| // Copyright 2016 The Fuchsia Authors |
| // |
| // Use of this source code is governed by a MIT-style |
| // license that can be found in the LICENSE file or at |
| // https://opensource.org/licenses/MIT |
| |
| #include "userboot-elf.h" |
| |
| #include <elf.h> |
| #include <string.h> |
| #include <zircon/compiler.h> |
| #include <zircon/processargs.h> |
| #include <zircon/syscalls.h> |
| |
| #include <iterator> |
| |
| #include <elfload/elfload.h> |
| #include <fbl/algorithm.h> |
| |
| #include "bootfs.h" |
| #include "util.h" |
| |
| #define INTERP_PREFIX "lib/" |
| |
| static zx_vaddr_t load(const zx::debuglog& log, const char* what, const zx::vmar& vmar, |
| const zx::vmo& vmo, uintptr_t* interp_off, size_t* interp_len, |
| zx::vmar* segments_vmar, size_t* stack_size, bool return_entry) { |
| elf_load_header_t header; |
| uintptr_t phoff; |
| zx_status_t status = elf_load_prepare(vmo.get(), NULL, 0, &header, &phoff); |
| check(log, status, "elf_load_prepare failed"); |
| |
| elf_phdr_t phdrs[header.e_phnum]; |
| status = elf_load_read_phdrs(vmo.get(), phdrs, phoff, header.e_phnum); |
| check(log, status, "elf_load_read_phdrs failed"); |
| |
| if (interp_off != NULL && elf_load_find_interp(phdrs, header.e_phnum, interp_off, interp_len)) |
| return 0; |
| |
| if (stack_size != NULL) { |
| for (size_t i = 0; i < header.e_phnum; ++i) { |
| if (phdrs[i].p_type == PT_GNU_STACK && phdrs[i].p_memsz > 0) |
| *stack_size = phdrs[i].p_memsz; |
| } |
| } |
| |
| zx_vaddr_t base, entry; |
| zx_handle_t* vmar_ptr = (segments_vmar) ? segments_vmar->reset_and_get_address() : NULL; |
| status = elf_load_map_segments(vmar.get(), &header, phdrs, vmo.get(), vmar_ptr, &base, &entry); |
| check(log, status, "elf_load_map_segments failed"); |
| |
| printl(log, "userboot: loaded %s at %p, entry point %p\n", what, (void*)base, (void*)entry); |
| return return_entry ? entry : base; |
| } |
| |
| zx_vaddr_t elf_load_vdso(const zx::debuglog& log, const zx::vmar& vmar, const zx::vmo& vmo) { |
| return load(log, "vDSO", vmar, vmo, NULL, NULL, NULL, NULL, false); |
| } |
| |
| enum loader_bootstrap_handle_index { |
| BOOTSTRAP_EXEC_VMO, |
| BOOTSTRAP_LOGGER, |
| BOOTSTRAP_PROC, |
| BOOTSTRAP_ROOT_VMAR, |
| BOOTSTRAP_SEGMENTS_VMAR, |
| BOOTSTRAP_THREAD, |
| BOOTSTRAP_LOADER_SVC, |
| BOOTSTRAP_HANDLES |
| }; |
| |
| #define LOADER_BOOTSTRAP_ENVIRON "LD_DEBUG=1" |
| #define LOADER_BOOTSTRAP_ENVIRON_NUM 1 |
| |
| struct loader_bootstrap_message { |
| zx_proc_args_t header; |
| uint32_t handle_info[BOOTSTRAP_HANDLES]; |
| char env[sizeof(LOADER_BOOTSTRAP_ENVIRON)]; |
| }; |
| |
| static void stuff_loader_bootstrap(const zx::debuglog& log, const zx::process& proc, |
| const zx::vmar& root_vmar, const zx::thread& thread, |
| const zx::channel& to_child, zx::vmar segments_vmar, zx::vmo vmo, |
| zx::channel* loader_svc) { |
| #pragma GCC diagnostic push |
| #pragma GCC diagnostic ignored "-Wmissing-field-initializers" |
| struct loader_bootstrap_message msg = { |
| .header = |
| { |
| .protocol = ZX_PROCARGS_PROTOCOL, |
| .version = ZX_PROCARGS_VERSION, |
| .handle_info_off = offsetof(struct loader_bootstrap_message, handle_info), |
| .environ_off = offsetof(struct loader_bootstrap_message, env), |
| .environ_num = LOADER_BOOTSTRAP_ENVIRON_NUM, |
| }, |
| .handle_info = |
| { |
| [BOOTSTRAP_EXEC_VMO] = PA_HND(PA_VMO_EXECUTABLE, 0), |
| [BOOTSTRAP_LOGGER] = PA_HND(PA_FD, 0), |
| [BOOTSTRAP_PROC] = PA_HND(PA_PROC_SELF, 0), |
| [BOOTSTRAP_ROOT_VMAR] = PA_HND(PA_VMAR_ROOT, 0), |
| [BOOTSTRAP_SEGMENTS_VMAR] = PA_HND(PA_VMAR_LOADED, 0), |
| [BOOTSTRAP_THREAD] = PA_HND(PA_THREAD_SELF, 0), |
| [BOOTSTRAP_LOADER_SVC] = PA_HND(PA_LDSVC_LOADER, 0), |
| }, |
| .env = LOADER_BOOTSTRAP_ENVIRON, |
| }; |
| #pragma GCC diagnostic pop |
| zx_handle_t handles[] = { |
| [BOOTSTRAP_EXEC_VMO] = vmo.release(), |
| [BOOTSTRAP_LOGGER] = ZX_HANDLE_INVALID, |
| [BOOTSTRAP_PROC] = ZX_HANDLE_INVALID, |
| [BOOTSTRAP_ROOT_VMAR] = ZX_HANDLE_INVALID, |
| [BOOTSTRAP_SEGMENTS_VMAR] = segments_vmar.release(), |
| [BOOTSTRAP_THREAD] = ZX_HANDLE_INVALID, |
| [BOOTSTRAP_LOADER_SVC] = ZX_HANDLE_INVALID, |
| }; |
| check(log, zx_handle_duplicate(log.get(), ZX_RIGHT_SAME_RIGHTS, &handles[BOOTSTRAP_LOGGER]), |
| "zx_handle_duplicate failed"); |
| check(log, zx_handle_duplicate(proc.get(), ZX_RIGHT_SAME_RIGHTS, &handles[BOOTSTRAP_PROC]), |
| "zx_handle_duplicate failed"); |
| check(log, |
| zx_handle_duplicate(root_vmar.get(), ZX_RIGHT_SAME_RIGHTS, &handles[BOOTSTRAP_ROOT_VMAR]), |
| "zx_handle_duplicate failed"); |
| check(log, zx_handle_duplicate(thread.get(), ZX_RIGHT_SAME_RIGHTS, &handles[BOOTSTRAP_THREAD]), |
| "zx_handle_duplicate failed"); |
| check(log, |
| zx_channel_create(0, loader_svc->reset_and_get_address(), &handles[BOOTSTRAP_LOADER_SVC]), |
| "zx_channel_create failed"); |
| |
| zx_status_t status = to_child.write(0, &msg, sizeof(msg), handles, std::size(handles)); |
| check(log, status, "zx_channel_write of loader bootstrap message failed"); |
| } |
| |
| zx_vaddr_t elf_load_bootfs(const zx::debuglog& log, const Bootfs& bootfs, const char* root_prefix, |
| const zx::process& proc, const zx::vmar& vmar, const zx::thread& thread, |
| const char* filename, const zx::channel& to_child, size_t* stack_size, |
| zx::channel* loader_svc) { |
| zx::vmo vmo = bootfs.Open(root_prefix, filename, "program"); |
| |
| uintptr_t interp_off = 0; |
| size_t interp_len = 0; |
| zx_vaddr_t entry = |
| load(log, filename, vmar, vmo, &interp_off, &interp_len, NULL, stack_size, true); |
| if (interp_len > 0) { |
| // While PT_INTERP names can be arbitrarily large, bootfs entries |
| // have names of bounded length. |
| constexpr size_t kInterpMaxLen = ZBI_BOOTFS_MAX_NAME_LEN; |
| constexpr size_t kInterpPrefixLen = sizeof(INTERP_PREFIX) - 1; |
| static_assert(kInterpMaxLen >= kInterpPrefixLen); |
| constexpr size_t kInterpSuffixLen = kInterpMaxLen - kInterpPrefixLen; |
| |
| if (interp_len > kInterpSuffixLen) { |
| return ZX_ERR_INVALID_ARGS; |
| } |
| |
| // Add one for the trailing nul. |
| char interp[kInterpMaxLen + 1]; |
| |
| // Copy the prefix. |
| memcpy(interp, INTERP_PREFIX, kInterpPrefixLen); |
| |
| // Copy the suffix. |
| zx_status_t status = vmo.read(&interp[kInterpPrefixLen], interp_off, interp_len); |
| if (status != ZX_OK) |
| fail(log, "zx_vmo_read failed: %d", status); |
| |
| // Copy the nul. |
| interp[kInterpPrefixLen + interp_len] = '\0'; |
| |
| printl(log, "'%s' has PT_INTERP \"%s\"", filename, interp); |
| |
| zx::vmo interp_vmo = bootfs.Open(root_prefix, interp, "dynamic linker"); |
| zx::vmar interp_vmar; |
| entry = load(log, interp, vmar, interp_vmo, NULL, NULL, &interp_vmar, NULL, true); |
| |
| stuff_loader_bootstrap(log, proc, vmar, thread, to_child, std::move(interp_vmar), |
| std::move(vmo), loader_svc); |
| } |
| return entry; |
| } |