• Emese Revfy's avatar
    GCC plugin infrastructure · 6b90bd4b
    Emese Revfy authored
    This patch allows to build the whole kernel with GCC plugins. It was ported from
    grsecurity/PaX. The infrastructure supports building out-of-tree modules and
    building in a separate directory. Cross-compilation is supported too.
    Currently the x86, arm, arm64 and uml architectures enable plugins.
    
    The directory of the gcc plugins is scripts/gcc-plugins. You can use a file or a directory
    there. The plugins compile with these options:
     * -fno-rtti: gcc is compiled with this option so the plugins must use it too
     * -fno-exceptions: this is inherited from gcc too
     * -fasynchronous-unwind-tables: this is inherited from gcc too
     * -ggdb: it is useful for debugging a plugin (better backtrace on internal
        errors)
     * -Wno-narrowing: to suppress warnings from gcc headers (ipa-utils.h)
     * -Wno-unused-variable: to suppress warnings from gcc headers (gcc_version
        variable, plugin-version.h)
    
    The infrastructure introduces a new Makefile target called gcc-plugins. It
    supports all gcc versions from 4.5 to 6.0. The scripts/gcc-plugin.sh script
    chooses the proper host compiler (gcc-4.7 can be built by either gcc or g++).
    This script also checks the availability of the included headers in
    scripts/gcc-plugins/gcc-common.h.
    
    The gcc-common.h header contains frequently included headers for GCC plugins
    and it has a compatibility layer for the supported gcc versions.
    
    The gcc-generate-*-pass.h headers automatically generate the registration
    structures for GIMPLE, SIMPLE_IPA, IPA and RTL passes.
    
    Note that 'make clean' keeps the *.so files (only the distclean or mrproper
    targets clean all) because they are needed for out-of-tree modules.
    
    Based on work created by the PaX Team.
    Signed-off-by: 's avatarEmese Revfy <re.emese@gmail.com>
    Acked-by: 's avatarKees Cook <keescook@chromium.org>
    Signed-off-by: 's avatarMichal Marek <mmarek@suse.com>
    6b90bd4b