diff options
| author | Mark Wielaard <mark@klomp.org> | 2018-11-13 21:18:09 +0100 |
|---|---|---|
| committer | Mark Wielaard <mark@klomp.org> | 2018-11-13 21:30:17 +0100 |
| commit | cf10453f8252df81225796d98548ba6eac113df3 (patch) | |
| tree | 13cea388f62135b702fe1db133dd842e1bf2873a | |
| parent | d3e6266754b95244063aa1e40c531fdd57259332 (diff) | |
libelf: Correctly setup alignment of SHF_COMPRESSED section data.
We didn't set the alignment of SHF_COMPRESSED sections correctly.
Those sections start with an Elf(32|64)_Chdr. Make sure sh_addralign
is setup to be able to read such a struct directly. Likewise don't
trust the alignment set on any SHF_COMPRESSED section, but always
make the (raw) compressed data aligned correctly for the reading the
Elf(32|64)_Chdr directly.
Signed-off-by: Mark Wielaard <mark@klomp.org>
| -rw-r--r-- | libelf/ChangeLog | 7 | ||||
| -rw-r--r-- | libelf/elf_compress.c | 4 | ||||
| -rw-r--r-- | libelf/elf_getdata.c | 10 |
3 files changed, 17 insertions, 4 deletions
diff --git a/libelf/ChangeLog b/libelf/ChangeLog index ab078cb5..93820d19 100644 --- a/libelf/ChangeLog +++ b/libelf/ChangeLog @@ -1,3 +1,10 @@ +2018-11-13 Mark Wielaard <mark@klomp.org> + + * elf_getdata.c (__libelf_set_rawdata_wrlock): Explicitly set the + alignment of SHF_COMPRESSED data to the alignment of ELF_T_CHDR. + * elf_compress.c (elf_compress): After compression set sh_addralign + to the alignment of ELF_T_CHDR. + 2018-11-09 Mark Wielaard <mark@klomp.org> * elf_compress_gnu.c (elf_compress_gnu): Use elf_getdata. diff --git a/libelf/elf_compress.c b/libelf/elf_compress.c index d96245df..be9eeaba 100644 --- a/libelf/elf_compress.c +++ b/libelf/elf_compress.c @@ -455,14 +455,14 @@ elf_compress (Elf_Scn *scn, int type, unsigned int flags) { Elf32_Shdr *shdr = elf32_getshdr (scn); shdr->sh_size = new_size; - shdr->sh_addralign = 1; + shdr->sh_addralign = __libelf_type_align (ELFCLASS32, ELF_T_CHDR); shdr->sh_flags |= SHF_COMPRESSED; } else { Elf64_Shdr *shdr = elf64_getshdr (scn); shdr->sh_size = new_size; - shdr->sh_addralign = 1; + shdr->sh_addralign = __libelf_type_align (ELFCLASS64, ELF_T_CHDR); shdr->sh_flags |= SHF_COMPRESSED; } diff --git a/libelf/elf_getdata.c b/libelf/elf_getdata.c index 2043bba2..639a798e 100644 --- a/libelf/elf_getdata.c +++ b/libelf/elf_getdata.c @@ -268,9 +268,15 @@ __libelf_set_rawdata_wrlock (Elf_Scn *scn) /* First a test whether the section is valid at all. */ size_t entsize; - /* Compressed data has a header, but then compressed data. */ + /* Compressed data has a header, but then compressed data. + Make sure to set the alignment of the header explicitly, + don't trust the file alignment for the section, it is + often wrong. */ if ((flags & SHF_COMPRESSED) != 0) - entsize = 1; + { + entsize = 1; + align = __libelf_type_align (elf->class, ELF_T_CHDR); + } else if (type == SHT_HASH) { GElf_Ehdr ehdr_mem; |