[PATCH v3 1/2] treewide: Add a flag to detect the Apple T2 chip
From: Atharva Tiwari <hidden>
Date: 2026-07-21 06:34:39
Also in:
keyrings, linux-integrity, linux-pci, linux-usb, lkml, platform-driver-x86
Subsystem:
extended verification module (evm), integrity measurement architecture (ima), pci subsystem, security subsystem, the rest, x86 architecture (32-bit and 64-bit), x86 platform drivers · Maintainers:
Mimi Zohar, Roberto Sassu, Dmitry Kasatkin, Bjorn Helgaas, Paul Moore, James Morris, "Serge E. Hallyn", Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen, Hans de Goede, Ilpo Järvinen
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 <redacted> --- 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