Re: [PATCH v2] Suport for bi-endianess in elf file

[Andrei Borzenkov <arvidjaar@gmail.com>]

В Fri, 24 Jul 2015 21:00:50 +0200
"Vladimir 'phcoder' Serbinenko" <phcoder@gmail.com> пишет:

> Le 23 juil. 2015 16:11, "Paulo Flabiano Smorigo" <
> pfsmorigo@linux.vnet.ibm.com> a écrit :
> >
> > Updated version with the suggestions from Andrei Borzenkov.
> >
> > * grub-core/kern/elf.c: check and switch endianess with grub_{be,le}_to
> > cpu functions.
> > * grub-core/kern/elfXX.c: Likewise.
> >
> > Also-by: Tomohiro B Berry <tbberry@us.ibm.com>
> > ---
> >  grub-core/kern/elf.c   | 51 ++++++++++++++++++++++++++++++---
> >  grub-core/kern/elfXX.c | 76
> ++++++++++++++++++++++++++++++++++++++++++++++++++
> >  2 files changed, 123 insertions(+), 4 deletions(-)
> >
> > diff --git a/grub-core/kern/elf.c b/grub-core/kern/elf.c
> > index 5f99c43..1be9c1c 100644
> > --- a/grub-core/kern/elf.c
> > +++ b/grub-core/kern/elf.c
> > @@ -28,6 +28,11 @@
> >
> >  GRUB_MOD_LICENSE ("GPLv3+");
> >
> > +#if defined(__powerpc__) && defined(GRUB_MACHINE_IEEE1275)
> > +void grub_elf32_check_endianess (grub_elf_t elf);
> > +void grub_elf64_check_endianess (grub_elf_t elf);
> > +#endif /* defined(__powerpc__) && defined(GRUB_MACHINE_IEEE1275) */
> > +
> >  /* Check if EHDR is a valid ELF header.  */
> >  static grub_err_t
> >  grub_elf_check_header (grub_elf_t elf)
> > @@ -38,8 +43,19 @@ 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 defined(__powerpc__) && defined(GRUB_MACHINE_IEEE1275)
> > +  if (grub_elf_is_elf32 (elf))
> > +      grub_elf32_check_endianess (elf);
> > +  else if (grub_elf_is_elf64 (elf))
> > +      grub_elf64_check_endianess (elf);
> > +  else
> > +    return grub_error (GRUB_ERR_BAD_OS, N_("Uknown ELF class"));
> > +#endif /* defined(__powerpc__) && defined(GRUB_MACHINE_IEEE1275) */
> > +
> > +  if (e->e_version != EV_CURRENT)
> >      return grub_error (GRUB_ERR_BAD_OS, N_("invalid arch-independent ELF
> magic"));
> >
> >    return GRUB_ERR_NONE;
> > @@ -116,7 +132,11 @@ grub_elf_open (const char *name)
> >    return elf;
> >  }
> >
> > -
> > +#define grub_be_to_halfXX grub_be_to_cpu16
> > +#define grub_le_to_halfXX grub_le_to_cpu16
> > +#define grub_be_to_wordXX grub_be_to_cpu32
> > +#define grub_le_to_wordXX grub_le_to_cpu32
> > +
> >  /* 32-bit */
> >  #define ehdrXX ehdr32
> >  #define ELFCLASSXX ELFCLASS32
> > @@ -127,7 +147,15 @@ 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_be_to_addrXX grub_be_to_cpu32
> > +#define grub_le_to_addrXX grub_le_to_cpu32
> > +#define grub_be_to_offXX grub_be_to_cpu32
> > +#define grub_le_to_offXX grub_le_to_cpu32
> > +#define grub_be_to_XwordXX grub_be_to_cpu32
> > +#define grub_le_to_XwordXX grub_le_to_cpu32
> > +#define grub_elfXX_check_endianess grub_elf32_check_endianess
> >
> >  #include "elfXX.c"
> >
> > @@ -140,9 +168,16 @@ 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_be_to_addrXX
> > +#undef grub_le_to_addrXX
> > +#undef grub_be_to_offXX
> > +#undef grub_le_to_offXX
> > +#undef grub_be_to_XwordXX
> > +#undef grub_le_to_XwordXX
> > +#undef grub_elfXX_check_endianess
> >
> > -
> >  /* 64-bit */
> >  #define ehdrXX ehdr64
> >  #define ELFCLASSXX ELFCLASS64
> > @@ -153,6 +188,14 @@ 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_be_to_addrXX grub_be_to_cpu64
> > +#define grub_le_to_addrXX grub_le_to_cpu64
> > +#define grub_be_to_offXX grub_be_to_cpu64
> > +#define grub_le_to_offXX grub_le_to_cpu64
> > +#define grub_be_to_XwordXX grub_be_to_cpu64
> > +#define grub_le_to_XwordXX grub_le_to_cpu64
> > +#define grub_elfXX_check_endianess grub_elf64_check_endianess
> >
> >  #include "elfXX.c"
> > diff --git a/grub-core/kern/elfXX.c b/grub-core/kern/elfXX.c
> > index 1d09971..c14e071 100644
> > --- a/grub-core/kern/elfXX.c
> > +++ b/grub-core/kern/elfXX.c
> > @@ -31,6 +31,39 @@ grub_elfXX_load_phdrs (grub_elf_t elf)
> >        return grub_errno;
> >      }
> >
> > +#if defined(__powerpc__) && defined(GRUB_MACHINE_IEEE1275)
> > +  ElfXX_Phdr *phdr;
> > +  for (phdr = elf->phdrs;
> > +       phdr && phdr < (ElfXX_Phdr *) elf->phdrs +
> elf->ehdr.ehdrXX.e_phnum;
> > +       phdr++)
> > +    {
> > +      if (elf->ehdr.ehdrXX.e_ident[EI_DATA] == ELFDATA2LSB)
> > +        {
> > +          phdr->p_type = grub_le_to_wordXX (phdr->p_type);
> > +          phdr->p_flags = grub_le_to_wordXX (phdr->p_flags);
> > +          phdr->p_offset = grub_le_to_offXX (phdr->p_offset);
> > +          phdr->p_vaddr = grub_le_to_addrXX (phdr->p_vaddr);
> > +          phdr->p_paddr = grub_le_to_addrXX (phdr->p_paddr);
> > +          phdr->p_filesz = grub_le_to_XwordXX (phdr->p_filesz);
> > +          phdr->p_memsz = grub_le_to_XwordXX (phdr->p_memsz);
> > +          phdr->p_align = grub_le_to_XwordXX (phdr->p_align);
> > +        }
> > +#if !defined(GRUB_CPU_WORDS_BIGENDIAN) && 0
> &&0. Really. AFAICT this breaks bigendian elf support. Please test your
> patch with be kernel

It boots BE ppc64 kernel up to "init not found" :)