Thanks Deborah, Le mercredi 24 mai 2023 à 17:20 -0700, Deborah Brouwer a écrit : > From: Nicolas Dufresne <nicolas.dufresne@xxxxxxxxxxxxx> > > The code was still assuming libtools being use, so it didn't work > installed anymore. Also, it didn't work installed if the full > v4l2-tracer path was being passed. > > Fix this by always trying next by libv4l2tracer.so loading (using stat() > to validate) and always fallback to the installed path otherwise. > > Signed-off-by: Nicolas Dufresne <nicolas.dufresne@xxxxxxxxxxxxx> Mind adding you Singed-off-by ? > --- > Hi - thanks to Nicolas for this patch. > I tested tracing and retracing on both installed and uninstalled > v4l2-tracer including with and without an absolute path and it > all works as expected. > > Note that I've got three sets of v4l2-tracer patches outstanding now, > but they all still apply independently of each other: > > Tuner patches: > https://lore.kernel.org/linux-media/cover.1684453027.git.deborah.brouwer@xxxxxxxxxxxxx/ > > Debug patches: > https://lore.kernel.org/linux-media/cover.1681245372.git.deborah.brouwer@xxxxxxxxxxxxx/ > > Thanks, > Deb > > utils/v4l2-tracer/v4l2-tracer.cpp | 33 +++++++++++++++++-------------- > 1 file changed, 18 insertions(+), 15 deletions(-) > > diff --git a/utils/v4l2-tracer/v4l2-tracer.cpp b/utils/v4l2-tracer/v4l2-tracer.cpp > index e3f002a9..7c3662be 100644 > --- a/utils/v4l2-tracer/v4l2-tracer.cpp > +++ b/utils/v4l2-tracer/v4l2-tracer.cpp > @@ -5,6 +5,7 @@ > > #include "retrace.h" > #include <climits> > +#include <sys/stat.h> > #include <sys/wait.h> > #include <time.h> > > @@ -295,24 +296,26 @@ int tracer(int argc, char *argv[], bool retrace) > fclose(trace_file); > > /* > - * Preload the libv4l2tracer library. If the program is installed, load the library > - * from its installed location, otherwise load it locally. If it's loaded locally, > - * use ./configure --disable-dyn-libv4l. > + * Preload the libv4l2tracer library. The libv4l2tracer is looked up next to > + * the executable first in order to support uninstalled build. > */ > std::string libv4l2tracer_path; > std::string program = argv[0]; > - std::size_t idx = program.rfind("/v4l2-tracer"); > - if (idx != std::string::npos) { > - libv4l2tracer_path = program.replace(program.begin() + idx + 1, program.end(), ".libs"); > - DIR *directory_pointer = opendir(libv4l2tracer_path.c_str()); > - if (directory_pointer == nullptr) > - libv4l2tracer_path = program.replace(program.begin() + idx, program.end(), "./.libs"); > - else > - closedir(directory_pointer); > - } else { > - libv4l2tracer_path = LIBTRACER_PATH; > - } > - libv4l2tracer_path += "/libv4l2tracer.so"; > + std::size_t idx = program.rfind("/"); > + struct stat sb; > + > + if (idx == std::string::npos) > + idx = 0; > + else > + idx++; > + > + /* look for libv4l2tracer next to the executable */ > + libv4l2tracer_path = program.replace(program.begin() + idx, program.end(), "libv4l2tracer.so"); > + > + /* otherwise, use the installation path */ > + if (stat(libv4l2tracer_path.c_str(), &sb) == -1) > + libv4l2tracer_path = std::string(LIBTRACER_PATH) + "/libv4l2tracer.so"; > + > if (is_verbose()) > fprintf(stderr, "Loading libv4l2tracer: %s\n", libv4l2tracer_path.c_str()); > setenv("LD_PRELOAD", libv4l2tracer_path.c_str(), 0);
