Ubuntu's libc-bin (2.15-0ubuntu20.2) on x86_64 uses DW_CFA_val_expression
in describing the pthread spinlock operations __lll_unlock_wake() and
__lll_lock_wait(). libunwind 1.1 doesn't understand that opcode and
so backtraces from those operations are truncated.
This changeset adds basic support for it, by adding a new type to
dwarf_loc_t that describes the register's actual contents rather than
its location. I've only implemented the new type for x86_64, and
stubbed it out for all other architectures -- it looks like a lot
of that code is duplicated so oughtn't to be that hard, but I don't
have test cases for them.
Tested that DW_CFA_val_expression works on x86_64 (by using
https://code.google.com/p/gperftools/ on a lock-heavy program).
Build-tested on x86, x86_64 and arm. The unit tests don't pass for me
on any of those archs, but this cset doesn't break anything that was
passing before.
Signed-off-by: Tim Deegan <tjd@phlegethon.org>
This patch adds support for the powerpc64le-linux platform. It consists
of two main features:
- Support little-endian byte order
This is done via a "big_endian" member of struct unw_addr_space,
which is evaluated by common code via the dwarf_is_big_endian
macro, and also in endian-aware code in unw_is_signal_frame.
- Support the ELFv2 ABI
This is done via an "abi" member of struct unw_addr_space. This
is currently only needed in tdep_get_func_addr, since the ELFv2
ABI does not use function descriptors.
Both new members are initialized in unw_create_addr_space and
ppc64_local_addr_space_init, following the mips precedent.
Since ppc32 and ppc64 now no longer share the unw_create_addr_space
implementation, the file is duplicated from the ppc directory into
ppc32/ppc64.
Tested on powerpc64-linux and powerpc64le-linux. Support on LE
seems to be as good as existing BE support; I have not attempted to
fix the existing shortcomings of PPC support that already cause a
number to tests to fail due to unimplemented features.
Signed-off-by: Ulrich Weigand <uweigand@de.ibm.com>
On systems where the system compiler supports Altivec by default,
the libunwind Makefile will attempt to build an extra test case
ppc64-test-altivec. Unfortunately, the link step will fail since
the Makefile does not actually link against the libunwind library.
Fixed by adding the appropriate LDADD macro.
Signed-off-by: Ulrich Weigand <uweigand@de.ibm.com>
The ppc64 implementation of tdep_get_func_addr would crash when
attempting to retrieve the address of a function in a shared
library. The problem was that it needs to dereference the
function descriptor, but common code was passing the *unrelocated*
adddress of the descriptor to the tdep_get_func_addr routine.
Instead, common code would attempt to relocate the *result* of
tdep_get_func_addr, which is also wrong: the ppc64 implementation
reads the function address from the in-memory copy of the
descriptor, which is already relocation and contains the final
address.
This patch fixes the problem by relocating the descriptor address
before passing it to tdep_get_func_addr, instead of relocating
the result of tdep_get_func_addr. Since ppc64 is the only
non-trivial implementation of tdep_get_func_addr, this cannot
affect any other platform.
Signed-off-by: Ulrich Weigand <uweigand@de.ibm.com>
The dwarf_eval_expr routine uses macros push, pop, and pick to
manipulate the DWARF expression stack. When these macros are
nested, e.g. in the implementation of DW_OP_dup:
push (pick (0));
the combination can lead to unfortunate results.
In particular, when substituting into:
do {
if (tos >= MAX_EXPR_STACK_SIZE)
{
Debug (1, "Stack overflow\n");
return -UNW_EINVAL;
}
stack[tos++] = (x);
} while (0)
a value of "x" that makes use of "tos" (as instances of the
pick or pop macros do), the resulting expression will both
use and modify tos without an intervening sequence point,
which is undefined behavior according to the C standard.
And in fact with current GCC on PowerPC, this leads to a
miscompilation of the DW_OP_dup implementation.
This patch fixes the problem by assigning "x" to a
temporary variable before modifying tos.
Signed-off-by: Ulrich Weigand <uweigand@de.ibm.com>
liblzuma used in decoding MiniDebuginfo is not listed in
libunwind.pc.
Changes in version 2 of patch:
* Don't check HAVE_LZMA. It is redundant.
* Make liblzma as private libraries in use.
Both are suggested by Mike Frysinger <vapier@gentoo.org>.
Signed-off-by: Masatake YAMATO <yamato@redhat.com>
pkg-config metadata template files are missing Cflags keyword
which is required to properly compile against libunwind using
PKG_* autoconf macros
Acked-by: Mike Frysinger <vapier@gentoo.org>
The DWARF code allocates its unwind_info objects out of a
memory pool. The code which frees the object therefore calls
the mempool freeing code. However, there are cases where the
free code will be run with an unwind_info that was allocated
through a different mechanism (e.g. an ARM exidx table entry).
In these cases, the object should not be freed through the
mempool code.
To correct this, a check was added to ensure that the unwind_info
is of the appropriate type before passing the object along to the
mempool to be freed.
This change adds some special cases to allow libunwind to compile
for QNX.
* QNX's copy of <elf.h> and <link.h> reside in sys/ instead. To deal
with this, an AC_CHECK_HEADERS() was added to check for the files
in both locations.
* Similarly, QNX does not have <endian.h>. In cases where the file is
not found, logic was added to refer to QNX-specific macros to determine
endianness.
* The QCC compiler, which is a wrapper around GCC, cannot handle some
standard GCC options. Therefore, logic was added to check for QCC,
and when it is found, to suppress the use of -lgcc, and to express the
option -nostartfiles as -Wc,-nostartfiles instead, which is correctly
passed on to the underlying GCC.
* Finally, the support file os-qnx.c was added, patterned after the existing
os-*.c files. Only local image lookup is currently supported (see the
comments for more information), but this is sufficient for QNX, since
ptrace is not supported there anyway, and that is the only case where the
function is required to do remote image lookup.
Change-Id: Ie7934f94a7317bdde59335f2acd4c3a97c0384c1
During the install, symlinks are added from libunwind-<arch> to
libunwind-generic. However, on platforms that don't support
symlinking (such as Windows), the $(LN_S) macro is defined
as 'cp -p' instead. This works fine, except that since the
target of the symlink is a relative path, the copy will only
succeed if the current directory is the directory that contains
the file.
The solution to this problem suggested in the Autotools manual
(see http://www.gnu.org/software/automake/manual/automake.html#Extending)
is to simply cd into the correct directory first. This patch
makes that change for the symlinks that are being made during install.
[ edit: use relative path for the link name as well ]
The crasher test is used as part of the coredump test suite,
but is being built regardless of whether that support has been
configured or not. This patch changes the build so that it is
only built when coredump support is enabled.
Currently, libunwind-setjmp is built whenever local unwinding is
built. This patch adds an explicit flag to control it instead.
The default if not specified is to follow the old behavior.
This change adds a manual override to control building of the ptrace
library, similar to the existing --enable-coredump option. The
default is set based on the existence of sys/ptrace.h, allowing it
to be automatically disabled for platforms that do not have ptrace.
When libunwind is built for a ppc32 target, for example the yocto distro
for qemuppc, and configured with options --enable-debug-frame and
--enable-debug, then the shortfall in the size of the 'opaque' member
of the unw_cursor_t type throws an assert in mi_init().
The calculations for the ppc32 target size of UNW_TDEP_CURSOR_LEN in
the comment block based on the register count plus overhead sum to 280
words. However, that value is not reflected in the ppc32 header, which
defines the size as 200. Fixing the ppc32 header value to 280 makes the
unw_cursor_t type larger than struct cursor type and the assert tests
true at run-time in mi_init().
Signed-off-by Dave Lerner <dave.lerner@windriver.com>
Make sure that we have included `config.h' before checking HAVE_LZMA.
This makes a difference at least on MIPS, where we include `elfxx.c'
directly. For other platforms this does not make much difference, as we
are already indirectly including `config.h' from other headers.
We do not modify `_UPT_reg_offset', so let's set it `const'. Given that
the array is exported, it's technically possible that some library user
is actually modifying the content, but does not seem really all that
likely.
src/ptrace/_UPT_find_proc_info.c: In function 'get_unwind_info':
src/ptrace/_UPT_find_proc_info.c:67: warning: implicit declaration of function 'ia64_find_unwind_table'
