| /* SPDX-License-Identifier: GPL-2.0-only */ |
| |
| #include <assert.h> |
| #include <cbmem.h> |
| #include <cbfs.h> |
| #include <string.h> |
| #include <console/console.h> |
| #include <program_loading.h> |
| #include <rmodule.h> |
| #include <types.h> |
| |
| /* Change this define to get more verbose debugging for module loading. */ |
| #define PK_ADJ_LEVEL BIOS_NEVER |
| |
| const size_t region_alignment = MIN_UNSAFE(DYN_CBMEM_ALIGN_SIZE, 4096); |
| |
| static inline int rmodule_is_loaded(const struct rmodule *module) |
| { |
| return module->location != NULL; |
| } |
| |
| /* Calculate a loaded program address based on the blob address. */ |
| static inline void *rmodule_load_addr(const struct rmodule *module, |
| uintptr_t blob_addr) |
| { |
| char *loc = module->location; |
| return &loc[blob_addr - module->header->module_link_start_address]; |
| } |
| |
| /* Initialize a rmodule structure based on raw data. */ |
| int rmodule_parse(void *ptr, struct rmodule *module) |
| { |
| char *base; |
| struct rmodule_header *rhdr; |
| |
| base = ptr; |
| rhdr = ptr; |
| |
| if (rhdr == NULL) |
| return -1; |
| |
| /* Sanity check the raw data. */ |
| if (rhdr->magic != RMODULE_MAGIC) |
| return -1; |
| if (rhdr->version != RMODULE_VERSION_1) |
| return -1; |
| |
| /* Indicate the module hasn't been loaded yet. */ |
| module->location = NULL; |
| |
| /* The rmodule only needs a reference to the reloc_header. */ |
| module->header = rhdr; |
| |
| /* The payload lives after the header. */ |
| module->payload = &base[rhdr->payload_begin_offset]; |
| module->payload_size = rhdr->payload_end_offset - |
| rhdr->payload_begin_offset; |
| module->relocations = &base[rhdr->relocations_begin_offset]; |
| |
| return 0; |
| } |
| |
| int rmodule_memory_size(const struct rmodule *module) |
| { |
| return module->header->module_program_size; |
| } |
| |
| void *rmodule_parameters(const struct rmodule *module) |
| { |
| if (!rmodule_is_loaded(module)) |
| return NULL; |
| |
| /* Indicate if there are no parameters. */ |
| if (module->header->parameters_begin == module->header->parameters_end) |
| return NULL; |
| |
| return rmodule_load_addr(module, module->header->parameters_begin); |
| } |
| |
| int rmodule_entry_offset(const struct rmodule *module) |
| { |
| return module->header->module_entry_point - |
| module->header->module_link_start_address; |
| } |
| |
| void *rmodule_entry(const struct rmodule *module) |
| { |
| if (!rmodule_is_loaded(module)) |
| return NULL; |
| |
| return rmodule_load_addr(module, module->header->module_entry_point); |
| } |
| |
| static void rmodule_clear_bss(struct rmodule *module) |
| { |
| char *begin; |
| int size; |
| |
| begin = rmodule_load_addr(module, module->header->bss_begin); |
| size = module->header->bss_end - module->header->bss_begin; |
| memset(begin, 0, size); |
| } |
| |
| static inline size_t rmodule_number_relocations(const struct rmodule *module) |
| { |
| size_t r; |
| |
| r = module->header->relocations_end_offset; |
| r -= module->header->relocations_begin_offset; |
| r /= sizeof(uintptr_t); |
| return r; |
| } |
| |
| static void rmodule_copy_payload(const struct rmodule *module) |
| { |
| printk(BIOS_DEBUG, "Loading module at %p with entry %p. " |
| "filesize: 0x%x memsize: 0x%x\n", |
| module->location, rmodule_entry(module), |
| module->payload_size, rmodule_memory_size(module)); |
| |
| /* No need to copy the payload if the load location and the |
| * payload location are the same. */ |
| if (module->location == module->payload) |
| return; |
| |
| memcpy(module->location, module->payload, module->payload_size); |
| } |
| |
| static int rmodule_relocate(const struct rmodule *module) |
| { |
| size_t num_relocations; |
| const uintptr_t *reloc; |
| uintptr_t adjustment; |
| |
| /* Each relocation needs to be adjusted relative to the beginning of |
| * the loaded program. */ |
| adjustment = (uintptr_t)rmodule_load_addr(module, 0); |
| |
| reloc = module->relocations; |
| num_relocations = rmodule_number_relocations(module); |
| |
| printk(BIOS_DEBUG, "Processing %zu relocs. Offset value of 0x%08lx\n", |
| num_relocations, (unsigned long)adjustment); |
| |
| while (num_relocations > 0) { |
| uintptr_t *adjust_loc; |
| |
| /* If the adjustment location is non-NULL adjust it. */ |
| adjust_loc = rmodule_load_addr(module, *reloc); |
| printk(PK_ADJ_LEVEL, "Adjusting %p: 0x%08lx -> 0x%08lx\n", |
| adjust_loc, (unsigned long) *adjust_loc, |
| (unsigned long) (*adjust_loc + adjustment)); |
| *adjust_loc += adjustment; |
| |
| reloc++; |
| num_relocations--; |
| } |
| |
| return 0; |
| } |
| |
| int rmodule_load_alignment(const struct rmodule *module) |
| { |
| /* The load alignment is the start of the program's linked address. |
| * The base address where the program is loaded needs to be a multiple |
| * of the program's starting link address. That way all data alignment |
| * in the program is preserved. Default to 4KiB. */ |
| return 4096; |
| } |
| |
| int rmodule_load(void *base, struct rmodule *module) |
| { |
| /* |
| * In order to load the module at a given address, the following steps |
| * take place: |
| * 1. Copy payload to base address. |
| * 2. Adjust relocations within the module to new base address. |
| * 3. Clear the bss segment last since the relocations live where |
| * the bss is. If an rmodule is being loaded from its load |
| * address the relocations need to be processed before the bss. |
| */ |
| module->location = base; |
| rmodule_copy_payload(module); |
| if (rmodule_relocate(module)) |
| return -1; |
| rmodule_clear_bss(module); |
| |
| prog_segment_loaded((uintptr_t)module->location, |
| rmodule_memory_size(module), SEG_FINAL); |
| |
| return 0; |
| } |
| |
| static void *rmodule_cbfs_allocator(void *rsl_arg, size_t unused, |
| const union cbfs_mdata *mdata) |
| { |
| struct rmod_stage_load *rsl = rsl_arg; |
| |
| assert(IS_POWER_OF_2(region_alignment) && |
| region_alignment >= sizeof(struct rmodule_header)); |
| |
| /* The CBFS core just passes us the decompressed size of the file, but |
| we need to know the memlen of the binary image. We need to find and |
| parse the stage header explicitly. */ |
| const struct cbfs_file_attr_stageheader *sattr = cbfs_find_attr(mdata, |
| CBFS_FILE_ATTR_TAG_STAGEHEADER, sizeof(*sattr)); |
| if (!sattr) { |
| printk(BIOS_ERR, "rmodule '%s' has no stage header!\n", |
| rsl->prog->name); |
| return NULL; |
| } |
| |
| const size_t memlen = be32toh(sattr->memlen); |
| |
| /* Place the rmodule according to alignment. The rmodule files |
| * themselves are packed as a header and a payload, however the rmodule |
| * itself is linked along with the header. The header starts at address |
| * 0. Immediately following the header in the file is the program, |
| * however its starting address is determined by the rmodule linker |
| * script. In short, sizeof(struct rmodule_header) can be less than |
| * or equal to the linked address of the program. Therefore we want |
| * to place the rmodule so that the program falls on the aligned |
| * address with the header just before it. Therefore, we need at least |
| * a page to account for the size of the header. */ |
| size_t region_size = ALIGN_UP(memlen + region_alignment, 4096); |
| /* The program starts immediately after the header. However, |
| * it needs to be aligned to a 4KiB boundary. Therefore, adjust the |
| * program location so that the program lands on a page boundary. The |
| * layout looks like the following: |
| * |
| * +--------------------------------+ region_alignment + region_size |
| * | >= 0 bytes from alignment | |
| * +--------------------------------+ program end (4KiB aligned) |
| * | program size | |
| * +--------------------------------+ program_begin (4KiB aligned) |
| * | sizeof(struct rmodule_header) | |
| * +--------------------------------+ rmodule header start |
| * | >= 0 bytes from alignment | |
| * +--------------------------------+ region_alignment |
| */ |
| |
| uint8_t *stage_region = cbmem_add(rsl->cbmem_id, region_size); |
| if (stage_region == NULL) |
| return NULL; |
| |
| return stage_region + region_alignment - sizeof(struct rmodule_header); |
| } |
| |
| int rmodule_stage_load(struct rmod_stage_load *rsl) |
| { |
| struct rmodule rmod_stage; |
| |
| if (rsl->prog == NULL || prog_name(rsl->prog) == NULL) |
| return -1; |
| |
| if (prog_locate_hook(rsl->prog)) |
| return -1; |
| |
| void *rmod_loc = cbfs_alloc(prog_name(rsl->prog), |
| rmodule_cbfs_allocator, rsl, NULL); |
| if (!rmod_loc) |
| return -1; |
| |
| if (rmodule_parse(rmod_loc, &rmod_stage)) |
| return -1; |
| |
| if (rmodule_load(rmod_loc + sizeof(struct rmodule_header), &rmod_stage)) |
| return -1; |
| |
| prog_set_area(rsl->prog, rmod_stage.location, |
| rmodule_memory_size(&rmod_stage)); |
| |
| /* Allow caller to pick up parameters, if available. */ |
| rsl->params = rmodule_parameters(&rmod_stage); |
| |
| prog_set_entry(rsl->prog, rmodule_entry(&rmod_stage), rsl->params); |
| |
| return 0; |
| } |