In both systemtap and libabigail there is a need to get the actual Dwarf
underlying an Dwarf_Die or Dwarf_Attribute. Following a DIE reference
might end up in an alternate Dwarf since the addition of DWZ multifile
forms. Both Dwarf_Die and Dwarf_Attribute already contain a Dwarf_CU
handle. Add a function dwarf_cu_getdwarf to retrieve the underlying
Dwarf using the Dwarf_CU.
Signed-off-by: Mark Wielaard <mjw@redhat.com>
glibc now supplies these (compatible) structs instead of including the
kernel's <asm/ptrace.h> header, so let's use them. Annoyingly this will
cause new elfutils to FTBFS on old glibc, and vice versa. So include a
new configure check for the new struct names and use the old ones if
they are not avilable.
Signed-off-by: Kyle McMartin <kyle@redhat.com>
Signed-off-by: Mark Wielaard <mjw@redhat.com>
The big endian vs little endian changes are already handled by detecting
the EI_DATA data encoding. And the function descriptors are already not
used when we see there is no .opd section. This change adds new checks
for st_other bits, new relocations and recognizes DT_PPC64_OPT.
Signed-off-by: Menanteau Guy <menantea@linux.vnet.ibm.com>
Signed-off-by: Mark Wielaard <mjw@redhat.com>
The DW_TAG_mutable_type was only mentioned in an early draft of DWARFv3.
But was removed because there are no C++ mutable qualified types. It was
replaced by a new attribute DW_AT_mutable on DW_TAG_member DIEs. The new
attribute is available in dwarf.h.
http://dwarfstd.org/ShowIssue.php?issue=050223.1
DW_TAG_mutable_type was only used internally in some backends (which
just ignored it anyway). dwarves did use it to turn it into a string
value, libabigail used it and ignored it (patches to remove sent).
GCC, GDB and binutils don't use nor define it.
Signed-off-by: Mark Wielaard <mjw@redhat.com>
The ARM EABI says that the zero bit of function symbol st_value indicates
whether the symbol points to a THUMB or ARM function. Also the return
value address in an unwind will contain the same extra bit to indicate
whether to return to a regular ARM or THUMB function. Add a new ebl
function to mask off such bits and turn a function value into a function
address so that we get the actual value that a function symbol or return
address points to. It isn't easily possible to reuse the existing
ebl_resolve_sym_value for this purpose, so we end up with another hook
that can be used from dwfl_module_getsym, handle_cfi and elflint.
Signed-off-by: Mark Wielaard <mjw@redhat.com>
On some architectures (Debian armhl) system calls go through
__libc_do_syscall instead of __kernel_vsyscall. Accept either of
these symbol names for the first backtrace frame.
Signed-off-by: Mark Wielaard <mjw@redhat.com>
The special arm check in check_unsupported should only trigger for native
tests, otherwise on arm various backtrace tests would be skipped that
should work just fine.
Signed-off-by: Mark Wielaard <mjw@redhat.com>
Use libdw/memory-access.h macros read_4ubyte_unaligned_noncvt and
read_8ubyte_unaligned_noncvt to access possibly unaligned data in
core files.
Signed-off-by: Mark Wielaard <mjw@redhat.com>
When dwfl_attach_state fails functions that need the process state should
return the error that caused the attach to fail. Use this in the backtrace
test to signal any attach failure. This makes sure that architectures that
don't provide unwinder support get properly detected (and the tests SKIPs)
Also don't assert when trying to attach a non-core ELF file, but return an
error to indicate failure.
Signed-off-by: Mark Wielaard <mjw@redhat.com>
As pointed out in https://bugzilla.redhat.com/show_bug.cgi?id=1107654
commit 191080 introduced a thinko that caused dwfl_standard_argp
to fail if the Dwfl couldn't be attached. Instead of generating a warning
as the comment intended, the failure would be fatal. But even warning
about dwfl_core_file_attach () or dwfl_linux_proc_attach () failing
would be a mistake. The caller/user might not be interested in such
a non-fatal issue. So just ignore if the call failed for whatever reason.
If the caller is interested in warning up front about this issue, then
dwfl_pid () should be called to check the Dwfl is attached. Things should
work just fine for anything that doesn't call any of the dwfl_state related
functions.
Signed-off-by: Mark Wielaard <mjw@redhat.com>
Don't crash and burn when a section doesn't have a name (possibly invalid
ELF file string table). Just try the next section instead of calling strcmp
on NULL.
Signed-off-by: Mark Wielaard <mjw@redhat.com>
If the section sh_size of the original and undo section are equal then
match them and don't set split_bss. This is also what prelink's
undo_sections allows.
Signed-off-by: Mark Wielaard <mjw@redhat.com>
Older versions of GNU binutils strip would drop some ELF header flags.
Causing the main ELF file and the separate .debug file to have mismatched
ELF header fields. Unfortunately some distros are still shipping such files.
eu-unstrip doesn't want to recombine such files. Add a more explicit
explanation which fields don't match and provide a --force, -F flag to
force combining such files anyway (producing a warning).
https://bugzilla.redhat.com/show_bug.cgi?id=698005https://bugzilla.redhat.com/show_bug.cgi?id=806474
Signed-off-by: Mark Wielaard <mjw@redhat.com>
And implement for arm and ia64. Both have special section types that
are valid targets for a reloc. Both refer to unwind data. elflint now
just calls ebl_check_reloc_target_type instead of hard coding the
expected section types.
Signed-off-by: Mark Wielaard <mjw@redhat.com>
Compilers and demanglers might treat local/static functions different
between versions. In particular g++ 4.1.2 and libstdc++ mangle and
demangle the static void cxxfunc (int i) function as _Z7cxxfunci.
While g++ 4.8.2 and libstdc++ mangle and demangle it as _ZL7cxxfunci.
Signed-off-by: Mark Wielaard <mjw@redhat.com>
Don't hard code the Dwarf dwz alt multi file search but allow the user
to override it through the standard Dwfl_Callbacks. Also move ownership
completely to the user of dwarf_setalt by removing free_alt from Dwarf
and adding alt, fd and elf fields to Dwfl_Module. Add a relative .dwz
file test case.
Signed-off-by: Mark Wielaard <mjw@redhat.com>
Move internal function __libdwfl_find_build_id to libdwelf and use it to
add a public dwelf_elf_gnu_build_id function to extract the NT_GNU_BUILD_ID
from an ELF file using either the shdrs or phdrs. Adjust internal callers
and add a testcase.
Signed-off-by: Mark Wielaard <mjw@redhat.com>
New public header elfutils/libdwelf.h for low-level DWARF/ELF helper
functions. The new function dwelf_elf_gnu_debuglink returns the name and
crc as found in the .gnu_debuglink section of an ELF file.
Signed-off-by: Mark Wielaard <mjw@redhat.com>
The printed array should have at least space for the terminating zero char.
Found by gcc -fsanitize=undefined while running run-readelf-vmcoreinfo.sh.
runtime error: variable length array bound evaluates to non-positive value 0
Signed-off-by: Mark Wielaard <mjw@redhat.com>
Found by gcc -fsanitize=undefined while running the backtrace-core-ppc test.
runtime error: shift exponent 45 is too large for 32-bit type 'unsigned int'
Signed-off-by: Mark Wielaard <mjw@redhat.com>
As pointed out by gcc -fsanitize=undefined left shifting a negative value
is undefined. Replace it with a multiplication of the signed value as
suggested by Richard Henderson and Josh Stone.
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>
readelf uses libdw to open the Dwarf and read some of the DWARF data.
But it also uses its own parsers to display some of the low-level
unprocessed data. If the DWARF debug section was zlib compressed it
should actually use the decompressed section data from libdw instead
of the raw section data.
Includes a testcase for those sections that couldn't be properly
displayed when compressed before.
Signed-off-by: Mark Wielaard <mjw@redhat.com>
Add aarch64 backend functions frame_nregs and set_initial_registers_tid.
Mark pc_register in aarch64 prstatus_regs as pc_register.
Add backtrace-core-aarch64 testcase.
Signed-off-by: Mark Wielaard <mjw@redhat.com>
Add the initial register setup for AARCH64 running ARM code (so
called compat mode). This makes 'eu-stack -p' happy on ARM binaries
while running on a AARCH64 kernel.
Signed-off-by: Jean Pihet <jean.pihet@linaro.org>
Signed-off-by: Mark Wielaard <mjw@redhat.com>
This is tested now in a native aarch64 build by tests/run-elflint-self.sh
since we added some .o files to the self tests.
Signed-off-by: Mark Wielaard <mjw@redhat.com>
If the last PT_LOAD segment that contains the whole shdrs also extends
the segment in memory beyond the end of file the program might be reusing
the memory space that we expect the shdrs to be in. Don't trust the shdrs
are valid in that case.
Signed-off-by: Mark Wielaard <mjw@redhat.com>
Mark Wielaard