diff mbox series

[10/13] efi/capsule: Add support for Quark security header

Message ID 20170602135207.21708-11-ard.biesheuvel@linaro.org
State New
Headers show
Series First batch of EFI updates for v4.13 | expand

Commit Message

Ard Biesheuvel June 2, 2017, 1:52 p.m. UTC
From: Jan Kiszka <jan.kiszka@siemens.com>


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_identify_image is only effective on Quark processors.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>

Cc: Matt Fleming <matt@codeblueprint.co.uk>
Tested-by: "Bryan O'Donoghue" <pure.logic@nexus-software.ie>

Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

---
 arch/x86/platform/efi/quirks.c | 137 +++++++++++++++++++++++++++++++++++++++++
 drivers/firmware/efi/Kconfig   |   9 +++
 2 files changed, 146 insertions(+)

-- 
2.9.3

Comments

Ingo Molnar June 5, 2017, 3:50 p.m. UTC | #1
* Ard Biesheuvel <ard.biesheuvel@linaro.org> wrote:

> From: Jan Kiszka <jan.kiszka@siemens.com>

> 

> 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_identify_image is only effective on Quark processors.


So there's no efi_capsule_identify_image() function anywhere - this wants to be 
efi_capsule_setup_info(), right?

I have edited the changelog accordingly.

> +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.


BTW., there's no need to further put this behind a Kconfig option: the quirk seems 
targeted enough, and the whole point of runtime quirks is so that can be applied 
safely within generic kernels. Turning them off via Kconfig seems wrong.

Thanks,

	Ingo
Ingo Molnar June 5, 2017, 4:11 p.m. UTC | #2
* Ard Biesheuvel <ard.biesheuvel@linaro.org> wrote:

> >> +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.

> >

> > BTW., there's no need to further put this behind a Kconfig option: the quirk seems

> > targeted enough, and the whole point of runtime quirks is so that can be applied

> > safely within generic kernels. Turning them off via Kconfig seems wrong.

> >

> 

> Not entirely: enabling this quirk will remove the ability to select

> EFI_CAPSULE_LOADER as a module. So making it unconditional makes

> EFI_CAPSULE_LOADER builtin-only for 32-bit x86. This is necessary for

> the override of __weak symbols in the generic capsule code to work as

> expected.

> 

> This was a compromise between allowing no capsule loader quirks at

> all, and having an elaborate framework with hooks in various places

> (which invariably ends up parameterizing the wrong things if you have

> only one real world quirk to design your framework around).


Ok, I see - fair enough!

Thanks,

	Ingo
diff mbox series

Patch

diff --git a/arch/x86/platform/efi/quirks.c b/arch/x86/platform/efi/quirks.c
index 26615991d69c..93867ee08eac 100644
--- a/arch/x86/platform/efi/quirks.c
+++ b/arch/x86/platform/efi/quirks.c
@@ -15,12 +15,66 @@ 
 #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;
@@ -501,3 +555,86 @@  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
diff --git a/drivers/firmware/efi/Kconfig b/drivers/firmware/efi/Kconfig
index 2e78b0b96d74..394db40ed374 100644
--- a/drivers/firmware/efi/Kconfig
+++ b/drivers/firmware/efi/Kconfig
@@ -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