On Sat, Aug 14, 2021 at 4:27 PM Masahiro Yamada <masahiroy@xxxxxxxxxx> wrote: > > On Fri, Aug 13, 2021 at 6:46 AM 'Sami Tolvanen' via Clang Built Linux > <clang-built-linux@xxxxxxxxxxxxxxxx> wrote: > > > > With CONFIG_LTO_CLANG, we currently link modules into native > > code just before modpost, which means with TRIM_UNUSED_KSYMS > > enabled, we still look at the LLVM bitcode in the .o files when > > generating the list of used symbols. As the bitcode doesn't > > yet have calls to compiler intrinsics and llvm-nm doesn't see > > function references that only exist in function-level inline > > assembly, we currently need a whitelist for TRIM_UNUSED_KSYMS to > > work with LTO. > > > > This change moves module LTO linking to happen earlier, and > > thus avoids the issue with LLVM bitcode and TRIM_UNUSED_KSYMS > > entirely, allowing us to also drop the whitelist from > > gen_autoksyms.sh. > > > > Link: https://github.com/ClangBuiltLinux/linux/issues/1369 > > Signed-off-by: Sami Tolvanen <samitolvanen@xxxxxxxxxx> > > Reviewed-by: Alexander Lobakin <alobakin@xxxxx> > > Tested-by: Alexander Lobakin <alobakin@xxxxx> > > --- > > Changes in v3: > > - Added missing FORCE. > > > > All the modules are recompiled every time. Oops, .lto.o is missing from targets still, which breaks if_changed. Fixed in v4. Thanks for testing! Sami
