From 1d8ca53d581fb9e088ca2a91ca72788f32f7ec59 Mon Sep 17 00:00:00 2001 From: Kieran Bingham Date: Tue, 4 Feb 2020 18:00:04 +0000 Subject: libcamera: ipa_manager: Search for IPA libraries in build tree When libcamera is built and tested (or used at all) before installing to the configured prefix path, it will be unable to locate the IPA binaries, or IPA binaries previously installed in the system paths may be incorrect to load. Utilise the build_rpath dynamic tag which is stripped out by meson at install time to determine at runtime if the library currently executing has been installed or not. When not installed and running from a build tree, identify the location of that tree by finding the path of the active libcamera.so itself, and from that point add a relative path to be able to load the most recently built IPA modules. Signed-off-by: Kieran Bingham Reviewed-by: Laurent Pinchart --- src/libcamera/ipa_manager.cpp | 52 ++++++++++++++++++++++++++++++++++++++++++- src/libcamera/meson.build | 6 +++++ 2 files changed, 57 insertions(+), 1 deletion(-) diff --git a/src/libcamera/ipa_manager.cpp b/src/libcamera/ipa_manager.cpp index de99a0bc..238433dc 100644 --- a/src/libcamera/ipa_manager.cpp +++ b/src/libcamera/ipa_manager.cpp @@ -9,6 +9,9 @@ #include #include +#include +#include +#include #include #include @@ -24,6 +27,35 @@ * \brief Image Processing Algorithm module manager */ +static bool isLibcameraInstalled() +{ + /* musl doesn't declare _DYNAMIC in link.h, declare it manually. */ + extern ElfW(Dyn) _DYNAMIC[]; + + /* + * DT_RUNPATH (DT_RPATH when the linker uses old dtags) is removed on + * install. + */ + for (const ElfW(Dyn) *dyn = _DYNAMIC; dyn->d_tag != DT_NULL; ++dyn) { + if (dyn->d_tag == DT_RUNPATH || dyn->d_tag == DT_RPATH) + return false; + } + + return true; +} + +static std::string libcameraPath() +{ + Dl_info info; + + /* Look up our own symbol. */ + int ret = dladdr(reinterpret_cast(libcameraPath), &info); + if (ret == 0) + return nullptr; + + return info.dli_fname; +} + namespace libcamera { LOG_DEFINE_CATEGORY(IPAManager) @@ -112,7 +144,25 @@ IPAManager::IPAManager() << "No IPA found in '" << modulePaths << "'"; } - /* Load IPAs from the installed system path. */ + /* + * When libcamera is used before it is installed, load IPAs from the + * same build directory as the libcamera library itself. This requires + * identifying the path of the libcamera.so, and referencing a relative + * path for the IPA from that point. We need to recurse one level of + * sub-directories to match the build tree. + */ + if (!isLibcameraInstalled()) { + std::string ipaBuildPath = utils::dirname(libcameraPath()) + "/../ipa"; + constexpr int maxDepth = 1; + + LOG(IPAManager, Info) + << "libcamera is not installed. Adding '" + << ipaBuildPath << "' to the IPA search path"; + + ipaCount += addDir(ipaBuildPath.c_str(), maxDepth); + } + + /* Finally try to load IPAs from the installed system path. */ ipaCount += addDir(IPA_MODULE_DIR); if (!ipaCount) diff --git a/src/libcamera/meson.build b/src/libcamera/meson.build index 1e5b54b3..88658ac5 100644 --- a/src/libcamera/meson.build +++ b/src/libcamera/meson.build @@ -107,11 +107,17 @@ if get_option('android') libcamera_link_with += android_camera_metadata endif +# We add '/' to the build_rpath as a 'safe' path to act as a boolean flag. +# The build_rpath is stripped at install time by meson, so we determine at +# runtime if the library is running from an installed location by checking +# for the presence or abscence of the dynamic tag. + libcamera = shared_library('camera', libcamera_sources, install : true, link_with : libcamera_link_with, include_directories : includes, + build_rpath : '/', dependencies : libcamera_deps) libcamera_dep = declare_dependency(sources : [libcamera_api, libcamera_ipa_api, libcamera_h], -- cgit v1.2.1