| Message ID | 147986059202.13790.3471243422582131819.stgit@warthog.procyon.org.uk (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Wed, Nov 23, 2016 at 12:23:12AM +0000, David Howells wrote: > From: Josh Boyer <jwboyer@fedoraproject.org> > > UEFI machines can be booted in Secure Boot mode. Add a EFI_SECURE_BOOT bit > that can be passed to efi_enabled() to find out whether secure boot is > enabled. > > This will be used by the SysRq+x handler, registered by the x86 arch, to find > out whether secure boot mode is enabled so that it can be disabled. > > Signed-off-by: Josh Boyer <jwboyer@fedoraproject.org> > Signed-off-by: David Howells <dhowells@redhat.com> > --- > > arch/x86/kernel/setup.c | 7 +++++++ > include/linux/efi.h | 1 + > 2 files changed, 8 insertions(+) > > diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c > index 9c337b0e8ba7..522915d6de1f 100644 > --- a/arch/x86/kernel/setup.c > +++ b/arch/x86/kernel/setup.c > @@ -1160,6 +1160,13 @@ void __init setup_arch(char **cmdline_p) > > io_delay_init(); > > +#ifdef CONFIG_EFI > + if (boot_params.secure_boot) { > + set_bit(EFI_SECURE_BOOT, &efi.flags); > + pr_info("Secure boot enabled\n"); > + } > +#endif > + Section 20 of Documentation/CodingStyle recommends IS_ENABLED() instead of #ifdef. Also, CONFIG_EFI_STUB might be more apt than CONFIG_EFI. Thanks, Lukas > /* > * Parse the ACPI tables for possible boot-time SMP configuration. > */ > diff --git a/include/linux/efi.h b/include/linux/efi.h > index ff01ad6f2823..d95bb9e69974 100644 > --- a/include/linux/efi.h > +++ b/include/linux/efi.h > @@ -1066,6 +1066,7 @@ extern int __init efi_setup_pcdp_console(char *); > #define EFI_ARCH_1 7 /* First arch-specific bit */ > #define EFI_DBG 8 /* Print additional debug info at runtime */ > #define EFI_NX_PE_DATA 9 /* Can runtime data regions be mapped non-executable? */ > +#define EFI_SECURE_BOOT 10 /* Are we in Secure Boot mode? */ > > #ifdef CONFIG_EFI > /* > -- To unsubscribe from this list: send the line "unsubscribe linux-security-module" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Lukas Wunner <lukas@wunner.de> wrote: > > +#ifdef CONFIG_EFI > > + if (boot_params.secure_boot) { > > + set_bit(EFI_SECURE_BOOT, &efi.flags); > > + pr_info("Secure boot enabled\n"); > > + } > > +#endif > > + > > Section 20 of Documentation/CodingStyle recommends IS_ENABLED() > instead of #ifdef. The problem is this: arch/x86/include/asm/bitops.h:75: undefined reference to `efi' To quote section 20: "... Thus, you still have to use an #ifdef if the code inside the block references symbols that will not exist if the condition is not met." > Also, CONFIG_EFI_STUB might be more apt than CONFIG_EFI. Other stuff in the same function is contingent on CONFIG_EFI. EFI_STUB is to do with how the thing can be booted, I think - not whether EFI support is enabled. David -- To unsubscribe from this list: send the line "unsubscribe linux-security-module" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
David Howells <dhowells@redhat.com> wrote: > > > +#ifdef CONFIG_EFI > > > + if (boot_params.secure_boot) { > > > + set_bit(EFI_SECURE_BOOT, &efi.flags); > > > + pr_info("Secure boot enabled\n"); > > > + } > > > +#endif > > > + > > > > Section 20 of Documentation/CodingStyle recommends IS_ENABLED() > > instead of #ifdef. > > The problem is this: > > arch/x86/include/asm/bitops.h:75: undefined reference to `efi' > > To quote section 20: "... Thus, you still have to use an #ifdef if the code > inside the block references symbols that will not exist if the condition is > not met." Okay, I take that back - it does actually work. However, should I follow the scheme of the rest of the file? David -- To unsubscribe from this list: send the line "unsubscribe linux-security-module" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c index 9c337b0e8ba7..522915d6de1f 100644 --- a/arch/x86/kernel/setup.c +++ b/arch/x86/kernel/setup.c @@ -1160,6 +1160,13 @@ void __init setup_arch(char **cmdline_p) io_delay_init(); +#ifdef CONFIG_EFI + if (boot_params.secure_boot) { + set_bit(EFI_SECURE_BOOT, &efi.flags); + pr_info("Secure boot enabled\n"); + } +#endif + /* * Parse the ACPI tables for possible boot-time SMP configuration. */ diff --git a/include/linux/efi.h b/include/linux/efi.h index ff01ad6f2823..d95bb9e69974 100644 --- a/include/linux/efi.h +++ b/include/linux/efi.h @@ -1066,6 +1066,7 @@ extern int __init efi_setup_pcdp_console(char *); #define EFI_ARCH_1 7 /* First arch-specific bit */ #define EFI_DBG 8 /* Print additional debug info at runtime */ #define EFI_NX_PE_DATA 9 /* Can runtime data regions be mapped non-executable? */ +#define EFI_SECURE_BOOT 10 /* Are we in Secure Boot mode? */ #ifdef CONFIG_EFI /*