On Tue, 2022-08-30 at 15:48 +0200, Jiri Olsa wrote: > On Tue, Aug 30, 2022 at 12:25:25AM +0200, Daniel Borkmann wrote: > > On 8/26/22 8:46 PM, Jiri Olsa wrote: > > > hi, > > > as discussed [1] sending fix that moves bpf dispatcher function > > > of out > > > ftrace locations together with Peter's > > > HAVE_DYNAMIC_FTRACE_NO_PATCHABLE > > > dependency change. > > > > Looks like the series breaks s390x builds; BPF CI link: > > > > https://github.com/kernel-patches/bpf/runs/8079411784?check_suite_focus=true > > > > [...] > > CC net/xfrm/xfrm_state.o > > CC net/packet/af_packet.o > > {standard input}: Assembler messages: > > {standard input}:16055: Error: bad expression > > {standard input}:16056: Error: bad expression > > {standard input}:16057: Error: bad expression > > {standard input}:16058: Error: bad expression > > {standard input}:16059: Error: bad expression > > CC drivers/s390/char/raw3270.o > > CC net/ipv6/ip6_output.o > > [...] > > CC net/xfrm/xfrm_output.o > > CC net/ipv6/ip6_input.o > > {standard input}:16055: Error: invalid operands (*ABS* and *UND* > > sections) for `%' > > {standard input}:16056: Error: invalid operands (*ABS* and *UND* > > sections) for `%' > > {standard input}:16057: Error: invalid operands (*ABS* and *UND* > > sections) for `%' > > {standard input}:16058: Error: invalid operands (*ABS* and *UND* > > sections) for `%' > > {standard input}:16059: Error: invalid operands (*ABS* and *UND* > > sections) for `%' > > make[3]: *** [scripts/Makefile.build:249: net/core/filter.o] > > Error 1 > > make[2]: *** [scripts/Makefile.build:465: net/core] Error 2 > > make[2]: *** Waiting for unfinished jobs.... > > CC net/ipv4/tcp_fastopen.o > > [...] > > CC lib/percpu-refcount.o > > make[1]: *** [Makefile:1855: net] Error 2 > > CC lib/rhashtable.o > > make[1]: *** Waiting for unfinished jobs.... > > CC lib/base64.o > > [...] > > AR lib/built-in.a > > CC kernel/kheaders.o > > AR kernel/built-in.a > > make: *** [Makefile:353: __build_one_by_one] Error 2 > > Error: Process completed with exit code 2. > > > it does not break on my cross build with gcc 12, but I can > reproduce with gcc 8 (CI seems to be on gcc 9) > > the problem seems to be wrong assembler code with extra '%' > that's generated for patchable_function_entry(5) > > gcc 8 generates: > > .LPFE1: > nopr %%r0 > nopr %%r0 > nopr %%r0 > nopr %%r0 > nopr %%r0 > > and gcc 12 generates: > > .LPFE1: > nopr %r0 > nopr %r0 > nopr %r0 > nopr %r0 > nopr %r0 > > perhaps we need to upgrade gcc in CI? cc-ing Ilya, any idea? > > thanks, > jirka It's not obvious to me which gcc commit fixed this; I will bisect and find out. This will take some time. However, officially, the kernel must be buildable by gcc 5.1+. Whatever I find, it's unlikely that we'll be able to backport it that far. Therefore I think we need to find a way to conditionally do something else when using broken gccs. Or maybe just keep this x86-only after all. Best regards, Ilya
