From: Jarkko Sakkinen <jarkko@kernel.org>
To: Atharva Tiwari <atharvatiwarilinuxdev@gmail.com>
Cc: "Bjorn Helgaas" <bhelgaas@google.com>,
"Thomas Gleixner" <tglx@kernel.org>,
"Ingo Molnar" <mingo@redhat.com>,
"Borislav Petkov" <bp@alien8.de>,
"Dave Hansen" <dave.hansen@linux.intel.com>,
x86@kernel.org, "H. Peter Anvin" <hpa@zytor.com>,
"Andreas Noever" <andreas.noever@gmail.com>,
"Mika Westerberg" <westeri@kernel.org>,
"Yehezkel Bernat" <YehezkelShB@gmail.com>,
"Hans de Goede" <hansg@kernel.org>,
"Ilpo Järvinen" <ilpo.jarvinen@linux.intel.com>,
"Mimi Zohar" <zohar@linux.ibm.com>,
"Roberto Sassu" <roberto.sassu@huawei.com>,
"Dmitry Kasatkin" <dmitry.kasatkin@gmail.com>,
"Eric Snowberg" <eric.snowberg@oracle.com>,
"Paul Moore" <paul@paul-moore.com>,
"James Morris" <jmorris@namei.org>,
"Serge E. Hallyn" <serge@hallyn.com>,
linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-usb@vger.kernel.org, platform-driver-x86@vger.kernel.org,
linux-integrity@vger.kernel.org, keyrings@vger.kernel.org,
linux-security-module@vger.kernel.org
Subject: Re: [PATCH v2 1/2] treewide: Add a flag to detect the Apple T2 chip
Date: Tue, 21 Jul 2026 13:56:07 +0300 [thread overview]
Message-ID: <al9QR4v0Z_jkS44N@kernel.org> (raw)
In-Reply-To: <20260721054506.11871-2-atharvatiwarilinuxdev@gmail.com>
On Tue, Jul 21, 2026 at 01:45:01AM -0400, Atharva Tiwari wrote:
> 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 <atharvatiwarilinuxdev@gmail.com>
> ---
> arch/x86/kernel/quirks.c | 105 ++++++++++++++++++
> include/linux/platform_data/x86/apple.h | 5 +
> security/integrity/platform_certs/load_uefi.c | 38 ++-----
> 3 files changed, 118 insertions(+), 30 deletions(-)
>
> diff --git a/arch/x86/kernel/quirks.c b/arch/x86/kernel/quirks.c
> index a92f18db9610..74b29738d404 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[] = {
> + {
> + .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..50bbcc5134fc 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_t2_chip false
> #endif
>
> #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
>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
BR, Jarkko
next prev parent reply other threads:[~2026-07-21 10:56 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-07-21 5:45 [PATCH v2 0/2] Add Apple T2 NHI device links Atharva Tiwari
2026-07-21 5:45 ` [PATCH v2 1/2] treewide: Add a flag to detect the Apple T2 chip Atharva Tiwari
2026-07-21 10:56 ` Jarkko Sakkinen [this message]
2026-07-21 5:45 ` [PATCH v2 2/2] thunderbolt: Add device links for Apple T2 NHI Atharva Tiwari
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