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https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
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b283477d39
Now that we have a static inline helper to discover the platform's secure boot mode that can be shared between the EFI stub and the kernel proper, switch to it, and drop some comments about keeping them in sync manually. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
149 lines
4.3 KiB
C
149 lines
4.3 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright (c) 2014 Oracle Co., Daniel Kiper
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*/
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#include <linux/bitops.h>
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#include <linux/efi.h>
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#include <linux/init.h>
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#include <linux/string.h>
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#include <xen/xen.h>
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#include <xen/xen-ops.h>
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#include <xen/interface/platform.h>
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#include <asm/page.h>
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#include <asm/setup.h>
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#include <asm/xen/hypercall.h>
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static efi_char16_t vendor[100] __initdata;
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static efi_system_table_t efi_systab_xen __initdata = {
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.hdr = {
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.signature = EFI_SYSTEM_TABLE_SIGNATURE,
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.revision = 0, /* Initialized later. */
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.headersize = 0, /* Ignored by Linux Kernel. */
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.crc32 = 0, /* Ignored by Linux Kernel. */
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.reserved = 0
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},
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.fw_vendor = EFI_INVALID_TABLE_ADDR, /* Initialized later. */
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.fw_revision = 0, /* Initialized later. */
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.con_in_handle = EFI_INVALID_TABLE_ADDR, /* Not used under Xen. */
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.con_in = NULL, /* Not used under Xen. */
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.con_out_handle = EFI_INVALID_TABLE_ADDR, /* Not used under Xen. */
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.con_out = NULL, /* Not used under Xen. */
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.stderr_handle = EFI_INVALID_TABLE_ADDR, /* Not used under Xen. */
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.stderr = EFI_INVALID_TABLE_ADDR, /* Not used under Xen. */
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.runtime = (efi_runtime_services_t *)EFI_INVALID_TABLE_ADDR,
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/* Not used under Xen. */
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.boottime = (efi_boot_services_t *)EFI_INVALID_TABLE_ADDR,
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/* Not used under Xen. */
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.nr_tables = 0, /* Initialized later. */
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.tables = EFI_INVALID_TABLE_ADDR /* Initialized later. */
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};
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static efi_system_table_t __init *xen_efi_probe(void)
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{
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struct xen_platform_op op = {
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.cmd = XENPF_firmware_info,
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.u.firmware_info = {
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.type = XEN_FW_EFI_INFO,
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.index = XEN_FW_EFI_CONFIG_TABLE
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}
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};
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union xenpf_efi_info *info = &op.u.firmware_info.u.efi_info;
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if (!xen_initial_domain() || HYPERVISOR_platform_op(&op) < 0)
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return NULL;
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/* Here we know that Xen runs on EFI platform. */
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xen_efi_runtime_setup();
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efi_systab_xen.tables = info->cfg.addr;
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efi_systab_xen.nr_tables = info->cfg.nent;
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op.cmd = XENPF_firmware_info;
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op.u.firmware_info.type = XEN_FW_EFI_INFO;
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op.u.firmware_info.index = XEN_FW_EFI_VENDOR;
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info->vendor.bufsz = sizeof(vendor);
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set_xen_guest_handle(info->vendor.name, vendor);
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if (HYPERVISOR_platform_op(&op) == 0) {
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efi_systab_xen.fw_vendor = __pa_symbol(vendor);
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efi_systab_xen.fw_revision = info->vendor.revision;
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} else
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efi_systab_xen.fw_vendor = __pa_symbol(L"UNKNOWN");
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op.cmd = XENPF_firmware_info;
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op.u.firmware_info.type = XEN_FW_EFI_INFO;
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op.u.firmware_info.index = XEN_FW_EFI_VERSION;
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if (HYPERVISOR_platform_op(&op) == 0)
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efi_systab_xen.hdr.revision = info->version;
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op.cmd = XENPF_firmware_info;
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op.u.firmware_info.type = XEN_FW_EFI_INFO;
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op.u.firmware_info.index = XEN_FW_EFI_RT_VERSION;
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if (HYPERVISOR_platform_op(&op) == 0)
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efi.runtime_version = info->version;
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return &efi_systab_xen;
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}
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/*
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* Determine whether we're in secure boot mode.
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*/
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static enum efi_secureboot_mode xen_efi_get_secureboot(void)
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{
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static efi_guid_t shim_guid = EFI_SHIM_LOCK_GUID;
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enum efi_secureboot_mode mode;
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efi_status_t status;
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u8 moksbstate;
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unsigned long size;
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mode = efi_get_secureboot_mode(efi.get_variable);
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if (mode == efi_secureboot_mode_unknown) {
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pr_err("Could not determine UEFI Secure Boot status.\n");
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return efi_secureboot_mode_unknown;
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}
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if (mode != efi_secureboot_mode_enabled)
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return mode;
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/* See if a user has put the shim into insecure mode. */
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size = sizeof(moksbstate);
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status = efi.get_variable(L"MokSBStateRT", &shim_guid,
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NULL, &size, &moksbstate);
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/* If it fails, we don't care why. Default to secure. */
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if (status != EFI_SUCCESS)
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goto secure_boot_enabled;
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if (moksbstate == 1)
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return efi_secureboot_mode_disabled;
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secure_boot_enabled:
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pr_info("UEFI Secure Boot is enabled.\n");
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return efi_secureboot_mode_enabled;
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}
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void __init xen_efi_init(struct boot_params *boot_params)
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{
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efi_system_table_t *efi_systab_xen;
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efi_systab_xen = xen_efi_probe();
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if (efi_systab_xen == NULL)
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return;
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strncpy((char *)&boot_params->efi_info.efi_loader_signature, "Xen",
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sizeof(boot_params->efi_info.efi_loader_signature));
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boot_params->efi_info.efi_systab = (__u32)__pa(efi_systab_xen);
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boot_params->efi_info.efi_systab_hi = (__u32)(__pa(efi_systab_xen) >> 32);
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boot_params->secure_boot = xen_efi_get_secureboot();
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set_bit(EFI_BOOT, &efi.flags);
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set_bit(EFI_PARAVIRT, &efi.flags);
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set_bit(EFI_64BIT, &efi.flags);
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}
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