/* SPDX-License-Identifier: GPL-2.0-only */ #include <assert.h> #include <cbmem.h> #include <cbfs.h> #include <stdint.h> #include <stdlib.h> #include <string.h> #include <console/console.h> #include <program_loading.h> #include <rmodule.h> /* Change this define to get more verbose debugging for module loading. */ #define PK_ADJ_LEVEL BIOS_NEVER 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; } int rmodule_calc_region(unsigned int region_alignment, size_t rmodule_size, size_t *region_size, int *load_offset) { /* region_alignment must be a power of 2. */ if (region_alignment & (region_alignment - 1)) BUG(); if (region_alignment < 4096) region_alignment = 4096; /* Sanity check rmodule_header size. The code below assumes it is less * than the minimum alignment required. */ if (region_alignment < sizeof(struct rmodule_header)) BUG(); /* 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. */ *region_size = ALIGN(rmodule_size + 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 */ *load_offset = region_alignment; return region_alignment - sizeof(struct rmodule_header); } int rmodule_stage_load(struct rmod_stage_load *rsl) { struct rmodule rmod_stage; size_t region_size; char *stage_region; int rmodule_offset; int load_offset; struct cbfs_stage stage; void *rmod_loc; struct region_device *fh; if (rsl->prog == NULL || prog_name(rsl->prog) == NULL) return -1; fh = prog_rdev(rsl->prog); if (rdev_readat(fh, &stage, 0, sizeof(stage)) != sizeof(stage)) return -1; rmodule_offset = rmodule_calc_region(DYN_CBMEM_ALIGN_SIZE, stage.memlen, ®ion_size, &load_offset); stage_region = cbmem_add(rsl->cbmem_id, region_size); if (stage_region == NULL) return -1; rmod_loc = &stage_region[rmodule_offset]; printk(BIOS_INFO, "Decompressing stage %s @ %p (%d bytes)\n", prog_name(rsl->prog), rmod_loc, stage.memlen); if (!cbfs_load_and_decompress(fh, sizeof(stage), stage.len, rmod_loc, stage.memlen, stage.compression)) return -1; if (rmodule_parse(rmod_loc, &rmod_stage)) return -1; if (rmodule_load(&stage_region[load_offset], &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; }