/* * Copyright (c) 2006-2023, RT-Thread Development Team * * SPDX-License-Identifier: Apache-2.0 * * Change Logs: * Date Author Notes * 2023-08-23 zhangsz first version */ #include #ifdef RT_USING_LDSO #include #include #include #include #include #include "lwp.h" #include "lwp_arch.h" #ifdef ARCH_MM_MMU #include #endif #define DBG_TAG "load.elf" #ifdef ELF_DEBUG_ENABLE #define DBG_LVL DBG_LOG #else #define DBG_LVL DBG_INFO #endif #include #define ELF_INVALID_FD -1 #define ELF_PHDR_NUM_MAX 128 #define FILE_LENGTH_MAX 0xC0000000 #define MEM_SIZE_MAX 0xC0000000 #define ELF_PATH_MAX 256 #define FLF_PATH_MIN 1 #define ELF_PAGESTART(_v) ((_v) & ~(rt_ubase_t)(ARCH_PAGE_SIZE - 1)) #define ELF_PAGEOFFSET(_v) ((_v) & (ARCH_PAGE_SIZE - 1)) #define ELF_PAGEALIGN(_v) (((_v) + ARCH_PAGE_SIZE - 1) & ~(ARCH_PAGE_SIZE - 1)) #define ELF_EXEC_LOAD_ADDR USER_VADDR_START #define ELF_INTERP_LOAD_ADDR LDSO_LOAD_VADDR #define ELF_AUX_ENT(aux, id, val) \ do \ { \ rt_base_t a = id; \ lwp_data_put(lwp, aux++, &a, sizeof(rt_ubase_t)); \ a = val; \ lwp_data_put(lwp, aux++, &a, sizeof(rt_ubase_t)); \ } while (0) typedef struct { int fd; char *filename; rt_size_t file_len; Elf_Ehdr ehdr; Elf_Phdr *phdr; rt_ubase_t map_size; } elf_info_t; typedef struct { struct rt_lwp *lwp; struct process_aux *aux; elf_info_t exec_info; elf_info_t interp_info; rt_ubase_t load_addr; rt_ubase_t e_entry; rt_ubase_t interp_base; } elf_load_info_t; static void elf_user_dump(struct rt_lwp *lwp, void *va, size_t len) { #ifdef ELF_DEBUG_DUMP uint8_t *k_va; int ret; if (len < 16) len = 16; rt_kprintf("\r\n"); rt_kprintf("%s : user va : %p, len : 0x%x(%d)\n", __func__, va, len, len); k_va = rt_malloc(len); if (k_va == RT_NULL) { rt_kprintf("%s : malloc failed\n", __func__); return; } rt_memset(k_va, 0, len); ret = lwp_data_get(lwp, k_va, va, len); if (ret != len) { rt_kprintf("%s : lwp_get_from_user failed, ret = %d\n", __func__, ret); return; } rt_kprintf("%s : k_va : %p\n", __func__, k_va); for (size_t i = 0; i < len; i += 16) { rt_kprintf(" %02x %02x %02x %02x %02x %02x %02x %02x ", k_va[i], k_va[i+1], k_va[i+2], k_va[i+3], k_va[i+4], k_va[i+5], k_va[i+6], k_va[i+7]); rt_kprintf(" %02x %02x %02x %02x %02x %02x %02x %02x \n", k_va[i+8], k_va[i+9], k_va[i+10], k_va[i+11], k_va[i+12], k_va[i+13], k_va[i+14], k_va[i+15]); } rt_kprintf("\r\n"); rt_free(k_va); #endif } rt_ubase_t elf_random_offset(void) { #ifdef ELF_LOAD_RANDOMIZE return (rt_tick_get() % 65535) * ARCH_PAGE_SIZE; #else return ELF_PAGEALIGN(0); #endif } static void *file_mmap(struct rt_lwp *lwp, int fd, rt_ubase_t load_addr, rt_ubase_t map_size, size_t prot, size_t flags, rt_ubase_t offset) { uint8_t *map_va; map_va = (uint8_t *)lwp_mmap2(lwp, (void *)load_addr, map_size, prot, flags, fd, offset >> ARCH_PAGE_SHIFT); if (!map_va || (map_va != (uint8_t *)load_addr)) { LOG_E("%s : lwp map user failed!", __func__); return RT_NULL; } LOG_D(" %s : map va = %p load_addr : %p size : 0x%x", __func__, map_va, load_addr, map_size); return map_va; } static int elf_file_open(const char *filename) { int fd = -1; fd = open(filename, O_BINARY | O_RDONLY, 0); if (fd < 0) { LOG_E("%s : elf file [%s] open failed!", __func__, filename); } return fd; } static int elf_file_close(int fd) { return close(fd); } static int elf_file_length(char *filename, rt_size_t *file_len) { int ret; struct stat s = { 0 }; ret = stat(filename, &s); if (ret != 0) { LOG_E("%s : error", __func__); return -RT_ERROR; } *file_len = (rt_size_t)s.st_size; return RT_EOK; } static int elf_file_read(rt_int32_t fd, rt_uint8_t *buffer, size_t size, off_t offset) { ssize_t read_len; off_t pos; if (size > 0) { pos = lseek(fd, offset, SEEK_SET); if (pos != offset) { LOG_E("%s : seek file offset: 0x%x failed", __func__, offset); return -RT_ERROR; } read_len = read(fd, buffer, size); if (read_len != size) { LOG_E("%s : read from offset: 0x%x error", __func__, offset); return -RT_ERROR; } } return RT_EOK; } static rt_int32_t elf_check_ehdr(const Elf_Ehdr *ehdr, rt_uint32_t file_len) { if (memcmp(ehdr->e_ident, ELFMAG, SELFMAG) != 0) { LOG_E("%s : e_ident error", __func__); return -RT_ERROR; } if ((ehdr->e_type != ET_EXEC) && (ehdr->e_type != ET_DYN)) { LOG_E("%s : e_type error", __func__); return -RT_ERROR; } if (ehdr->e_machine == EM_NONE) { LOG_E("%s : e_machine is EM_NONE", __func__); return -RT_ERROR; } if (ehdr->e_phnum > ELF_PHDR_NUM_MAX) { LOG_E("%s : e_phnum error", __func__); return -RT_ERROR; } if (ehdr->e_phoff > file_len) { LOG_E("%s : e_phoff error", __func__); return -RT_ERROR; } LOG_D("%s : e_entry : 0x%x", __func__, ehdr->e_entry); return RT_EOK; } static int elf_check_phdr(const Elf_Phdr *phdr) { if (phdr->p_filesz > FILE_LENGTH_MAX) { LOG_E("%s : phdr p_filesz 0x%x error", __func__, phdr->p_filesz); return -RT_ERROR; } if (phdr->p_offset > FILE_LENGTH_MAX) { LOG_E("%s : phdr p_offset 0x%x error", __func__, phdr->p_offset); return -RT_ERROR; } if (phdr->p_memsz > MEM_SIZE_MAX) { LOG_E("%s[%d], phdr p_memsz 0x%x error", __func__, phdr->p_memsz); return -RT_ERROR; } LOG_D("%s : phdr p_vaddr : 0x%x", __func__, phdr->p_vaddr); return RT_EOK; } static int elf_load_ehdr(elf_info_t *elf_info) { int ret; ret = elf_file_open(elf_info->filename); if (ret < 0) { LOG_E("%s : elf_file_open %s failed", __func__, elf_info->filename); return ret; } elf_info->fd = ret; ret = elf_file_length(elf_info->filename, &elf_info->file_len); if (ret != RT_EOK) { return -RT_ERROR; } ret = elf_file_read(elf_info->fd, (rt_uint8_t *)&elf_info->ehdr, sizeof(Elf_Ehdr), 0); if (ret != RT_EOK) { LOG_E("%s : elf_file_read failed, ret : %d", __func__, ret); return -RT_ERROR; } ret = elf_check_ehdr(&elf_info->ehdr, elf_info->file_len); if (ret != RT_EOK) { LOG_E("%s : elf_check_ehdr failed, ret : %d", __func__, ret); return -RT_ERROR; } return RT_EOK; } static int elf_load_phdr(elf_info_t *elf_info) { Elf_Ehdr *ehdr = &elf_info->ehdr; uint32_t size; int ret; if (ehdr->e_phnum < 1) { return -RT_ERROR; } if (ehdr->e_phentsize != sizeof(Elf_Phdr)) { return -RT_ERROR; } size = sizeof(Elf_Phdr) * ehdr->e_phnum; if ((ehdr->e_phoff + size) > elf_info->file_len) { return -RT_ERROR; } elf_info->phdr = rt_malloc(size); if (elf_info->phdr == RT_NULL) { LOG_E("%s : alloc phdr failed", __func__); return -RT_ENOMEM; } ret = elf_file_read(elf_info->fd, (rt_uint8_t *)elf_info->phdr, size, ehdr->e_phoff); if (ret != RT_EOK) { rt_free(elf_info->phdr); elf_info->phdr = RT_NULL; LOG_E("%s : elf_file_read failed, ret = %d", __func__, ret); return -RT_ERROR; } return RT_EOK; } static int elf_load_interp(elf_load_info_t *load_info) { Elf_Phdr *phdr = load_info->exec_info.phdr; int ret; int i; for (i = 0; i < load_info->exec_info.ehdr.e_phnum; ++i, ++phdr) { if (phdr->p_type != PT_INTERP) { continue; } if (elf_check_phdr(phdr) != RT_EOK) { return -RT_ERROR; } if ((phdr->p_filesz > ELF_PATH_MAX) || (phdr->p_filesz < FLF_PATH_MIN)) { LOG_E("%s : phdr p_filesz error", __func__, phdr->p_filesz); return -RT_ERROR; } if (phdr->p_offset + phdr->p_filesz > load_info->exec_info.file_len) { LOG_E("%s : phdr p_offset error", __func__, phdr->p_offset); return -RT_ERROR; } load_info->interp_info.filename = rt_malloc(phdr->p_filesz); if (load_info->interp_info.filename == RT_NULL) { LOG_E("%s : alloc elf interpreter failed", __func__); return -RT_ENOMEM; } ret = elf_file_read(load_info->exec_info.fd, (rt_uint8_t *)load_info->interp_info.filename, phdr->p_filesz, phdr->p_offset); if (ret != RT_EOK) { LOG_E("%s : elf_file_read failed, ret = %d", __func__, ret); ret = -RT_ERROR; goto error_exit; } if (load_info->interp_info.filename[phdr->p_filesz - 1] != '\0') { LOG_E("%s : elf interpreter is invalid", __func__); ret = -RT_ERROR; goto error_exit; } LOG_D("%s : elf interpreter : %s", __func__, load_info->interp_info.filename); ret = elf_load_ehdr(&load_info->interp_info); if (ret != RT_EOK) { LOG_E("%s : elf_load_ehdr failed, ret = %d", __func__, ret); goto error_exit; } ret = elf_load_phdr(&load_info->interp_info); if (ret != RT_EOK) { LOG_E("%s : elf_load_phdr failed, ret = %d", __func__, ret); goto error_exit; } break; } return RT_EOK; error_exit: return ret; } static int total_mapping_size(elf_info_t *elf_info) { int i; int first_idx = -1; int last_idx = -1; for (i = 0; i < elf_info->ehdr.e_phnum; i++) { if (elf_info->phdr[i].p_type == PT_LOAD) { last_idx = i; if (first_idx == -1) first_idx = i; } } if (first_idx == -1) return -1; elf_info->map_size = elf_info->phdr[last_idx].p_vaddr + elf_info->phdr[last_idx].p_memsz - ELF_PAGESTART(elf_info->phdr[first_idx].p_vaddr); return 0; } static rt_ubase_t elf_map(struct rt_lwp *lwp, const Elf_Phdr *elf_phdr, int fd, rt_ubase_t addr, size_t prot, size_t flags, rt_ubase_t map_size) { rt_ubase_t map_va = 0; rt_ubase_t va_offset; addr = ELF_PAGESTART(addr); va_offset = elf_phdr->p_offset - ELF_PAGEOFFSET(elf_phdr->p_vaddr); rt_ubase_t size; if (map_size != 0) { size = map_size; } else { size = elf_phdr->p_memsz + ELF_PAGEOFFSET(elf_phdr->p_vaddr); if (size == 0) { return addr; } } map_va = (rt_ubase_t)file_mmap(lwp, fd, addr, size, prot, flags, va_offset); return map_va; } static int elf_zero_bss(struct rt_lwp *lwp, int fd, const Elf_Phdr *phdr, rt_ubase_t bss_start, rt_ubase_t bss_end) { lwp_data_set(lwp, (void *)bss_start, 0, bss_end - bss_start); return RT_EOK; } static int elf_file_mmap(elf_load_info_t *load_info, elf_info_t *elf_info, rt_ubase_t *elfload_addr, rt_uint32_t map_size, rt_ubase_t *load_base) { int ret, i; rt_ubase_t map_va, bss_start, bss_end; Elf_Ehdr *ehdr = &elf_info->ehdr; Elf_Phdr *phdr = elf_info->phdr; const Elf_Phdr *tmp_phdr = phdr; int fd = elf_info->fd; rt_ubase_t load_addr; size_t prot = PROT_READ | PROT_WRITE; size_t flags = MAP_FIXED | MAP_PRIVATE; for (i = 0; i < ehdr->e_phnum; ++i, ++tmp_phdr) { if (tmp_phdr->p_type != PT_LOAD) { continue; } if (ehdr->e_type == ET_EXEC) { if (elf_check_phdr(tmp_phdr) != RT_EOK) { LOG_E("%s : elf_check_phdr failed", __func__); return -RT_ERROR; } } load_addr = tmp_phdr->p_vaddr + *load_base; LOG_D("%s : p_vaddr : 0x%x, load_addr : 0x%x", __func__, tmp_phdr->p_vaddr, load_addr); if ((tmp_phdr->p_vaddr == 0) && (*load_base == 0)) { flags &= ~MAP_FIXED; } map_va = elf_map(load_info->lwp, tmp_phdr, fd, load_addr, prot, flags, map_size); if (!map_va) { LOG_E("%s : elf_map failed", __func__); return -ENOMEM; } map_size = 0; elf_user_dump(load_info->lwp, (void *)load_addr, 64); if ((tmp_phdr->p_memsz > tmp_phdr->p_filesz) && (tmp_phdr->p_flags & PF_W)) { bss_start = load_addr + tmp_phdr->p_filesz; bss_end = load_addr + tmp_phdr->p_memsz; ret = elf_zero_bss(load_info->lwp, fd, tmp_phdr, bss_start, bss_end); if (ret) { LOG_E("%s : elf_zero_bss error", __func__); return ret; } } if (*elfload_addr == 0) { *elfload_addr = map_va + ELF_PAGEOFFSET(tmp_phdr->p_vaddr); LOG_D("%s elf_load_addr : %p, vAddr : %p, load_base : %p, map_va : %p", __func__, *elfload_addr, tmp_phdr->p_vaddr, *load_base, map_va); } if ((*load_base == 0) && (ehdr->e_type == ET_DYN)) { *load_base = map_va; } } return RT_EOK; } static int load_elf_interp(elf_load_info_t *load_info, rt_ubase_t *interp_base) { int ret; rt_ubase_t load_base = ELF_INTERP_LOAD_ADDR + elf_random_offset(); ret = total_mapping_size(&load_info->interp_info); if (ret) { LOG_E("%s : total_mapping_size failed", __func__); return -RT_ERROR; } LOG_D("%s : total_mapping_size 0x%x", __func__, load_info->interp_info.map_size); return elf_file_mmap(load_info, &load_info->interp_info, interp_base, load_info->interp_info.map_size, &load_base); } static int elf_aux_fill(elf_load_info_t *load_info) { uint8_t *random; struct process_aux *aux = load_info->aux; elf_addr_t *aux_info; uint32_t random_value = rt_tick_get(); size_t prot = PROT_READ | PROT_WRITE; size_t flags = MAP_PRIVATE; rt_lwp_t lwp = load_info->lwp; void *va; if (!aux) { LOG_E("%s : aux is null", __func__); return -1; } aux_info = (elf_addr_t *)aux->item; ELF_AUX_ENT(aux_info, AT_PAGESZ, ARCH_PAGE_SIZE); va = lwp_mmap2(lwp, (void *)(USER_VADDR_TOP - ARCH_PAGE_SIZE * 2), ARCH_PAGE_SIZE, prot, flags, -1, 0); if (!va) { LOG_E("lwp map user failed!"); return -RT_ERROR; } random = (uint8_t *)(USER_VADDR_TOP - ARCH_PAGE_SIZE - sizeof(char[16])); lwp_data_put(load_info->lwp, random, &random_value, sizeof(random_value)); ELF_AUX_ENT(aux_info, AT_RANDOM, (size_t)random); ELF_AUX_ENT(aux_info, AT_PHDR, (size_t)load_info->load_addr + load_info->exec_info.ehdr.e_phoff); ELF_AUX_ENT(aux_info, AT_PHNUM, (size_t)load_info->exec_info.ehdr.e_phnum); ELF_AUX_ENT(aux_info, AT_PHENT, sizeof(Elf_Phdr)); ELF_AUX_ENT(aux_info, AT_BASE, load_info->interp_base); ELF_AUX_ENT(aux_info, AT_FLAGS, 0); ELF_AUX_ENT(aux_info, AT_ENTRY, load_info->exec_info.ehdr.e_entry); ELF_AUX_ENT(aux_info, AT_UID, 0); ELF_AUX_ENT(aux_info, AT_EUID, 0); ELF_AUX_ENT(aux_info, AT_GID, 0); ELF_AUX_ENT(aux_info, AT_EGID, 0); ELF_AUX_ENT(aux_info, AT_HWCAP, 0); ELF_AUX_ENT(aux_info, AT_CLKTCK, 0); ELF_AUX_ENT(aux_info, AT_SECURE, 0); return 0; } static int elf_load_segment(elf_load_info_t *load_info) { int ret; rt_ubase_t app_load_base = 0; load_info->load_addr = 0; load_info->interp_base = 0; load_info->exec_info.map_size = 0; if (load_info->exec_info.ehdr.e_type == ET_DYN) { ret = total_mapping_size(&load_info->exec_info); if (ret) { LOG_E("%s : total_mapping_size failed", __func__); return -RT_ERROR; } LOG_D("%s : map_size : 0x%x", __func__, load_info->exec_info.map_size); app_load_base = ELF_EXEC_LOAD_ADDR + elf_random_offset(); } ret = elf_file_mmap(load_info, &load_info->exec_info, &load_info->load_addr, load_info->exec_info.map_size, &app_load_base); elf_file_close(load_info->exec_info.fd); if (ret != RT_EOK) { LOG_W("%s : elf_file_close exec failed", __func__); } load_info->exec_info.fd = ELF_INVALID_FD; if (load_info->interp_info.fd != ELF_INVALID_FD) { ret = load_elf_interp(load_info, &load_info->interp_base); if (ret) { LOG_E("%s : load_elf_interp failed, ret = %d", __func__, ret); return ret; } elf_file_close(load_info->interp_info.fd); if (ret != RT_EOK) { LOG_W("%s : elf_file_close interp failed, ret = %d", __func__, ret); } load_info->interp_info.fd = ELF_INVALID_FD; load_info->e_entry = load_info->interp_info.ehdr.e_entry + load_info->interp_base; load_info->exec_info.ehdr.e_entry = load_info->exec_info.ehdr.e_entry + app_load_base; } else { load_info->e_entry = load_info->exec_info.ehdr.e_entry; } load_info->lwp->text_entry = (void *)load_info->e_entry; LOG_D("%s : lwp->text_entry : %p loadaddr : %p", __func__, load_info->lwp->text_entry, app_load_base); elf_user_dump(load_info->lwp, load_info->lwp->text_entry, 64); ret = elf_aux_fill(load_info); if (ret) { LOG_E("%s : elf_aux_fill failed", __func__); return ret; } return RT_EOK; } static void elf_load_deinit(elf_load_info_t *load_info) { if (load_info->exec_info.fd != ELF_INVALID_FD) { elf_file_close(load_info->exec_info.fd); } if (load_info->interp_info.fd != ELF_INVALID_FD) { elf_file_close(load_info->interp_info.fd); } if (load_info->exec_info.phdr != RT_NULL) { rt_free(load_info->exec_info.phdr); } if (load_info->exec_info.filename != RT_NULL) { rt_free(load_info->exec_info.filename); } if (load_info->interp_info.phdr != RT_NULL) { rt_free(load_info->interp_info.phdr); } if (load_info->interp_info.filename != RT_NULL) { rt_free(load_info->interp_info.filename); } } static int elf_load_app(elf_info_t *exec_info) { int ret; ret = elf_load_ehdr(exec_info); if (ret != RT_EOK) { return ret; } ret = elf_load_phdr(exec_info); if (ret != RT_EOK) { return ret; } return ret; } static int elf_file_load(elf_load_info_t *load_info) { int ret; ret = elf_load_app(&load_info->exec_info); if (ret != RT_EOK) { goto OUT; } ret = elf_load_interp(load_info); if (ret != RT_EOK) { goto OUT; } ret = elf_load_segment(load_info); if (ret != RT_EOK) { goto OUT; } OUT: elf_load_deinit(load_info); return ret; } int lwp_load(const char *filename, struct rt_lwp *lwp, uint8_t *load_addr, size_t addr_size, struct process_aux *aux_ua) { elf_load_info_t load_info = { 0 }; int len; int ret; if (filename == RT_NULL) { LOG_E("%s : file is NULL", __func__); return -RT_ERROR; } len = rt_strlen(filename); if (len < FLF_PATH_MIN || len > ELF_PATH_MAX) { LOG_E("%s : file length (%d) invalid", __func__, len); return -RT_ERROR; } load_info.exec_info.filename = rt_malloc(len + 1); if (!load_info.exec_info.filename) { LOG_E("%s : alloc filename failed", __func__, len); return -RT_ERROR; } else { rt_memset(load_info.exec_info.filename, 0, len + 1); rt_strncpy(load_info.exec_info.filename, filename, len); } load_info.lwp = lwp; load_info.aux = aux_ua; load_info.exec_info.fd = ELF_INVALID_FD; load_info.interp_info.fd = ELF_INVALID_FD; load_info.load_addr = (rt_ubase_t)load_addr; /* copy file name to process name */ rt_strncpy(lwp->cmd, filename, RT_NAME_MAX); lwp->exe_file = dfs_normalize_path(NULL, filename); // malloc ret = elf_file_load(&load_info); if (ret != RT_EOK) { LOG_E("%s : elf_file_load error, ret : %d", __func__, ret); return ret; } return RT_EOK; } #endif