On Wed, Aug 23, 2023 at 4:02 PM Masahiro Yamada <masahiroy@xxxxxxxxxx> wrote: > > On Wed, Aug 23, 2023 at 3:00 AM Fangrui Song <maskray@xxxxxxxxxx> wrote: > > > > On Tue, Aug 22, 2023 at 10:49 AM Denis Nikitin <denik@xxxxxxxxxxxx> wrote: > > > > > > .llvm.call-graph-profile section is added by clang when the kernel is > > > built with profiles (e.g. -fprofile-sample-use= or -fprofile-use=). > > > > > > The section contains edge information derived from text sections, > > > so .llvm.call-graph-profile itself doesn't need more analysis as > > > the text sections have been analyzed. > > > > > > This change fixes the kernel build with clang and a sample profile > > > which currently fails with: > > > > > > "FATAL: modpost: Please add code to calculate addend for this architecture" > > > Curious. > > This message is only displayed for REL. > > (Please not it is located in section_rel() function) > > > I think modern architectures use RELA instead of REL. > Which architecture are we talking about? Aarch64. There was also a report on x86-64 but the error message could be different there. > > > What does the output of this command look like? > > $ llvm-readelf -S vmlinux.o | grep .llvm.call-graph-profile > > > Is it REL? > [119] .llvm.call-graph-profile LLVM_CALL_GRAPH_PROFILE 0000000000000000 1c74a458 0104c8 08 E 0 0 1 [120] .rel.llvm.call-graph-profile REL 0000000000000000 1c75a920 041320 10 I 26090 119 8 Thanks, Denis
