Implement cross-endian ELF load for powerpc

This commit is contained in:
Paulo Flabiano Smorigo 2015-10-26 22:07:26 +01:00 committed by Vladimir Serbinenko
parent 9e5f70174e
commit bf3df4070f
2 changed files with 105 additions and 2 deletions

View file

@ -28,6 +28,23 @@
GRUB_MOD_LICENSE ("GPLv3+");
#if defined(__powerpc__) && defined(GRUB_MACHINE_IEEE1275)
#define GRUB_ELF_ENABLE_BI_ENDIAN 1
#else
#define GRUB_ELF_ENABLE_BI_ENDIAN 0
#endif
#if defined(GRUB_CPU_WORDS_BIGENDIAN)
#define GRUB_ELF_NATIVE_ENDIANNESS ELFDATA2MSB
#define GRUB_ELF_OPPOSITE_ENDIANNESS ELFDATA2LSB
#else
#define GRUB_ELF_NATIVE_ENDIANNESS ELFDATA2LSB
#define GRUB_ELF_OPPOSITE_ENDIANNESS ELFDATA2MSB
#endif
static int grub_elf32_check_endianess_and_bswap_ehdr (grub_elf_t elf);
static int grub_elf64_check_endianess_and_bswap_ehdr (grub_elf_t elf);
/* Check if EHDR is a valid ELF header. */
static grub_err_t
grub_elf_check_header (grub_elf_t elf)
@ -38,8 +55,25 @@ grub_elf_check_header (grub_elf_t elf)
|| e->e_ident[EI_MAG1] != ELFMAG1
|| e->e_ident[EI_MAG2] != ELFMAG2
|| e->e_ident[EI_MAG3] != ELFMAG3
|| e->e_ident[EI_VERSION] != EV_CURRENT
|| e->e_version != EV_CURRENT)
|| e->e_ident[EI_VERSION] != EV_CURRENT)
return grub_error (GRUB_ERR_BAD_OS, N_("invalid arch-independent ELF magic"));
if (grub_elf_is_elf32 (elf))
{
if (!grub_elf32_check_endianess_and_bswap_ehdr (elf)) {
return grub_error (GRUB_ERR_BAD_OS, "invalid ELF endianness magic");
}
}
else if (grub_elf_is_elf64 (elf))
{
if (!grub_elf64_check_endianess_and_bswap_ehdr (elf)) {
return grub_error (GRUB_ERR_BAD_OS, "invalid ELF endianness magic");
}
}
else
return grub_error (GRUB_ERR_BAD_OS, "unknown ELF class");
if (e->e_version != EV_CURRENT)
return grub_error (GRUB_ERR_BAD_OS, N_("invalid arch-independent ELF magic"));
return GRUB_ERR_NONE;
@ -117,6 +151,9 @@ grub_elf_open (const char *name)
}
#define grub_swap_bytes_halfXX grub_swap_bytes16
#define grub_swap_bytes_wordXX grub_swap_bytes32
/* 32-bit */
#define ehdrXX ehdr32
#define ELFCLASSXX ELFCLASS32
@ -127,7 +164,12 @@ grub_elf_open (const char *name)
#define grub_elf_is_elfXX grub_elf_is_elf32
#define grub_elfXX_load_phdrs grub_elf32_load_phdrs
#define ElfXX_Phdr Elf32_Phdr
#define ElfXX_Ehdr Elf32_Ehdr
#define grub_uintXX_t grub_uint32_t
#define grub_swap_bytes_addrXX grub_swap_bytes32
#define grub_swap_bytes_offXX grub_swap_bytes32
#define grub_swap_bytes_XwordXX grub_swap_bytes32
#define grub_elfXX_check_endianess_and_bswap_ehdr grub_elf32_check_endianess_and_bswap_ehdr
#include "elfXX.c"
@ -140,7 +182,12 @@ grub_elf_open (const char *name)
#undef grub_elf_is_elfXX
#undef grub_elfXX_load_phdrs
#undef ElfXX_Phdr
#undef ElfXX_Ehdr
#undef grub_uintXX_t
#undef grub_swap_bytes_addrXX
#undef grub_swap_bytes_offXX
#undef grub_swap_bytes_XwordXX
#undef grub_elfXX_check_endianess_and_bswap_ehdr
/* 64-bit */
@ -153,6 +200,11 @@ grub_elf_open (const char *name)
#define grub_elf_is_elfXX grub_elf_is_elf64
#define grub_elfXX_load_phdrs grub_elf64_load_phdrs
#define ElfXX_Phdr Elf64_Phdr
#define ElfXX_Ehdr Elf64_Ehdr
#define grub_uintXX_t grub_uint64_t
#define grub_swap_bytes_addrXX grub_swap_bytes64
#define grub_swap_bytes_offXX grub_swap_bytes64
#define grub_swap_bytes_XwordXX grub_swap_bytes64
#define grub_elfXX_check_endianess_and_bswap_ehdr grub_elf64_check_endianess_and_bswap_ehdr
#include "elfXX.c"

View file

@ -31,6 +31,25 @@ grub_elfXX_load_phdrs (grub_elf_t elf)
return grub_errno;
}
#if GRUB_ELF_ENABLE_BI_ENDIAN
if (elf->ehdr.ehdrXX.e_ident[EI_DATA] == GRUB_ELF_OPPOSITE_ENDIANNESS)
{
ElfXX_Phdr *phdr;
for (phdr = elf->phdrs; (char *) phdr < (char *) elf->phdrs + phdrs_size;
phdr = (ElfXX_Phdr *) ((char *) phdr + elf->ehdr.ehdrXX.e_phentsize))
{
phdr->p_type = grub_swap_bytes_wordXX (phdr->p_type);
phdr->p_flags = grub_swap_bytes_wordXX (phdr->p_flags);
phdr->p_offset = grub_swap_bytes_offXX (phdr->p_offset);
phdr->p_vaddr = grub_swap_bytes_addrXX (phdr->p_vaddr);
phdr->p_paddr = grub_swap_bytes_addrXX (phdr->p_paddr);
phdr->p_filesz = grub_swap_bytes_XwordXX (phdr->p_filesz);
phdr->p_memsz = grub_swap_bytes_XwordXX (phdr->p_memsz);
phdr->p_align = grub_swap_bytes_XwordXX (phdr->p_align);
}
}
#endif /* GRUB_ELF_ENABLE_BI_ENDIAN */
return GRUB_ERR_NONE;
}
@ -154,3 +173,35 @@ grub_elfXX_load (grub_elf_t elf, const char *filename,
return grub_errno;
}
static int
grub_elfXX_check_endianess_and_bswap_ehdr (grub_elf_t elf)
{
ElfXX_Ehdr *e = &(elf->ehdr.ehdrXX);
if (e->e_ident[EI_DATA] == GRUB_ELF_NATIVE_ENDIANNESS)
{
return 1;
}
#if GRUB_ELF_ENABLE_BI_ENDIAN
if (e->e_ident[EI_DATA] == GRUB_ELF_OPPOSITE_ENDIANNESS)
{
e->e_type = grub_swap_bytes_halfXX (e->e_type);
e->e_machine = grub_swap_bytes_halfXX (e->e_machine);
e->e_version = grub_swap_bytes_wordXX (e->e_version);
e->e_entry = grub_swap_bytes_addrXX (e->e_entry);
e->e_phoff = grub_swap_bytes_offXX (e->e_phoff);
e->e_shoff = grub_swap_bytes_offXX (e->e_shoff);
e->e_flags = grub_swap_bytes_wordXX (e->e_flags);
e->e_ehsize = grub_swap_bytes_halfXX (e->e_ehsize);
e->e_phentsize = grub_swap_bytes_halfXX (e->e_phentsize);
e->e_phnum = grub_swap_bytes_halfXX (e->e_phnum);
e->e_shentsize = grub_swap_bytes_halfXX (e->e_shentsize);
e->e_shnum = grub_swap_bytes_halfXX (e->e_shnum);
e->e_shstrndx = grub_swap_bytes_halfXX (e->e_shstrndx);
return 1;
}
#endif /* GRUB_ELF_ENABLE_BI_ENDIAN */
return 0;
}