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    SubjectRe: [PATCH V2 08/10] efi: Enable secure boot lockdown automatically when enabled in firmware
    Quoting Matthew Garrett (mjg@redhat.com):
    > The firmware has a set of flags that indicate whether secure boot is enabled
    > and enforcing. Use them to indicate whether the kernel should lock itself
    > down.
    >
    > Signed-off-by: Matthew Garrett <mjg@redhat.com>

    (purely for the non-firmware bits) seems good, thanks.

    Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>

    > ---
    > Documentation/x86/zero-page.txt | 2 ++
    > arch/x86/boot/compressed/eboot.c | 32 ++++++++++++++++++++++++++++++++
    > arch/x86/include/asm/bootparam.h | 3 ++-
    > arch/x86/kernel/setup.c | 3 +++
    > include/linux/cred.h | 2 ++
    > 5 files changed, 41 insertions(+), 1 deletion(-)
    >
    > diff --git a/Documentation/x86/zero-page.txt b/Documentation/x86/zero-page.txt
    > index cf5437d..7f9ed48 100644
    > --- a/Documentation/x86/zero-page.txt
    > +++ b/Documentation/x86/zero-page.txt
    > @@ -27,6 +27,8 @@ Offset Proto Name Meaning
    > 1E9/001 ALL eddbuf_entries Number of entries in eddbuf (below)
    > 1EA/001 ALL edd_mbr_sig_buf_entries Number of entries in edd_mbr_sig_buffer
    > (below)
    > +1EB/001 ALL kbd_status Numlock is enabled
    > +1EC/001 ALL secure_boot Kernel should enable secure boot lockdowns
    > 290/040 ALL edd_mbr_sig_buffer EDD MBR signatures
    > 2D0/A00 ALL e820_map E820 memory map table
    > (array of struct e820entry)
    > diff --git a/arch/x86/boot/compressed/eboot.c b/arch/x86/boot/compressed/eboot.c
    > index b3e0227..3789356 100644
    > --- a/arch/x86/boot/compressed/eboot.c
    > +++ b/arch/x86/boot/compressed/eboot.c
    > @@ -724,6 +724,36 @@ fail:
    > return status;
    > }
    >
    > +static int get_secure_boot(efi_system_table_t *_table)
    > +{
    > + u8 sb, setup;
    > + unsigned long datasize = sizeof(sb);
    > + efi_guid_t var_guid = EFI_GLOBAL_VARIABLE_GUID;
    > + efi_status_t status;
    > +
    > + status = efi_call_phys5(sys_table->runtime->get_variable,
    > + L"SecureBoot", &var_guid, NULL, &datasize, &sb);
    > +
    > + if (status != EFI_SUCCESS)
    > + return 0;
    > +
    > + if (sb == 0)
    > + return 0;
    > +
    > +
    > + status = efi_call_phys5(sys_table->runtime->get_variable,
    > + L"SetupMode", &var_guid, NULL, &datasize,
    > + &setup);
    > +
    > + if (status != EFI_SUCCESS)
    > + return 0;
    > +
    > + if (setup == 1)
    > + return 0;
    > +
    > + return 1;
    > +}
    > +
    > /*
    > * Because the x86 boot code expects to be passed a boot_params we
    > * need to create one ourselves (usually the bootloader would create
    > @@ -1018,6 +1048,8 @@ struct boot_params *efi_main(void *handle, efi_system_table_t *_table,
    > if (sys_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE)
    > goto fail;
    >
    > + boot_params->secure_boot = get_secure_boot(sys_table);
    > +
    > setup_graphics(boot_params);
    >
    > status = efi_call_phys3(sys_table->boottime->allocate_pool,
    > diff --git a/arch/x86/include/asm/bootparam.h b/arch/x86/include/asm/bootparam.h
    > index 2ad874c..c7338e0 100644
    > --- a/arch/x86/include/asm/bootparam.h
    > +++ b/arch/x86/include/asm/bootparam.h
    > @@ -114,7 +114,8 @@ struct boot_params {
    > __u8 eddbuf_entries; /* 0x1e9 */
    > __u8 edd_mbr_sig_buf_entries; /* 0x1ea */
    > __u8 kbd_status; /* 0x1eb */
    > - __u8 _pad6[5]; /* 0x1ec */
    > + __u8 secure_boot; /* 0x1ec */
    > + __u8 _pad6[4]; /* 0x1ed */
    > struct setup_header hdr; /* setup header */ /* 0x1f1 */
    > __u8 _pad7[0x290-0x1f1-sizeof(struct setup_header)];
    > __u32 edd_mbr_sig_buffer[EDD_MBR_SIG_MAX]; /* 0x290 */
    > diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
    > index f4b9b80..239bf2a 100644
    > --- a/arch/x86/kernel/setup.c
    > +++ b/arch/x86/kernel/setup.c
    > @@ -947,6 +947,9 @@ void __init setup_arch(char **cmdline_p)
    >
    > io_delay_init();
    >
    > + if (boot_params.secure_boot)
    > + secureboot_enable();
    > +
    > /*
    > * Parse the ACPI tables for possible boot-time SMP configuration.
    > */
    > diff --git a/include/linux/cred.h b/include/linux/cred.h
    > index ebbed2c..a24faf1 100644
    > --- a/include/linux/cred.h
    > +++ b/include/linux/cred.h
    > @@ -170,6 +170,8 @@ extern int set_security_override_from_ctx(struct cred *, const char *);
    > extern int set_create_files_as(struct cred *, struct inode *);
    > extern void __init cred_init(void);
    >
    > +extern void secureboot_enable(void);
    > +
    > /*
    > * check for validity of credentials
    > */
    > --
    > 1.7.11.4
    >
    > --
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    > the body of a message to majordomo@vger.kernel.org
    > More majordomo info at http://vger.kernel.org/majordomo-info.html


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