From: Andrii Nakryiko andrii@kernel.org
mainline inclusion from mainline-5.13-rc1 commit 14137f3c62186799b01eea8a338f90c9cbc57f00 category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I5EUVD CVE: NA
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...
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Pass all individual BPF object files (generated from progs/*.c) through `bpftool gen object` command to validate that BPF static linker doesn't corrupt them.
As an additional sanity checks, validate that passing resulting object files through linker again results in identical ELF files. Exact same ELF contents can be guaranteed only after two passes, as after the first pass ELF sections order changes, and thus .BTF.ext data sections order changes. That, in turn, means that strings are added into the final BTF string sections in different order, so .BTF strings data might not be exactly the same. But doing another round of linking afterwards should result in the identical ELF file, which is checked with additional `diff` command.
Signed-off-by: Andrii Nakryiko andrii@kernel.org Signed-off-by: Alexei Starovoitov ast@kernel.org Link: https://lore.kernel.org/bpf/20210318194036.3521577-12-andrii@kernel.org (cherry picked from commit 14137f3c62186799b01eea8a338f90c9cbc57f00) Signed-off-by: Wang Yufen wangyufen@huawei.com --- tools/testing/selftests/bpf/Makefile | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-)
diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile index cd0e436be9d9..d730b4bfbccf 100644 --- a/tools/testing/selftests/bpf/Makefile +++ b/tools/testing/selftests/bpf/Makefile @@ -348,12 +348,13 @@ $(TRUNNER_BPF_OBJS): $(TRUNNER_OUTPUT)/%.o: \ $$(call $(TRUNNER_BPF_BUILD_RULE),$$<,$$@, \ $(TRUNNER_BPF_CFLAGS))
-$(TRUNNER_BPF_SKELS): $(TRUNNER_OUTPUT)/%.skel.h: \ - $(TRUNNER_OUTPUT)/%.o \ - $(BPFTOOL) \ - | $(TRUNNER_OUTPUT) +$(TRUNNER_BPF_SKELS): %.skel.h: %.o $(BPFTOOL) | $(TRUNNER_OUTPUT) $$(call msg,GEN-SKEL,$(TRUNNER_BINARY),$$@) - $(Q)$$(BPFTOOL) gen skeleton $$< > $$@ + $(Q)$$(BPFTOOL) gen object $$(<:.o=.linked.o) $$< + $(Q)$$(BPFTOOL) gen object $$(<:.o=.linked2.o) $$(<:.o=.linked.o) + $(Q)$$(BPFTOOL) gen object $$(<:.o=.linked3.o) $$(<:.o=.linked2.o) + $(Q)diff $$(<:.o=.linked2.o) $$(<:.o=.linked3.o) + $(Q)$$(BPFTOOL) gen skeleton $$(<:.o=.linked.o) name $$(notdir $$(<:.o=)) > $$@ endif
# ensure we set up tests.h header generation rule just once