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Diffstat (limited to '')
| -rw-r--r-- | src/boot/efi/pe.c | 338 |
1 files changed, 338 insertions, 0 deletions
diff --git a/src/boot/efi/pe.c b/src/boot/efi/pe.c new file mode 100644 index 0000000..3d5da14 --- /dev/null +++ b/src/boot/efi/pe.c @@ -0,0 +1,338 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ + +#include <efi.h> +#include <efilib.h> + +#include "missing_efi.h" +#include "pe.h" +#include "util.h" + +#define DOS_FILE_MAGIC "MZ" +#define PE_FILE_MAGIC "PE\0\0" +#define MAX_SECTIONS 96 + +#if defined(__i386__) +# define TARGET_MACHINE_TYPE EFI_IMAGE_MACHINE_IA32 +# define TARGET_MACHINE_TYPE_COMPATIBILITY EFI_IMAGE_MACHINE_X64 +#elif defined(__x86_64__) +# define TARGET_MACHINE_TYPE EFI_IMAGE_MACHINE_X64 +#elif defined(__aarch64__) +# define TARGET_MACHINE_TYPE EFI_IMAGE_MACHINE_AARCH64 +#elif defined(__arm__) +# define TARGET_MACHINE_TYPE EFI_IMAGE_MACHINE_ARMTHUMB_MIXED +#elif defined(__riscv) && __riscv_xlen == 64 +# define TARGET_MACHINE_TYPE EFI_IMAGE_MACHINE_RISCV64 +#else +# error Unknown EFI arch +#endif + +#ifndef TARGET_MACHINE_TYPE_COMPATIBILITY +# define TARGET_MACHINE_TYPE_COMPATIBILITY 0 +#endif + +typedef struct DosFileHeader { + uint8_t Magic[2]; + uint16_t LastSize; + uint16_t nBlocks; + uint16_t nReloc; + uint16_t HdrSize; + uint16_t MinAlloc; + uint16_t MaxAlloc; + uint16_t ss; + uint16_t sp; + uint16_t Checksum; + uint16_t ip; + uint16_t cs; + uint16_t RelocPos; + uint16_t nOverlay; + uint16_t reserved[4]; + uint16_t OEMId; + uint16_t OEMInfo; + uint16_t reserved2[10]; + uint32_t ExeHeader; +} _packed_ DosFileHeader; + +typedef struct CoffFileHeader { + uint16_t Machine; + uint16_t NumberOfSections; + uint32_t TimeDateStamp; + uint32_t PointerToSymbolTable; + uint32_t NumberOfSymbols; + uint16_t SizeOfOptionalHeader; + uint16_t Characteristics; +} _packed_ CoffFileHeader; + +#define OPTHDR32_MAGIC 0x10B /* PE32 OptionalHeader */ +#define OPTHDR64_MAGIC 0x20B /* PE32+ OptionalHeader */ + +typedef struct PeOptionalHeader { + uint16_t Magic; + uint8_t LinkerMajor; + uint8_t LinkerMinor; + uint32_t SizeOfCode; + uint32_t SizeOfInitializedData; + uint32_t SizeOfUninitializeData; + uint32_t AddressOfEntryPoint; + uint32_t BaseOfCode; + union { + struct { /* PE32 */ + uint32_t BaseOfData; + uint32_t ImageBase32; + }; + uint64_t ImageBase64; /* PE32+ */ + }; + uint32_t SectionAlignment; + uint32_t FileAlignment; + uint16_t MajorOperatingSystemVersion; + uint16_t MinorOperatingSystemVersion; + uint16_t MajorImageVersion; + uint16_t MinorImageVersion; + uint16_t MajorSubsystemVersion; + uint16_t MinorSubsystemVersion; + uint32_t Win32VersionValue; + uint32_t SizeOfImage; + uint32_t SizeOfHeaders; + uint32_t CheckSum; + uint16_t Subsystem; + uint16_t DllCharacteristics; + /* fields with different sizes for 32/64 omitted */ +} _packed_ PeOptionalHeader; + +typedef struct PeFileHeader { + uint8_t Magic[4]; + CoffFileHeader FileHeader; + PeOptionalHeader OptionalHeader; +} _packed_ PeFileHeader; + +typedef struct PeSectionHeader { + uint8_t Name[8]; + uint32_t VirtualSize; + uint32_t VirtualAddress; + uint32_t SizeOfRawData; + uint32_t PointerToRawData; + uint32_t PointerToRelocations; + uint32_t PointerToLinenumbers; + uint16_t NumberOfRelocations; + uint16_t NumberOfLinenumbers; + uint32_t Characteristics; +} _packed_ PeSectionHeader; + +static inline bool verify_dos(const DosFileHeader *dos) { + assert(dos); + return memcmp(dos->Magic, DOS_FILE_MAGIC, STRLEN(DOS_FILE_MAGIC)) == 0; +} + +static inline bool verify_pe(const PeFileHeader *pe, bool allow_compatibility) { + assert(pe); + return memcmp(pe->Magic, PE_FILE_MAGIC, STRLEN(PE_FILE_MAGIC)) == 0 && + (pe->FileHeader.Machine == TARGET_MACHINE_TYPE || + (allow_compatibility && pe->FileHeader.Machine == TARGET_MACHINE_TYPE_COMPATIBILITY)) && + pe->FileHeader.NumberOfSections > 0 && + pe->FileHeader.NumberOfSections <= MAX_SECTIONS && + IN_SET(pe->OptionalHeader.Magic, OPTHDR32_MAGIC, OPTHDR64_MAGIC); +} + +static inline UINTN section_table_offset(const DosFileHeader *dos, const PeFileHeader *pe) { + assert(dos); + assert(pe); + return dos->ExeHeader + offsetof(PeFileHeader, OptionalHeader) + pe->FileHeader.SizeOfOptionalHeader; +} + +static void locate_sections( + const PeSectionHeader section_table[], + UINTN n_table, + const char * const sections[], + UINTN *offsets, + UINTN *sizes, + bool in_memory) { + + assert(section_table); + assert(sections); + assert(offsets); + assert(sizes); + + size_t prev_section_addr = 0; + + for (UINTN i = 0; i < n_table; i++) { + const PeSectionHeader *sect = section_table + i; + + if (in_memory) { + if (prev_section_addr > sect->VirtualAddress) + log_error_stall(u"Overlapping PE sections detected. Boot may fail due to image memory corruption!"); + prev_section_addr = sect->VirtualAddress + sect->VirtualSize; + } + + for (UINTN j = 0; sections[j]; j++) { + if (memcmp(sect->Name, sections[j], strlen8(sections[j])) != 0) + continue; + + offsets[j] = in_memory ? sect->VirtualAddress : sect->PointerToRawData; + sizes[j] = sect->VirtualSize; + } + } +} + +static uint32_t get_compatibility_entry_address(const DosFileHeader *dos, const PeFileHeader *pe) { + UINTN addr = 0, size = 0; + static const char *sections[] = { ".compat", NULL }; + + /* The kernel may provide alternative PE entry points for different PE architectures. This allows + * booting a 64bit kernel on 32bit EFI that is otherwise running on a 64bit CPU. The locations of any + * such compat entry points are located in a special PE section. */ + + locate_sections((const PeSectionHeader *) ((const uint8_t *) dos + section_table_offset(dos, pe)), + pe->FileHeader.NumberOfSections, + sections, + &addr, + &size, + /*in_memory=*/true); + + if (size == 0) + return 0; + + typedef struct { + uint8_t type; + uint8_t size; + uint16_t machine_type; + uint32_t entry_point; + } _packed_ LinuxPeCompat1; + + while (size >= sizeof(LinuxPeCompat1) && addr % __alignof__(LinuxPeCompat1) == 0) { + LinuxPeCompat1 *compat = (LinuxPeCompat1 *) ((uint8_t *) dos + addr); + + if (compat->type == 0 || compat->size == 0 || compat->size > size) + break; + + if (compat->type == 1 && + compat->size >= sizeof(LinuxPeCompat1) && + compat->machine_type == TARGET_MACHINE_TYPE) + return compat->entry_point; + + addr += compat->size; + size -= compat->size; + } + + return 0; +} + +EFI_STATUS pe_kernel_info(const void *base, uint32_t *ret_compat_address) { + assert(base); + assert(ret_compat_address); + + const DosFileHeader *dos = (const DosFileHeader *) base; + if (!verify_dos(dos)) + return EFI_LOAD_ERROR; + + const PeFileHeader *pe = (const PeFileHeader *) ((const uint8_t *) base + dos->ExeHeader); + if (!verify_pe(pe, /* allow_compatibility= */ true)) + return EFI_LOAD_ERROR; + + /* Support for LINUX_INITRD_MEDIA_GUID was added in kernel stub 1.0. */ + if (pe->OptionalHeader.MajorImageVersion < 1) + return EFI_UNSUPPORTED; + + if (pe->FileHeader.Machine == TARGET_MACHINE_TYPE) { + *ret_compat_address = 0; + return EFI_SUCCESS; + } + + uint32_t compat_address = get_compatibility_entry_address(dos, pe); + if (compat_address == 0) + /* Image type not supported and no compat entry found. */ + return EFI_UNSUPPORTED; + + *ret_compat_address = compat_address; + return EFI_SUCCESS; +} + +EFI_STATUS pe_memory_locate_sections(const void *base, const char * const sections[], UINTN *addrs, UINTN *sizes) { + const DosFileHeader *dos; + const PeFileHeader *pe; + UINTN offset; + + assert(base); + assert(sections); + assert(addrs); + assert(sizes); + + dos = (const DosFileHeader *) base; + if (!verify_dos(dos)) + return EFI_LOAD_ERROR; + + pe = (const PeFileHeader *) ((uint8_t *) base + dos->ExeHeader); + if (!verify_pe(pe, /* allow_compatibility= */ false)) + return EFI_LOAD_ERROR; + + offset = section_table_offset(dos, pe); + locate_sections((PeSectionHeader *) ((uint8_t *) base + offset), + pe->FileHeader.NumberOfSections, + sections, + addrs, + sizes, + /*in_memory=*/true); + + return EFI_SUCCESS; +} + +EFI_STATUS pe_file_locate_sections( + EFI_FILE *dir, + const char16_t *path, + const char * const sections[], + UINTN *offsets, + UINTN *sizes) { + _cleanup_free_ PeSectionHeader *section_table = NULL; + _cleanup_(file_closep) EFI_FILE *handle = NULL; + DosFileHeader dos; + PeFileHeader pe; + UINTN len, section_table_len; + EFI_STATUS err; + + assert(dir); + assert(path); + assert(sections); + assert(offsets); + assert(sizes); + + err = dir->Open(dir, &handle, (char16_t *) path, EFI_FILE_MODE_READ, 0ULL); + if (err != EFI_SUCCESS) + return err; + + len = sizeof(dos); + err = handle->Read(handle, &len, &dos); + if (err != EFI_SUCCESS) + return err; + if (len != sizeof(dos) || !verify_dos(&dos)) + return EFI_LOAD_ERROR; + + err = handle->SetPosition(handle, dos.ExeHeader); + if (err != EFI_SUCCESS) + return err; + + len = sizeof(pe); + err = handle->Read(handle, &len, &pe); + if (err != EFI_SUCCESS) + return err; + if (len != sizeof(pe) || !verify_pe(&pe, /* allow_compatibility= */ false)) + return EFI_LOAD_ERROR; + + section_table_len = pe.FileHeader.NumberOfSections * sizeof(PeSectionHeader); + section_table = xmalloc(section_table_len); + if (!section_table) + return EFI_OUT_OF_RESOURCES; + + err = handle->SetPosition(handle, section_table_offset(&dos, &pe)); + if (err != EFI_SUCCESS) + return err; + + len = section_table_len; + err = handle->Read(handle, &len, section_table); + if (err != EFI_SUCCESS) + return err; + if (len != section_table_len) + return EFI_LOAD_ERROR; + + locate_sections(section_table, pe.FileHeader.NumberOfSections, + sections, offsets, sizes, /*in_memory=*/false); + + return EFI_SUCCESS; +} |