Commit 0e470763 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'efi-next-for-v6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi 

Pull EFI updates from Ard Biesheuvel:
 "A bit more going on than usual in the EFI subsystem. The main driver
  for this has been the introduction of the LoonArch architecture last
  cycle, which inspired some cleanup and refactoring of the EFI code.
  Another driver for EFI changes this cycle and in the future is
  confidential compute.

  The LoongArch architecture does not use either struct bootparams or DT
  natively [yet], and so passing information between the EFI stub and
  the core kernel using either of those is undesirable. And in general,
  overloading DT has been a source of issues on arm64, so using DT for
  this on new architectures is a to avoid for the time being (even if we
  might converge on something DT based for non-x86 architectures in the
  future). For this reason, in addition to the patch that enables EFI
  boot for LoongArch, there are a number of refactoring patches applied
  on top of which separate the DT bits from the generic EFI stub bits.
  These changes are on a separate topich branch that has been shared
  with the LoongArch maintainers, who will include it in their pull
  request as well. This is not ideal, but the best way to manage the
  conflicts without stalling LoongArch for another cycle.

  Another development inspired by LoongArch is the newly added support
  for EFI based decompressors. Instead of adding yet another
  arch-specific incarnation of this pattern for LoongArch, we are
  introducing an EFI app based on the existing EFI libstub
  infrastructure that encapulates the decompression code we use on other
  architectures, but in a way that is fully generic. This has been
  developed and tested in collaboration with distro and systemd folks,
  who are eager to start using this for systemd-boot and also for arm64
  secure boot on Fedora. Note that the EFI zimage files this introduces
  can also be decompressed by non-EFI bootloaders if needed, as the
  image header describes the location of the payload inside the image,
  and the type of compression that was used. (Note that Fedora's arm64
  GRUB is buggy [0] so you'll need a recent version or switch to
  systemd-boot in order to use this.)

  Finally, we are adding TPM measurement of the kernel command line
  provided by EFI. There is an oversight in the TCG spec which results
  in a blind spot for command line arguments passed to loaded images,
  which means that either the loader or the stub needs to take the
  measurement. Given the combinatorial explosion I am anticipating when
  it comes to firmware/bootloader stacks and firmware based attestation
  protocols (SEV-SNP, TDX, DICE, DRTM), it is good to set a baseline now
  when it comes to EFI measured boot, which is that the kernel measures
  the initrd and command line. Intermediate loaders can measure
  additional assets if needed, but with the baseline in place, we can
  deploy measured boot in a meaningful way even if you boot into Linux
  straight from the EFI firmware.

  Summary:

   - implement EFI boot support for LoongArch

   - implement generic EFI compressed boot support for arm64, RISC-V and
     LoongArch, none of which implement a decompressor today

   - measure the kernel command line into the TPM if measured boot is in
     effect

   - refactor the EFI stub code in order to isolate DT dependencies for
     architectures other than x86

   - avoid calling SetVirtualAddressMap() on arm64 if the configured
     size of the VA space guarantees that doing so is unnecessary

   - move some ARM specific code out of the generic EFI source files

   - unmap kernel code from the x86 mixed mode 1:1 page tables"

* tag 'efi-next-for-v6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi: (24 commits)
  efi/arm64: libstub: avoid SetVirtualAddressMap() when possible
  efi: zboot: create MemoryMapped() device path for the parent if needed
  efi: libstub: fix up the last remaining open coded boot service call
  efi/arm: libstub: move ARM specific code out of generic routines
  efi/libstub: measure EFI LoadOptions
  efi/libstub: refactor the initrd measuring functions
  efi/loongarch: libstub: remove dependency on flattened DT
  efi: libstub: install boot-time memory map as config table
  efi: libstub: remove DT dependency from generic stub
  efi: libstub: unify initrd loading between architectures
  efi: libstub: remove pointless goto kludge
  efi: libstub: simplify efi_get_memory_map() and struct efi_boot_memmap
  efi: libstub: avoid efi_get_memory_map() for allocating the virt map
  efi: libstub: drop pointless get_memory_map() call
  efi: libstub: fix type confusion for load_options_size
  arm64: efi: enable generic EFI compressed boot
  loongarch: efi: enable generic EFI compressed boot
  riscv: efi: enable generic EFI compressed boot
  efi/libstub: implement generic EFI zboot
  efi/libstub: move efi_system_table global var into separate object
  ...
parents a6afa419 d3549a93

Documentation/arm/uefi.rst

+0 −4
Original line number Diff line number Diff line
@@ -65,10 +65,6 @@ linux,uefi-mmap-desc-size 32-bit Size in bytes of each entry in the UEFI 


linux,uefi-mmap-desc-ver    32-bit   Version of the mmap descriptor format.



linux,initrd-start          64-bit   Physical start address of an initrd



linux,initrd-end            64-bit   Physical end address of an initrd



kaslr-seed                  64-bit   Entropy used to randomize the kernel image

                                     base address location.

==========================  ======   ===========================================

arch/arm/include/asm/efi.h

+2 −1
Original line number Diff line number Diff line
@@ -17,6 +17,7 @@ 


#ifdef CONFIG_EFI

void efi_init(void);

void arm_efi_init(void);



int efi_create_mapping(struct mm_struct *mm, efi_memory_desc_t *md);

int efi_set_mapping_permissions(struct mm_struct *mm, efi_memory_desc_t *md);
@@ -37,7 +38,7 @@ void efi_virtmap_load(void); 
void efi_virtmap_unload(void);



#else

#define efi_init()

#define arm_efi_init()

#endif /* CONFIG_EFI */



/* arch specific definitions used by the stub code */

arch/arm/kernel/efi.c

+79 −0
Original line number Diff line number Diff line
@@ -4,6 +4,7 @@ 
 */



#include <linux/efi.h>

#include <linux/memblock.h>

#include <asm/efi.h>

#include <asm/mach/map.h>

#include <asm/mmu_context.h>
@@ -73,3 +74,81 @@ int __init efi_create_mapping(struct mm_struct *mm, efi_memory_desc_t *md) 
		return efi_set_mapping_permissions(mm, md);

	return 0;

}



static unsigned long __initdata screen_info_table = EFI_INVALID_TABLE_ADDR;

static unsigned long __initdata cpu_state_table = EFI_INVALID_TABLE_ADDR;



const efi_config_table_type_t efi_arch_tables[] __initconst = {

	{LINUX_EFI_ARM_SCREEN_INFO_TABLE_GUID, &screen_info_table},

	{LINUX_EFI_ARM_CPU_STATE_TABLE_GUID, &cpu_state_table},

	{}

};



static void __init load_screen_info_table(void)

{

	struct screen_info *si;



	if (screen_info_table != EFI_INVALID_TABLE_ADDR) {

		si = early_memremap_ro(screen_info_table, sizeof(*si));

		if (!si) {

			pr_err("Could not map screen_info config table\n");

			return;

		}

		screen_info = *si;

		early_memunmap(si, sizeof(*si));



		/* dummycon on ARM needs non-zero values for columns/lines */

		screen_info.orig_video_cols = 80;

		screen_info.orig_video_lines = 25;



		if (memblock_is_map_memory(screen_info.lfb_base))

			memblock_mark_nomap(screen_info.lfb_base,

					    screen_info.lfb_size);

	}

}



static void __init load_cpu_state_table(void)

{

	if (cpu_state_table != EFI_INVALID_TABLE_ADDR) {

		struct efi_arm_entry_state *state;

		bool dump_state = true;



		state = early_memremap_ro(cpu_state_table,

					  sizeof(struct efi_arm_entry_state));

		if (state == NULL) {

			pr_warn("Unable to map CPU entry state table.\n");

			return;

		}



		if ((state->sctlr_before_ebs & 1) == 0)

			pr_warn(FW_BUG "EFI stub was entered with MMU and Dcache disabled, please fix your firmware!\n");

		else if ((state->sctlr_after_ebs & 1) == 0)

			pr_warn(FW_BUG "ExitBootServices() returned with MMU and Dcache disabled, please fix your firmware!\n");

		else

			dump_state = false;



		if (dump_state || efi_enabled(EFI_DBG)) {

			pr_info("CPSR at EFI stub entry        : 0x%08x\n",

				state->cpsr_before_ebs);

			pr_info("SCTLR at EFI stub entry       : 0x%08x\n",

				state->sctlr_before_ebs);

			pr_info("CPSR after ExitBootServices() : 0x%08x\n",

				state->cpsr_after_ebs);

			pr_info("SCTLR after ExitBootServices(): 0x%08x\n",

				state->sctlr_after_ebs);

		}

		early_memunmap(state, sizeof(struct efi_arm_entry_state));

	}

}



void __init arm_efi_init(void)

{

	efi_init();



	load_screen_info_table();



	/* ARM does not permit early mappings to persist across paging_init() */

	efi_memmap_unmap();



	load_cpu_state_table();

}

arch/arm/kernel/setup.c

+1 −1
Original line number Diff line number Diff line
@@ -1141,7 +1141,7 @@ void __init setup_arch(char **cmdline_p) 
#endif

	setup_dma_zone(mdesc);

	xen_early_init();

	efi_init();

	arm_efi_init();

	/*

	 * Make sure the calculation for lowmem/highmem is set appropriately

	 * before reserving/allocating any memory

arch/arm64/Makefile

+7 −2
Original line number Diff line number Diff line
@@ -151,12 +151,17 @@ libs-$(CONFIG_EFI_STUB) += $(objtree)/drivers/firmware/efi/libstub/lib.a 


# Default target when executing plain make

boot		:= arch/arm64/boot



ifeq ($(CONFIG_EFI_ZBOOT),)

KBUILD_IMAGE	:= $(boot)/Image.gz

else

KBUILD_IMAGE	:= $(boot)/vmlinuz.efi

endif



all:	Image.gz

all:	$(notdir $(KBUILD_IMAGE))





Image: vmlinux

Image vmlinuz.efi: vmlinux

	$(Q)$(MAKE) $(build)=$(boot) $(boot)/$@



Image.%: Image