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 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
We can use the __sync builtin atomics also on other architectures than
IA64. GCC 4.7 documentation notes that these builtins are ``legacy'' --
adding support for the newer GCC __atomic atomics should be fairly easy.
Instead of maintaining a pointer to the `sos_memory' array, maintain an
index that tells the next free position. When atomic operations are
available, the allocation boils down to a single fetch-and-add
operation.
Rename the `ALIGN' macro to `UNW_ALIGN', and move it from
`_UCD_internal.h' to `libunwind_i.h' so that we can share it with the
mempool code. `ALIGN' was clashing with system headers on FreeBSD:
In file included from src/coredump/_UCD_access_reg_freebsd.c:26:
src/coredump/_UCD_internal.h:102:1: warning: "ALIGN" redefined
In file included from /usr/include/sys/param.h:115,
from src/coredump/_UCD_lib.h:52,
from src/coredump/_UCD_access_reg_freebsd.c:24:
/usr/include/machine/param.h:79:1: warning: this is the location of the previous definition
This is a common part of struct UPT_info
and struct UCD_info (to be introduced later).
Make _UPTi_find_unwind_table function operate only on this part
of struct UPT_info.
Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Define GNU and processor specific values for the Phdr p_type field in case
they aren't defined by <elf.h> already.
Signed-off-by: Ken Werner <ken.werner@linaro.org>
This change prevents libunwind_i.h from using a self-defined MAP_ANONYMOUS and
therefore avoids collisions in case the system header gets pulled in later.
Signed-off-by: Ken Werner <ken.werner@linaro.org>
Insert static branch prediction predicates in useful places and avoid
unnecessary code in the hottest paths. Bypass unnecessary indirect
calls, in particular to access_mem(), when known to be safe.
Greetings,
Here is the second part, actually implementing the configure option.
Thanks,
--
Paul Pluzhnikov
commit cf823ed0d4d2447aa91af0e3cb5fbb6a6cba5068
Author: Paul Pluzhnikov <ppluzhnikov@google.com>
Date: Mon Sep 21 11:37:38 2009 -0700
New configure option to allow caller to block signals.
routine and add address-space argument. This is needed because on
PPC64, a the function-name symbol refers to a function descriptor
(unlike, for example, on ia64, where the @fptr() operator is needed to
refer to a function descriptor). Thus, in order to look up the name
of a function, we need to dereference the function descriptor. To
make matters more "interesting", the function descriptors are normally
resolved by the dynamic linker, so we can't get their values from the
ELF file. Instead, we have to read them from the running image, hence
the need for the address-space argument.
