Re-enable DTB table rebuilding

This commit is contained in:
topjohnwu 2021-01-14 05:45:05 -08:00
parent aec06a6f61
commit c91c070343

View File

@ -124,38 +124,52 @@ static void dtb_print(const char *file, bool fstab) {
munmap(dtb, size);
}
static bool dtb_patch_rebuild(uint8_t *dtb, size_t dtb_sz, const char *file);
static bool dtb_patch(const char *file) {
bool keepverity = check_env("KEEPVERITY");
bool patched = false;
bool keep_verity = check_env("KEEPVERITY");
bool have_system = false;
vector<pair<char *, int>> flags_list;
size_t size;
uint8_t *dtb;
fprintf(stderr, "Loading dtbs from [%s]\n", file);
mmap_rw(file, dtb, size);
// Loop through all the dtbs
run_finally f([=]{ munmap(dtb, size); });
// First traverse through DTB to determine whether we need a rebuild
int dtb_num = 0;
for (int i = 0; i < size; ++i) {
if (memcmp(dtb + i, FDT_MAGIC_STR, 4) == 0) {
auto fdt = dtb + i;
fprintf(stderr, "Loading dtb.%04d\n", dtb_num);
if (int fstab = find_fstab(fdt); fstab >= 0) {
int node;
fdt_for_each_subnode(node, fdt, fstab) {
const char *name = fdt_get_name(fdt, node, nullptr);
fprintf(stderr, "Found fstab entry [%s]\n", name);
if (!keepverity) {
if (!keep_verity) {
int len;
auto value = fdt_getprop(fdt, node, "fsmgr_flags", &len);
patched |= patch_verity(const_cast<void *>(value), len) != len;
char *value = (char *) fdt_getprop(fdt, node, "fsmgr_flags", &len);
flags_list.emplace_back(value, len);
}
if (name == "system"sv)
have_system = true;
}
}
++dtb_num;
i += fdt_totalsize(fdt) - 1;
++dtb_num;
}
}
fprintf(stderr, "\n");
munmap(dtb, size);
return patched;
if (!have_system) {
// Patch in place with rw mmap
bool patched = false;
for (auto &[value, len] : flags_list)
patched |= patch_verity(value, len) != len;
return patched;
} else {
// Need to rebuild dtb due to additional props
return dtb_patch_rebuild(dtb, size, file);
}
}
int dtb_commands(int argc, char *argv[]) {
@ -176,279 +190,246 @@ int dtb_commands(int argc, char *argv[]) {
}
namespace {
// Unused, but keep these precious code as they took TONs of effort to write
struct fdt_blob {
void *fdt;
uint32_t offset;
uint32_t len;
};
struct fdt_blob {
void *fdt;
uint32_t offset;
uint32_t len;
};
template <class Iter>
class fdt_map_iter {
public:
typedef decltype(std::declval<typename Iter::value_type::second_type>().fdt) value_type;
typedef value_type* pointer;
typedef value_type& reference;
}
explicit fdt_map_iter(Iter j) : i(j) {}
fdt_map_iter& operator++() { ++i; return *this; }
fdt_map_iter operator++(int) { auto tmp = *this; ++(*this); return tmp; }
fdt_map_iter& operator--() { --i; return *this; }
fdt_map_iter operator--(int) { auto tmp = *this; --(*this); return tmp; }
bool operator==(fdt_map_iter j) const { return i == j.i; }
bool operator!=(fdt_map_iter j) const { return !(*this == j); }
reference operator*() { return i->second.fdt; }
pointer operator->() { return &i->second.fdt; }
private:
Iter i;
};
template<class Iter>
inline fdt_map_iter<Iter> make_iter(Iter j) { return fdt_map_iter<Iter>(j); }
template <typename Iter>
static bool fdt_patch(Iter first, Iter last) {
bool keepverity = check_env("KEEPVERITY");
bool redirect = check_env("TWOSTAGEINIT");
bool modified = false;
int idx = 0;
for (auto it = first; it != last; ++it) {
++idx;
auto fdt = *it;
int fstab = find_fstab(fdt);
if (fstab < 0)
continue;
fprintf(stderr, "Found fstab in dtb.%04d\n", idx - 1);
int block;
fdt_for_each_subnode(block, fdt, fstab) {
const char *name = fdt_get_name(fdt, block, nullptr);
fprintf(stderr, "Found entry [%s] in fstab\n", name);
if (!keepverity) {
int size;
auto value = fdt_getprop(fdt, block, "fsmgr_flags", &size);
char *copy = static_cast<char *>(memcpy(malloc(size), value, size));
if (patch_verity(copy, size) != size) {
modified = true;
fdt_setprop_string(fdt, block, "fsmgr_flags", copy);
}
free(copy);
}
if (redirect && name == "system"sv) {
modified = true;
fprintf(stderr, "Changing mnt_point to /system_root\n");
fdt_setprop_string(fdt, block, "mnt_point", "/system_root");
}
}
static bool fdt_patch(void *fdt) {
int fstab = find_fstab(fdt);
if (fstab < 0)
return false;
bool modified = false;
int node;
fdt_for_each_subnode(node, fdt, fstab) {
const char *name = fdt_get_name(fdt, node, nullptr);
// Always patch verity if 2SI
int len;
auto value = (const char *) fdt_getprop(fdt, node, "fsmgr_flags", &len);
string copy(value, len);
uint32_t new_len = patch_verity(copy.data(), len);
if (new_len != len) {
modified = true;
fdt_setprop(fdt, node, "fsmgr_flags", copy.data(), new_len);
}
if (name == "system"sv) {
fprintf(stderr, "Setting [mnt_point] to [/system_root]\n");
fdt_setprop_string(fdt, node, "mnt_point", "/system_root");
modified = true;
}
return modified;
}
return modified;
}
#define MAX_FDT_GROWTH 256
template <class Table, class Header>
static int dt_table_patch(const Header *hdr, const char *out) {
map<uint32_t, fdt_blob> dtb_map;
auto buf = reinterpret_cast<const uint8_t *>(hdr);
auto tables = reinterpret_cast<const Table *>(hdr + 1);
template <class Table, class Header>
static bool dt_table_patch(const Header *hdr, const char *out) {
map<uint32_t, fdt_blob> dtb_map;
auto buf = reinterpret_cast<const uint8_t *>(hdr);
auto tables = reinterpret_cast<const Table *>(buf + sizeof(Header));
constexpr bool is_dt_table = std::is_same_v<Header, dt_table_header>;
constexpr bool is_aosp = std::is_same_v<Header, dt_table_header>;
using endian_conv = uint32_t (*)(uint32_t);
endian_conv be_to_le;
endian_conv le_to_be;
if constexpr (is_dt_table) {
be_to_le = fdt32_to_cpu;
le_to_be = cpu_to_fdt32;
} else {
be_to_le = le_to_be = [](uint32_t x) -> auto { return x; };
// AOSP DTB store ints in big endian
using endian_conv = uint32_t (*)(uint32_t);
endian_conv be_to_le;
endian_conv le_to_be;
if constexpr (is_aosp) {
be_to_le = fdt32_to_cpu;
le_to_be = cpu_to_fdt32;
} else {
be_to_le = le_to_be = [](uint32_t x) { return x; };
}
// Collect all dtbs
auto num_dtb = be_to_le(hdr->num_dtbs);
for (int i = 0; i < num_dtb; ++i) {
auto offset = be_to_le(tables[i].offset);
if (dtb_map.count(offset) == 0) {
auto blob = buf + offset;
uint32_t size = fdt_totalsize(blob);
auto fdt = xmalloc(size + MAX_FDT_GROWTH);
memcpy(fdt, blob, size);
fdt_open_into(fdt, fdt, size + MAX_FDT_GROWTH);
dtb_map[offset] = { fdt, offset };
}
}
if (dtb_map.empty())
return false;
// Collect all dtbs
auto num_dtb = be_to_le(hdr->num_dtbs);
for (int i = 0; i < num_dtb; ++i) {
auto offset = be_to_le(tables[i].offset);
if (dtb_map.count(offset) == 0) {
auto blob = buf + offset;
uint32_t size = fdt_totalsize(blob);
auto fdt = xmalloc(size + MAX_FDT_GROWTH);
memcpy(fdt, blob, size);
fdt_open_into(fdt, fdt, size + MAX_FDT_GROWTH);
dtb_map[offset] = { fdt, offset };
}
}
if (dtb_map.empty())
return 1;
// Patch fdt
bool modified = false;
for (auto &[_, blob] : dtb_map)
modified |= fdt_patch(blob.fdt);
if (!modified)
return false;
// Patch fdt
if (!fdt_patch(make_iter(dtb_map.begin()), make_iter(dtb_map.end())))
return 1;
unlink(out);
int fd = xopen(out, O_RDWR | O_CREAT | O_CLOEXEC, 0644);
unlink(out);
int fd = xopen(out, O_RDWR | O_CREAT | O_CLOEXEC, 0644);
// This value is only used if AOSP DTB
uint32_t total_size = 0;
uint32_t total_size = 0;
// Copy headers and tables
total_size += xwrite(fd, buf, dtb_map.begin()->first);
// Copy headers and tables
total_size += xwrite(fd, buf, dtb_map.begin()->first);
// mmap rw to patch table values retroactively
auto mmap_sz = lseek(fd, 0, SEEK_CUR);
auto addr = (uint8_t *) xmmap(nullptr, mmap_sz, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
// mmap rw to patch table values retroactively
auto mmap_sz = lseek(fd, 0, SEEK_CUR);
auto addr = (uint8_t *) xmmap(nullptr, mmap_sz, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
// Guess alignment using gcd
uint32_t align = 1;
if constexpr (!is_aosp) {
auto it = dtb_map.begin();
align = (it++)->first;
for (; it != dtb_map.end(); ++it)
align = binary_gcd(align, it->first);
}
// Guess alignment using gcd
uint32_t align = 1;
if constexpr (!is_dt_table) {
auto it = dtb_map.begin();
align = (it++)->first;
for (; it != dtb_map.end(); ++it)
align = binary_gcd(align, it->first);
}
// Write dtbs
for (auto &val : dtb_map) {
val.second.offset = lseek(fd, 0, SEEK_CUR);
auto fdt = val.second.fdt;
fdt_pack(fdt);
auto size = fdt_totalsize(fdt);
total_size += xwrite(fd, fdt, size);
// Write dtbs
for (auto &val : dtb_map) {
val.second.offset = lseek(fd, 0, SEEK_CUR);
auto fdt = val.second.fdt;
fdt_pack(fdt);
auto size = fdt_totalsize(fdt);
total_size += xwrite(fd, fdt, size);
if constexpr (!is_aosp) {
val.second.len = do_align(size, align);
write_zero(fd, align_off(lseek(fd, 0, SEEK_CUR), align));
// total_size += align_off(lseek(fd, 0, SEEK_CUR), align); /* Not needed */
free(fdt);
}
// Patch headers
if constexpr (is_dt_table) {
auto hdr_rw = reinterpret_cast<Header *>(addr);
hdr_rw->total_size = le_to_be(total_size);
}
auto tables_rw = reinterpret_cast<Table *>(addr + sizeof(Header));
for (int i = 0; i < num_dtb; ++i) {
auto &blob = dtb_map[be_to_le(tables_rw[i].offset)];
tables_rw[i].offset = le_to_be(blob.offset);
tables_rw[i].len = le_to_be(blob.len);
}
munmap(addr, mmap_sz);
close(fd);
return 0;
free(fdt);
}
static int blob_patch(uint8_t *dtb, size_t dtb_sz, const char *out) {
vector<uint8_t *> fdt_list;
vector<uint32_t> padding_list;
for (int i = 0; i < dtb_sz; ++i) {
if (memcmp(dtb + i, FDT_MAGIC_STR, 4) == 0) {
auto len = fdt_totalsize(dtb + i);
auto fdt = static_cast<uint8_t *>(xmalloc(len + MAX_FDT_GROWTH));
memcpy(fdt, dtb + i, len);
fdt_pack(fdt);
uint32_t padding = len - fdt_totalsize(fdt);
padding_list.push_back(padding);
fdt_open_into(fdt, fdt, len + MAX_FDT_GROWTH);
fdt_list.push_back(fdt);
i += len - 1;
}
}
// Patch headers
if constexpr (is_aosp) {
auto hdr_rw = reinterpret_cast<Header *>(addr);
hdr_rw->total_size = le_to_be(total_size);
}
auto tables_rw = reinterpret_cast<Table *>(addr + sizeof(Header));
for (int i = 0; i < num_dtb; ++i) {
auto &blob = dtb_map[be_to_le(tables_rw[i].offset)];
tables_rw[i].offset = le_to_be(blob.offset);
tables_rw[i].len = le_to_be(blob.len);
}
if (!fdt_patch(fdt_list.begin(), fdt_list.end()))
return 1;
munmap(addr, mmap_sz);
close(fd);
unlink(out);
int fd = xopen(out, O_WRONLY | O_CREAT | O_CLOEXEC, 0644);
return true;
}
for (int i = 0; i < fdt_list.size(); ++i) {
auto fdt = fdt_list[i];
static bool blob_patch(uint8_t *dtb, size_t dtb_sz, const char *out) {
vector<uint8_t *> fdt_list;
vector<uint32_t> padding_list;
for (int i = 0; i < dtb_sz; ++i) {
if (memcmp(dtb + i, FDT_MAGIC_STR, 4) == 0) {
auto len = fdt_totalsize(dtb + i);
auto fdt = static_cast<uint8_t *>(xmalloc(len + MAX_FDT_GROWTH));
memcpy(fdt, dtb + i, len);
fdt_pack(fdt);
// Only add padding back if it is anything meaningful
if (padding_list[i] > 4) {
auto len = fdt_totalsize(fdt);
fdt_set_totalsize(fdt, len + padding_list[i]);
}
xwrite(fd, fdt, fdt_totalsize(fdt));
free(fdt);
uint32_t padding = len - fdt_totalsize(fdt);
padding_list.push_back(padding);
fdt_open_into(fdt, fdt, len + MAX_FDT_GROWTH);
fdt_list.push_back(fdt);
i += len - 1;
}
close(fd);
return 0;
}
bool modified = false;
for (auto fdt : fdt_list)
modified |= fdt_patch(fdt);
if (!modified)
return false;
unlink(out);
int fd = xopen(out, O_WRONLY | O_CREAT | O_CLOEXEC, 0644);
for (int i = 0; i < fdt_list.size(); ++i) {
auto fdt = fdt_list[i];
fdt_pack(fdt);
// Only add padding back if it is anything meaningful
if (padding_list[i] > 4) {
auto len = fdt_totalsize(fdt);
fdt_set_totalsize(fdt, len + padding_list[i]);
}
xwrite(fd, fdt, fdt_totalsize(fdt));
free(fdt);
}
close(fd);
return true;
}
#define MATCH(s) (memcmp(dtb, s, sizeof(s) - 1) == 0)
[[maybe_unused]] static int dtb_patch(const char *in, const char *out) {
if (!out)
out = in;
size_t dtb_sz ;
uint8_t *dtb;
fprintf(stderr, "Loading dtbs from [%s]\n", in);
mmap_ro(in, dtb, dtb_sz);
run_finally f([&]{ munmap(dtb, dtb_sz); });
if (MATCH(QCDT_MAGIC)) {
auto hdr = reinterpret_cast<qcdt_hdr*>(dtb);
switch (hdr->version) {
case 1:
fprintf(stderr, "QCDT v1\n");
return dt_table_patch<qctable_v1>(hdr, out);
case 2:
fprintf(stderr, "QCDT v2\n");
return dt_table_patch<qctable_v2>(hdr, out);
case 3:
fprintf(stderr, "QCDT v3\n");
return dt_table_patch<qctable_v3>(hdr, out);
default:
return 1;
}
} else if (MATCH(DTBH_MAGIC)) {
auto hdr = reinterpret_cast<dtbh_hdr *>(dtb);
switch (hdr->version) {
case 2:
fprintf(stderr, "DTBH v2\n");
return dt_table_patch<bhtable_v2>(hdr, out);
default:
return 1;
}
} else if (MATCH(PXADT_MAGIC)) {
auto hdr = reinterpret_cast<pxadt_hdr *>(dtb);
switch (hdr->version) {
case 1:
fprintf(stderr, "PXA-DT v1\n");
return dt_table_patch<pxatable_v1>(hdr, out);
default:
return 1;
}
} else if (MATCH(PXA19xx_MAGIC)) {
auto hdr = reinterpret_cast<pxa19xx_hdr *>(dtb);
switch (hdr->version) {
case 1:
fprintf(stderr, "PXA-19xx v1\n");
return dt_table_patch<pxatable_v1>(hdr, out);
default:
return 1;
}
} else if (MATCH(SPRD_MAGIC)) {
auto hdr = reinterpret_cast<sprd_hdr *>(dtb);
switch (hdr->version) {
case 1:
fprintf(stderr, "SPRD v1\n");
return dt_table_patch<sprdtable_v1>(hdr, out);
default:
return 1;
}
} else if (MATCH(DT_TABLE_MAGIC)) {
auto hdr = reinterpret_cast<dt_table_header *>(dtb);
switch (hdr->version) {
case 0:
fprintf(stderr, "DT_TABLE v0\n");
return dt_table_patch<dt_table_entry>(hdr, out);
default:
return 1;
}
} else {
return blob_patch(dtb, dtb_sz, out);
static bool dtb_patch_rebuild(uint8_t *dtb, size_t dtb_sz, const char *file) {
if (MATCH(QCDT_MAGIC)) {
auto hdr = reinterpret_cast<qcdt_hdr*>(dtb);
switch (hdr->version) {
case 1:
fprintf(stderr, "QCDT v1\n");
return dt_table_patch<qctable_v1>(hdr, file);
case 2:
fprintf(stderr, "QCDT v2\n");
return dt_table_patch<qctable_v2>(hdr, file);
case 3:
fprintf(stderr, "QCDT v3\n");
return dt_table_patch<qctable_v3>(hdr, file);
default:
return false;
}
} else if (MATCH(DTBH_MAGIC)) {
auto hdr = reinterpret_cast<dtbh_hdr *>(dtb);
switch (hdr->version) {
case 2:
fprintf(stderr, "DTBH v2\n");
return dt_table_patch<bhtable_v2>(hdr, file);
default:
return false;
}
} else if (MATCH(PXADT_MAGIC)) {
auto hdr = reinterpret_cast<pxadt_hdr *>(dtb);
switch (hdr->version) {
case 1:
fprintf(stderr, "PXA-DT v1\n");
return dt_table_patch<pxatable_v1>(hdr, file);
default:
return false;
}
} else if (MATCH(PXA19xx_MAGIC)) {
auto hdr = reinterpret_cast<pxa19xx_hdr *>(dtb);
switch (hdr->version) {
case 1:
fprintf(stderr, "PXA-19xx v1\n");
return dt_table_patch<pxatable_v1>(hdr, file);
default:
return false;
}
} else if (MATCH(SPRD_MAGIC)) {
auto hdr = reinterpret_cast<sprd_hdr *>(dtb);
switch (hdr->version) {
case 1:
fprintf(stderr, "SPRD v1\n");
return dt_table_patch<sprdtable_v1>(hdr, file);
default:
return false;
}
} else if (MATCH(DT_TABLE_MAGIC)) {
auto hdr = reinterpret_cast<dt_table_header *>(dtb);
switch (hdr->version) {
case 0:
fprintf(stderr, "DT_TABLE v0\n");
return dt_table_patch<dt_table_entry>(hdr, file);
default:
return false;
}
} else {
return blob_patch(dtb, dtb_sz, file);
}
}