diff options
Diffstat (limited to 'drivers/firmware/efi/libstub')
| -rw-r--r-- | drivers/firmware/efi/libstub/Makefile | 15 | ||||
| -rw-r--r-- | drivers/firmware/efi/libstub/arm-stub.c | 67 | ||||
| -rw-r--r-- | drivers/firmware/efi/libstub/efi-stub-helper.c | 43 | ||||
| -rw-r--r-- | drivers/firmware/efi/libstub/efistub.h | 8 | ||||
| -rw-r--r-- | drivers/firmware/efi/libstub/fdt.c | 62 |
5 files changed, 173 insertions, 22 deletions
diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile index b14bc2b9fb4d..280bc0a63365 100644 --- a/drivers/firmware/efi/libstub/Makefile +++ b/drivers/firmware/efi/libstub/Makefile @@ -19,8 +19,23 @@ KBUILD_CFLAGS := $(cflags-y) \ $(call cc-option,-fno-stack-protector) GCOV_PROFILE := n +KASAN_SANITIZE := n lib-y := efi-stub-helper.o lib-$(CONFIG_EFI_ARMSTUB) += arm-stub.o fdt.o CFLAGS_fdt.o += -I$(srctree)/scripts/dtc/libfdt/ + +# +# arm64 puts the stub in the kernel proper, which will unnecessarily retain all +# code indefinitely unless it is annotated as __init/__initdata/__initconst etc. +# So let's apply the __init annotations at the section level, by prefixing +# the section names directly. This will ensure that even all the inline string +# literals are covered. +# +extra-$(CONFIG_ARM64) := $(lib-y) +lib-$(CONFIG_ARM64) := $(patsubst %.o,%.init.o,$(lib-y)) + +OBJCOPYFLAGS := --prefix-alloc-sections=.init +$(obj)/%.init.o: $(obj)/%.o FORCE + $(call if_changed,objcopy) diff --git a/drivers/firmware/efi/libstub/arm-stub.c b/drivers/firmware/efi/libstub/arm-stub.c index eb48a1a1a576..dcae482a9a17 100644 --- a/drivers/firmware/efi/libstub/arm-stub.c +++ b/drivers/firmware/efi/libstub/arm-stub.c @@ -17,10 +17,10 @@ #include "efistub.h" -static int __init efi_secureboot_enabled(efi_system_table_t *sys_table_arg) +static int efi_secureboot_enabled(efi_system_table_t *sys_table_arg) { - static efi_guid_t const var_guid __initconst = EFI_GLOBAL_VARIABLE_GUID; - static efi_char16_t const var_name[] __initconst = { + static efi_guid_t const var_guid = EFI_GLOBAL_VARIABLE_GUID; + static efi_char16_t const var_name[] = { 'S', 'e', 'c', 'u', 'r', 'e', 'B', 'o', 'o', 't', 0 }; efi_get_variable_t *f_getvar = sys_table_arg->runtime->get_variable; @@ -164,7 +164,7 @@ efi_status_t handle_kernel_image(efi_system_table_t *sys_table, * for both archictectures, with the arch-specific code provided in the * handle_kernel_image() function. */ -unsigned long __init efi_entry(void *handle, efi_system_table_t *sys_table, +unsigned long efi_entry(void *handle, efi_system_table_t *sys_table, unsigned long *image_addr) { efi_loaded_image_t *image; @@ -295,3 +295,62 @@ fail_free_image: fail: return EFI_ERROR; } + +/* + * This is the base address at which to start allocating virtual memory ranges + * for UEFI Runtime Services. This is in the low TTBR0 range so that we can use + * any allocation we choose, and eliminate the risk of a conflict after kexec. + * The value chosen is the largest non-zero power of 2 suitable for this purpose + * both on 32-bit and 64-bit ARM CPUs, to maximize the likelihood that it can + * be mapped efficiently. + */ +#define EFI_RT_VIRTUAL_BASE 0x40000000 + +/* + * efi_get_virtmap() - create a virtual mapping for the EFI memory map + * + * This function populates the virt_addr fields of all memory region descriptors + * in @memory_map whose EFI_MEMORY_RUNTIME attribute is set. Those descriptors + * are also copied to @runtime_map, and their total count is returned in @count. + */ +void efi_get_virtmap(efi_memory_desc_t *memory_map, unsigned long map_size, + unsigned long desc_size, efi_memory_desc_t *runtime_map, + int *count) +{ + u64 efi_virt_base = EFI_RT_VIRTUAL_BASE; + efi_memory_desc_t *out = runtime_map; + int l; + + for (l = 0; l < map_size; l += desc_size) { + efi_memory_desc_t *in = (void *)memory_map + l; + u64 paddr, size; + + if (!(in->attribute & EFI_MEMORY_RUNTIME)) + continue; + + /* + * Make the mapping compatible with 64k pages: this allows + * a 4k page size kernel to kexec a 64k page size kernel and + * vice versa. + */ + paddr = round_down(in->phys_addr, SZ_64K); + size = round_up(in->num_pages * EFI_PAGE_SIZE + + in->phys_addr - paddr, SZ_64K); + + /* + * Avoid wasting memory on PTEs by choosing a virtual base that + * is compatible with section mappings if this region has the + * appropriate size and physical alignment. (Sections are 2 MB + * on 4k granule kernels) + */ + if (IS_ALIGNED(in->phys_addr, SZ_2M) && size >= SZ_2M) + efi_virt_base = round_up(efi_virt_base, SZ_2M); + + in->virt_addr = efi_virt_base + in->phys_addr - paddr; + efi_virt_base += size; + + memcpy(out, in, desc_size); + out = (void *)out + desc_size; + ++*count; + } +} diff --git a/drivers/firmware/efi/libstub/efi-stub-helper.c b/drivers/firmware/efi/libstub/efi-stub-helper.c index a920fec8fe88..af5d63c7cc53 100644 --- a/drivers/firmware/efi/libstub/efi-stub-helper.c +++ b/drivers/firmware/efi/libstub/efi-stub-helper.c @@ -32,6 +32,15 @@ static unsigned long __chunk_size = EFI_READ_CHUNK_SIZE; +/* + * Allow the platform to override the allocation granularity: this allows + * systems that have the capability to run with a larger page size to deal + * with the allocations for initrd and fdt more efficiently. + */ +#ifndef EFI_ALLOC_ALIGN +#define EFI_ALLOC_ALIGN EFI_PAGE_SIZE +#endif + struct file_info { efi_file_handle_t *handle; u64 size; @@ -66,25 +75,29 @@ efi_status_t efi_get_memory_map(efi_system_table_t *sys_table_arg, unsigned long key; u32 desc_version; - *map_size = sizeof(*m) * 32; -again: + *map_size = 0; + *desc_size = 0; + key = 0; + status = efi_call_early(get_memory_map, map_size, NULL, + &key, desc_size, &desc_version); + if (status != EFI_BUFFER_TOO_SMALL) + return EFI_LOAD_ERROR; + /* * Add an additional efi_memory_desc_t because we're doing an * allocation which may be in a new descriptor region. */ - *map_size += sizeof(*m); + *map_size += *desc_size; status = efi_call_early(allocate_pool, EFI_LOADER_DATA, *map_size, (void **)&m); if (status != EFI_SUCCESS) goto fail; - *desc_size = 0; - key = 0; status = efi_call_early(get_memory_map, map_size, m, &key, desc_size, &desc_version); if (status == EFI_BUFFER_TOO_SMALL) { efi_call_early(free_pool, m); - goto again; + return EFI_LOAD_ERROR; } if (status != EFI_SUCCESS) @@ -101,7 +114,7 @@ fail: } -unsigned long __init get_dram_base(efi_system_table_t *sys_table_arg) +unsigned long get_dram_base(efi_system_table_t *sys_table_arg) { efi_status_t status; unsigned long map_size; @@ -150,10 +163,10 @@ efi_status_t efi_high_alloc(efi_system_table_t *sys_table_arg, * a specific address. We are doing page-based allocations, * so we must be aligned to a page. */ - if (align < EFI_PAGE_SIZE) - align = EFI_PAGE_SIZE; + if (align < EFI_ALLOC_ALIGN) + align = EFI_ALLOC_ALIGN; - nr_pages = round_up(size, EFI_PAGE_SIZE) / EFI_PAGE_SIZE; + nr_pages = round_up(size, EFI_ALLOC_ALIGN) / EFI_PAGE_SIZE; again: for (i = 0; i < map_size / desc_size; i++) { efi_memory_desc_t *desc; @@ -235,10 +248,10 @@ efi_status_t efi_low_alloc(efi_system_table_t *sys_table_arg, * a specific address. We are doing page-based allocations, * so we must be aligned to a page. */ - if (align < EFI_PAGE_SIZE) - align = EFI_PAGE_SIZE; + if (align < EFI_ALLOC_ALIGN) + align = EFI_ALLOC_ALIGN; - nr_pages = round_up(size, EFI_PAGE_SIZE) / EFI_PAGE_SIZE; + nr_pages = round_up(size, EFI_ALLOC_ALIGN) / EFI_PAGE_SIZE; for (i = 0; i < map_size / desc_size; i++) { efi_memory_desc_t *desc; unsigned long m = (unsigned long)map; @@ -292,7 +305,7 @@ void efi_free(efi_system_table_t *sys_table_arg, unsigned long size, if (!size) return; - nr_pages = round_up(size, EFI_PAGE_SIZE) / EFI_PAGE_SIZE; + nr_pages = round_up(size, EFI_ALLOC_ALIGN) / EFI_PAGE_SIZE; efi_call_early(free_pages, addr, nr_pages); } @@ -561,7 +574,7 @@ efi_status_t efi_relocate_kernel(efi_system_table_t *sys_table_arg, * to the preferred address. If that fails, allocate as low * as possible while respecting the required alignment. */ - nr_pages = round_up(alloc_size, EFI_PAGE_SIZE) / EFI_PAGE_SIZE; + nr_pages = round_up(alloc_size, EFI_ALLOC_ALIGN) / EFI_PAGE_SIZE; status = efi_call_early(allocate_pages, EFI_ALLOCATE_ADDRESS, EFI_LOADER_DATA, nr_pages, &efi_addr); diff --git a/drivers/firmware/efi/libstub/efistub.h b/drivers/firmware/efi/libstub/efistub.h index 304ab295ca1a..47437b16b186 100644 --- a/drivers/firmware/efi/libstub/efistub.h +++ b/drivers/firmware/efi/libstub/efistub.h @@ -5,6 +5,10 @@ /* error code which can't be mistaken for valid address */ #define EFI_ERROR (~0UL) +#undef memcpy +#undef memset +#undef memmove + void efi_char16_printk(efi_system_table_t *, efi_char16_t *); efi_status_t efi_open_volume(efi_system_table_t *sys_table_arg, void *__image, @@ -39,4 +43,8 @@ efi_status_t allocate_new_fdt_and_exit_boot(efi_system_table_t *sys_table, void *get_fdt(efi_system_table_t *sys_table); +void efi_get_virtmap(efi_memory_desc_t *memory_map, unsigned long map_size, + unsigned long desc_size, efi_memory_desc_t *runtime_map, + int *count); + #endif diff --git a/drivers/firmware/efi/libstub/fdt.c b/drivers/firmware/efi/libstub/fdt.c index c846a9608cbd..91da56c4fd54 100644 --- a/drivers/firmware/efi/libstub/fdt.c +++ b/drivers/firmware/efi/libstub/fdt.c @@ -14,6 +14,8 @@ #include <linux/libfdt.h> #include <asm/efi.h> +#include "efistub.h" + efi_status_t update_fdt(efi_system_table_t *sys_table, void *orig_fdt, unsigned long orig_fdt_size, void *fdt, int new_fdt_size, char *cmdline_ptr, @@ -193,9 +195,26 @@ efi_status_t allocate_new_fdt_and_exit_boot(efi_system_table_t *sys_table, unsigned long map_size, desc_size; u32 desc_ver; unsigned long mmap_key; - efi_memory_desc_t *memory_map; + efi_memory_desc_t *memory_map, *runtime_map; unsigned long new_fdt_size; efi_status_t status; + int runtime_entry_count = 0; + + /* + * 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. + */ + status = efi_get_memory_map(sys_table, &runtime_map, &map_size, + &desc_size, &desc_ver, &mmap_key); + if (status != EFI_SUCCESS) { + pr_efi_err(sys_table, "Unable to retrieve UEFI memory map.\n"); + return status; + } + + pr_efi(sys_table, + "Exiting boot services and installing virtual address map...\n"); /* * Estimate size of new FDT, and allocate memory for it. We @@ -248,12 +267,48 @@ efi_status_t allocate_new_fdt_and_exit_boot(efi_system_table_t *sys_table, } } + /* + * 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 into SetVirtualAddressMap() + */ + efi_get_virtmap(memory_map, map_size, desc_size, runtime_map, + &runtime_entry_count); + /* Now we are ready to exit_boot_services.*/ status = sys_table->boottime->exit_boot_services(handle, mmap_key); + if (status == EFI_SUCCESS) { + efi_set_virtual_address_map_t *svam; - if (status == EFI_SUCCESS) - return status; + /* Install the new virtual address map */ + svam = sys_table->runtime->set_virtual_address_map; + status = svam(runtime_entry_count * desc_size, desc_size, + desc_ver, runtime_map); + + /* + * We are beyond the point of no return here, so if the call to + * SetVirtualAddressMap() failed, we need to signal that to the + * incoming kernel but proceed normally otherwise. + */ + if (status != EFI_SUCCESS) { + int l; + + /* + * Set the virtual address field of all + * EFI_MEMORY_RUNTIME entries to 0. This will signal + * 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; + + if (p->attribute & EFI_MEMORY_RUNTIME) + p->virt_addr = 0; + } + } + return EFI_SUCCESS; + } pr_efi_err(sys_table, "Exit boot services failed.\n"); @@ -264,6 +319,7 @@ fail_free_new_fdt: efi_free(sys_table, new_fdt_size, *new_fdt_addr); fail: + sys_table->boottime->free_pool(runtime_map); return EFI_LOAD_ERROR; } |