• David 'Digit' Turner's avatar
    Fix the C library initialization to avoid calling static C++ constructors twice. · 03eabfe6
    David 'Digit' Turner authored
    The problem was due to the fact that, in the case of dynamic executables,
    the dynamic linker calls the DT_PREINIT_ARRAY, DT_INIT and DT_INIT_ARRAY
    constructors when loading shared libraries and dynamic executables,
    *before* calling the executable's entry point (i.e. arch-$ARCH/bionic/crtbegin_dynamic.c)
    which in turns call __libc_init() in libc.so, as defined by bionic/libc_init_dynamic.c
    
    The latter did call these constructors array again, mistakenly.
    
    The patch also updates the documentation of many related functions.
    
    Also adds a new section to linker/README.TXT explaining restrictions on
    C library usage.
    
    The patch has been tested on a Dream for stability issues with
    proprietary blobs:
    
    - H264 decoding works
    - Camera + Video recording works
    - GPS works
    - Sensors work
    
    The tests in system/extra/tests/bionic/libc/common/test_static_cpp_mutex.cpp has been
    run and shows the static C++ constructor being called only once.
    03eabfe6
libc_init_common.c 3.55 KB