libdwfl: dwfl_standard_argp should not fail when not able to attach Dwfl.

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>
libdwfl: Record dwfl_attach_state error and return it on failure.

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>
libdwfl: linux-core-attach.c handle possible unaligned data access.

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>
tests: backtrace-subr.sh add check_native_unsupported.

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>
tests: backtrace.c accept __libc_do_syscall as first frame symname.

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>
tests/backtrace.c (frame_callback): Error on seeing more than 16 frames.

Don't fill up the test logs with obviously bogus frames.

Signed-off-by: Mark Wielaard <mjw@redhat.com>
backends (*_return_value_location): call dwarf_peeled_die_type

... instead of inlining equivalent code.

Signed-off-by: Petr Machata <pmachata@redhat.com>
libebl: Add ebl_func_addr_mask plus ARM backend implementation.

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>
dwarf.h: Remove non-existing DW_TAG_mutable_type.

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>
Make the attach code build again on non-Linux hosts.

Signed-off-by: Kurt Roeckx <kurt@roeckx.be>
backends: aarch64_return_value_location should handle DW_ATE_boolean.

Found with run-native-test.sh om debian arm64.
http://bugs.debian.org/753552

Signed-off-by: Mark Wielaard <mjw@redhat.com>
Update elf.h from glibc.

Includes new bits needed for ppc64le ELFv2 abi.
https://bugzilla.redhat.com/show_bug.cgi?id=1110249

Signed-off-by: Mark Wielaard <mjw@redhat.com>
Add ppc64le ELFv2 abi support to backends and elflint.

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>
m4: Handle cross-compile situations in biarch.m4 tests.

Reported-by: Leonard Crestez <lcrestez@ixiacom.com>
Signed-off-by: Mark Wielaard <mjw@redhat.com>