mirror of
https://chromium.googlesource.com/crosvm/crosvm
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28359e141f
Replace the uses of read_struct() and read_struct_slice() with the safe DataInit::from_reader() implementation. BUG=b:197263364 TEST=./test_all TEST=Boot bzImage kernel TEST=Boot raw ELF kernel extracted with extract_vmlinux Change-Id: I80f98243bfb58a7ae93e1686bc4d92b0cd485cda Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosvm/+/3108249 Tested-by: kokoro <noreply+kokoro@google.com> Commit-Queue: Daniel Verkamp <dverkamp@chromium.org> Reviewed-by: Chirantan Ekbote <chirantan@chromium.org>
99 lines
2.9 KiB
Rust
99 lines
2.9 KiB
Rust
// Copyright 2019 The Chromium OS Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style license that can be
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// found in the LICENSE file.
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// Loader for bzImage-format Linux kernels as described in
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// https://www.kernel.org/doc/Documentation/x86/boot.txt
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use std::fmt::{self, Display};
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use std::io::{Read, Seek, SeekFrom};
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use base::AsRawDescriptor;
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use data_model::DataInit;
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use vm_memory::{GuestAddress, GuestMemory};
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use crate::bootparam::boot_params;
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#[derive(Debug, PartialEq)]
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pub enum Error {
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BadSignature,
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InvalidSetupSects,
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InvalidSysSize,
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ReadBootParams,
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ReadKernelImage,
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SeekBootParams,
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SeekKernelStart,
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}
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pub type Result<T> = std::result::Result<T, Error>;
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impl std::error::Error for Error {}
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impl Display for Error {
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fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
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use self::Error::*;
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let description = match self {
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BadSignature => "bad kernel header signature",
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InvalidSetupSects => "invalid setup_sects value",
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InvalidSysSize => "invalid syssize value",
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ReadBootParams => "unable to read boot_params",
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ReadKernelImage => "unable to read kernel image",
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SeekBootParams => "unable to seek to boot_params",
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SeekKernelStart => "unable to seek to kernel start",
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};
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write!(f, "bzImage loader: {}", description)
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}
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}
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/// Loads a kernel from a bzImage to a slice
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///
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/// # Arguments
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///
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/// * `guest_mem` - The guest memory region the kernel is written to.
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/// * `kernel_start` - The offset into `guest_mem` at which to load the kernel.
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/// * `kernel_image` - Input bzImage.
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pub fn load_bzimage<F>(
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guest_mem: &GuestMemory,
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kernel_start: GuestAddress,
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mut kernel_image: &mut F,
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) -> Result<(boot_params, u64)>
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where
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F: Read + Seek + AsRawDescriptor,
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{
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kernel_image
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.seek(SeekFrom::Start(0))
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.map_err(|_| Error::SeekBootParams)?;
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let params = boot_params::from_reader(&mut kernel_image).map_err(|_| Error::ReadBootParams)?;
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// bzImage header signature "HdrS"
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if params.hdr.header != 0x53726448 {
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return Err(Error::BadSignature);
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}
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let setup_sects = if params.hdr.setup_sects == 0 {
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4u64
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} else {
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params.hdr.setup_sects as u64
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};
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let kernel_offset = setup_sects
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.checked_add(1)
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.ok_or(Error::InvalidSetupSects)?
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.checked_mul(512)
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.ok_or(Error::InvalidSetupSects)?;
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let kernel_size = (params.hdr.syssize as usize)
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.checked_mul(16)
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.ok_or(Error::InvalidSysSize)?;
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kernel_image
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.seek(SeekFrom::Start(kernel_offset))
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.map_err(|_| Error::SeekKernelStart)?;
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// Load the whole kernel image to kernel_start
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guest_mem
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.read_to_memory(kernel_start, kernel_image, kernel_size)
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.map_err(|_| Error::ReadKernelImage)?;
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Ok((params, kernel_start.offset() + kernel_size as u64))
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}
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