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ta_elf.c
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// SPDX-License-Identifier: BSD-2-Clause
/*
* Copyright (c) 2019, Linaro Limited
* Copyright (c) 2020-2023, Arm Limited
*/
#include <assert.h>
#include <config.h>
#include <confine_array_index.h>
#include <ctype.h>
#include <elf32.h>
#include <elf64.h>
#include <elf_common.h>
#include <ldelf.h>
#include <link.h>
#include <stdio.h>
#include <stdlib.h>
#include <string_ext.h>
#include <string.h>
#include <tee_api_types.h>
#include <tee_internal_api_extensions.h>
#include <unw/unwind.h>
#include <user_ta_header.h>
#include <util.h>
#include "sys.h"
#include "ta_elf.h"
/*
* Layout of a 32-bit struct dl_phdr_info for a 64-bit ldelf to access a 32-bit
* TA
*/
struct dl_phdr_info32 {
uint32_t dlpi_addr;
uint32_t dlpi_name;
uint32_t dlpi_phdr;
uint16_t dlpi_phnum;
uint64_t dlpi_adds;
uint64_t dlpi_subs;
uint32_t dlpi_tls_modid;
uint32_t dlpi_tls_data;
};
static vaddr_t ta_stack;
static vaddr_t ta_stack_size;
struct ta_elf_queue main_elf_queue = TAILQ_HEAD_INITIALIZER(main_elf_queue);
/*
* Main application is always ID 1, shared libraries with TLS take IDs 2 and
* above
*/
static void assign_tls_mod_id(struct ta_elf *elf)
{
static size_t last_tls_mod_id = 1;
if (elf->is_main)
assert(last_tls_mod_id == 1); /* Main always comes first */
elf->tls_mod_id = last_tls_mod_id++;
}
static struct ta_elf *queue_elf_helper(const TEE_UUID *uuid)
{
struct ta_elf *elf = calloc(1, sizeof(*elf));
if (!elf)
return NULL;
TAILQ_INIT(&elf->segs);
elf->uuid = *uuid;
TAILQ_INSERT_TAIL(&main_elf_queue, elf, link);
return elf;
}
static struct ta_elf *queue_elf(const TEE_UUID *uuid)
{
struct ta_elf *elf = ta_elf_find_elf(uuid);
if (elf)
return NULL;
elf = queue_elf_helper(uuid);
if (!elf)
err(TEE_ERROR_OUT_OF_MEMORY, "queue_elf_helper");
return elf;
}
struct ta_elf *ta_elf_find_elf(const TEE_UUID *uuid)
{
struct ta_elf *elf = NULL;
TAILQ_FOREACH(elf, &main_elf_queue, link)
if (!memcmp(uuid, &elf->uuid, sizeof(*uuid)))
return elf;
return NULL;
}
#if defined(ARM32) || defined(ARM64)
static TEE_Result e32_parse_ehdr(struct ta_elf *elf, Elf32_Ehdr *ehdr)
{
if (ehdr->e_ident[EI_VERSION] != EV_CURRENT ||
ehdr->e_ident[EI_CLASS] != ELFCLASS32 ||
ehdr->e_ident[EI_DATA] != ELFDATA2LSB ||
ehdr->e_ident[EI_OSABI] != ELFOSABI_NONE ||
ehdr->e_type != ET_DYN || ehdr->e_machine != EM_ARM ||
(ehdr->e_flags & EF_ARM_ABIMASK) != EF_ARM_ABI_VERSION ||
#ifndef CFG_WITH_VFP
(ehdr->e_flags & EF_ARM_ABI_FLOAT_HARD) ||
#endif
ehdr->e_phentsize != sizeof(Elf32_Phdr) ||
ehdr->e_shentsize != sizeof(Elf32_Shdr))
return TEE_ERROR_BAD_FORMAT;
elf->is_32bit = true;
elf->e_entry = ehdr->e_entry;
elf->e_phoff = ehdr->e_phoff;
elf->e_shoff = ehdr->e_shoff;
elf->e_phnum = ehdr->e_phnum;
elf->e_shnum = ehdr->e_shnum;
elf->e_phentsize = ehdr->e_phentsize;
elf->e_shentsize = ehdr->e_shentsize;
return TEE_SUCCESS;
}
#ifdef ARM64
static TEE_Result e64_parse_ehdr(struct ta_elf *elf, Elf64_Ehdr *ehdr)
{
if (ehdr->e_ident[EI_VERSION] != EV_CURRENT ||
ehdr->e_ident[EI_CLASS] != ELFCLASS64 ||
ehdr->e_ident[EI_DATA] != ELFDATA2LSB ||
ehdr->e_ident[EI_OSABI] != ELFOSABI_NONE ||
ehdr->e_type != ET_DYN || ehdr->e_machine != EM_AARCH64 ||
ehdr->e_flags || ehdr->e_phentsize != sizeof(Elf64_Phdr) ||
ehdr->e_shentsize != sizeof(Elf64_Shdr))
return TEE_ERROR_BAD_FORMAT;
elf->is_32bit = false;
elf->e_entry = ehdr->e_entry;
elf->e_phoff = ehdr->e_phoff;
elf->e_shoff = ehdr->e_shoff;
elf->e_phnum = ehdr->e_phnum;
elf->e_shnum = ehdr->e_shnum;
elf->e_phentsize = ehdr->e_phentsize;
elf->e_shentsize = ehdr->e_shentsize;
return TEE_SUCCESS;
}
#else /*ARM64*/
static TEE_Result e64_parse_ehdr(struct ta_elf *elf __unused,
Elf64_Ehdr *ehdr __unused)
{
return TEE_ERROR_NOT_SUPPORTED;
}
#endif /*ARM64*/
#endif /* ARM32 || ARM64 */
#if defined(RV64)
static TEE_Result e32_parse_ehdr(struct ta_elf *elf __unused,
Elf32_Ehdr *ehdr __unused)
{
return TEE_ERROR_BAD_FORMAT;
}
static TEE_Result e64_parse_ehdr(struct ta_elf *elf, Elf64_Ehdr *ehdr)
{
if (ehdr->e_ident[EI_VERSION] != EV_CURRENT ||
ehdr->e_ident[EI_CLASS] != ELFCLASS64 ||
ehdr->e_ident[EI_DATA] != ELFDATA2LSB ||
ehdr->e_ident[EI_OSABI] != ELFOSABI_NONE ||
ehdr->e_type != ET_DYN || ehdr->e_machine != EM_RISCV ||
ehdr->e_phentsize != sizeof(Elf64_Phdr) ||
ehdr->e_shentsize != sizeof(Elf64_Shdr))
return TEE_ERROR_BAD_FORMAT;
elf->is_32bit = false;
elf->e_entry = ehdr->e_entry;
elf->e_phoff = ehdr->e_phoff;
elf->e_shoff = ehdr->e_shoff;
elf->e_phnum = ehdr->e_phnum;
elf->e_shnum = ehdr->e_shnum;
elf->e_phentsize = ehdr->e_phentsize;
elf->e_shentsize = ehdr->e_shentsize;
return TEE_SUCCESS;
}
#endif /* RV64 */
static void check_phdr_in_range(struct ta_elf *elf, unsigned int type,
vaddr_t addr, size_t memsz)
{
vaddr_t max_addr = 0;
if (ADD_OVERFLOW(addr, memsz, &max_addr))
err(TEE_ERROR_BAD_FORMAT, "Program header %#x overflow", type);
/*
* elf->load_addr and elf->max_addr are both using the
* final virtual addresses, while this program header is
* relative to 0.
*/
if (max_addr > elf->max_addr - elf->load_addr)
err(TEE_ERROR_BAD_FORMAT, "Program header %#x out of bounds",
type);
}
static void read_dyn(struct ta_elf *elf, vaddr_t addr,
size_t idx, unsigned int *tag, size_t *val)
{
if (elf->is_32bit) {
Elf32_Dyn *dyn = (Elf32_Dyn *)(addr + elf->load_addr);
*tag = dyn[idx].d_tag;
*val = dyn[idx].d_un.d_val;
} else {
Elf64_Dyn *dyn = (Elf64_Dyn *)(addr + elf->load_addr);
*tag = dyn[idx].d_tag;
*val = dyn[idx].d_un.d_val;
}
}
static void check_range(struct ta_elf *elf, const char *name, const void *ptr,
size_t sz)
{
size_t max_addr = 0;
if ((vaddr_t)ptr < elf->load_addr)
err(TEE_ERROR_BAD_FORMAT, "%s %p out of range", name, ptr);
if (ADD_OVERFLOW((vaddr_t)ptr, sz, &max_addr))
err(TEE_ERROR_BAD_FORMAT, "%s range overflow", name);
if (max_addr > elf->max_addr)
err(TEE_ERROR_BAD_FORMAT,
"%s %p..%#zx out of range", name, ptr, max_addr);
}
static void check_hashtab(struct ta_elf *elf, void *ptr, size_t num_buckets,
size_t num_chains)
{
/*
* Starting from 2 as the first two words are mandatory and hold
* num_buckets and num_chains. So this function is called twice,
* first to see that there's indeed room for num_buckets and
* num_chains and then to see that all of it fits.
* See http://www.sco.com/developers/gabi/latest/ch5.dynamic.html#hash
*/
size_t num_words = 2;
size_t sz = 0;
if (!IS_ALIGNED_WITH_TYPE(ptr, uint32_t))
err(TEE_ERROR_BAD_FORMAT, "Bad alignment of DT_HASH %p", ptr);
if (ADD_OVERFLOW(num_words, num_buckets, &num_words) ||
ADD_OVERFLOW(num_words, num_chains, &num_words) ||
MUL_OVERFLOW(num_words, sizeof(uint32_t), &sz))
err(TEE_ERROR_BAD_FORMAT, "DT_HASH overflow");
check_range(elf, "DT_HASH", ptr, sz);
}
static void check_gnu_hashtab(struct ta_elf *elf, void *ptr)
{
struct gnu_hashtab *h = ptr;
size_t num_words = 4; /* nbuckets, symoffset, bloom_size, bloom_shift */
size_t bloom_words = 0;
size_t sz = 0;
if (!IS_ALIGNED_WITH_TYPE(ptr, uint32_t))
err(TEE_ERROR_BAD_FORMAT, "Bad alignment of DT_GNU_HASH %p",
ptr);
if (elf->gnu_hashtab_size < sizeof(*h))
err(TEE_ERROR_BAD_FORMAT, "DT_GNU_HASH too small");
/* Check validity of h->nbuckets and h->bloom_size */
if (elf->is_32bit)
bloom_words = h->bloom_size;
else
bloom_words = h->bloom_size * 2;
if (ADD_OVERFLOW(num_words, h->nbuckets, &num_words) ||
ADD_OVERFLOW(num_words, bloom_words, &num_words) ||
MUL_OVERFLOW(num_words, sizeof(uint32_t), &sz) ||
sz > elf->gnu_hashtab_size)
err(TEE_ERROR_BAD_FORMAT, "DT_GNU_HASH overflow");
}
static void save_hashtab(struct ta_elf *elf)
{
uint32_t *hashtab = NULL;
size_t n = 0;
if (elf->is_32bit) {
Elf32_Shdr *shdr = elf->shdr;
for (n = 0; n < elf->e_shnum; n++) {
void *addr = (void *)(vaddr_t)(shdr[n].sh_addr +
elf->load_addr);
if (shdr[n].sh_type == SHT_HASH) {
elf->hashtab = addr;
} else if (shdr[n].sh_type == SHT_GNU_HASH) {
elf->gnu_hashtab = addr;
elf->gnu_hashtab_size = shdr[n].sh_size;
}
}
} else {
Elf64_Shdr *shdr = elf->shdr;
for (n = 0; n < elf->e_shnum; n++) {
void *addr = (void *)(vaddr_t)(shdr[n].sh_addr +
elf->load_addr);
if (shdr[n].sh_type == SHT_HASH) {
elf->hashtab = addr;
} else if (shdr[n].sh_type == SHT_GNU_HASH) {
elf->gnu_hashtab = addr;
elf->gnu_hashtab_size = shdr[n].sh_size;
}
}
}
if (elf->hashtab) {
check_hashtab(elf, elf->hashtab, 0, 0);
hashtab = elf->hashtab;
check_hashtab(elf, elf->hashtab, hashtab[0], hashtab[1]);
}
if (elf->gnu_hashtab)
check_gnu_hashtab(elf, elf->gnu_hashtab);
}
static void save_soname_from_segment(struct ta_elf *elf, unsigned int type,
vaddr_t addr, size_t memsz)
{
size_t dyn_entsize = 0;
size_t num_dyns = 0;
size_t n = 0;
unsigned int tag = 0;
size_t val = 0;
char *str_tab = NULL;
if (type != PT_DYNAMIC)
return;
if (elf->is_32bit)
dyn_entsize = sizeof(Elf32_Dyn);
else
dyn_entsize = sizeof(Elf64_Dyn);
assert(!(memsz % dyn_entsize));
num_dyns = memsz / dyn_entsize;
for (n = 0; n < num_dyns; n++) {
read_dyn(elf, addr, n, &tag, &val);
if (tag == DT_STRTAB) {
str_tab = (char *)(val + elf->load_addr);
break;
}
}
for (n = 0; n < num_dyns; n++) {
read_dyn(elf, addr, n, &tag, &val);
if (tag == DT_SONAME) {
elf->soname = str_tab + val;
break;
}
}
}
static void save_soname(struct ta_elf *elf)
{
size_t n = 0;
if (elf->is_32bit) {
Elf32_Phdr *phdr = elf->phdr;
for (n = 0; n < elf->e_phnum; n++)
save_soname_from_segment(elf, phdr[n].p_type,
phdr[n].p_vaddr,
phdr[n].p_memsz);
} else {
Elf64_Phdr *phdr = elf->phdr;
for (n = 0; n < elf->e_phnum; n++)
save_soname_from_segment(elf, phdr[n].p_type,
phdr[n].p_vaddr,
phdr[n].p_memsz);
}
}
static void e32_save_symtab(struct ta_elf *elf, size_t tab_idx)
{
Elf32_Shdr *shdr = elf->shdr;
size_t str_idx = shdr[tab_idx].sh_link;
elf->dynsymtab = (void *)(shdr[tab_idx].sh_addr + elf->load_addr);
if (!IS_ALIGNED_WITH_TYPE(elf->dynsymtab, Elf32_Sym))
err(TEE_ERROR_BAD_FORMAT, "Bad alignment of dynsymtab %p",
elf->dynsymtab);
check_range(elf, "Dynsymtab", elf->dynsymtab, shdr[tab_idx].sh_size);
if (shdr[tab_idx].sh_size % sizeof(Elf32_Sym))
err(TEE_ERROR_BAD_FORMAT,
"Size of dynsymtab not an even multiple of Elf32_Sym");
elf->num_dynsyms = shdr[tab_idx].sh_size / sizeof(Elf32_Sym);
if (str_idx >= elf->e_shnum)
err(TEE_ERROR_BAD_FORMAT, "Dynstr section index out of range");
elf->dynstr = (void *)(shdr[str_idx].sh_addr + elf->load_addr);
check_range(elf, "Dynstr", elf->dynstr, shdr[str_idx].sh_size);
elf->dynstr_size = shdr[str_idx].sh_size;
}
static void e64_save_symtab(struct ta_elf *elf, size_t tab_idx)
{
Elf64_Shdr *shdr = elf->shdr;
size_t str_idx = shdr[tab_idx].sh_link;
elf->dynsymtab = (void *)(vaddr_t)(shdr[tab_idx].sh_addr +
elf->load_addr);
if (!IS_ALIGNED_WITH_TYPE(elf->dynsymtab, Elf64_Sym))
err(TEE_ERROR_BAD_FORMAT, "Bad alignment of .dynsym/DYNSYM %p",
elf->dynsymtab);
check_range(elf, ".dynsym/DYNSYM", elf->dynsymtab,
shdr[tab_idx].sh_size);
if (shdr[tab_idx].sh_size % sizeof(Elf64_Sym))
err(TEE_ERROR_BAD_FORMAT,
"Size of .dynsym/DYNSYM not an even multiple of Elf64_Sym");
elf->num_dynsyms = shdr[tab_idx].sh_size / sizeof(Elf64_Sym);
if (str_idx >= elf->e_shnum)
err(TEE_ERROR_BAD_FORMAT,
".dynstr/STRTAB section index out of range");
elf->dynstr = (void *)(vaddr_t)(shdr[str_idx].sh_addr + elf->load_addr);
check_range(elf, ".dynstr/STRTAB", elf->dynstr, shdr[str_idx].sh_size);
elf->dynstr_size = shdr[str_idx].sh_size;
}
static void save_symtab(struct ta_elf *elf)
{
size_t n = 0;
if (elf->is_32bit) {
Elf32_Shdr *shdr = elf->shdr;
for (n = 0; n < elf->e_shnum; n++) {
if (shdr[n].sh_type == SHT_DYNSYM) {
e32_save_symtab(elf, n);
break;
}
}
} else {
Elf64_Shdr *shdr = elf->shdr;
for (n = 0; n < elf->e_shnum; n++) {
if (shdr[n].sh_type == SHT_DYNSYM) {
e64_save_symtab(elf, n);
break;
}
}
}
save_hashtab(elf);
save_soname(elf);
}
static void init_elf(struct ta_elf *elf)
{
TEE_Result res = TEE_SUCCESS;
vaddr_t va = 0;
uint32_t flags = LDELF_MAP_FLAG_SHAREABLE;
size_t sz = 0;
res = sys_open_ta_bin(&elf->uuid, &elf->handle);
if (res)
err(res, "sys_open_ta_bin(%pUl)", (void *)&elf->uuid);
/*
* Map it read-only executable when we're loading a library where
* the ELF header is included in a load segment.
*/
if (!elf->is_main)
flags |= LDELF_MAP_FLAG_EXECUTABLE;
res = sys_map_ta_bin(&va, SMALL_PAGE_SIZE, flags, elf->handle, 0, 0, 0);
if (res)
err(res, "sys_map_ta_bin");
elf->ehdr_addr = va;
if (!elf->is_main) {
elf->load_addr = va;
elf->max_addr = va + SMALL_PAGE_SIZE;
elf->max_offs = SMALL_PAGE_SIZE;
}
if (!IS_ELF(*(Elf32_Ehdr *)va))
err(TEE_ERROR_BAD_FORMAT, "TA is not an ELF");
res = e32_parse_ehdr(elf, (void *)va);
if (res == TEE_ERROR_BAD_FORMAT)
res = e64_parse_ehdr(elf, (void *)va);
if (res)
err(res, "Cannot parse ELF");
if (MUL_OVERFLOW(elf->e_phnum, elf->e_phentsize, &sz) ||
ADD_OVERFLOW(sz, elf->e_phoff, &sz))
err(TEE_ERROR_BAD_FORMAT, "Program headers size overflow");
if (sz > SMALL_PAGE_SIZE)
err(TEE_ERROR_NOT_SUPPORTED, "Cannot read program headers");
elf->phdr = (void *)(va + elf->e_phoff);
}
static size_t roundup(size_t v)
{
return ROUNDUP(v, SMALL_PAGE_SIZE);
}
static size_t rounddown(size_t v)
{
return ROUNDDOWN(v, SMALL_PAGE_SIZE);
}
static void add_segment(struct ta_elf *elf, size_t offset, size_t vaddr,
size_t filesz, size_t memsz, size_t flags, size_t align)
{
struct segment *seg = calloc(1, sizeof(*seg));
if (!seg)
err(TEE_ERROR_OUT_OF_MEMORY, "calloc");
if (memsz < filesz)
err(TEE_ERROR_BAD_FORMAT, "Memsz smaller than filesz");
seg->offset = offset;
seg->vaddr = vaddr;
seg->filesz = filesz;
seg->memsz = memsz;
seg->flags = flags;
seg->align = align;
TAILQ_INSERT_TAIL(&elf->segs, seg, link);
}
static void parse_load_segments(struct ta_elf *elf)
{
size_t n = 0;
if (elf->is_32bit) {
Elf32_Phdr *phdr = elf->phdr;
for (n = 0; n < elf->e_phnum; n++)
if (phdr[n].p_type == PT_LOAD) {
add_segment(elf, phdr[n].p_offset,
phdr[n].p_vaddr, phdr[n].p_filesz,
phdr[n].p_memsz, phdr[n].p_flags,
phdr[n].p_align);
} else if (phdr[n].p_type == PT_ARM_EXIDX) {
elf->exidx_start = phdr[n].p_vaddr;
elf->exidx_size = phdr[n].p_filesz;
} else if (phdr[n].p_type == PT_TLS) {
assign_tls_mod_id(elf);
}
} else {
Elf64_Phdr *phdr = elf->phdr;
for (n = 0; n < elf->e_phnum; n++)
if (phdr[n].p_type == PT_LOAD) {
add_segment(elf, phdr[n].p_offset,
phdr[n].p_vaddr, phdr[n].p_filesz,
phdr[n].p_memsz, phdr[n].p_flags,
phdr[n].p_align);
} else if (phdr[n].p_type == PT_TLS) {
elf->tls_start = phdr[n].p_vaddr;
elf->tls_filesz = phdr[n].p_filesz;
elf->tls_memsz = phdr[n].p_memsz;
} else if (IS_ENABLED(CFG_TA_BTI) &&
phdr[n].p_type == PT_GNU_PROPERTY) {
elf->prop_start = phdr[n].p_vaddr;
elf->prop_align = phdr[n].p_align;
elf->prop_memsz = phdr[n].p_memsz;
}
}
}
static void copy_remapped_to(struct ta_elf *elf, const struct segment *seg)
{
uint8_t *dst = (void *)(seg->vaddr + elf->load_addr);
size_t n = 0;
size_t offs = seg->offset;
size_t num_bytes = seg->filesz;
if (offs < elf->max_offs) {
n = MIN(elf->max_offs - offs, num_bytes);
memcpy(dst, (void *)(elf->max_addr + offs - elf->max_offs), n);
dst += n;
offs += n;
num_bytes -= n;
}
if (num_bytes) {
TEE_Result res = sys_copy_from_ta_bin(dst, num_bytes,
elf->handle, offs);
if (res)
err(res, "sys_copy_from_ta_bin");
elf->max_offs += offs;
}
}
static void adjust_segments(struct ta_elf *elf)
{
struct segment *seg = NULL;
struct segment *prev_seg = NULL;
size_t prev_end_addr = 0;
size_t align = 0;
size_t mask = 0;
/* Sanity check */
TAILQ_FOREACH(seg, &elf->segs, link) {
size_t dummy __maybe_unused = 0;
assert(seg->align >= SMALL_PAGE_SIZE);
assert(!ADD_OVERFLOW(seg->vaddr, seg->memsz, &dummy));
assert(seg->filesz <= seg->memsz);
assert((seg->offset & SMALL_PAGE_MASK) ==
(seg->vaddr & SMALL_PAGE_MASK));
prev_seg = TAILQ_PREV(seg, segment_head, link);
if (prev_seg) {
assert(seg->vaddr >= prev_seg->vaddr + prev_seg->memsz);
assert(seg->offset >=
prev_seg->offset + prev_seg->filesz);
}
if (!align)
align = seg->align;
assert(align == seg->align);
}
mask = align - 1;
seg = TAILQ_FIRST(&elf->segs);
if (seg)
seg = TAILQ_NEXT(seg, link);
while (seg) {
prev_seg = TAILQ_PREV(seg, segment_head, link);
prev_end_addr = prev_seg->vaddr + prev_seg->memsz;
/*
* This segment may overlap with the last "page" in the
* previous segment in two different ways:
* 1. Virtual address (and offset) overlaps =>
* Permissions needs to be merged. The offset must have
* the SMALL_PAGE_MASK bits set as vaddr and offset must
* add up with prevsion segment.
*
* 2. Only offset overlaps =>
* The same page in the ELF is mapped at two different
* virtual addresses. As a limitation this segment must
* be mapped as writeable.
*/
/* Case 1. */
if (rounddown(seg->vaddr) < prev_end_addr) {
assert((seg->vaddr & mask) == (seg->offset & mask));
assert(prev_seg->memsz == prev_seg->filesz);
/*
* Merge the segments and their permissions.
* Note that the may be a small hole between the
* two sections.
*/
prev_seg->filesz = seg->vaddr + seg->filesz -
prev_seg->vaddr;
prev_seg->memsz = seg->vaddr + seg->memsz -
prev_seg->vaddr;
prev_seg->flags |= seg->flags;
TAILQ_REMOVE(&elf->segs, seg, link);
free(seg);
seg = TAILQ_NEXT(prev_seg, link);
continue;
}
/* Case 2. */
if ((seg->offset & mask) &&
rounddown(seg->offset) <
(prev_seg->offset + prev_seg->filesz)) {
assert(seg->flags & PF_W);
seg->remapped_writeable = true;
}
/*
* No overlap, but we may need to align address, offset and
* size.
*/
seg->filesz += seg->vaddr - rounddown(seg->vaddr);
seg->memsz += seg->vaddr - rounddown(seg->vaddr);
seg->vaddr = rounddown(seg->vaddr);
seg->offset = rounddown(seg->offset);
seg = TAILQ_NEXT(seg, link);
}
}
static void populate_segments_legacy(struct ta_elf *elf)
{
TEE_Result res = TEE_SUCCESS;
struct segment *seg = NULL;
vaddr_t va = 0;
assert(elf->is_legacy);
TAILQ_FOREACH(seg, &elf->segs, link) {
struct segment *last_seg = TAILQ_LAST(&elf->segs, segment_head);
size_t pad_end = roundup(last_seg->vaddr + last_seg->memsz -
seg->vaddr - seg->memsz);
size_t num_bytes = roundup(seg->memsz);
if (!elf->load_addr)
va = 0;
else
va = seg->vaddr + elf->load_addr;
if (!(seg->flags & PF_R))
err(TEE_ERROR_NOT_SUPPORTED,
"Segment must be readable");
res = sys_map_zi(num_bytes, 0, &va, 0, pad_end);
if (res)
err(res, "sys_map_zi");
res = sys_copy_from_ta_bin((void *)va, seg->filesz,
elf->handle, seg->offset);
if (res)
err(res, "sys_copy_from_ta_bin");
if (!elf->load_addr)
elf->load_addr = va;
elf->max_addr = va + num_bytes;
elf->max_offs = seg->offset + seg->filesz;
}
}
static size_t get_pad_begin(void)
{
#ifdef CFG_TA_ASLR
size_t min = CFG_TA_ASLR_MIN_OFFSET_PAGES;
size_t max = CFG_TA_ASLR_MAX_OFFSET_PAGES;
TEE_Result res = TEE_SUCCESS;
uint32_t rnd32 = 0;
size_t rnd = 0;
COMPILE_TIME_ASSERT(CFG_TA_ASLR_MIN_OFFSET_PAGES <
CFG_TA_ASLR_MAX_OFFSET_PAGES);
if (max > min) {
res = sys_gen_random_num(&rnd32, sizeof(rnd32));
if (res) {
DMSG("Random read failed: %#"PRIx32, res);
return min * SMALL_PAGE_SIZE;
}
rnd = rnd32 % (max - min);
}
return (min + rnd) * SMALL_PAGE_SIZE;
#else /*!CFG_TA_ASLR*/
return 0;
#endif /*!CFG_TA_ASLR*/
}
static void populate_segments(struct ta_elf *elf)
{
TEE_Result res = TEE_SUCCESS;
struct segment *seg = NULL;
vaddr_t va = 0;
size_t pad_begin = 0;
assert(!elf->is_legacy);
TAILQ_FOREACH(seg, &elf->segs, link) {
struct segment *last_seg = TAILQ_LAST(&elf->segs, segment_head);
size_t pad_end = roundup(last_seg->vaddr + last_seg->memsz -
seg->vaddr - seg->memsz);
if (seg->remapped_writeable) {
size_t num_bytes = roundup(seg->vaddr + seg->memsz) -
rounddown(seg->vaddr);
assert(elf->load_addr);
va = rounddown(elf->load_addr + seg->vaddr);
assert(va >= elf->max_addr);
res = sys_map_zi(num_bytes, 0, &va, 0, pad_end);
if (res)
err(res, "sys_map_zi");
copy_remapped_to(elf, seg);
elf->max_addr = va + num_bytes;
} else {
uint32_t flags = 0;
size_t filesz = seg->filesz;
size_t memsz = seg->memsz;
size_t offset = seg->offset;
size_t vaddr = seg->vaddr;
if (offset < elf->max_offs) {
/*
* We're in a load segment which overlaps
* with (or is covered by) the first page
* of a shared library.
*/
if (vaddr + filesz < SMALL_PAGE_SIZE) {
size_t num_bytes = 0;
/*
* If this segment is completely
* covered, take next.
*/
if (vaddr + memsz <= SMALL_PAGE_SIZE)
continue;
/*
* All data of the segment is
* loaded, but we need to zero
* extend it.
*/
va = elf->max_addr;
num_bytes = roundup(vaddr + memsz) -
roundup(vaddr) -
SMALL_PAGE_SIZE;
assert(num_bytes);
res = sys_map_zi(num_bytes, 0, &va, 0,
0);
if (res)
err(res, "sys_map_zi");
elf->max_addr = roundup(va + num_bytes);
continue;
}
/* Partial overlap, remove the first page. */
vaddr += SMALL_PAGE_SIZE;
filesz -= SMALL_PAGE_SIZE;
memsz -= SMALL_PAGE_SIZE;
offset += SMALL_PAGE_SIZE;
}
if (!elf->load_addr) {
va = 0;
pad_begin = get_pad_begin();
/*
* If mapping with pad_begin fails we'll
* retry without pad_begin, effectively
* disabling ASLR for the current ELF file.
*/
} else {
va = vaddr + elf->load_addr;
pad_begin = 0;
}
if (seg->flags & PF_W)
flags |= LDELF_MAP_FLAG_WRITEABLE;
else
flags |= LDELF_MAP_FLAG_SHAREABLE;
if (seg->flags & PF_X)
flags |= LDELF_MAP_FLAG_EXECUTABLE;
if (!(seg->flags & PF_R))
err(TEE_ERROR_NOT_SUPPORTED,
"Segment must be readable");
if (flags & LDELF_MAP_FLAG_WRITEABLE) {
res = sys_map_zi(memsz, 0, &va, pad_begin,
pad_end);
if (pad_begin && res == TEE_ERROR_OUT_OF_MEMORY)
res = sys_map_zi(memsz, 0, &va, 0,
pad_end);
if (res)
err(res, "sys_map_zi");
res = sys_copy_from_ta_bin((void *)va, filesz,
elf->handle, offset);
if (res)
err(res, "sys_copy_from_ta_bin");
} else {
if (filesz != memsz)
err(TEE_ERROR_BAD_FORMAT,
"Filesz and memsz mismatch");
res = sys_map_ta_bin(&va, filesz, flags,
elf->handle, offset,
pad_begin, pad_end);
if (pad_begin && res == TEE_ERROR_OUT_OF_MEMORY)
res = sys_map_ta_bin(&va, filesz, flags,
elf->handle,
offset, 0,
pad_end);
if (res)
err(res, "sys_map_ta_bin");
}
if (!elf->load_addr)
elf->load_addr = va;
elf->max_addr = roundup(va + memsz);
elf->max_offs += filesz;
}
}
}
static void ta_elf_add_bti(struct ta_elf *elf)
{
TEE_Result res = TEE_SUCCESS;
struct segment *seg = NULL;
uint32_t flags = LDELF_MAP_FLAG_EXECUTABLE | LDELF_MAP_FLAG_BTI;
TAILQ_FOREACH(seg, &elf->segs, link) {
vaddr_t va = elf->load_addr + seg->vaddr;
if (seg->flags & PF_X) {
res = sys_set_prot(va, seg->memsz, flags);
if (res)
err(res, "sys_set_prot");
}
}
}
static void parse_property_segment(struct ta_elf *elf)
{
char *desc = NULL;
size_t align = elf->prop_align;
size_t desc_offset = 0;
size_t prop_offset = 0;
vaddr_t va = 0;
Elf_Note *note = NULL;
char *name = NULL;
if (!IS_ENABLED(CFG_TA_BTI) || !elf->prop_start)
return;
check_phdr_in_range(elf, PT_GNU_PROPERTY, elf->prop_start,
elf->prop_memsz);
va = elf->load_addr + elf->prop_start;
note = (void *)va;
name = (char *)(note + 1);
if (elf->prop_memsz < sizeof(*note) + sizeof(ELF_NOTE_GNU))
return;
if (note->n_type != NT_GNU_PROPERTY_TYPE_0 ||
note->n_namesz != sizeof(ELF_NOTE_GNU) ||
memcmp(name, ELF_NOTE_GNU, sizeof(ELF_NOTE_GNU)) ||
!IS_POWER_OF_TWO(align))
return;
desc_offset = ROUNDUP(sizeof(*note) + sizeof(ELF_NOTE_GNU), align);
if (desc_offset > elf->prop_memsz ||
ROUNDUP(desc_offset + note->n_descsz, align) > elf->prop_memsz)
return;
desc = (char *)(va + desc_offset);
do {
Elf_Prop *prop = (void *)(desc + prop_offset);
size_t data_offset = prop_offset + sizeof(*prop);
if (note->n_descsz < data_offset)
return;
data_offset = confine_array_index(data_offset, note->n_descsz);
if (prop->pr_type == GNU_PROPERTY_AARCH64_FEATURE_1_AND) {
uint32_t *pr_data = (void *)(desc + data_offset);
if (note->n_descsz < (data_offset + sizeof(*pr_data)) &&
prop->pr_datasz != sizeof(*pr_data))
return;
if (*pr_data & GNU_PROPERTY_AARCH64_FEATURE_1_BTI) {
DMSG("BTI Feature present in note property");
elf->bti_enabled = true;
}
}
prop_offset += ROUNDUP(sizeof(*prop) + prop->pr_datasz, align);
} while (prop_offset < note->n_descsz);
}
static void map_segments(struct ta_elf *elf)
{
TEE_Result res = TEE_SUCCESS;
parse_load_segments(elf);
adjust_segments(elf);
if (TAILQ_FIRST(&elf->segs)->offset < SMALL_PAGE_SIZE) {
vaddr_t va = 0;
size_t sz = elf->max_addr - elf->load_addr;