Add a flag to detect Apple T2 chips on Intel Macs.
Cache the result to avoid repeated checks. That will
be used in upcoming patches.

Signed-off-by: Atharva Tiwari <[email protected]>
---
 arch/x86/kernel/quirks.c                      | 105 ++++++++++++++++++
 include/linux/platform_data/x86/apple.h       |   5 +
 .../platform_certs/keyring_handler.h          |   8 --
 security/integrity/platform_certs/load_uefi.c |  38 ++-----
 4 files changed, 118 insertions(+), 38 deletions(-)

diff --git a/arch/x86/kernel/quirks.c b/arch/x86/kernel/quirks.c
index a92f18db9610..300d6436060d 100644
--- a/arch/x86/kernel/quirks.c
+++ b/arch/x86/kernel/quirks.c
@@ -664,8 +664,113 @@ DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x2083, 
quirk_intel_purley_xeon_ras
 bool x86_apple_machine;
 EXPORT_SYMBOL(x86_apple_machine);
 
+bool has_apple_t2_chip;
+EXPORT_SYMBOL(has_apple_t2_chip);
+
+static const struct dmi_system_id apple_t2_devices[] __initconst = {
+       {
+               .matches = {
+                       DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
+                       DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro15,1"),
+               },
+       },
+       {
+               .matches = {
+                       DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
+                       DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro15,2"),
+               },
+       },
+       {
+               .matches = {
+                       DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
+                       DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro15,3"),
+               },
+       },
+       {
+               .matches = {
+                       DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
+                       DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro15,4"),
+               },
+       },
+       {
+               .matches = {
+                       DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
+                       DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro16,1"),
+               },
+       },
+       {
+               .matches = {
+                       DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
+                       DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro16,2"),
+               },
+       },
+       {
+               .matches = {
+                       DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
+                       DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro16,3"),
+               },
+       },
+       {
+               .matches = {
+                       DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
+                       DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro16,4"),
+               },
+       },
+       {
+               .matches = {
+                       DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
+                       DMI_MATCH(DMI_PRODUCT_NAME, "MacBookAir8,1"),
+               },
+       },
+       {
+               .matches = {
+                       DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
+                       DMI_MATCH(DMI_PRODUCT_NAME, "MacBookAir8,2"),
+               },
+       },
+       {
+               .matches = {
+                       DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
+                       DMI_MATCH(DMI_PRODUCT_NAME, "MacBookAir9,1"),
+               },
+       },
+       {
+               .matches = {
+                       DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
+                       DMI_MATCH(DMI_PRODUCT_NAME, "Macmini8,1"),
+               },
+       },
+       {
+               .matches = {
+                       DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
+                       DMI_MATCH(DMI_PRODUCT_NAME, "MacPro7,1"),
+               },
+       },
+       {
+               .matches = {
+                       DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
+                       DMI_MATCH(DMI_PRODUCT_NAME, "iMac20,1"),
+               },
+       },
+       {
+               .matches = {
+                       DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
+                       DMI_MATCH(DMI_PRODUCT_NAME, "iMac20,2"),
+               },
+       },
+       {
+               .matches = {
+                       DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
+                       DMI_MATCH(DMI_PRODUCT_NAME, "iMacPro1,1"),
+               },
+       },
+       { }
+};
+
 void __init early_platform_quirks(void)
 {
        x86_apple_machine = dmi_match(DMI_SYS_VENDOR, "Apple Inc.") ||
                            dmi_match(DMI_SYS_VENDOR, "Apple Computer, Inc.");
+
+       has_apple_t2_chip = dmi_check_system(apple_t2_devices);
 }
diff --git a/include/linux/platform_data/x86/apple.h 
b/include/linux/platform_data/x86/apple.h
index 079e816c3c21..47b27dceab18 100644
--- a/include/linux/platform_data/x86/apple.h
+++ b/include/linux/platform_data/x86/apple.h
@@ -6,8 +6,13 @@
  * x86_apple_machine - whether the machine is an x86 Apple Macintosh
  */
 extern bool x86_apple_machine;
+/**
+ * has_apple_t2_chip - whether the machine has the Apple T2 chip
+ */
+extern bool has_apple_t2_chip;
 #else
 #define x86_apple_machine false
+#define has_apple_t2_chip false
 #endif
 
 #endif
diff --git a/security/integrity/platform_certs/keyring_handler.h 
b/security/integrity/platform_certs/keyring_handler.h
index f92895cc50f6..a355f4400179 100644
--- a/security/integrity/platform_certs/keyring_handler.h
+++ b/security/integrity/platform_certs/keyring_handler.h
@@ -45,11 +45,3 @@ efi_element_handler_t 
get_handler_for_code_signing_keys(const efi_guid_t *sig_ty
 efi_element_handler_t get_handler_for_dbx(const efi_guid_t *sig_type);
 
 #endif
-
-#ifndef UEFI_QUIRK_SKIP_CERT
-#define UEFI_QUIRK_SKIP_CERT(vendor, product) \
-                .matches = { \
-                       DMI_MATCH(DMI_BOARD_VENDOR, vendor), \
-                       DMI_MATCH(DMI_PRODUCT_NAME, product), \
-               },
-#endif
diff --git a/security/integrity/platform_certs/load_uefi.c 
b/security/integrity/platform_certs/load_uefi.c
index c0d6948446c3..b4096d4c828d 100644
--- a/security/integrity/platform_certs/load_uefi.c
+++ b/security/integrity/platform_certs/load_uefi.c
@@ -3,42 +3,16 @@
 #include <linux/kernel.h>
 #include <linux/sched.h>
 #include <linux/cred.h>
-#include <linux/dmi.h>
 #include <linux/err.h>
 #include <linux/efi.h>
 #include <linux/slab.h>
 #include <linux/ima.h>
+#include <linux/platform_data/x86/apple.h>
 #include <keys/asymmetric-type.h>
 #include <keys/system_keyring.h>
 #include "../integrity.h"
 #include "keyring_handler.h"
 
-/*
- * On T2 Macs reading the db and dbx efi variables to load UEFI Secure Boot
- * certificates causes occurrence of a page fault in Apple's firmware and
- * a crash disabling EFI runtime services. The following quirk skips reading
- * these variables.
- */
-static const struct dmi_system_id uefi_skip_cert[] = {
-       { UEFI_QUIRK_SKIP_CERT("Apple Inc.", "MacBookPro15,1") },
-       { UEFI_QUIRK_SKIP_CERT("Apple Inc.", "MacBookPro15,2") },
-       { UEFI_QUIRK_SKIP_CERT("Apple Inc.", "MacBookPro15,3") },
-       { UEFI_QUIRK_SKIP_CERT("Apple Inc.", "MacBookPro15,4") },
-       { UEFI_QUIRK_SKIP_CERT("Apple Inc.", "MacBookPro16,1") },
-       { UEFI_QUIRK_SKIP_CERT("Apple Inc.", "MacBookPro16,2") },
-       { UEFI_QUIRK_SKIP_CERT("Apple Inc.", "MacBookPro16,3") },
-       { UEFI_QUIRK_SKIP_CERT("Apple Inc.", "MacBookPro16,4") },
-       { UEFI_QUIRK_SKIP_CERT("Apple Inc.", "MacBookAir8,1") },
-       { UEFI_QUIRK_SKIP_CERT("Apple Inc.", "MacBookAir8,2") },
-       { UEFI_QUIRK_SKIP_CERT("Apple Inc.", "MacBookAir9,1") },
-       { UEFI_QUIRK_SKIP_CERT("Apple Inc.", "Macmini8,1") },
-       { UEFI_QUIRK_SKIP_CERT("Apple Inc.", "MacPro7,1") },
-       { UEFI_QUIRK_SKIP_CERT("Apple Inc.", "iMac20,1") },
-       { UEFI_QUIRK_SKIP_CERT("Apple Inc.", "iMac20,2") },
-       { UEFI_QUIRK_SKIP_CERT("Apple Inc.", "iMacPro1,1") },
-       { }
-};
-
 /*
  * Look to see if a UEFI variable called MokIgnoreDB exists and return true if
  * it does.
@@ -165,10 +139,14 @@ static int __init load_uefi_certs(void)
        unsigned long dbsize = 0, dbxsize = 0, mokxsize = 0;
        efi_status_t status;
        int rc = 0;
-       const struct dmi_system_id *dmi_id;
 
-       dmi_id = dmi_first_match(uefi_skip_cert);
-       if (dmi_id) {
+       /*
+        * On T2 Macs reading the db and dbx efi variables to load UEFI Secure 
Boot
+        * certificates causes occurrence of a page fault in Apple's firmware 
and
+        * a crash disabling EFI runtime services. The following quirk skips 
reading
+        * these variables.
+        */
+       if (has_apple_t2_chip) {
                pr_err("Reading UEFI Secure Boot Certs is not supported on T2 
Macs.\n");
                return false;
        }
-- 
2.43.0


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