Some years ago, in commit b1d0b0fc "libelf: Use int64_t for offsets in
libelf.h", we changed the public interface to use 64bit offsets/sizes.
This wasn't really a API change, before we relied on loff_t always
being 64bits on all platforms.
We didn't change the implementation to use the int64_t type though.
That was a little confusing, since the function definitions used a
different type, int64_t, from the function implementations, off_t.
Since we always build with _FILE_OFFSET_BITS=64 this should be fine.
But it was a bit sloppy and confusing.
Worse is that we got the translation of offset/sizes wrong in a
couple of places when translating to ELF types. In various places
we would use Elf32_Word or Elf64_Word. But both are 32bit (unsigned)
types! As is GElf_Word. Elf32_Off is 32bits and Elf64_Off is 64bits.
But we were not using those consistently.
This patch introduces comments for the usage of [G]Elf(32|64)Word in
libelf that are correct. And introduces Elf(32|64)_SizeWord in
elf32_updatenull.c where we want to make a difference between sizes
and offsets (the ELF variants are both unsigned, while int64_t/loff_t
is signed).
It also includes a new run-large-elf-file.sh test that creates a
large ELF files (one 64bit, little endian, rel and another big endian,
non-rel) and runs eu-strip, eu-elflint, eu-unstrip and eu-elfcmp.
Before this patch, that test case fails and creates corrupt ELF files.
The test is guarded by some checks that try to make sure there is
enough disk space and memory available on the machine. The test is
skipped otherwise.
Signed-off-by: Mark Wielaard <mark@klomp.org>
When ELF_C_RDWR_MMAP is used libelf might have to write overlapping memory
when moving the section data or headers. Make sure to use memmove, not
memcpy. Also the size of the underlying file might have to change. That
means we will have to also extend the mmap region with mremap. Since we
are using direct pointers into the mmapped area we cannot move the mmap,
only extend it. This might still fail if there is not enough free memory
available to extend the mmap region.
Two new test programs have been added. elfcopy which copies a whole elf
file (using either ELF_C_WRITE or ELF_C_WRITE_MMAP). And addsections which
adds new sections to an existing ELF file (using either ELF_C_RDWR or
ELF_C_RDWR_MMAP). The newly added test will fail under valgrind without
the fixes.
Signed-off-by: Mark Wielaard <mark@klomp.org>
Don't use posix_fallocate when not using mmap. It is enough to ftruncate
the file to the right size. pwrite will report an error if there is no
disk space left. And on file systems that don't support fallocate it
might duplicate writes in that case. When using posix_fallocate do ignore
most errors. Other libc implementations don't guarantee the call actually
works always and even with glibc there might be an unexpected error from
the fallback code when the file system doesn't support fallocate. That is
pretty nasty since we might get a SIGBUS in that case when writing to the
mmapped memory. But the chance of that happening is very small. And will
normally never happen with glibc. So only report an error when
posix_fallocate reports ENOSPC.
Signed-off-by: Mark Wielaard <mjw@redhat.com>
When elf_update.c (write_file) doesn't know the current maximum file length
it might have to reduce the file size. posix_fallocate can only extend the
file. So always call ftruncate before that to set the file size and making
sure the backing store is fully there. Add test cases for checking strip
in place (eu-strip without -o) actually reduces the file size. But only
for non-ET_REL files. We might not be able to strip ET_REL files (except
when they are kernel modules) because they might contain "dangling" symbol
table entries.
https://bugzilla.redhat.com/show_bug.cgi?id=1232206
Signed-off-by: Mark Wielaard <mjw@redhat.com>
This fixes an obscure SIGBUS error when using ELF_C_WRITE_MMAP on an ELF
file that needs extending when the underlying file system is (nearly) full.
Use posix_fallocate to make sure the file content is really there. Using
ftruncate might mean the file is extended, but space isn't allocated yet.
This might cause a SIGBUS once we write into the mmapped space and the disk
is full.
Using fallocate might fail on some file systems. posix_fallocate is
required to extend the file and allocate enough space even if the
underlying filesystem would normally return EOPNOTSUPP or the kernel
doesn't implement the fallocate syscall. Also posix_fallocate has been in
glibc since 2.1.94, while support for fallocate was only added in 2.10
and kernel 2.6.23.
Signed-off-by: Mark Wielaard <mjw@redhat.com>
The --enable-mudflap configure build has been broken for 2 years without
anybody apparently noticing. GCC 4.9 removed mudflap support. Before
release we now run make distcheck with valgrind support. Removal of the
mudflap configure option simplifies the build a little.
Signed-off-by: Mark Wielaard <mjw@redhat.com>
* Change name from "Red Hat elfutils" to "elfutils".
* Update license of standalone tools and test from GPLv2 to GPLv3+.
* Change license of libraries from GPLv2+exception to GPLv2/LGPLv3+.
* Add Developer Certificate of Origin based contributor policy.
top-level:
- COPYING: Upgraded from GPLv2 to GPLv3.
- CONTRIBUTING, COPYING-GPLv2, COPYING-LGPLv3: New files.
- NEWS: Added note about new contribution and license policy.
- Makefile.am: Updated to GPLv3, added new files to EXTRA_DIST.
- configure.ac: Update to GPLv3, changed AC_INIT name to 'elfutils'.
backends, lib, libasm, libcpu, libdw, libdwfl, libebl, libelf:
- All files updated to GPLv2/LGPLv3+. Except some very small files
(<5 lines) which didn't have any headers at all before, the linker
.maps files and the libcpu/defs files which only contain data and
libelf/elf.h which comes from glibc and is under LGPLv2+.
config:
- elfutils.spec.in: Add new License: headers and new %doc files.
- Update all license headers to GPLv2/LGPLv3+ for files used by libs.
src, tests:
- All files updated to GPLv3+. Except for the test bz2 data files, the
linker maps and script files and some very small files (<5 lines)
that don't have any headers.
Signed-off-by: Richard Fontana <rfontana@redhat.com>
Signed-off-by: Mark Wielaard <mjw@redhat.com>
zhanghaibo