grub2/grub-core/kern/efi/init.c
Javier Martinez Canillas 98b00a403c efi: Lockdown the GRUB when the UEFI Secure Boot is enabled
If the UEFI Secure Boot is enabled then the GRUB must be locked down
to prevent executing code that can potentially be used to subvert its
verification mechanisms.

Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2021-03-02 15:54:15 +01:00

96 lines
2.4 KiB
C

/* init.c - generic EFI initialization and finalization */
/*
* GRUB -- GRand Unified Bootloader
* Copyright (C) 2006,2007 Free Software Foundation, Inc.
*
* GRUB is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* GRUB is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with GRUB. If not, see <http://www.gnu.org/licenses/>.
*/
#include <grub/efi/efi.h>
#include <grub/efi/console.h>
#include <grub/efi/disk.h>
#include <grub/efi/sb.h>
#include <grub/lockdown.h>
#include <grub/term.h>
#include <grub/misc.h>
#include <grub/env.h>
#include <grub/mm.h>
#include <grub/kernel.h>
grub_addr_t grub_modbase;
void
grub_efi_init (void)
{
grub_modbase = grub_efi_modules_addr ();
/* First of all, initialize the console so that GRUB can display
messages. */
grub_console_init ();
/* Initialize the memory management system. */
grub_efi_mm_init ();
/*
* Lockdown the GRUB and register the shim_lock verifier
* if the UEFI Secure Boot is enabled.
*/
if (grub_efi_get_secureboot () == GRUB_EFI_SECUREBOOT_MODE_ENABLED)
{
grub_lockdown ();
grub_shim_lock_verifier_setup ();
}
efi_call_4 (grub_efi_system_table->boot_services->set_watchdog_timer,
0, 0, 0, NULL);
grub_efidisk_init ();
}
void (*grub_efi_net_config) (grub_efi_handle_t hnd,
char **device,
char **path);
void
grub_machine_get_bootlocation (char **device, char **path)
{
grub_efi_loaded_image_t *image = NULL;
char *p;
image = grub_efi_get_loaded_image (grub_efi_image_handle);
if (!image)
return;
*device = grub_efidisk_get_device_name (image->device_handle);
if (!*device && grub_efi_net_config)
{
grub_efi_net_config (image->device_handle, device, path);
return;
}
*path = grub_efi_get_filename (image->file_path);
if (*path)
{
/* Get the directory. */
p = grub_strrchr (*path, '/');
if (p)
*p = '\0';
}
}
void
grub_efi_fini (void)
{
grub_efidisk_fini ();
grub_console_fini ();
}