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author | Linus Torvalds <torvalds@linux-foundation.org> | 2022-10-09 08:56:54 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2022-10-09 08:56:54 -0700 |
commit | 0e470763d84dcad27284067647dfb4b1a94dfce0 (patch) | |
tree | 34b7ab8b490ce5bb74255c5810357fc6fc819eba /drivers/firmware/efi/libstub/fdt.c | |
parent | a6afa4199d3d038fbfdff5511f7523b0e30cb774 (diff) | |
parent | d3549a938b73f203ef522562ae9f2d38aa43d234 (diff) | |
download | linux-0e470763d84dcad27284067647dfb4b1a94dfce0.tar.gz linux-0e470763d84dcad27284067647dfb4b1a94dfce0.tar.bz2 linux-0e470763d84dcad27284067647dfb4b1a94dfce0.zip |
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/fdt.c')
-rw-r--r-- | drivers/firmware/efi/libstub/fdt.c | 175 |
1 files changed, 93 insertions, 82 deletions
diff --git a/drivers/firmware/efi/libstub/fdt.c b/drivers/firmware/efi/libstub/fdt.c index fe567be0f118..4f4d98e51fbf 100644 --- a/drivers/firmware/efi/libstub/fdt.c +++ b/drivers/firmware/efi/libstub/fdt.c @@ -28,8 +28,7 @@ static void fdt_update_cell_size(void *fdt) } static efi_status_t update_fdt(void *orig_fdt, unsigned long orig_fdt_size, - void *fdt, int new_fdt_size, char *cmdline_ptr, - u64 initrd_addr, u64 initrd_size) + void *fdt, int new_fdt_size, char *cmdline_ptr) { int node, num_rsv; int status; @@ -93,21 +92,6 @@ static efi_status_t update_fdt(void *orig_fdt, unsigned long orig_fdt_size, goto fdt_set_fail; } - /* Set initrd address/end in device tree, if present */ - if (initrd_size != 0) { - u64 initrd_image_end; - u64 initrd_image_start = cpu_to_fdt64(initrd_addr); - - status = fdt_setprop_var(fdt, node, "linux,initrd-start", initrd_image_start); - if (status) - goto fdt_set_fail; - - initrd_image_end = cpu_to_fdt64(initrd_addr + initrd_size); - status = fdt_setprop_var(fdt, node, "linux,initrd-end", initrd_image_end); - if (status) - goto fdt_set_fail; - } - /* Add FDT entries for EFI runtime services in chosen node. */ node = fdt_subnode_offset(fdt, 0, "chosen"); fdt_val64 = cpu_to_fdt64((u64)(unsigned long)efi_system_table); @@ -170,25 +154,25 @@ static efi_status_t update_fdt_memmap(void *fdt, struct efi_boot_memmap *map) if (node < 0) return EFI_LOAD_ERROR; - fdt_val64 = cpu_to_fdt64((unsigned long)*map->map); + fdt_val64 = cpu_to_fdt64((unsigned long)map->map); err = fdt_setprop_inplace_var(fdt, node, "linux,uefi-mmap-start", fdt_val64); if (err) return EFI_LOAD_ERROR; - fdt_val32 = cpu_to_fdt32(*map->map_size); + fdt_val32 = cpu_to_fdt32(map->map_size); err = fdt_setprop_inplace_var(fdt, node, "linux,uefi-mmap-size", fdt_val32); if (err) return EFI_LOAD_ERROR; - fdt_val32 = cpu_to_fdt32(*map->desc_size); + fdt_val32 = cpu_to_fdt32(map->desc_size); err = fdt_setprop_inplace_var(fdt, node, "linux,uefi-mmap-desc-size", fdt_val32); if (err) return EFI_LOAD_ERROR; - fdt_val32 = cpu_to_fdt32(*map->desc_ver); + fdt_val32 = cpu_to_fdt32(map->desc_ver); err = fdt_setprop_inplace_var(fdt, node, "linux,uefi-mmap-desc-ver", fdt_val32); if (err) @@ -198,22 +182,25 @@ static efi_status_t update_fdt_memmap(void *fdt, struct efi_boot_memmap *map) } struct exit_boot_struct { + struct efi_boot_memmap *boot_memmap; efi_memory_desc_t *runtime_map; - int *runtime_entry_count; + int runtime_entry_count; void *new_fdt_addr; }; -static efi_status_t exit_boot_func(struct efi_boot_memmap *map, - void *priv) +static efi_status_t exit_boot_func(struct efi_boot_memmap *map, void *priv) { struct exit_boot_struct *p = priv; + + p->boot_memmap = map; + /* * Update the memory map with virtual addresses. The function will also * populate @runtime_map with copies of just the EFI_MEMORY_RUNTIME * entries so that we can pass it straight to SetVirtualAddressMap() */ - efi_get_virtmap(*map->map, *map->map_size, *map->desc_size, - p->runtime_map, p->runtime_entry_count); + efi_get_virtmap(map->map, map->map_size, map->desc_size, + p->runtime_map, &p->runtime_entry_count); return update_fdt_memmap(p->new_fdt_addr, map); } @@ -223,86 +210,86 @@ static efi_status_t exit_boot_func(struct efi_boot_memmap *map, #endif /* - * Allocate memory for a new FDT, then add EFI, commandline, and - * initrd related fields to the FDT. This routine increases the - * FDT allocation size until the allocated memory is large - * enough. EFI allocations are in EFI_PAGE_SIZE granules, - * which are fixed at 4K bytes, so in most cases the first - * allocation should succeed. - * EFI boot services are exited at the end of this function. - * There must be no allocations between the get_memory_map() - * call and the exit_boot_services() call, so the exiting of - * boot services is very tightly tied to the creation of the FDT - * with the final memory map in it. + * Allocate memory for a new FDT, then add EFI and commandline related fields + * to the FDT. This routine increases the FDT allocation size until the + * allocated memory is large enough. EFI allocations are in EFI_PAGE_SIZE + * granules, which are fixed at 4K bytes, so in most cases the first allocation + * should succeed. EFI boot services are exited at the end of this function. + * There must be no allocations between the get_memory_map() call and the + * exit_boot_services() call, so the exiting of boot services is very tightly + * tied to the creation of the FDT with the final memory map in it. */ - +static efi_status_t allocate_new_fdt_and_exit_boot(void *handle, + efi_loaded_image_t *image, unsigned long *new_fdt_addr, - u64 initrd_addr, u64 initrd_size, - char *cmdline_ptr, - unsigned long fdt_addr, - unsigned long fdt_size) + char *cmdline_ptr) { - unsigned long map_size, desc_size, buff_size; + unsigned long desc_size; u32 desc_ver; - unsigned long mmap_key; - efi_memory_desc_t *memory_map, *runtime_map; efi_status_t status; - int runtime_entry_count; - struct efi_boot_memmap map; struct exit_boot_struct priv; + unsigned long fdt_addr = 0; + unsigned long fdt_size = 0; - map.map = &runtime_map; - map.map_size = &map_size; - map.desc_size = &desc_size; - map.desc_ver = &desc_ver; - map.key_ptr = &mmap_key; - map.buff_size = &buff_size; + if (!efi_novamap) { + status = efi_alloc_virtmap(&priv.runtime_map, &desc_size, + &desc_ver); + if (status != EFI_SUCCESS) { + efi_err("Unable to retrieve UEFI memory map.\n"); + return status; + } + } /* - * Get a copy of the current memory map that we will use to prepare - * the input for SetVirtualAddressMap(). We don't have to worry about - * subsequent allocations adding entries, since they could not affect - * the number of EFI_MEMORY_RUNTIME regions. + * 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. */ - status = efi_get_memory_map(&map); - if (status != EFI_SUCCESS) { - efi_err("Unable to retrieve UEFI memory map.\n"); - return status; + if (!IS_ENABLED(CONFIG_EFI_ARMSTUB_DTB_LOADER) || + efi_get_secureboot() != 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 && status != EFI_NOT_READY) { + efi_err("Failed to load device tree!\n"); + goto fail; + } } + 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_info("Exiting boot services...\n"); - map.map = &memory_map; status = efi_allocate_pages(MAX_FDT_SIZE, new_fdt_addr, ULONG_MAX); if (status != EFI_SUCCESS) { efi_err("Unable to allocate memory for new device tree.\n"); goto fail; } - /* - * Now that we have done our final memory allocation (and free) - * we can get the memory map key needed for exit_boot_services(). - */ - status = efi_get_memory_map(&map); - if (status != EFI_SUCCESS) - goto fail_free_new_fdt; - status = update_fdt((void *)fdt_addr, fdt_size, - (void *)*new_fdt_addr, MAX_FDT_SIZE, cmdline_ptr, - initrd_addr, initrd_size); + (void *)*new_fdt_addr, MAX_FDT_SIZE, cmdline_ptr); if (status != EFI_SUCCESS) { efi_err("Unable to construct new device tree.\n"); goto fail_free_new_fdt; } - runtime_entry_count = 0; - priv.runtime_map = runtime_map; - priv.runtime_entry_count = &runtime_entry_count; - priv.new_fdt_addr = (void *)*new_fdt_addr; + priv.new_fdt_addr = (void *)*new_fdt_addr; - status = efi_exit_boot_services(handle, &map, &priv, exit_boot_func); + status = efi_exit_boot_services(handle, &priv, exit_boot_func); if (status == EFI_SUCCESS) { efi_set_virtual_address_map_t *svam; @@ -312,8 +299,8 @@ efi_status_t allocate_new_fdt_and_exit_boot(void *handle, /* Install the new virtual address map */ svam = efi_system_table->runtime->set_virtual_address_map; - status = svam(runtime_entry_count * desc_size, desc_size, - desc_ver, runtime_map); + status = svam(priv.runtime_entry_count * desc_size, desc_size, + desc_ver, priv.runtime_map); /* * We are beyond the point of no return here, so if the call to @@ -321,6 +308,7 @@ efi_status_t allocate_new_fdt_and_exit_boot(void *handle, * incoming kernel but proceed normally otherwise. */ if (status != EFI_SUCCESS) { + efi_memory_desc_t *p; int l; /* @@ -329,8 +317,9 @@ efi_status_t allocate_new_fdt_and_exit_boot(void *handle, * the incoming kernel that no virtual translation has * been installed. */ - for (l = 0; l < map_size; l += desc_size) { - efi_memory_desc_t *p = (void *)memory_map + l; + for (l = 0; l < priv.boot_memmap->map_size; + l += priv.boot_memmap->desc_size) { + p = (void *)priv.boot_memmap->map + l; if (p->attribute & EFI_MEMORY_RUNTIME) p->virt_addr = 0; @@ -345,11 +334,33 @@ fail_free_new_fdt: efi_free(MAX_FDT_SIZE, *new_fdt_addr); fail: - efi_system_table->boottime->free_pool(runtime_map); + efi_free(fdt_size, fdt_addr); + + efi_bs_call(free_pool, priv.runtime_map); return EFI_LOAD_ERROR; } +efi_status_t efi_boot_kernel(void *handle, efi_loaded_image_t *image, + unsigned long kernel_addr, char *cmdline_ptr) +{ + unsigned long fdt_addr; + efi_status_t status; + + status = allocate_new_fdt_and_exit_boot(handle, image, &fdt_addr, + cmdline_ptr); + if (status != EFI_SUCCESS) { + efi_err("Failed to update FDT and exit boot services\n"); + return status; + } + + if (IS_ENABLED(CONFIG_ARM)) + efi_handle_post_ebs_state(); + + efi_enter_kernel(kernel_addr, fdt_addr, fdt_totalsize((void *)fdt_addr)); + /* not reached */ +} + void *get_fdt(unsigned long *fdt_size) { void *fdt; |