch/x86/include/asm/bootparam.h3
-rw-r--r--arch/x86/include/asm/fixmap.h3
-rw-r--r--arch/x86/include/asm/tboot.h197
-rw-r--r--arch/x86/kernel/Makefile1
-rw-r--r--arch/x86/kernel/setup.c4
-rw-r--r--arch/x86/kernel/tboot.c379
-rw-r--r--security/Kconfig30
9 files changed, 827 insertions, 1 deletions
diff --git a/Documentation/intel_txt.txt b/Documentation/intel_txt.txt
new file mode 100644
index 000000000000..f40a1f030019
--- /dev/null
+++ b/Documentation/intel_txt.txt
@@ -0,0 +1,210 @@
1Intel(R) TXT Overview:
2=====================
3
4Intel's technology for safer computing, Intel(R) Trusted Execution
5Technology (Intel(R) TXT), defines platform-level enhancements that
6provide the building blocks for creating trusted platforms.
7
8Intel TXT was formerly known by the code name LaGrande Technology (LT).
9
10Intel TXT in Brief:
11o Provides dynamic root of trust for measurement (DRTM)
12o Data protection in case of improper shutdown
13o Measurement and verification of launched environment
14
15Intel TXT is part of the vPro(TM) brand and is also available some
16non-vPro systems. It is currently available on desktop systems
17based on the Q35, X38, Q45, and Q43 Express chipsets (e.g. Dell
18Optiplex 755, HP dc7800, etc.) and mobile systems based on the GM45,
19PM45, and GS45 Express chipsets.
20
21For more information, see http://www.intel.com/technology/security/.
22This site also has a link to the Intel TXT MLE Developers Manual,
23which has been updated for the new released platforms.
24
25Intel TXT has been presented at various events over the past few
26years, some of which are:
27 LinuxTAG 2008:
28 http://www.linuxtag.org/2008/en/conf/events/vp-donnerstag/
29 details.html?talkid=110
30 TRUST2008:
31 http://www.trust2008.eu/downloads/Keynote-Speakers/
32 3_David-Grawrock_The-Front-Door-of-Trusted-Computing.pdf
33 IDF 2008, Shanghai:
34 http://inteldeveloperforum.com.edgesuite.net/shanghai_2008/
35 aep/PROS003/index.html
36 IDFs 2006, 2007 (I'm not sure if/where they are online)
37
38Trusted Boot Project Overview:
39=============================
40
41Trusted Boot (tboot) is an open source, pre- kernel/VMM module that
42uses Intel TXT to perform a measured and verified launch of an OS
43kernel/VMM.
44
45It is hosted on SourceForge at http://sourceforge.net/projects/tboot.
46The mercurial source repo is available at http://www.bughost.org/
47repos.hg/tboot.hg.
48
49Tboot currently supports launching Xen (open source VMM/hypervisor
50w/ TXT support since v3.2), and now Linux kernels.
51
52
53Value Proposition for Linux or "Why should you care?"
54=====================================================
55
56While there are many products and technologies that attempt to
57measure or protect the integrity of a running kernel, they all
58assume the kernel is "good" to begin with. The Integrity
59Measurement Architecture (IMA) and Linux Integrity Module interface
60are examples of such solutions.
61
62To get trust in the initial kernel without using Intel TXT, a
63static root of trust must be used. This bases trust in BIOS
64starting at system reset and requires measurement of all code
65executed between system reset through the completion of the kernel
66boot as well as data objects used by that code. In the case of a
67Linux kernel, this means all of BIOS, any option ROMs, the
68bootloader and the boot config. In practice, this is a lot of
69code/data, much of which is subject to change from boot to boot
70(e.g. changing NICs may change option ROMs). Without reference
71hashes, these measurement changes are difficult to assess or
72confirm as benign. This process also does not provide DMA
73protection, memory configuration/alias checks and locks, crash
74protection, or policy support.
75
76By using the hardware-based root of trust that Intel TXT provides,
77many of these issues can be mitigated. Specifically: many
78pre-launch components can be removed from the trust chain, DMA
79protection is provided to all launched components, a large number
80of platform configuration checks are performed and values locked,
81protection is provided for any data in the event of an improper
82shutdown, and there is support for policy-based execution/verification.
83This provides a more stable measurement and a higher assurance of
84system configuration and initial state than would be otherwise
85possible. Since the tboot project is open source, source code for
86almost all parts of the trust chain is available (excepting SMM and
87Intel-provided firmware).
88
89How Does it Work?
90=================
91
92o Tboot is an executable that is launched by the bootloader as
93 the "kernel" (the binary the bootloader executes).
94o It performs all of the work necessary to determine if the
95 platform supports Intel TXT and, if so, executes the GETSEC[SENTER]
96 processor instruction that initiates the dynamic root of trust.
97 - If tboot determines that the system does not support Intel TXT
98 or is not configured correctly (e.g. the SINIT AC Module was
99 incorrect), it will directly launch the kernel with no changes
100 to any state.
101 - Tboot will output various information about its progress to the
102 terminal, serial port, and/or an in-memory log; the output
103 locations can be configured with a command line switch.
104o The GETSEC[SENTER] instruction will return control to tboot and
105 tboot then verifies certain aspects of the environment (e.g. TPM NV
106 lock, e820 table does not have invalid entries, etc.).
107o It will wake the APs from the special sleep state the GETSEC[SENTER]
108 instruction had put them in and place them into a wait-for-SIPI
109 state.
110 - Because the processors will not respond to an INIT or SIPI when
111 in the TXT environment, it is necessary to create a small VT-x
112 guest for the APs. When they run in this guest, they will
113 simply wait for the INIT-SIPI-SIPI sequence, which will cause
114 VMEXITs, and then disable VT and jump to the SIPI vector. This
115 approach seemed like a better choice than having to insert
116 special code into the kernel's MP wakeup sequence.
117o Tboot then applies an (optional) user-defined launch policy to
118 verify the kernel and initrd.
119 - This policy is rooted in TPM NV and is described in the tboot
120 project. The tboot project also contains code for tools to
121 create and provision the policy.
122 - Policies are completely under user control and if not present
123 then any kernel will be launched.
124 - Policy action is flexible and can include halting on failures
125 or simply logging them and continuing.
126o Tboot adjusts the e820 table provided by the bootloader to reserve
127 its own location in memory as well as to reserve certain other
128 TXT-related regions.
129o As part of it's launch, tboot DMA protects all of RAM (using the
130 VT-d PMRs). Thus, the kernel must be booted with 'intel_iommu=on'
131 in order to remove this blanket protection and use VT-d's
132 page-level protection.
133o Tboot will populate a shared page with some data about itself and
134 pass this to the Linux kernel as it transfers control.
135 - The location of the shared page is passed via the boot_params
136 struct as a physical address.
137o The kernel will look for the tboot shared page address and, if it
138 exists, map it.
139o As one of the checks/protections provided by TXT, it makes a copy
140 of the VT-d DMARs in a DMA-protected region of memory and verifies
141 them for correctness. The VT-d code will detect if the kernel was
142 launched with tboot and use this copy instead of the one in the
143 ACPI table.
144o At this point, tboot and TXT are out of the picture until a
145 shutdown (S<n>)
146o In order to put a system into any of the sleep states after a TXT
147 launch, TXT must first be exited. This is to prevent attacks that
148 attempt to crash the system to gain control on reboot and steal
149 data left in memory.
150 - The kernel will perform all of its sleep preparation and
151 populate the shared page with the ACPI data needed to put the
152 platform in the desired sleep state.
153 - Then the kernel jumps into tboot via the vector specified in the
154 shared page.
155 - Tboot will clean up the environment and disable TXT, then use the
156 kernel-provided ACPI information to actually place the platform
157 into the desired sleep state.
158 - In the case of S3, tboot will also register itself as the resume
159 vector. This is necessary because it must re-establish the
160 measured environment upon resume. Once the TXT environment
161 has been restored, it will restore the TPM PCRs and then
162 transfer control back to the kernel's S3 resume vector.
163 In order to preserve system integrity across S3, the kernel
164 provides tboot with a set of memory ranges (kernel
165 code/data/bss, S3 resume code, and AP trampoline) that tboot
166 will calculate a MAC (message authentication code) over and then
167 seal with the TPM. On resume and once the measured environment
168 has been re-established, tboot will re-calculate the MAC and
169 verify it against the sealed value. Tboot's policy determines
170 what happens if the verification fails.
171
172That's pretty much it for TXT support.
173
174
175Configuring the System:
176======================
177
178This code works with 32bit, 32bit PAE, and 64bit (x86_64) kernels.
179
180In BIOS, the user must enable: TPM, TXT, VT-x, VT-d. Not all BIOSes
181allow these to be individually enabled/disabled and the screens in
182which to find them are BIOS-specific.
183
184grub.conf needs to be modified as follows:
185 title Linux 2.6.29-tip w/ tboot
186 root (hd0,0)
187 kernel /tboot.gz logging=serial,vga,memory
188 module /vmlinuz-2.6.29-tip intel_iommu=on ro
189 root=LABEL=/ rhgb console=ttyS0,115200 3
190 module /initrd-2.6.29-tip.img
191 module /Q35_SINIT_17.BIN
192
193The kernel option for enabling Intel TXT support is found under the
194Security top-level menu and is called "Enable Intel(R) Trusted
195Execution Technology (TXT)". It is marked as EXPERIMENTAL and
196depends on the generic x86 support (to allow maximum flexibility in
197kernel build options), since the tboot code will detect whether the
198platform actually supports Intel TXT and thus whether any of the
199kernel code is executed.
200
201The Q35_SINIT_17.BIN file is what Intel TXT refers to as an
202Authenticated Code Module. It is specific to the chipset in the
203system and can also be found on the Trusted Boot site. It is an
204(unencrypted) module signed by Intel that is used as part of the
205DRTM process to verify and configure the system. It is signed
206because it operates at a higher privilege level in the system than
207any other macrocode and its correct operation is critical to the
208establishment of the DRTM. The process for determining the correct
209SINIT ACM for a system is documented in the SINIT-guide.txt file
210that is on the tboot SourceForge site under the SINIT ACM downloads.
diff --git a/Documentation/x86/zero-page.txt b/Documentation/x86/zero-page.txt
index 4f913857b8a2..feb37e177010 100644
--- a/Documentation/x86/zero-page.txt
+++ b/Documentation/x86/zero-page.txt
@@ -12,6 +12,7 @@ Offset Proto Name Meaning
12000/040 ALL screen_info Text mode or frame buffer information 12000/040 ALL screen_info Text mode or frame buffer information
13 (struct screen_info) 13 (struct screen_info)
14040/014 ALL apm_bios_info APM BIOS information (struct apm_bios_info) 14040/014 ALL apm_bios_info APM BIOS information (struct apm_bios_info)
15058/008 ALL tboot_addr Physical address of tboot shared page
15060/010 ALL ist_info Intel SpeedStep (IST) BIOS support information 16060/010 ALL ist_info Intel SpeedStep (IST) BIOS support information
16 (struct ist_info) 17 (struct ist_info)
17080/010 ALL hd0_info hd0 disk parameter, OBSOLETE!! 18080/010 ALL hd0_info hd0 disk parameter, OBSOLETE!!
diff --git a/arch/x86/include/asm/bootparam.h b/arch/x86/include/asm/bootparam.h
index 1724e8de317c..6ca20218dd72 100644
--- a/arch/x86/include/asm/bootparam.h
+++ b/arch/x86/include/asm/bootparam.h
@@ -85,7 +85,8 @@ struct efi_info {
85struct boot_params { 85struct boot_params {
86 struct screen_info screen_info; /* 0x000 */ 86 struct screen_info screen_info; /* 0x000 */
87 struct apm_bios_info apm_bios_info; /* 0x040 */ 87 struct apm_bios_info apm_bios_info; /* 0x040 */
88 __u8 _pad2[12]; /* 0x054 */ 88 __u8 _pad2[4]; /* 0x054 */
89 __u64 tboot_addr; /* 0x058 */
89 struct ist_info ist_info; /* 0x060 */ 90 struct ist_info ist_info; /* 0x060 */
90 __u8 _pad3[16]; /* 0x070 */ 91 __u8 _pad3[16]; /* 0x070 */
91 __u8 hd0_info[16]; /* obsolete! */ /* 0x080 */ 92 __u8 hd0_info[16]; /* obsolete! */ /* 0x080 */
diff --git a/arch/x86/include/asm/fixmap.h b/arch/x86/include/asm/fixmap.h
index 7b2d71df39a6..14f9890eb495 100644
--- a/arch/x86/include/asm/fixmap.h
+++ b/arch/x86/include/asm/fixmap.h
@@ -132,6 +132,9 @@ enum fixed_addresses {
132#ifdef CONFIG_X86_32 132#ifdef CONFIG_X86_32
133 FIX_WP_TEST, 133 FIX_WP_TEST,
134#endif 134#endif
135#ifdef CONFIG_INTEL_TXT
136 FIX_TBOOT_BASE,
137#endif
135 __end_of_fixed_addresses 138 __end_of_fixed_addresses
136}; 139};
137 140
diff --git a/arch/x86/include/asm/tboot.h b/arch/x86/include/asm/tboot.h
new file mode 100644
index 000000000000..b13929d4e5f4
--- /dev/null
+++ b/arch/x86/include/asm/tboot.h
@@ -0,0 +1,197 @@
1/*
2 * tboot.h: shared data structure with tboot and kernel and functions
3 * used by kernel for runtime support of Intel(R) Trusted
4 * Execution Technology
5 *
6 * Copyright (c) 2006-2009, Intel Corporation
7 *
8 * This program is free software; you can redistribute it and/or modify it
9 * under the terms and conditions of the GNU General Public License,
10 * version 2, as published by the Free Software Foundation.
11 *
12 * This program is distributed in the hope it will be useful, but WITHOUT
13 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
15 * more details.
16 *
17 * You should have received a copy of the GNU General Public License along with
18 * this program; if not, write to the Free Software Foundation, Inc.,
19 * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 */
22
23#ifndef _ASM_TBOOT_H
24#define _ASM_TBOOT_H
25
26#include <acpi/acpi.h>
27
28/* these must have the values from 0-5 in this order */
29enum {
30 TB_SHUTDOWN_REBOOT = 0,
31 TB_SHUTDOWN_S5,
32 TB_SHUTDOWN_S4,
33 TB_SHUTDOWN_S3,
34 TB_SHUTDOWN_HALT,
35 TB_SHUTDOWN_WFS
36};
37
38#ifdef CONFIG_INTEL_TXT
39
40/* used to communicate between tboot and the launched kernel */
41
42#define TB_KEY_SIZE 64 /* 512 bits */
43
44#define MAX_TB_MAC_REGIONS 32
45
46struct tboot_mac_region {
47 u64 start; /* must be 64 byte -aligned */
48 u32 size; /* must be 64 byte -granular */
49} __packed;
50
51/* GAS - Generic Address Structure (ACPI 2.0+) */
52struct tboot_acpi_generic_address {
53 u8 space_id;
54 u8 bit_width;
55 u8 bit_offset;
56 u8 access_width;
57 u64 address;
58} __packed;
59
60/*
61 * combines Sx info from FADT and FACS tables per ACPI 2.0+ spec
62 * (http://www.acpi.info/)
63 */
64struct tboot_acpi_sleep_info {
65 struct tboot_acpi_generic_address pm1a_cnt_blk;
66 struct tboot_acpi_generic_address pm1b_cnt_blk;
67 struct tboot_acpi_generic_address pm1a_evt_blk;
68 struct tboot_acpi_generic_address pm1b_evt_blk;
69 u16 pm1a_cnt_val;
70 u16 pm1b_cnt_val;
71 u64 wakeup_vector;
72 u32 vector_width;
73 u64 kernel_s3_resume_vector;
74} __packed;
75
76/*
77 * shared memory page used for communication between tboot and kernel
78 */
79struct tboot {
80 /*
81 * version 3+ fields:
82 */
83
84 /* TBOOT_UUID */
85 u8 uuid[16];
86
87 /* version number: 5 is current */
88 u32 version;
89
90 /* physical addr of tb_log_t log */
91 u32 log_addr;
92
93 /*
94 * physical addr of entry point for tboot shutdown and
95 * type of shutdown (TB_SHUTDOWN_*) being requested
96 */
97 u32 shutdown_entry;
98 u32 shutdown_type;
99
100 /* kernel-specified ACPI info for Sx shutdown */
101 struct tboot_acpi_sleep_info acpi_sinfo;
102
103 /* tboot location in memory (physical) */
104 u32 tboot_base;
105 u32 tboot_size;
106
107 /* memory regions (phys addrs) for tboot to MAC on S3 */
108 u8 num_mac_regions;
109 struct tboot_mac_region mac_regions[MAX_TB_MAC_REGIONS];
110
111
112 /*
113 * version 4+ fields:
114 */
115
116 /* symmetric key for use by kernel; will be encrypted on S3 */
117 u8 s3_key[TB_KEY_SIZE];
118
119
120 /*
121 * version 5+ fields:
122 */
123
124 /* used to 4byte-align num_in_wfs */
125 u8 reserved_align[3];
126
127 /* number of processors in wait-for-SIPI */
128 u32 num_in_wfs;
129} __packed;
130
131/*
132 * UUID for tboot data struct to facilitate matching
133 * defined as {663C8DFF-E8B3-4b82-AABF-19EA4D057A08} by tboot, which is
134 * represented as {} in the char array used here
135 */
136#define TBOOT_UUID {0xff, 0x8d, 0x3c, 0x66, 0xb3, 0xe8, 0x82, 0x4b, 0xbf,\
137 0xaa, 0x19, 0xea, 0x4d, 0x5, 0x7a, 0x8}
138
139extern struct tboot *tboot;
140
141static inline int tboot_enabled(void)
142{
143 return tboot != NULL;
144}
145
146extern void tboot_probe(void);
147extern void tboot_create_trampoline(void);
148extern void tboot_shutdown(u32 shutdown_type);
149extern void tboot_sleep(u8 sleep_state, u32 pm1a_control, u32 pm1b_control);
150extern int tboot_wait_for_aps(int num_aps);
151extern struct acpi_table_header *tboot_get_dmar_table(
152 struct acpi_table_header *dmar_tbl);
153extern int tboot_force_iommu(void);
154
155#else /* CONFIG_INTEL_TXT */
156
157static inline int tboot_enabled(void)
158{
159 return 0;
160}
161
162static inline void tboot_probe(void)
163{
164}
165
166static inline void tboot_create_trampoline(void)
167{
168}
169
170static inline void tboot_shutdown(u32 shutdown_type)
171{
172}
173
174static inline void tboot_sleep(u8 sleep_state, u32 pm1a_control,
175 u32 pm1b_control)
176{
177}
178
179static inline int tboot_wait_for_aps(int num_aps)
180{
181 return 0;
182}
183
184static inline struct acpi_table_header *tboot_get_dmar_table(
185 struct acpi_table_header *dmar_tbl)
186{
187 return dmar_tbl;
188}
189
190static inline int tboot_force_iommu(void)
191{
192 return 0;
193}
194
195#endif /* !CONFIG_INTEL_TXT */
196
197#endif /* _ASM_TBOOT_H */
diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index 430d5b24af7b..832cb838cb48 100644
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -52,6 +52,7 @@ obj-$(CONFIG_X86_DS_SELFTEST) += ds_selftest.o
52obj-$(CONFIG_X86_32) += tls.o 52obj-$(CONFIG_X86_32) += tls.o
53obj-$(CONFIG_IA32_EMULATION) += tls.o 53obj-$(CONFIG_IA32_EMULATION) += tls.o
54obj-y += step.o 54obj-y += step.o
55obj-$(CONFIG_INTEL_TXT) += tboot.o
55obj-$(CONFIG_STACKTRACE) += stacktrace.o 56obj-$(CONFIG_STACKTRACE) += stacktrace.o
56obj-y += cpu/ 57obj-y += cpu/
57obj-y += acpi/ 58obj-y += acpi/
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index de2cab132844..80d6e9e32483 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -145,6 +145,8 @@ struct boot_params __initdata boot_params;
145struct boot_params boot_params; 145struct boot_params boot_params;
146#endif 146#endif
147 147
148#include <asm/tboot.h>
149
148/* 150/*
149 * Machine setup.. 151 * Machine setup..
150 */ 152 */
@@ -964,6 +966,8 @@ void __init setup_arch(char **cmdline_p)
964 paravirt_pagetable_setup_done(swapper_pg_dir); 966 paravirt_pagetable_setup_done(swapper_pg_dir);
965 paravirt_post_allocator_init(); 967 paravirt_post_allocator_init();
966 968
969 tboot_probe();
970
967#ifdef CONFIG_X86_64 971#ifdef CONFIG_X86_64
968 map_vsyscall(); 972 map_vsyscall();
969#endif 973#endif
diff --git a/arch/x86/kernel/tboot.c b/arch/x86/kernel/tboot.c
new file mode 100644
index 000000000000..263591afd29e
--- /dev/null
+++ b/arch/x86/kernel/tboot.c
@@ -0,0 +1,379 @@
1/*
2 * tboot.c: main implementation of helper functions used by kernel for
3 * runtime support of Intel(R) Trusted Execution Technology
4 *
5 * Copyright (c) 2006-2009, Intel Corporation
6 *
7 * This program is free software; you can redistribute it and/or modify it
8 * under the terms and conditions of the GNU General Public License,
9 * version 2, as published by the Free Software Foundation.
10 *
11 * This program is distributed in the hope it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
14 * more details.
15 *
16 * You should have received a copy of the GNU General Public License along with
17 * this program; if not, write to the Free Software Foundation, Inc.,
18 * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
19 *
20 */
21
22#include <linux/dma_remapping.h>
23#include <linux/init_task.h>
24#include <linux/spinlock.h>
25#include <linux/sched.h>
26#include <linux/init.h>
27#include <linux/dmar.h>
28#include <linux/pfn.h>
29#include <linux/mm.h>
30
31#include <asm/trampoline.h>
32#include <asm/processor.h>
33#include <asm/bootparam.h>
34#include <asm/pgtable.h>
35#include <asm/pgalloc.h>
36#include <asm/setup.h>
37#include <asm/tboot.h>
38#include <asm/e820.h>
39#include <asm/io.h>
40
41#include "acpi/realmode/wakeup.h"
42
43/* Global pointer to shared data; NULL means no measured launch. */
44struct tboot *tboot __read_mostly;
45
46/* timeout for APs (in secs) to enter wait-for-SIPI state during shutdown */
47#define AP_WAIT_TIMEOUT 1
48
49#undef pr_fmt
50#define pr_fmt(fmt) "tboot: " fmt
51
52static u8 tboot_uuid[16] __initdata = TBOOT_UUID;
53
54void __init tboot_probe(void)
55{
56 /* Look for valid page-aligned address for shared page. */
57 if (!boot_params.tboot_addr)
58 return;
59 /*
60 * also verify that it is mapped as we expect it before calling
61 * set_fixmap(), to reduce chance of garbage value causing crash
62 */
63 if (!e820_any_mapped(boot_params.tboot_addr,
64 boot_params.tboot_addr, E820_RESERVED)) {
65 pr_warning("non-0 tboot_addr but it is not of type E820_RESERVED\n");
66 return;
67 }
68
69 /* only a natively booted kernel should be using TXT */
70 if (paravirt_enabled()) {
71 pr_warning("non-0 tboot_addr but pv_ops is enabled\n");
72 return;
73 }
74
75 /* Map and check for tboot UUID. */
76 set_fixmap(FIX_TBOOT_BASE, boot_params.tboot_addr);
77 tboot = (struct tboot *)fix_to_virt(FIX_TBOOT_BASE);
78 if (memcmp(&tboot_uuid, &tboot->uuid, sizeof(tboot->uuid))) {
79 pr_warning("tboot at 0x%llx is invalid\n",
80 boot_params.tboot_addr);
81 tboot = NULL;
82 return;
83 }
84 if (tboot->version < 5) {
85 pr_warning("tboot version is invalid: %u\n", tboot->version);
86 tboot = NULL;
87 return;
88 }
89
90 pr_info("found shared page at phys addr 0x%llx:\n",
91 boot_params.tboot_addr);
92 pr_debug("version: %d\n", tboot->version);
93 pr_debug("log_addr: 0x%08x\n", tboot->log_addr);
94 pr_debug("shutdown_entry: 0x%x\n", tboot->shutdown_entry);
95 pr_debug("tboot_base: 0x%08x\n", tboot->tboot_base);
96 pr_debug("tboot_size: 0x%x\n", tboot->tboot_size);
97}
98
99static pgd_t *tboot_pg_dir;
100static struct mm_struct tboot_mm = {
101 .mm_rb = RB_ROOT,
102 .pgd = swapper_pg_dir,
103 .mm_users = ATOMIC_INIT(2),
104 .mm_count = ATOMIC_INIT(1),
105 .mmap_sem = __RWSEM_INITIALIZER(init_mm.mmap_sem),
106 .page_table_lock = __SPIN_LOCK_UNLOCKED(init_mm.page_table_lock),
107 .mmlist = LIST_HEAD_INIT(init_mm.mmlist),
108 .cpu_vm_mask = CPU_MASK_ALL,
109};
110
111static inline void switch_to_tboot_pt(void)
112{
113 write_cr3(virt_to_phys(tboot_pg_dir));
114}
115
116static int map_tboot_page(unsigned long vaddr, unsigned long pfn,
117 pgprot_t prot)
118{
119 pgd_t *pgd;
120 pud_t *pud;
121 pmd_t *pmd;
122 pte_t *pte;
123
124 pgd = pgd_offset(&tboot_mm, vaddr);
125 pud = pud_alloc(&tboot_mm, pgd, vaddr);
126 if (!pud)
127 return -1;
128 pmd = pmd_alloc(&tboot_mm, pud, vaddr);
129 if (!pmd)
130 return -1;
131 pte = pte_alloc_map(&tboot_mm, pmd, vaddr);
132 if (!pte)
133 return -1;
134 set_pte_at(&tboot_mm, vaddr, pte, pfn_pte(pfn, prot));
135 pte_unmap(pte);
136 return 0;
137}
138
139static int map_tboot_pages(unsigned long vaddr, unsigned long start_pfn,
140 unsigned long nr)
141{
142 /* Reuse the original kernel mapping */
143 tboot_pg_dir = pgd_alloc(&tboot_mm);
144 if (!tboot_pg_dir)
145 return -1;
146
147 for (; nr > 0; nr--, vaddr += PAGE_SIZE, start_pfn++) {
148 if (map_tboot_page(vaddr, start_pfn, PAGE_KERNEL_EXEC))
149 return -1;
150 }
151
152 return 0;
153}
154
155void tboot_create_trampoline(void)
156{
157 u32 map_base, map_size;
158
159 if (!tboot_enabled())
160 return;
161
162 /* Create identity map for tboot shutdown code. */
163 map_base = PFN_DOWN(tboot->tboot_base);
164 map_size = PFN_UP(tboot->tboot_size);
165 if (map_tboot_pages(map_base << PAGE_SHIFT, map_base, map_size))
166 panic("tboot: Error mapping tboot pages (mfns) @ 0x%x, 0x%x\n", map_base, map_size);
167}
168
169static void set_mac_regions(void)
170{
171 tboot->num_mac_regions = 3;
172 /* S3 resume code */
173 tboot->mac_regions[0].start = PFN_PHYS(PFN_DOWN(acpi_wakeup_address));
174 tboot->mac_regions[0].size = PFN_UP(WAKEUP_SIZE) << PAGE_SHIFT;
175 /* AP trampoline code */
176 tboot->mac_regions[1].start =
177 PFN_PHYS(PFN_DOWN(virt_to_phys(trampoline_base)));
178 tboot->mac_regions[1].size = PFN_UP(TRAMPOLINE_SIZE) << PAGE_SHIFT;
179 /* kernel code + data + bss */
180 tboot->mac_regions[2].start = PFN_PHYS(PFN_DOWN(virt_to_phys(&_text)));
181 tboot->mac_regions[2].size = PFN_PHYS(PFN_UP(virt_to_phys(&_end))) -
182 PFN_PHYS(PFN_DOWN(virt_to_phys(&_text)));
183}
184
185void tboot_shutdown(u32 shutdown_type)
186{
187 void (*shutdown)(void);
188
189 if (!tboot_enabled())
190 return;
191
192 /*
193 * if we're being called before the 1:1 mapping is set up then just
194 * return and let the normal shutdown happen; this should only be
195 * due to very early panic()
196 */
197 if (!tboot_pg_dir)
198 return;
199
200 /* if this is S3 then set regions to MAC */
201 if (shutdown_type == TB_SHUTDOWN_S3)
202 set_mac_regions();
203
204 tboot->shutdown_type = shutdown_type;
205
206 switch_to_tboot_pt();
207
208 shutdown = (void(*)(void))(unsigned long)tboot->shutdown_entry;
209 shutdown();
210
211 /* should not reach here */
212 while (1)
213 halt();
214}
215
216static void tboot_copy_fadt(const struct acpi_table_fadt *fadt)
217{
218#define TB_COPY_GAS(tbg, g) \
219 tbg.space_id = g.space_id; \
220 tbg.bit_width = g.bit_width; \
221 tbg.bit_offset = g.bit_offset; \
222 tbg.access_width = g.access_width; \
223 tbg.address = g.address;
224
225 TB_COPY_GAS(tboot->acpi_sinfo.pm1a_cnt_blk, fadt->xpm1a_control_block);
226 TB_COPY_GAS(tboot->acpi_sinfo.pm1b_cnt_blk, fadt->xpm1b_control_block);
227 TB_COPY_GAS(tboot->acpi_sinfo.pm1a_evt_blk, fadt->xpm1a_event_block);
228 TB_COPY_GAS(tboot->acpi_sinfo.pm1b_evt_blk, fadt->xpm1b_event_block);
229
230 /*
231 * We need phys addr of waking vector, but can't use virt_to_phys() on
232 * &acpi_gbl_FACS because it is ioremap'ed, so calc from FACS phys
233 * addr.
234 */
235 tboot->acpi_sinfo.wakeup_vector = fadt->facs +
236 offsetof(struct acpi_table_facs, firmware_waking_vector);
237}
238
239void tboot_sleep(u8 sleep_state, u32 pm1a_control, u32 pm1b_control)
240{
241 static u32 acpi_shutdown_map[ACPI_S_STATE_COUNT] = {
242 /* S0,1,2: */ -1, -1, -1,
243 /* S3: */ TB_SHUTDOWN_S3,
244 /* S4: */ TB_SHUTDOWN_S4,
245 /* S5: */ TB_SHUTDOWN_S5 };
246
247 if (!tboot_enabled())
248 return;
249
250 tboot_copy_fadt(&acpi_gbl_FADT);
251 tboot->acpi_sinfo.pm1a_cnt_val = pm1a_control;
252 tboot->acpi_sinfo.pm1b_cnt_val = pm1b_control;
253 /* we always use the 32b wakeup vector */
254 tboot->acpi_sinfo.vector_width = 32;
255 tboot->acpi_sinfo.kernel_s3_resume_vector = acpi_wakeup_address;
256
257 if (sleep_state >= ACPI_S_STATE_COUNT ||
258 acpi_shutdown_map[sleep_state] == -1) {
259 pr_warning("unsupported sleep state 0x%x\n", sleep_state);
260 return;
261 }
262
263 tboot_shutdown(acpi_shutdown_map[sleep_state]);
264}
265
266int tboot_wait_for_aps(int num_aps)
267{
268 unsigned long timeout;
269
270 if (!tboot_enabled())
271 return 0;
272
273 timeout = jiffies + AP_WAIT_TIMEOUT*HZ;
274 while (atomic_read((atomic_t *)&tboot->num_in_wfs) != num_aps &&
275 time_before(jiffies, timeout))
276 cpu_relax();
277
278 return time_before(jiffies, timeout) ? 0 : 1;
279}
280
281/*
282 * TXT configuration registers (offsets from TXT_{PUB, PRIV}_CONFIG_REGS_BASE)
283 */
284
285#define TXT_PUB_CONFIG_REGS_BASE 0xfed30000
286#define TXT_PRIV_CONFIG_REGS_BASE 0xfed20000
287
288/* # pages for each config regs space - used by fixmap */
289#define NR_TXT_CONFIG_PAGES ((TXT_PUB_CONFIG_REGS_BASE - \
290 TXT_PRIV_CONFIG_REGS_BASE) >> PAGE_SHIFT)
291
292/* offsets from pub/priv config space */
293#define TXTCR_HEAP_BASE 0x0300
294#define TXTCR_HEAP_SIZE 0x0308
295
296#define SHA1_SIZE 20
297
298struct sha1_hash {
299 u8 hash[SHA1_SIZE];
300};
301
302struct sinit_mle_data {
303 u32 version; /* currently 6 */
304 struct sha1_hash bios_acm_id;
305 u32 edx_senter_flags;
306 u64 mseg_valid;
307 struct sha1_hash sinit_hash;
308 struct sha1_hash mle_hash;
309 struct sha1_hash stm_hash;
310 struct sha1_hash lcp_policy_hash;
311 u32 lcp_policy_control;
312 u32 rlp_wakeup_addr;
313 u32 reserved;
314 u32 num_mdrs;
315 u32 mdrs_off;
316 u32 num_vtd_dmars;
317 u32 vtd_dmars_off;
318} __packed;
319
320struct acpi_table_header *tboot_get_dmar_table(struct acpi_table_header *dmar_tbl)
321{
322 void *heap_base, *heap_ptr, *config;
323
324 if (!tboot_enabled())
325 return dmar_tbl;
326
327 /*
328 * ACPI tables may not be DMA protected by tboot, so use DMAR copy
329 * SINIT saved in SinitMleData in TXT heap (which is DMA protected)
330 */
331
332 /* map config space in order to get heap addr */
333 config = ioremap(TXT_PUB_CONFIG_REGS_BASE, NR_TXT_CONFIG_PAGES *
334 PAGE_SIZE);
335 if (!config)
336 return NULL;
337
338 /* now map TXT heap */
339 heap_base = ioremap(*(u64 *)(config + TXTCR_HEAP_BASE),
340 *(u64 *)(config + TXTCR_HEAP_SIZE));
341 iounmap(config);
342 if (!heap_base)
343 return NULL;
344
345 /* walk heap to SinitMleData */
346 /* skip BiosData */
347 heap_ptr = heap_base + *(u64 *)heap_base;
348 /* skip OsMleData */
349 heap_ptr += *(u64 *)heap_ptr;
350 /* skip OsSinitData */
351 heap_ptr += *(u64 *)heap_ptr;
352 /* now points to SinitMleDataSize; set to SinitMleData */
353 heap_ptr += sizeof(u64);
354 /* get addr of DMAR table */
355 dmar_tbl = (struct acpi_table_header *)(heap_ptr +
356 ((struct sinit_mle_data *)heap_ptr)->vtd_dmars_off -
357 sizeof(u64));
358
359 /* don't unmap heap because dmar.c needs access to this */
360
361 return dmar_tbl;
362}
363
364int tboot_force_iommu(void)
365{
366 if (!tboot_enabled())
367 return 0;
368
369 if (no_iommu || swiotlb || dmar_disabled)
370 pr_warning("Forcing Intel-IOMMU to enabled\n");
371
372 dmar_disabled = 0;
373#ifdef CONFIG_SWIOTLB
374 swiotlb = 0;
375#endif
376 no_iommu = 0;
377
378 return 1;
379}
diff --git a/security/Kconfig b/security/Kconfig
index d23c839038f0..edc7cbdc012a 100644
--- a/security/Kconfig
+++ b/security/Kconfig
@@ -113,6 +113,36 @@ config SECURITY_ROOTPLUG
113 113
114 If you are unsure how to answer this question, answer N. 114 If you are unsure how to answer this question, answer N.
115 115
116config INTEL_TXT
117 bool "Enable Intel(R) Trusted Execution Technology (Intel(R) TXT)"
118 depends on EXPERIMENTAL && X86 && DMAR && ACPI
119 help
120 This option enables support for booting the kernel with the
121 Trusted Boot (tboot) module. This will utilize
122 Intel(R) Trusted Execution Technology to perform a measured launch
123 of the kernel. If the system does not support Intel(R) TXT, this
124 will have no effect.
125
126 Intel TXT will provide higher assurance of sysem configuration and
127 initial state as well as data reset protection. This is used to
128 create a robust initial kernel measurement and verification, which
129 helps to ensure that kernel security mechanisms are functioning
130 correctly. This level of protection requires a root of trust outside
131 of the kernel itself.
132
133 Intel TXT also helps solve real end user concerns about having
134 confidence that their hardware is running the VMM or kernel that
135 it was conigured with, especially since they may be responsible for
136 providing such assurances to VMs and services running on it.
137
138 See <http://www.intel.com/technology/security/> for more information
139 about Intel(R) TXT.
140 See <http://tboot.sourceforge.net> for more information about tboot.
141 See Documentation/intel_txt.txt for a description of how to enable
142 Intel TXT support in a kernel boot.
143
144 If you are unsure as to whether this is required, answer N.
145
116source security/selinux/Kconfig 146source security/selinux/Kconfig
117source security/smack/Kconfig 147source security/smack/Kconfig
118source security/tomoyo/Kconfig 148source security/tomoyo/Kconfig
generated by cgit v1.2.2 (git 2.25.0) at 2024-11-05 21:48:54 -0500