libcamera: base: backtrace: Use libdw to provide symbolic names

libdw provides access to debugging information. This allows creating
better stack trace entries, with file names and line numbers, but also
with demangled symbols as the symbol name is available and can be passed
to abi::__cxa_demangle().

With libdw, the backtrace previously generated by backtrace_symbols()

src/cam/../libcamera/libcamera.so(_ZN9libcamera14VimcCameraData4initEv+0xbd) [0x7f7dbb73222d]
src/cam/../libcamera/libcamera.so(_ZN9libcamera19PipelineHandlerVimc5matchEPNS_16DeviceEnumeratorE+0x3e0) [0x7f7dbb731c40]
src/cam/../libcamera/libcamera.so(_ZN9libcamera13CameraManager7Private22createPipelineHandlersEv+0x1a7) [0x7f7dbb5ea027]
src/cam/../libcamera/libcamera.so(_ZN9libcamera13CameraManager7Private4initEv+0x98) [0x7f7dbb5e9dc8]
src/cam/../libcamera/libcamera.so(_ZN9libcamera13CameraManager7Private3runEv+0x9f) [0x7f7dbb5e9c5f]
src/cam/../libcamera/base/libcamera-base.so(_ZN9libcamera6Thread11startThreadEv+0xee) [0x7f7dbb3e95be]
src/cam/../libcamera/base/libcamera-base.so(+0x4f9d7) [0x7f7dbb3ec9d7]
src/cam/../libcamera/base/libcamera-base.so(+0x4f90e) [0x7f7dbb3ec90e]
src/cam/../libcamera/base/libcamera-base.so(+0x4f2c2) [0x7f7dbb3ec2c2]
/lib64/libpthread.so.0(+0x7e8e) [0x7f7dbab65e8e]
/lib64/libc.so.6(clone+0x3f) [0x7f7dbb10b26f]

becomes

libcamera::VimcCameraData::init()+0xbd (src/libcamera/libcamera.so [0x00007f9de605b22d])
libcamera::PipelineHandlerVimc::match(libcamera::DeviceEnumerator*)+0x3e0 (src/libcamera/libcamera.so [0x00007f9de605ac40])
libcamera::CameraManager::Private::createPipelineHandlers()+0x1a7 (src/libcamera/libcamera.so [0x00007f9de5f13027])
libcamera::CameraManager::Private::init()+0x98 (src/libcamera/libcamera.so [0x00007f9de5f12dc8])
libcamera::CameraManager::Private::run()+0x9f (src/libcamera/libcamera.so [0x00007f9de5f12c5f])
libcamera::Thread::startThread()+0xee (src/libcamera/base/libcamera-base.so [0x00007f9de5d125be])
decltype(*(std::__1::forward<libcamera::Thread*>(fp0)).*fp()) std::__1::__invoke<void (libcamera::Thread::*)(), libcamera::Thread*, void>(void (libcamera::Thread::*&&)(), libcamera::Thread*&&)+0x77 (src/libcamera/base/libcamera-base.so [0x00007f9de5d159d7])
void std::__1::__thread_execute<std::__1::unique_ptr<std::__1::__thread_struct, std::__1::default_delete<std::__1::__thread_struct> >, void (libcamera::Thread::*)(), libcamera::Thread*, 2ul>(std::__1::tuple<std::__1::unique_ptr<std::__1::__thread_struct, std::__1::default_delete<std::__1::__thread_struct> >, void (libcamera::Thread::*)(), libcamera::Thread*>&, std::__1::__tuple_indices<2ul>)+0x3e (src/libcamera/base/libcamera-base.so [0x00007f9de5d1590e])
void* std::__1::__thread_proxy<std::__1::tuple<std::__1::unique_ptr<std::__1::__thread_struct, std::__1::default_delete<std::__1::__thread_struct> >, void (libcamera::Thread::*)(), libcamera::Thread*> >(void*)+0x62 (src/libcamera/base/libcamera-base.so [0x00007f9de5d152c2])
start_thread+0xde (/var/tmp/portage/sys-libs/glibc-2.33-r1/work/glibc-2.33/nptl/pthread_create.c:482)
__clone+0x3f (../sysdeps/unix/sysv/linux/x86_64/clone.S:97)

The stack entries related to libcamera are missing source file name and
line information, which will be investigated separately, but this is
still an improvement.

Use libdw when available, falling back to backtrace_symbols() otherwise,
or if libdw fails for any reason.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

0 files changed, 0 insertions, 0 deletions