From nobody Sun Feb 8 23:35:15 2026 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4CE4521146C for ; Thu, 24 Apr 2025 08:10:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745482248; cv=none; b=VGtPzFFUat6YW7MlClSRUFS3FGAKmvh8E8nAYDkPik6MjNfLQq387CXPO+Zg1MqDchTLSE+veXVU4Yix1/k0yan5sqi8IDPSQKAMTMq8t0wsLyB1KmSMAGX7Xtoa8XXq0Jvynrh+uymOmSMcKpc3skucJRn98scaIRG/gU7atRM= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745482248; c=relaxed/simple; bh=TH67hndJf5FIDT/iNA8mLp4el/Q9YJ0KwNFDvaHNoy4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=LcnGKEjb17vV7RgKish7S0YTGbxFjVzEGwBz1jaOmKM3fkjmWuq98zORkQuTsr9fo8YxATNhXAYV4WDPiPILkosGU3sDhirThT+yXarT5Ia8gPBN2UQ83c/R5p/LbFlVtPH0Ra9GzIb0JqeXI7pgkordS706EGEcHkgLny9+0+Y= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=TJPG3UDm; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="TJPG3UDm" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1745482244; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=90i0OCg6Zt5Z8sKdLwCV2r9r1JKdc4QuwHkOEn9E9Jg=; b=TJPG3UDmtnwW7+nTpxub8Qceui+JehQJwm2RvEl3xc0nBE92AJMFkEeD3XXO/l9ZtEBAKF kyBbhDeGeDVRBlEaD/FvjPBdyqhwPZmnbYM4M9I6R1hVeP6Ur8BZgKJ6CqQ2NzNvwXU921 xaDK9Q4PAX0/G6abh5QwKOUs+e9aBDM= Received: from mx-prod-mc-02.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-79-3RHKMFU5PVm64rDqCSspaA-1; Thu, 24 Apr 2025 04:10:42 -0400 X-MC-Unique: 3RHKMFU5PVm64rDqCSspaA-1 X-Mimecast-MFC-AGG-ID: 3RHKMFU5PVm64rDqCSspaA_1745482240 Received: from mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.4]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-02.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 5FC2219560BA; Thu, 24 Apr 2025 08:10:39 +0000 (UTC) Received: from fedora.redhat.com (unknown [10.45.224.198]) by mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id B3B5B30001A2; Thu, 24 Apr 2025 08:10:25 +0000 (UTC) From: Vitaly Kuznetsov To: x86@kernel.org, linux-efi@vger.kernel.org Cc: Thomas Gleixner , Ingo Molnar , Dave Hansen , "H. Peter Anvin" , Ard Biesheuvel , Peter Jones , Daniel Berrange , Emanuele Giuseppe Esposito , Gerd Hoffmann , Greg KH , Luca Boccassi , Peter Zijlstra , Matthew Garrett , James Bottomley , Eric Snowberg , Paolo Bonzini , Paul Walmsley , Palmer Dabbelt , Albert Ou , Alexandre Ghiti , linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH 2/2] x86/efi: Implement support for embedding SBAT data for x86 Date: Thu, 24 Apr 2025 12:09:50 +0400 Message-ID: <20250424080950.289864-3-vkuznets@redhat.com> In-Reply-To: <20250424080950.289864-1-vkuznets@redhat.com> References: <20250424080950.289864-1-vkuznets@redhat.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.4 Content-Type: text/plain; charset="utf-8" Similar to zboot architectures, implement support for embedding SBAT data for x86. Put '.sbat' section to the very end of the binary. Note, the obsolete CRC-32 checksum (see commit 9c54baab4401 ("x86/boot: Drop CRC-32 checksum and the build tool that generates it")) is gone and while it would've been possible to reserve the last 4 bytes in '.sbat' section too (like it's done today in '.data'), it seems to be a pointless exercise: SBAT makes zero sense without a signature on the EFI binary so '.sbat' won't be at the very end of the file anyway. Any tool which uses the last 4 bytes of the file as a checksum is broken with signed EFI binaries already. Signed-off-by: Vitaly Kuznetsov --- arch/x86/boot/Makefile | 2 +- arch/x86/boot/compressed/Makefile | 2 ++ arch/x86/boot/compressed/vmlinux.lds.S | 13 +++++++++++++ arch/x86/boot/header.S | 13 +++++++++++++ drivers/firmware/efi/Kconfig | 2 +- 5 files changed, 30 insertions(+), 2 deletions(-) diff --git a/arch/x86/boot/Makefile b/arch/x86/boot/Makefile index 81f55da81967..5f7b52f0e7f5 100644 --- a/arch/x86/boot/Makefile +++ b/arch/x86/boot/Makefile @@ -71,7 +71,7 @@ $(obj)/vmlinux.bin: $(obj)/compressed/vmlinux FORCE =20 SETUP_OBJS =3D $(addprefix $(obj)/,$(setup-y)) =20 -sed-zoffset :=3D -e 's/^\([0-9a-fA-F]*\) [a-zA-Z] \(startup_32\|efi.._stub= _entry\|efi\(32\)\?_pe_entry\|input_data\|kernel_info\|_end\|_ehead\|_text\= |_e\?data\|z_.*\)$$/\#define ZO_\2 0x\1/p' +sed-zoffset :=3D -e 's/^\([0-9a-fA-F]*\) [a-zA-Z] \(startup_32\|efi.._stub= _entry\|efi\(32\)\?_pe_entry\|input_data\|kernel_info\|_end\|_ehead\|_text\= |_e\?data\|_e\?sbat\|z_.*\)$$/\#define ZO_\2 0x\1/p' =20 quiet_cmd_zoffset =3D ZOFFSET $@ cmd_zoffset =3D $(NM) $< | sed -n $(sed-zoffset) > $@ diff --git a/arch/x86/boot/compressed/Makefile b/arch/x86/boot/compressed/M= akefile index fdbce022db55..b9b80eccdc02 100644 --- a/arch/x86/boot/compressed/Makefile +++ b/arch/x86/boot/compressed/Makefile @@ -107,6 +107,8 @@ vmlinux-objs-$(CONFIG_UNACCEPTED_MEMORY) +=3D $(obj)/me= m.o vmlinux-objs-$(CONFIG_EFI) +=3D $(obj)/efi.o vmlinux-libs-$(CONFIG_EFI_STUB) +=3D $(objtree)/drivers/firmware/efi/libst= ub/lib.a =20 +vmlinux-objs-$(CONFIG_EFI_SBAT) +=3D $(objtree)/drivers/firmware/efi/libst= ub/sbat.o + $(obj)/vmlinux: $(vmlinux-objs-y) $(vmlinux-libs-y) FORCE $(call if_changed,ld) =20 diff --git a/arch/x86/boot/compressed/vmlinux.lds.S b/arch/x86/boot/compres= sed/vmlinux.lds.S index 3b2bc61c9408..d0a27905de90 100644 --- a/arch/x86/boot/compressed/vmlinux.lds.S +++ b/arch/x86/boot/compressed/vmlinux.lds.S @@ -49,9 +49,22 @@ SECTIONS *(.data.*) =20 /* Add 4 bytes of extra space for the obsolete CRC-32 checksum */ +#ifndef CONFIG_EFI_SBAT . =3D ALIGN(. + 4, 0x200); +#else + /* Avoid gap between '.data' and '.sbat' */ + . =3D ALIGN(. + 4, 0x1000); +#endif _edata =3D . ; } +#ifdef CONFIG_EFI_SBAT + .sbat : ALIGN(0x1000) { + _sbat =3D . ; + *(.sbat) + _esbat =3D ALIGN(0x200); + . =3D _esbat; + } +#endif . =3D ALIGN(L1_CACHE_BYTES); .bss : { _bss =3D . ; diff --git a/arch/x86/boot/header.S b/arch/x86/boot/header.S index b5c79f43359b..ab851490ef74 100644 --- a/arch/x86/boot/header.S +++ b/arch/x86/boot/header.S @@ -207,6 +207,19 @@ pecompat_fstart: IMAGE_SCN_MEM_READ | \ IMAGE_SCN_MEM_WRITE # Characteristics =20 +#ifdef CONFIG_EFI_SBAT + .ascii ".sbat\0\0\0" + .long ZO__esbat - ZO__sbat # VirtualSize + .long setup_size + ZO__sbat # VirtualAddress + .long ZO__esbat - ZO__sbat # SizeOfRawData + .long setup_size + ZO__sbat # PointerToRawData + + .long 0, 0, 0 + .long IMAGE_SCN_CNT_INITIALIZED_DATA | \ + IMAGE_SCN_MEM_READ | \ + IMAGE_SCN_MEM_DISCARDABLE # Characteristics +#endif + .set section_count, (. - section_table) / 40 #endif /* CONFIG_EFI_STUB */ =20 diff --git a/drivers/firmware/efi/Kconfig b/drivers/firmware/efi/Kconfig index 2edb0167ba49..5022a378fec1 100644 --- a/drivers/firmware/efi/Kconfig +++ b/drivers/firmware/efi/Kconfig @@ -283,7 +283,7 @@ config EFI_EMBEDDED_FIRMWARE =20 config EFI_SBAT bool "Embed SBAT section in the kernel" - depends on EFI_ZBOOT + depends on EFI_ZBOOT || (EFI_STUB && X86) help SBAT section provides a way to improve SecureBoot revocations of UEFI binaries by introducing a generation-based mechanism. With SBAT, older --=20 2.49.0