Re: [PATCH bpf-next RFC v1 7/8] bpf: enable TCP congestion control kfunc from modules
From: Andrii Nakryiko <hidden>
Date: 2021-09-01 00:48:30
Also in:
bpf
On Mon, Aug 30, 2021 at 10:34 AM Kumar Kartikeya Dwivedi [off-list ref] wrote:
This commit moves BTF ID lookup into the newly added registration helper, in a way that the bbr, cubic, and dctcp implementation set up their sets in the bpf_tcp_ca kfunc_btf_set list, while the ones not dependent on modules are looked up from the wrapper function. This lifts the restriction for them to be compiled as built in objects, and can be loaded as modules if required. Also modify link-vmlinux.sh to resolve_btfids in TCP congestion control modules if the config option is set, using the base BTF support added in the previous commit. See following commits for background on use of: CONFIG_X86 ifdef: 569c484f9995 (bpf: Limit static tcp-cc functions in the .BTF_ids list to x86) CONFIG_DYNAMIC_FTRACE ifdef: 7aae231ac93b (bpf: tcp: Limit calling some tcp cc functions to CONFIG_DYNAMIC_FTRACE) Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> --- include/linux/btf.h | 2 ++ kernel/bpf/btf.c | 2 ++ net/ipv4/bpf_tcp_ca.c | 34 +++------------------------------- net/ipv4/tcp_bbr.c | 28 +++++++++++++++++++++++++++- net/ipv4/tcp_cubic.c | 26 +++++++++++++++++++++++++- net/ipv4/tcp_dctcp.c | 26 +++++++++++++++++++++++++- scripts/Makefile.modfinal | 1 + 7 files changed, 85 insertions(+), 34 deletions(-)
[...]
quoted hunk ↗ jump to hunk
diff --git a/scripts/Makefile.modfinal b/scripts/Makefile.modfinal index 5e9b8057fb24..0755d4b8b74a 100644 --- a/scripts/Makefile.modfinal +++ b/scripts/Makefile.modfinal@@ -58,6 +58,7 @@ quiet_cmd_btf_ko = BTF [M] $@ cmd_btf_ko = \ if [ -f vmlinux ]; then \ LLVM_OBJCOPY="$(OBJCOPY)" $(PAHOLE) -J --btf_base vmlinux $@; \ + $(RESOLVE_BTFIDS) --no-fail -s vmlinux $@; \
why is this --no-fail?
else \
printf "Skipping BTF generation for %s due to unavailability of vmlinux\n" $@ 1>&2; \
fi;
--
2.33.0