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author | Linus Torvalds <torvalds@linux-foundation.org> | 2022-10-09 18:56:54 +0300 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2022-10-09 18:56:54 +0300 |
commit | 0e470763d84dcad27284067647dfb4b1a94dfce0 (patch) | |
tree | 34b7ab8b490ce5bb74255c5810357fc6fc819eba /drivers/firmware/efi/libstub/efi-stub.c | |
parent | a6afa4199d3d038fbfdff5511f7523b0e30cb774 (diff) | |
parent | d3549a938b73f203ef522562ae9f2d38aa43d234 (diff) | |
download | linux-0e470763d84dcad27284067647dfb4b1a94dfce0.tar.xz |
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
...
Diffstat (limited to 'drivers/firmware/efi/libstub/efi-stub.c')
-rw-r--r-- | drivers/firmware/efi/libstub/efi-stub.c | 118 |
1 files changed, 50 insertions, 68 deletions
diff --git a/drivers/firmware/efi/libstub/efi-stub.c b/drivers/firmware/efi/libstub/efi-stub.c index f515394cce6e..cf474f0dd261 100644 --- a/drivers/firmware/efi/libstub/efi-stub.c +++ b/drivers/firmware/efi/libstub/efi-stub.c @@ -10,7 +10,6 @@ */ #include <linux/efi.h> -#include <linux/libfdt.h> #include <asm/efi.h> #include "efistub.h" @@ -40,16 +39,22 @@ #ifdef CONFIG_ARM64 # define EFI_RT_VIRTUAL_LIMIT DEFAULT_MAP_WINDOW_64 -#elif defined(CONFIG_RISCV) +#elif defined(CONFIG_RISCV) || defined(CONFIG_LOONGARCH) # define EFI_RT_VIRTUAL_LIMIT TASK_SIZE_MIN -#else +#else /* Only if TASK_SIZE is a constant */ # define EFI_RT_VIRTUAL_LIMIT TASK_SIZE #endif -static u64 virtmap_base = EFI_RT_VIRTUAL_BASE; -static bool flat_va_mapping; +/* + * Some architectures map the EFI regions into the kernel's linear map using a + * fixed offset. + */ +#ifndef EFI_RT_VIRTUAL_OFFSET +#define EFI_RT_VIRTUAL_OFFSET 0 +#endif -const efi_system_table_t *efi_system_table; +static u64 virtmap_base = EFI_RT_VIRTUAL_BASE; +static bool flat_va_mapping = (EFI_RT_VIRTUAL_OFFSET != 0); static struct screen_info *setup_graphics(void) { @@ -124,16 +129,11 @@ efi_status_t __efiapi efi_pe_entry(efi_handle_t handle, unsigned long image_addr; unsigned long image_size = 0; /* addr/point and size pairs for memory management*/ - unsigned long initrd_addr = 0; - unsigned long initrd_size = 0; - unsigned long fdt_addr = 0; /* Original DTB */ - unsigned long fdt_size = 0; char *cmdline_ptr = NULL; int cmdline_size = 0; efi_guid_t loaded_image_proto = LOADED_IMAGE_PROTOCOL_GUID; unsigned long reserve_addr = 0; unsigned long reserve_size = 0; - enum efi_secureboot_mode secure_boot; struct screen_info *si; efi_properties_table_t *prop_tbl; @@ -154,8 +154,8 @@ efi_status_t __efiapi efi_pe_entry(efi_handle_t handle, * information about the running image, such as size and the command * line. */ - status = efi_system_table->boottime->handle_protocol(handle, - &loaded_image_proto, (void *)&image); + status = efi_bs_call(handle_protocol, handle, &loaded_image_proto, + (void *)&image); if (status != EFI_SUCCESS) { efi_err("Failed to get loaded image protocol\n"); goto fail; @@ -209,40 +209,8 @@ efi_status_t __efiapi efi_pe_entry(efi_handle_t handle, /* Ask the firmware to clear memory on unclean shutdown */ efi_enable_reset_attack_mitigation(); - secure_boot = efi_get_secureboot(); - - /* - * Unauthenticated device tree data is a security hazard, so ignore - * 'dtb=' unless UEFI Secure Boot is disabled. We assume that secure - * boot is enabled if we can't determine its state. - */ - if (!IS_ENABLED(CONFIG_EFI_ARMSTUB_DTB_LOADER) || - secure_boot != efi_secureboot_mode_disabled) { - if (strstr(cmdline_ptr, "dtb=")) - efi_err("Ignoring DTB from command line.\n"); - } else { - status = efi_load_dtb(image, &fdt_addr, &fdt_size); - - if (status != EFI_SUCCESS) { - efi_err("Failed to load device tree!\n"); - goto fail_free_image; - } - } - - if (fdt_addr) { - efi_info("Using DTB from command line\n"); - } else { - /* Look for a device tree configuration table entry. */ - fdt_addr = (uintptr_t)get_fdt(&fdt_size); - if (fdt_addr) - efi_info("Using DTB from configuration table\n"); - } - - if (!fdt_addr) - efi_info("Generating empty DTB\n"); - - efi_load_initrd(image, &initrd_addr, &initrd_size, ULONG_MAX, - efi_get_max_initrd_addr(image_addr)); + efi_load_initrd(image, ULONG_MAX, efi_get_max_initrd_addr(image_addr), + NULL); efi_random_get_seed(); @@ -254,8 +222,8 @@ efi_status_t __efiapi efi_pe_entry(efi_handle_t handle, * The easiest way to achieve that is to simply use a 1:1 mapping. */ prop_tbl = get_efi_config_table(EFI_PROPERTIES_TABLE_GUID); - flat_va_mapping = prop_tbl && - (prop_tbl->memory_protection_attribute & + flat_va_mapping |= prop_tbl && + (prop_tbl->memory_protection_attribute & EFI_PROPERTIES_RUNTIME_MEMORY_PROTECTION_NON_EXECUTABLE_PE_DATA); /* force efi_novamap if SetVirtualAddressMap() is unsupported */ @@ -284,25 +252,8 @@ efi_status_t __efiapi efi_pe_entry(efi_handle_t handle, install_memreserve_table(); - status = allocate_new_fdt_and_exit_boot(handle, &fdt_addr, - initrd_addr, initrd_size, - cmdline_ptr, fdt_addr, fdt_size); - if (status != EFI_SUCCESS) - goto fail_free_initrd; - - if (IS_ENABLED(CONFIG_ARM)) - efi_handle_post_ebs_state(); - - efi_enter_kernel(image_addr, fdt_addr, fdt_totalsize((void *)fdt_addr)); - /* not reached */ - -fail_free_initrd: - efi_err("Failed to update FDT and exit boot services\n"); + status = efi_boot_kernel(handle, image, image_addr, cmdline_ptr); - efi_free(initrd_size, initrd_addr); - efi_free(fdt_size, fdt_addr); - -fail_free_image: efi_free(image_size, image_addr); efi_free(reserve_size, reserve_addr); fail_free_screeninfo: @@ -314,6 +265,35 @@ fail: } /* + * efi_allocate_virtmap() - create a pool allocation for the virtmap + * + * Create an allocation that is of sufficient size to hold all the memory + * descriptors that will be passed to SetVirtualAddressMap() to inform the + * firmware about the virtual mapping that will be used under the OS to call + * into the firmware. + */ +efi_status_t efi_alloc_virtmap(efi_memory_desc_t **virtmap, + unsigned long *desc_size, u32 *desc_ver) +{ + unsigned long size, mmap_key; + efi_status_t status; + + /* + * Use the size of the current memory map as an upper bound for the + * size of the buffer we need to pass to SetVirtualAddressMap() to + * cover all EFI_MEMORY_RUNTIME regions. + */ + size = 0; + status = efi_bs_call(get_memory_map, &size, NULL, &mmap_key, desc_size, + desc_ver); + if (status != EFI_BUFFER_TOO_SMALL) + return EFI_LOAD_ERROR; + + return efi_bs_call(allocate_pool, EFI_LOADER_DATA, size, + (void **)virtmap); +} + +/* * efi_get_virtmap() - create a virtual mapping for the EFI memory map * * This function populates the virt_addr fields of all memory region descriptors @@ -328,6 +308,8 @@ void efi_get_virtmap(efi_memory_desc_t *memory_map, unsigned long map_size, efi_memory_desc_t *in, *out = runtime_map; int l; + *count = 0; + for (l = 0; l < map_size; l += desc_size) { u64 paddr, size; @@ -338,7 +320,7 @@ void efi_get_virtmap(efi_memory_desc_t *memory_map, unsigned long map_size, paddr = in->phys_addr; size = in->num_pages * EFI_PAGE_SIZE; - in->virt_addr = in->phys_addr; + in->virt_addr = in->phys_addr + EFI_RT_VIRTUAL_OFFSET; if (efi_novamap) { continue; } |