Messages in this thread | | | Date | Tue, 2 Jan 2024 15:07:10 +0100 | Subject | Re: [PATCH v2 2/3] arch/x86: Add <asm/ima-efi.h> for arch_ima_efi_boot_mode | From | Thomas Zimmermann <> |
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Hii Ard
Am 19.12.23 um 12:38 schrieb Ard Biesheuvel: > Hi Thomas, > > On Fri, 15 Dec 2023 at 13:26, Thomas Zimmermann <tzimmermann@suse.de> wrote: >> >> The header file <asm/efi.h> contains the macro arch_ima_efi_boot_mode, >> which expands to use struct boot_params from <asm/bootparams.h>. Many >> drivers include <linux/efi.h>, but do not use boot parameters. Changes >> to bootparam.h or its included headers can easily trigger large, >> unnessary rebuilds of the kernel. >> >> Moving x86's arch_ima_efi_boot_mode to <asm/ima-efi.h> and including >> <asm/setup.h> separates that dependency from the rest of the EFI >> interfaces. The only user is in ima_efi.c. As the file already declares >> a default value for arch_ima_efi_boot_mode, move this define into >> asm-generic for all other architectures. >> >> With arch_ima_efi_boot_mode removed from efi.h, <asm/bootparam.h> can >> later be removed from further x86 header files. >> > > Apologies if I missed this in v1 but is the new asm-generic header > really necessary? Could we instead turn arch_ima_efi_boot_mode into a > function that is a static inline { return unset; } by default, but can > be emitted out of line in one of the x86/platform/efi.c source files, > where referring to boot_params is fine?
I cannot figure out how to do this without *something* in asm-generic or adding if-CONFIG_X86 guards in ima-efi.c.
But I noticed that linux/efi.h already contains 2 or 3 ifdef branches for x86. Would it be an option to move this code into asm/efi.h (including a header file in asm-generic for the non-x86 variants) and add the arch_ima_efi_boot_mode() helper there as well? At least that wouldn't be a header for only a single define.
Best regards Thomas
> > > > > >> v2: >> * remove extra declaration of boot_params (Ard) >> > > Please don't put the revision log here, but below the --- so that 'git > am' will ignore it. > > >> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de> >> --- >> arch/x86/include/asm/efi.h | 3 --- >> arch/x86/include/asm/ima-efi.h | 11 +++++++++++ >> include/asm-generic/Kbuild | 1 + >> include/asm-generic/ima-efi.h | 16 ++++++++++++++++ >> security/integrity/ima/ima_efi.c | 5 +---- >> 5 files changed, 29 insertions(+), 7 deletions(-) >> create mode 100644 arch/x86/include/asm/ima-efi.h >> create mode 100644 include/asm-generic/ima-efi.h >> >> diff --git a/arch/x86/include/asm/efi.h b/arch/x86/include/asm/efi.h >> index c4555b269a1b..99f31176c892 100644 >> --- a/arch/x86/include/asm/efi.h >> +++ b/arch/x86/include/asm/efi.h >> @@ -418,9 +418,6 @@ extern int __init efi_memmap_split_count(efi_memory_desc_t *md, >> extern void __init efi_memmap_insert(struct efi_memory_map *old_memmap, >> void *buf, struct efi_mem_range *mem); >> >> -#define arch_ima_efi_boot_mode \ >> - ({ extern struct boot_params boot_params; boot_params.secure_boot; }) >> - >> #ifdef CONFIG_EFI_RUNTIME_MAP >> int efi_get_runtime_map_size(void); >> int efi_get_runtime_map_desc_size(void); >> diff --git a/arch/x86/include/asm/ima-efi.h b/arch/x86/include/asm/ima-efi.h >> new file mode 100644 >> index 000000000000..b4d904e66b39 >> --- /dev/null >> +++ b/arch/x86/include/asm/ima-efi.h >> @@ -0,0 +1,11 @@ >> +/* SPDX-License-Identifier: GPL-2.0 */ >> +#ifndef _ASM_X86_IMA_EFI_H >> +#define _ASM_X86_IMA_EFI_H >> + >> +#include <asm/setup.h> >> + >> +#define arch_ima_efi_boot_mode boot_params.secure_boot >> + >> +#include <asm-generic/ima-efi.h> >> + >> +#endif /* _ASM_X86_IMA_EFI_H */ >> diff --git a/include/asm-generic/Kbuild b/include/asm-generic/Kbuild >> index def242528b1d..4fd16e71e8cd 100644 >> --- a/include/asm-generic/Kbuild >> +++ b/include/asm-generic/Kbuild >> @@ -26,6 +26,7 @@ mandatory-y += ftrace.h >> mandatory-y += futex.h >> mandatory-y += hardirq.h >> mandatory-y += hw_irq.h >> +mandatory-y += ima-efi.h >> mandatory-y += io.h >> mandatory-y += irq.h >> mandatory-y += irq_regs.h >> diff --git a/include/asm-generic/ima-efi.h b/include/asm-generic/ima-efi.h >> new file mode 100644 >> index 000000000000..f87f5edef440 >> --- /dev/null >> +++ b/include/asm-generic/ima-efi.h >> @@ -0,0 +1,16 @@ >> +/* SPDX-License-Identifier: GPL-2.0+ */ >> + >> +#ifndef __ASM_GENERIC_IMA_EFI_H_ >> +#define __ASM_GENERIC_IMA_EFI_H_ >> + >> +#include <linux/efi.h> >> + >> +/* >> + * Only include this header file from your architecture's <asm/ima-efi.h>. >> + */ >> + >> +#ifndef arch_ima_efi_boot_mode >> +#define arch_ima_efi_boot_mode efi_secureboot_mode_unset >> +#endif >> + >> +#endif /* __ASM_GENERIC_FB_H_ */ >> diff --git a/security/integrity/ima/ima_efi.c b/security/integrity/ima/ima_efi.c >> index 138029bfcce1..56bbee271cec 100644 >> --- a/security/integrity/ima/ima_efi.c >> +++ b/security/integrity/ima/ima_efi.c >> @@ -6,10 +6,7 @@ >> #include <linux/module.h> >> #include <linux/ima.h> >> #include <asm/efi.h> >> - >> -#ifndef arch_ima_efi_boot_mode >> -#define arch_ima_efi_boot_mode efi_secureboot_mode_unset >> -#endif >> +#include <asm/ima-efi.h> >> >> static enum efi_secureboot_mode get_sb_mode(void) >> { >> -- >> 2.43.0 >> >>
-- Thomas Zimmermann Graphics Driver Developer SUSE Software Solutions Germany GmbH Frankenstrasse 146, 90461 Nuernberg, Germany GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman HRB 36809 (AG Nuernberg) [unhandled content-type:application/pgp-signature] | |