// SPDX-License-Identifier: GPL-2.0-only /* * tools/testing/selftests/kvm/lib/elf.c * * Copyright (C) 2018, Google LLC. */ #include "test_util.h" #include #include #include "kvm_util.h" #include "kvm_util_internal.h" static void elfhdr_get(const char *filename, Elf64_Ehdr *hdrp) { off_t offset_rv; /* Open the ELF file. */ int fd; fd = open(filename, O_RDONLY); TEST_ASSERT(fd >= 0, "Failed to open ELF file,\n" " filename: %s\n" " rv: %i errno: %i", filename, fd, errno); /* Read in and validate ELF Identification Record. * The ELF Identification record is the first 16 (EI_NIDENT) bytes * of the ELF header, which is at the beginning of the ELF file. * For now it is only safe to read the first EI_NIDENT bytes. Once * read and validated, the value of e_ehsize can be used to determine * the real size of the ELF header. */ unsigned char ident[EI_NIDENT]; test_read(fd, ident, sizeof(ident)); TEST_ASSERT((ident[EI_MAG0] == ELFMAG0) && (ident[EI_MAG1] == ELFMAG1) && (ident[EI_MAG2] == ELFMAG2) && (ident[EI_MAG3] == ELFMAG3), "ELF MAGIC Mismatch,\n" " filename: %s\n" " ident[EI_MAG0 - EI_MAG3]: %02x %02x %02x %02x\n" " Expected: %02x %02x %02x %02x", filename, ident[EI_MAG0], ident[EI_MAG1], ident[EI_MAG2], ident[EI_MAG3], ELFMAG0, ELFMAG1, ELFMAG2, ELFMAG3); TEST_ASSERT(ident[EI_CLASS] == ELFCLASS64, "Current implementation only able to handle ELFCLASS64,\n" " filename: %s\n" " ident[EI_CLASS]: %02x\n" " expected: %02x", filename, ident[EI_CLASS], ELFCLASS64); TEST_ASSERT(((BYTE_ORDER == LITTLE_ENDIAN) && (ident[EI_DATA] == ELFDATA2LSB)) || ((BYTE_ORDER == BIG_ENDIAN) && (ident[EI_DATA] == ELFDATA2MSB)), "Current " "implementation only able to handle\n" "cases where the host and ELF file endianness\n" "is the same:\n" " host BYTE_ORDER: %u\n" " host LITTLE_ENDIAN: %u\n" " host BIG_ENDIAN: %u\n" " ident[EI_DATA]: %u\n" " ELFDATA2LSB: %u\n" " ELFDATA2MSB: %u", BYTE_ORDER, LITTLE_ENDIAN, BIG_ENDIAN, ident[EI_DATA], ELFDATA2LSB, ELFDATA2MSB); TEST_ASSERT(ident[EI_VERSION] == EV_CURRENT, "Current implementation only able to handle current " "ELF version,\n" " filename: %s\n" " ident[EI_VERSION]: %02x\n" " expected: %02x", filename, ident[EI_VERSION], EV_CURRENT); /* Read in the ELF header. * With the ELF Identification portion of the ELF header * validated, especially that the value at EI_VERSION is * as expected, it is now safe to read the entire ELF header. */ offset_rv = lseek(fd, 0, SEEK_SET); TEST_ASSERT(offset_rv == 0, "Seek to ELF header failed,\n" " rv: %zi expected: %i", offset_rv, 0); test_read(fd, hdrp, sizeof(*hdrp)); TEST_ASSERT(hdrp->e_phentsize == sizeof(Elf64_Phdr), "Unexpected physical header size,\n" " hdrp->e_phentsize: %x\n" " expected: %zx", hdrp->e_phentsize, sizeof(Elf64_Phdr)); TEST_ASSERT(hdrp->e_shentsize == sizeof(Elf64_Shdr), "Unexpected section header size,\n" " hdrp->e_shentsize: %x\n" " expected: %zx", hdrp->e_shentsize, sizeof(Elf64_Shdr)); } /* VM ELF Load * * Input Args: * filename - Path to ELF file * * Output Args: None * * Input/Output Args: * vm - Pointer to opaque type that describes the VM. * * Return: None, TEST_ASSERT failures for all error conditions * * Loads the program image of the ELF file specified by filename, * into the virtual address space of the VM pointed to by vm. On entry * the VM needs to not be using any of the virtual address space used * by the image and it needs to have sufficient available physical pages, to * back the virtual pages used to load the image. */ void kvm_vm_elf_load(struct kvm_vm *vm, const char *filename, uint32_t data_memslot, uint32_t pgd_memslot) { off_t offset, offset_rv; Elf64_Ehdr hdr; /* Open the ELF file. */ int fd; fd = open(filename, O_RDONLY); TEST_ASSERT(fd >= 0, "Failed to open ELF file,\n" " filename: %s\n" " rv: %i errno: %i", filename, fd, errno); /* Read in the ELF header. */ elfhdr_get(filename, &hdr); /* For each program header. * The following ELF header members specify the location * and size of the program headers: * * e_phoff - File offset to start of program headers * e_phentsize - Size of each program header * e_phnum - Number of program header entries */ for (unsigned int n1 = 0; n1 < hdr.e_phnum; n1++) { /* Seek to the beginning of the program header. */ offset = hdr.e_phoff + (n1 * hdr.e_phentsize); offset_rv = lseek(fd, offset, SEEK_SET); TEST_ASSERT(offset_rv == offset, "Failed to seek to begining of program header %u,\n" " filename: %s\n" " rv: %jd errno: %i", n1, filename, (intmax_t) offset_rv, errno); /* Read in the program header. */ Elf64_Phdr phdr; test_read(fd, &phdr, sizeof(phdr)); /* Skip if this header doesn't describe a loadable segment. */ if (phdr.p_type != PT_LOAD) continue; /* Allocate memory for this segment within the VM. */ TEST_ASSERT(phdr.p_memsz > 0, "Unexpected loadable segment " "memsize of 0,\n" " phdr index: %u p_memsz: 0x%" PRIx64, n1, (uint64_t) phdr.p_memsz); vm_vaddr_t seg_vstart = phdr.p_vaddr; seg_vstart &= ~(vm_vaddr_t)(vm->page_size - 1); vm_vaddr_t seg_vend = phdr.p_vaddr + phdr.p_memsz - 1; seg_vend |= vm->page_size - 1; size_t seg_size = seg_vend - seg_vstart + 1; vm_vaddr_t vaddr = vm_vaddr_alloc(vm, seg_size, seg_vstart, data_memslot, pgd_memslot); TEST_ASSERT(vaddr == seg_vstart, "Unable to allocate " "virtual memory for segment at requested min addr,\n" " segment idx: %u\n" " seg_vstart: 0x%lx\n" " vaddr: 0x%lx", n1, seg_vstart, vaddr); memset(addr_gva2hva(vm, vaddr), 0, seg_size); /* TODO(lhuemill): Set permissions of each memory segment * based on the least-significant 3 bits of phdr.p_flags. */ /* Load portion of initial state that is contained within * the ELF file. */ if (phdr.p_filesz) { offset_rv = lseek(fd, phdr.p_offset, SEEK_SET); TEST_ASSERT(offset_rv == phdr.p_offset, "Seek to program segment offset failed,\n" " program header idx: %u errno: %i\n" " offset_rv: 0x%jx\n" " expected: 0x%jx\n", n1, errno, (intmax_t) offset_rv, (intmax_t) phdr.p_offset); test_read(fd, addr_gva2hva(vm, phdr.p_vaddr), phdr.p_filesz); } } }