efi/capsule: Add support for Quark security header
authorJan Kiszka <jan.kiszka@siemens.com>
Fri, 2 Jun 2017 13:52:04 +0000 (13:52 +0000)
committerIngo Molnar <mingo@kernel.org>
Mon, 5 Jun 2017 15:50:42 +0000 (17:50 +0200)
The firmware for Quark X102x prepends a security header to the capsule
which is needed to support the mandatory secure boot on this processor.
The header can be detected by checking for the "_CSH" signature and -
to avoid any GUID conflict - validating its size field to contain the
expected value. Then we need to look for the EFI header right after the
security header and pass the real header to __efi_capsule_setup_info.

To be minimal invasive and maximal safe, the quirk version of
efi_capsule_setup_info() is only effective on Quark processors.

Tested-by: Bryan O'Donoghue <pure.logic@nexus-software.ie>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/20170602135207.21708-11-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
arch/x86/platform/efi/quirks.c
drivers/firmware/efi/Kconfig

index e0cf95a83f3fab918eb73715d188e631e02a1425..8a99a2e96537a91db6574955aafeae1a5103ce02 100644 (file)
 #include <asm/e820/api.h>
 #include <asm/efi.h>
 #include <asm/uv/uv.h>
+#include <asm/cpu_device_id.h>
 
 #define EFI_MIN_RESERVE 5120
 
 #define EFI_DUMMY_GUID \
        EFI_GUID(0x4424ac57, 0xbe4b, 0x47dd, 0x9e, 0x97, 0xed, 0x50, 0xf0, 0x9f, 0x92, 0xa9)
 
+#define QUARK_CSH_SIGNATURE            0x5f435348      /* _CSH */
+#define QUARK_SECURITY_HEADER_SIZE     0x400
+
+/*
+ * Header prepended to the standard EFI capsule on Quark systems the are based
+ * on Intel firmware BSP.
+ * @csh_signature:     Unique identifier to sanity check signed module
+ *                     presence ("_CSH").
+ * @version:           Current version of CSH used. Should be one for Quark A0.
+ * @modulesize:                Size of the entire module including the module header
+ *                     and payload.
+ * @security_version_number_index: Index of SVN to use for validation of signed
+ *                     module.
+ * @security_version_number: Used to prevent against roll back of modules.
+ * @rsvd_module_id:    Currently unused for Clanton (Quark).
+ * @rsvd_module_vendor:        Vendor Identifier. For Intel products value is
+ *                     0x00008086.
+ * @rsvd_date:         BCD representation of build date as yyyymmdd, where
+ *                     yyyy=4 digit year, mm=1-12, dd=1-31.
+ * @headersize:                Total length of the header including including any
+ *                     padding optionally added by the signing tool.
+ * @hash_algo:         What Hash is used in the module signing.
+ * @cryp_algo:         What Crypto is used in the module signing.
+ * @keysize:           Total length of the key data including including any
+ *                     padding optionally added by the signing tool.
+ * @signaturesize:     Total length of the signature including including any
+ *                     padding optionally added by the signing tool.
+ * @rsvd_next_header:  32-bit pointer to the next Secure Boot Module in the
+ *                     chain, if there is a next header.
+ * @rsvd:              Reserved, padding structure to required size.
+ *
+ * See also QuartSecurityHeader_t in
+ * Quark_EDKII_v1.2.1.1/QuarkPlatformPkg/Include/QuarkBootRom.h
+ * from https://downloadcenter.intel.com/download/23197/Intel-Quark-SoC-X1000-Board-Support-Package-BSP
+ */
+struct quark_security_header {
+       u32 csh_signature;
+       u32 version;
+       u32 modulesize;
+       u32 security_version_number_index;
+       u32 security_version_number;
+       u32 rsvd_module_id;
+       u32 rsvd_module_vendor;
+       u32 rsvd_date;
+       u32 headersize;
+       u32 hash_algo;
+       u32 cryp_algo;
+       u32 keysize;
+       u32 signaturesize;
+       u32 rsvd_next_header;
+       u32 rsvd[2];
+};
+
 static efi_char16_t efi_dummy_name[6] = { 'D', 'U', 'M', 'M', 'Y', 0 };
 
 static bool efi_no_storage_paranoia;
@@ -504,3 +558,86 @@ bool efi_poweroff_required(void)
 {
        return acpi_gbl_reduced_hardware || acpi_no_s5;
 }
+
+#ifdef CONFIG_EFI_CAPSULE_QUIRK_QUARK_CSH
+
+static int qrk_capsule_setup_info(struct capsule_info *cap_info, void **pkbuff,
+                                 size_t hdr_bytes)
+{
+       struct quark_security_header *csh = *pkbuff;
+
+       /* Only process data block that is larger than the security header */
+       if (hdr_bytes < sizeof(struct quark_security_header))
+               return 0;
+
+       if (csh->csh_signature != QUARK_CSH_SIGNATURE ||
+           csh->headersize != QUARK_SECURITY_HEADER_SIZE)
+               return 1;
+
+       /* Only process data block if EFI header is included */
+       if (hdr_bytes < QUARK_SECURITY_HEADER_SIZE +
+                       sizeof(efi_capsule_header_t))
+               return 0;
+
+       pr_debug("Quark security header detected\n");
+
+       if (csh->rsvd_next_header != 0) {
+               pr_err("multiple Quark security headers not supported\n");
+               return -EINVAL;
+       }
+
+       *pkbuff += csh->headersize;
+       cap_info->total_size = csh->headersize;
+
+       /*
+        * Update the first page pointer to skip over the CSH header.
+        */
+       cap_info->pages[0] += csh->headersize;
+
+       return 1;
+}
+
+#define ICPU(family, model, quirk_handler) \
+       { X86_VENDOR_INTEL, family, model, X86_FEATURE_ANY, \
+         (unsigned long)&quirk_handler }
+
+static const struct x86_cpu_id efi_capsule_quirk_ids[] = {
+       ICPU(5, 9, qrk_capsule_setup_info),     /* Intel Quark X1000 */
+       { }
+};
+
+int efi_capsule_setup_info(struct capsule_info *cap_info, void *kbuff,
+                          size_t hdr_bytes)
+{
+       int (*quirk_handler)(struct capsule_info *, void **, size_t);
+       const struct x86_cpu_id *id;
+       int ret;
+
+       if (hdr_bytes < sizeof(efi_capsule_header_t))
+               return 0;
+
+       cap_info->total_size = 0;
+
+       id = x86_match_cpu(efi_capsule_quirk_ids);
+       if (id) {
+               /*
+                * The quirk handler is supposed to return
+                *  - a value > 0 if the setup should continue, after advancing
+                *    kbuff as needed
+                *  - 0 if not enough hdr_bytes are available yet
+                *  - a negative error code otherwise
+                */
+               quirk_handler = (typeof(quirk_handler))id->driver_data;
+               ret = quirk_handler(cap_info, &kbuff, hdr_bytes);
+               if (ret <= 0)
+                       return ret;
+       }
+
+       memcpy(&cap_info->header, kbuff, sizeof(cap_info->header));
+
+       cap_info->total_size += cap_info->header.imagesize;
+
+       return __efi_capsule_setup_info(cap_info);
+}
+
+#endif
index 2e78b0b96d741963cd1b5ce3f79d481bff318654..394db40ed37495112d23a59b7e1de72074761bae 100644 (file)
@@ -112,6 +112,15 @@ config EFI_CAPSULE_LOADER
 
          Most users should say N.
 
+config EFI_CAPSULE_QUIRK_QUARK_CSH
+       boolean "Add support for Quark capsules with non-standard headers"
+       depends on X86 && !64BIT
+       select EFI_CAPSULE_LOADER
+       default y
+       help
+         Add support for processing Quark X1000 EFI capsules, whose header
+         layout deviates from the layout mandated by the UEFI specification.
+
 config EFI_TEST
        tristate "EFI Runtime Service Tests Support"
        depends on EFI