diff options
Diffstat (limited to 'tools/testing/selftests/sgx/load.c')
-rw-r--r-- | tools/testing/selftests/sgx/load.c | 370 |
1 files changed, 370 insertions, 0 deletions
diff --git a/tools/testing/selftests/sgx/load.c b/tools/testing/selftests/sgx/load.c new file mode 100644 index 000000000..c9f658e44 --- /dev/null +++ b/tools/testing/selftests/sgx/load.c @@ -0,0 +1,370 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright(c) 2016-20 Intel Corporation. */ + +#include <assert.h> +#include <elf.h> +#include <errno.h> +#include <fcntl.h> +#include <stdbool.h> +#include <stdio.h> +#include <stdint.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> +#include <sys/ioctl.h> +#include <sys/mman.h> +#include <sys/stat.h> +#include <sys/time.h> +#include <sys/types.h> +#include "defines.h" +#include "main.h" + +void encl_delete(struct encl *encl) +{ + struct encl_segment *heap_seg; + + if (encl->encl_base) + munmap((void *)encl->encl_base, encl->encl_size); + + if (encl->bin) + munmap(encl->bin, encl->bin_size); + + if (encl->fd) + close(encl->fd); + + if (encl->segment_tbl) { + heap_seg = &encl->segment_tbl[encl->nr_segments - 1]; + munmap(heap_seg->src, heap_seg->size); + free(encl->segment_tbl); + } + + memset(encl, 0, sizeof(*encl)); +} + +static bool encl_map_bin(const char *path, struct encl *encl) +{ + struct stat sb; + void *bin; + int ret; + int fd; + + fd = open(path, O_RDONLY); + if (fd == -1) { + perror("enclave executable open()"); + return false; + } + + ret = stat(path, &sb); + if (ret) { + perror("enclave executable stat()"); + goto err; + } + + bin = mmap(NULL, sb.st_size, PROT_READ, MAP_PRIVATE, fd, 0); + if (bin == MAP_FAILED) { + perror("enclave executable mmap()"); + goto err; + } + + encl->bin = bin; + encl->bin_size = sb.st_size; + + close(fd); + return true; + +err: + close(fd); + return false; +} + +static bool encl_ioc_create(struct encl *encl) +{ + struct sgx_secs *secs = &encl->secs; + struct sgx_enclave_create ioc; + int rc; + + assert(encl->encl_base != 0); + + memset(secs, 0, sizeof(*secs)); + secs->ssa_frame_size = 1; + secs->attributes = SGX_ATTR_MODE64BIT; + secs->xfrm = 3; + secs->base = encl->encl_base; + secs->size = encl->encl_size; + + ioc.src = (unsigned long)secs; + rc = ioctl(encl->fd, SGX_IOC_ENCLAVE_CREATE, &ioc); + if (rc) { + perror("SGX_IOC_ENCLAVE_CREATE failed"); + munmap((void *)secs->base, encl->encl_size); + return false; + } + + return true; +} + +static bool encl_ioc_add_pages(struct encl *encl, struct encl_segment *seg) +{ + struct sgx_enclave_add_pages ioc; + struct sgx_secinfo secinfo; + int rc; + + memset(&secinfo, 0, sizeof(secinfo)); + secinfo.flags = seg->flags; + + ioc.src = (uint64_t)seg->src; + ioc.offset = seg->offset; + ioc.length = seg->size; + ioc.secinfo = (unsigned long)&secinfo; + if (seg->measure) + ioc.flags = SGX_PAGE_MEASURE; + else + ioc.flags = 0; + + rc = ioctl(encl->fd, SGX_IOC_ENCLAVE_ADD_PAGES, &ioc); + if (rc < 0) { + perror("SGX_IOC_ENCLAVE_ADD_PAGES failed"); + return false; + } + + return true; +} + +/* + * Parse the enclave code's symbol table to locate and return address of + * the provided symbol + */ +uint64_t encl_get_entry(struct encl *encl, const char *symbol) +{ + Elf64_Sym *symtab = NULL; + char *sym_names = NULL; + Elf64_Shdr *sections; + Elf64_Ehdr *ehdr; + int num_sym = 0; + int i; + + ehdr = encl->bin; + sections = encl->bin + ehdr->e_shoff; + + for (i = 0; i < ehdr->e_shnum; i++) { + if (sections[i].sh_type == SHT_SYMTAB) { + symtab = (Elf64_Sym *)((char *)encl->bin + sections[i].sh_offset); + num_sym = sections[i].sh_size / sections[i].sh_entsize; + break; + } + } + + for (i = 0; i < ehdr->e_shnum; i++) { + if (sections[i].sh_type == SHT_STRTAB) { + sym_names = (char *)encl->bin + sections[i].sh_offset; + break; + } + } + + if (!symtab || !sym_names) + return 0; + + for (i = 0; i < num_sym; i++) { + Elf64_Sym *sym = &symtab[i]; + + if (!strcmp(symbol, sym_names + sym->st_name)) + return (uint64_t)sym->st_value; + } + + return 0; +} + +bool encl_load(const char *path, struct encl *encl, unsigned long heap_size) +{ + const char device_path[] = "/dev/sgx_enclave"; + struct encl_segment *seg; + Elf64_Phdr *phdr_tbl; + off_t src_offset; + Elf64_Ehdr *ehdr; + struct stat sb; + void *ptr; + int i, j; + int ret; + int fd = -1; + + memset(encl, 0, sizeof(*encl)); + + fd = open(device_path, O_RDWR); + if (fd < 0) { + perror("Unable to open /dev/sgx_enclave"); + goto err; + } + + ret = stat(device_path, &sb); + if (ret) { + perror("device file stat()"); + goto err; + } + + ptr = mmap(NULL, PAGE_SIZE, PROT_READ, MAP_SHARED, fd, 0); + if (ptr == (void *)-1) { + perror("mmap for read"); + goto err; + } + munmap(ptr, PAGE_SIZE); + +#define ERR_MSG \ +"mmap() succeeded for PROT_READ, but failed for PROT_EXEC.\n" \ +" Check that /dev does not have noexec set:\n" \ +" \tmount | grep \"/dev .*noexec\"\n" \ +" If so, remount it executable: mount -o remount,exec /dev\n\n" + + ptr = mmap(NULL, PAGE_SIZE, PROT_EXEC, MAP_SHARED, fd, 0); + if (ptr == (void *)-1) { + fprintf(stderr, ERR_MSG); + goto err; + } + munmap(ptr, PAGE_SIZE); + + encl->fd = fd; + + if (!encl_map_bin(path, encl)) + goto err; + + ehdr = encl->bin; + phdr_tbl = encl->bin + ehdr->e_phoff; + + encl->nr_segments = 1; /* one for the heap */ + + for (i = 0; i < ehdr->e_phnum; i++) { + Elf64_Phdr *phdr = &phdr_tbl[i]; + + if (phdr->p_type == PT_LOAD) + encl->nr_segments++; + } + + encl->segment_tbl = calloc(encl->nr_segments, + sizeof(struct encl_segment)); + if (!encl->segment_tbl) + goto err; + + for (i = 0, j = 0; i < ehdr->e_phnum; i++) { + Elf64_Phdr *phdr = &phdr_tbl[i]; + unsigned int flags = phdr->p_flags; + + if (phdr->p_type != PT_LOAD) + continue; + + seg = &encl->segment_tbl[j]; + + if (!!(flags & ~(PF_R | PF_W | PF_X))) { + fprintf(stderr, + "%d has invalid segment flags 0x%02x.\n", i, + phdr->p_flags); + goto err; + } + + if (j == 0 && flags != (PF_R | PF_W)) { + fprintf(stderr, + "TCS has invalid segment flags 0x%02x.\n", + phdr->p_flags); + goto err; + } + + if (j == 0) { + src_offset = phdr->p_offset & PAGE_MASK; + encl->src = encl->bin + src_offset; + + seg->prot = PROT_READ | PROT_WRITE; + seg->flags = SGX_PAGE_TYPE_TCS << 8; + } else { + seg->prot = (phdr->p_flags & PF_R) ? PROT_READ : 0; + seg->prot |= (phdr->p_flags & PF_W) ? PROT_WRITE : 0; + seg->prot |= (phdr->p_flags & PF_X) ? PROT_EXEC : 0; + seg->flags = (SGX_PAGE_TYPE_REG << 8) | seg->prot; + } + + seg->offset = (phdr->p_offset & PAGE_MASK) - src_offset; + seg->size = (phdr->p_filesz + PAGE_SIZE - 1) & PAGE_MASK; + seg->src = encl->src + seg->offset; + seg->measure = true; + + j++; + } + + assert(j == encl->nr_segments - 1); + + seg = &encl->segment_tbl[j]; + seg->offset = encl->segment_tbl[j - 1].offset + encl->segment_tbl[j - 1].size; + seg->size = heap_size; + seg->src = mmap(NULL, heap_size, PROT_READ | PROT_WRITE, + MAP_ANONYMOUS | MAP_PRIVATE, -1, 0); + seg->prot = PROT_READ | PROT_WRITE; + seg->flags = (SGX_PAGE_TYPE_REG << 8) | seg->prot; + seg->measure = false; + + if (seg->src == MAP_FAILED) + goto err; + + encl->src_size = encl->segment_tbl[j].offset + encl->segment_tbl[j].size; + + for (encl->encl_size = 4096; encl->encl_size < encl->src_size; ) + encl->encl_size <<= 1; + + return true; + +err: + if (fd != -1) + close(fd); + encl_delete(encl); + return false; +} + +static bool encl_map_area(struct encl *encl) +{ + size_t encl_size = encl->encl_size; + void *area; + + area = mmap(NULL, encl_size * 2, PROT_NONE, + MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); + if (area == MAP_FAILED) { + perror("reservation mmap()"); + return false; + } + + encl->encl_base = ((uint64_t)area + encl_size - 1) & ~(encl_size - 1); + + munmap(area, encl->encl_base - (uint64_t)area); + munmap((void *)(encl->encl_base + encl_size), + (uint64_t)area + encl_size - encl->encl_base); + + return true; +} + +bool encl_build(struct encl *encl) +{ + struct sgx_enclave_init ioc; + int ret; + int i; + + if (!encl_map_area(encl)) + return false; + + if (!encl_ioc_create(encl)) + return false; + + /* + * Pages must be added before mapping VMAs because their permissions + * cap the VMA permissions. + */ + for (i = 0; i < encl->nr_segments; i++) { + struct encl_segment *seg = &encl->segment_tbl[i]; + + if (!encl_ioc_add_pages(encl, seg)) + return false; + } + + ioc.sigstruct = (uint64_t)&encl->sigstruct; + ret = ioctl(encl->fd, SGX_IOC_ENCLAVE_INIT, &ioc); + if (ret) { + perror("SGX_IOC_ENCLAVE_INIT failed"); + return false; + } + + return true; +} |