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LibDeviceTree: Refactor dump() to return ErrorOr, and use ReadonlyBytes

ReadonlyBytes is much nicer to use than a u8 const* + size_t.
This commit is contained in:
Andrew Kaster 2023-02-17 10:25:55 -07:00 committed by Linus Groh
parent 01f32a22b4
commit 895f54f487
3 changed files with 28 additions and 26 deletions

View file

@ -1,5 +1,5 @@
/* /*
* Copyright (c) 2021, Andrew Kaster <akaster@serenityos.org> * Copyright (c) 2021-2023, Andrew Kaster <akaster@serenityos.org>
* *
* SPDX-License-Identifier: BSD-2-Clause * SPDX-License-Identifier: BSD-2-Clause
*/ */
@ -7,11 +7,12 @@
#include <AK/DeprecatedString.h> #include <AK/DeprecatedString.h>
#include <AK/Endian.h> #include <AK/Endian.h>
#include <AK/Format.h> #include <AK/Format.h>
#include <AK/Try.h>
#include <LibDeviceTree/Validation.h> #include <LibDeviceTree/Validation.h>
namespace DeviceTree { namespace DeviceTree {
bool validate_flattened_device_tree(FlattenedDeviceTreeHeader const& header, u8 const* blob_start, size_t blob_size, Verbose verbose) bool validate_flattened_device_tree(FlattenedDeviceTreeHeader const& header, ReadonlyBytes raw_device_tree, Verbose verbose)
{ {
if (header.magic != 0xD00DFEEDU) { if (header.magic != 0xD00DFEEDU) {
if (verbose == Verbose::Yes) if (verbose == Verbose::Yes)
@ -31,27 +32,27 @@ bool validate_flattened_device_tree(FlattenedDeviceTreeHeader const& header, u8
return false; return false;
} }
if (header.totalsize != blob_size) { if (header.totalsize != raw_device_tree.size()) {
if (verbose == Verbose::Yes) if (verbose == Verbose::Yes)
warnln("FDT Header total size mismatch: {}, expected {}!", header.totalsize, blob_size); warnln("FDT Header total size mismatch: {}, expected {}!", header.totalsize, raw_device_tree.size());
return false; return false;
} }
if (header.off_dt_struct > blob_size) { if (header.off_dt_struct > raw_device_tree.size()) {
if (verbose == Verbose::Yes) if (verbose == Verbose::Yes)
warnln("FDT Header reports larger StructureBlock offset than possible: {} but total size is {}!", header.off_dt_struct, blob_size); warnln("FDT Header reports larger StructureBlock offset than possible: {} but total size is {}!", header.off_dt_struct, raw_device_tree.size());
return false; return false;
} }
if (header.off_dt_strings > blob_size) { if (header.off_dt_strings > raw_device_tree.size()) {
if (verbose == Verbose::Yes) if (verbose == Verbose::Yes)
warnln("FDT Header reports larger StringsBlock offset than possible: {} but total size is {}!", header.off_dt_strings, blob_size); warnln("FDT Header reports larger StringsBlock offset than possible: {} but total size is {}!", header.off_dt_strings, raw_device_tree.size());
return false; return false;
} }
if (header.off_mem_rsvmap > blob_size) { if (header.off_mem_rsvmap > raw_device_tree.size()) {
if (verbose == Verbose::Yes) if (verbose == Verbose::Yes)
warnln("FDT Header reports larger MemoryReservationBlock offset than possible: {} but total size is {}!", header.off_mem_rsvmap, blob_size); warnln("FDT Header reports larger MemoryReservationBlock offset than possible: {} but total size is {}!", header.off_mem_rsvmap, raw_device_tree.size());
return false; return false;
} }
@ -80,7 +81,7 @@ bool validate_flattened_device_tree(FlattenedDeviceTreeHeader const& header, u8
return false; return false;
} }
auto* mem_reserve_block = reinterpret_cast<FlattenedDeviceTreeReserveEntry const*>(&blob_start[header.off_mem_rsvmap]); auto* mem_reserve_block = reinterpret_cast<FlattenedDeviceTreeReserveEntry const*>(&raw_device_tree[header.off_mem_rsvmap]);
u64 next_block_offset = header.off_mem_rsvmap + sizeof(FlattenedDeviceTreeReserveEntry); u64 next_block_offset = header.off_mem_rsvmap + sizeof(FlattenedDeviceTreeReserveEntry);
while ((next_block_offset < header.off_dt_struct) && (*mem_reserve_block != FlattenedDeviceTreeReserveEntry {})) { while ((next_block_offset < header.off_dt_struct) && (*mem_reserve_block != FlattenedDeviceTreeReserveEntry {})) {
++mem_reserve_block; ++mem_reserve_block;
@ -95,23 +96,23 @@ bool validate_flattened_device_tree(FlattenedDeviceTreeHeader const& header, u8
// check for overlap. Overflow not possible b/c the fields are u32 // check for overlap. Overflow not possible b/c the fields are u32
u64 structure_block_size = header.off_dt_struct + header.size_dt_struct; u64 structure_block_size = header.off_dt_struct + header.size_dt_struct;
if ((structure_block_size > header.off_dt_strings) || (structure_block_size > blob_size)) { if ((structure_block_size > header.off_dt_strings) || (structure_block_size > raw_device_tree.size())) {
if (verbose == Verbose::Yes) if (verbose == Verbose::Yes)
warnln("FDT Header reports invalid StructureBlock block size: {} is too large given StringsBlock offset {} and total size {}", structure_block_size, header.off_dt_strings, blob_size); warnln("FDT Header reports invalid StructureBlock block size: {} is too large given StringsBlock offset {} and total size {}", structure_block_size, header.off_dt_strings, raw_device_tree.size());
return false; return false;
} }
u64 strings_block_size = header.off_dt_strings + header.size_dt_strings; u64 strings_block_size = header.off_dt_strings + header.size_dt_strings;
if (strings_block_size > blob_size) { if (strings_block_size > raw_device_tree.size()) {
if (verbose == Verbose::Yes) if (verbose == Verbose::Yes)
warnln("FDT Header reports invalid StringsBlock size: {} is too large given total size {}", strings_block_size, blob_size); warnln("FDT Header reports invalid StringsBlock size: {} is too large given total size {}", strings_block_size, raw_device_tree.size());
return false; return false;
} }
return true; return true;
} }
bool dump(FlattenedDeviceTreeHeader const& header, u8 const* blob_start, size_t blob_size) ErrorOr<void> dump(FlattenedDeviceTreeHeader const& header, ReadonlyBytes raw_device_tree)
{ {
outln("/dts-v1/;"); outln("/dts-v1/;");
outln("// magic: 0x{:08x}", header.magic); outln("// magic: 0x{:08x}", header.magic);
@ -125,11 +126,11 @@ bool dump(FlattenedDeviceTreeHeader const& header, u8 const* blob_start, size_t
outln("// size_dt_strings: 0x{:08x}", header.size_dt_strings); outln("// size_dt_strings: 0x{:08x}", header.size_dt_strings);
outln("// size_dt_struct: 0x{:08x}", header.size_dt_struct); outln("// size_dt_struct: 0x{:08x}", header.size_dt_struct);
if (!validate_flattened_device_tree(header, blob_start, blob_size, Verbose::Yes)) if (!validate_flattened_device_tree(header, raw_device_tree, Verbose::Yes))
return false; return Error::from_errno(EINVAL);
// Now that we know the device tree is valid, print out the rest of the information // Now that we know the device tree is valid, print out the rest of the information
auto* mem_reserve_block = reinterpret_cast<FlattenedDeviceTreeReserveEntry const*>(&blob_start[header.off_mem_rsvmap]); auto const* mem_reserve_block = reinterpret_cast<FlattenedDeviceTreeReserveEntry const*>(&raw_device_tree[header.off_mem_rsvmap]);
u64 next_block_offset = header.off_mem_rsvmap + sizeof(FlattenedDeviceTreeReserveEntry); u64 next_block_offset = header.off_mem_rsvmap + sizeof(FlattenedDeviceTreeReserveEntry);
while ((next_block_offset < header.off_dt_struct) && (*mem_reserve_block != FlattenedDeviceTreeReserveEntry {})) { while ((next_block_offset < header.off_dt_struct) && (*mem_reserve_block != FlattenedDeviceTreeReserveEntry {})) {
outln("/memreserve/ 0x{:08x} 0x{:08x};", mem_reserve_block->address, mem_reserve_block->size); outln("/memreserve/ 0x{:08x} 0x{:08x};", mem_reserve_block->address, mem_reserve_block->size);
@ -137,7 +138,7 @@ bool dump(FlattenedDeviceTreeHeader const& header, u8 const* blob_start, size_t
next_block_offset += sizeof(FlattenedDeviceTreeReserveEntry); next_block_offset += sizeof(FlattenedDeviceTreeReserveEntry);
} }
return true; return {};
} }
} // namespace DeviceTree } // namespace DeviceTree

View file

@ -1,5 +1,5 @@
/* /*
* Copyright (c) 2021, Andrew Kaster <akaster@serenityos.org> * Copyright (c) 2021-2023, Andrew Kaster <akaster@serenityos.org>
* *
* SPDX-License-Identifier: BSD-2-Clause * SPDX-License-Identifier: BSD-2-Clause
*/ */
@ -15,8 +15,8 @@ enum class Verbose {
Yes Yes
}; };
bool validate_flattened_device_tree(FlattenedDeviceTreeHeader const& header, u8 const* blob_start, size_t blob_size, Verbose = Verbose::No); bool validate_flattened_device_tree(FlattenedDeviceTreeHeader const& header, ReadonlyBytes raw_device_tree, Verbose = Verbose::No);
bool dump(FlattenedDeviceTreeHeader const& header, u8 const* blob_start, size_t blob_size); ErrorOr<void> dump(FlattenedDeviceTreeHeader const& header, ReadonlyBytes raw_device_tree);
} }

View file

@ -29,9 +29,10 @@ ErrorOr<int> serenity_main(Main::Arguments arguments)
return 1; return 1;
} }
auto* fdt_header = reinterpret_cast<DeviceTree::FlattenedDeviceTreeHeader const*>(file->data()); auto const* fdt_header = reinterpret_cast<DeviceTree::FlattenedDeviceTreeHeader const*>(file->data());
auto bytes = ReadonlyBytes { file->data(), file->size() };
bool valid = DeviceTree::dump(*fdt_header, static_cast<u8 const*>(file->data()), file->size()); TRY(DeviceTree::dump(*fdt_header, bytes));
return valid ? 0 : 1; return 0;
} }