Eric Lee / linux-smarc-t335x-v3.2

Download as
Browse Code ยป

Commit 4bd96a7a8185755b091233b16034c7436cbf57af

Authored by Shane Wang
Committed by H. Peter Anvin
1 parent a3d3203e4b
Exists in master and in 4 other branches v3.2_AM335xPSP_04.06.00.11, v3.2_NEWT335xPSP_04.06.00.11, v3.2_SBC_SMARTMEN, v3.2_SMARCT335xPSP_04.06.00.11

x86, tboot: Add support for S3 memory integrity protection 

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.

All MACing is done in tboot, based on a complexity analysis and tradeoff.

v3: 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.

Signed-off-by: Shane Wang <shane.wang@intel.com>
LKML-Reference: <4B973DDA.6050902@intel.com>
Signed-off-by: Joseph Cihula <joseph.cihula@intel.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

Showing 4 changed files with 37 additions and 17 deletions Side-by-side Diff

Documentation/intel_txt.txt
Diff comments   View file @ 4bd96a7
... ... @@ -161,13 +161,15 @@
161 161 has been restored, it will restore the TPM PCRs and then
162 162 transfer control back to the kernel's S3 resume vector.
163 163 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.
  164 + provides tboot with a set of memory ranges (RAM and RESERVED_KERN
  165 + in the e820 table, but not any memory that BIOS might alter over
  166 + the S3 transition) that tboot will calculate a MAC (message
  167 + authentication code) over and then seal with the TPM. On resume
  168 + and once the measured environment has been re-established, tboot
  169 + will re-calculate the MAC and verify it against the sealed value.
  170 + Tboot's policy determines what happens if the verification fails.
  171 + Note that the c/s 194 of tboot which has the new MAC code supports
  172 + this.
171 173  
172 174 That's pretty much it for TXT support.
173 175  
... ... @@ -2940,6 +2940,17 @@
2940 2940 F: Documentation/networking/README.ipw2200
2941 2941 F: drivers/net/wireless/ipw2x00/ipw2200.*
2942 2942  
  2943 +INTEL(R) TRUSTED EXECUTION TECHNOLOGY (TXT)
  2944 +M: Joseph Cihula <joseph.cihula@intel.com>
  2945 +M: Shane Wang <shane.wang@intel.com>
  2946 +L: tboot-devel@lists.sourceforge.net
  2947 +W: http://tboot.sourceforge.net
  2948 +T: Mercurial http://www.bughost.org/repos.hg/tboot.hg
  2949 +S: Supported
  2950 +F: Documentation/intel_txt.txt
  2951 +F: include/linux/tboot.h
  2952 +F: arch/x86/kernel/tboot.c
  2953 +
2943 2954 INTEL WIRELESS WIMAX CONNECTION 2400
2944 2955 M: Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
2945 2956 M: linux-wimax@intel.com
arch/x86/include/asm/e820.h
Diff comments   View file @ 4bd96a7
... ... @@ -45,7 +45,12 @@
45 45 #define E820_NVS 4
46 46 #define E820_UNUSABLE 5
47 47  
48   -/* reserved RAM used by kernel itself */
  48 +/*
  49 + * reserved RAM used by kernel itself
  50 + * if CONFIG_INTEL_TXT is enabled, memory of this type will be
  51 + * included in the S3 integrity calculation and so should not include
  52 + * any memory that BIOS might alter over the S3 transition
  53 + */
49 54 #define E820_RESERVED_KERN 128
50 55  
51 56 #ifndef __ASSEMBLY__
arch/x86/kernel/tboot.c
Diff comments   View file @ 4bd96a7
... ... @@ -175,6 +175,9 @@
175 175 struct tboot_mac_region *mr;
176 176 phys_addr_t end = start + size;
177 177  
  178 + if (tboot->num_mac_regions >= MAX_TB_MAC_REGIONS)
  179 + panic("tboot: Too many MAC regions\n");
  180 +
178 181 if (start && size) {
179 182 mr = &tboot->mac_regions[tboot->num_mac_regions++];
180 183 mr->start = round_down(start, PAGE_SIZE);
181 184  
182 185  
... ... @@ -184,18 +187,17 @@
184 187  
185 188 static int tboot_setup_sleep(void)
186 189 {
  190 + int i;
  191 +
187 192 tboot->num_mac_regions = 0;
188 193  
189   - /* S3 resume code */
190   - add_mac_region(acpi_wakeup_address, WAKEUP_SIZE);
  194 + for (i = 0; i < e820.nr_map; i++) {
  195 + if ((e820.map[i].type != E820_RAM)
  196 + && (e820.map[i].type != E820_RESERVED_KERN))
  197 + continue;
191 198  
192   -#ifdef CONFIG_X86_TRAMPOLINE
193   - /* AP trampoline code */
194   - add_mac_region(virt_to_phys(trampoline_base), TRAMPOLINE_SIZE);
195   -#endif
196   -
197   - /* kernel code + data + bss */
198   - add_mac_region(virt_to_phys(_text), _end - _text);
  199 + add_mac_region(e820.map[i].addr, e820.map[i].size);
  200 + }
199 201  
200 202 tboot->acpi_sinfo.kernel_s3_resume_vector = acpi_wakeup_address;
201 203