From: Andrii Nakryiko andrii@kernel.org
mainline inclusion from mainline-5.11-rc1 commit a67079b03165a17f9aceab3dd26b1638af68e0fc 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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bpf_testmod.ko build rule declared dependency on VMLINUX_BTF, but the variable itself was initialized after the rule was declared, which often caused bpf_testmod.ko to not be re-compiled. Fix by moving VMLINUX_BTF determination sooner.
Also enforce bpf_testmod.ko recompilation when we detect that vmlinux image changed by removing bpf_testmod/bpf_testmod.ko. This is necessary to generate correct module's split BTF. Without it, Kbuild's module build logic might determine that nothing changed on the kernel side and thus bpf_testmod.ko shouldn't be rebuilt, so won't re-generate module BTF, which often leads to module's BTF with wrong string offsets against vmlinux BTF. Removing .ko file forces Kbuild to re-build the module.
Reported-by: Alexei Starovoitov ast@kernel.org Fixes: 9f7fa225894c ("selftests/bpf: Add bpf_testmod kernel module for testing") Signed-off-by: Andrii Nakryiko andrii@kernel.org Link: https://lore.kernel.org/r/20201211015946.4062098-1-andrii@kernel.org Signed-off-by: Alexei Starovoitov ast@kernel.org (cherry picked from commit a67079b03165a17f9aceab3dd26b1638af68e0fc) Signed-off-by: Wang Yufen wangyufen@huawei.com
Conflicts: tools/testing/selftests/bpf/Makefile
Signed-off-by: Wang Yufen wangyufen@huawei.com --- tools/testing/selftests/bpf/Makefile | 21 +++++++++++---------- 1 file changed, 11 insertions(+), 10 deletions(-)
diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile index 729b4255343a..db52c29b073c 100644 --- a/tools/testing/selftests/bpf/Makefile +++ b/tools/testing/selftests/bpf/Makefile @@ -116,6 +116,16 @@ INCLUDE_DIR := $(SCRATCH_DIR)/include BPFOBJ := $(BUILD_DIR)/libbpf/libbpf.a RESOLVE_BTFIDS := $(BUILD_DIR)/resolve_btfids/resolve_btfids
+VMLINUX_BTF_PATHS ?= $(if $(O),$(O)/vmlinux) \ + $(if $(KBUILD_OUTPUT),$(KBUILD_OUTPUT)/vmlinux) \ + ../../../../vmlinux \ + /sys/kernel/btf/vmlinux \ + /boot/vmlinux-$(shell uname -r) +VMLINUX_BTF ?= $(abspath $(firstword $(wildcard $(VMLINUX_BTF_PATHS)))) +ifeq ($(VMLINUX_BTF),) +$(error Cannot find a vmlinux for VMLINUX_BTF at any of "$(VMLINUX_BTF_PATHS)") +endif + # Define simple and short `make test_progs`, `make test_sysctl`, etc targets # to build individual tests. # NOTE: Semicolon at the end is critical to override lib.mk's default static @@ -140,6 +150,7 @@ $(OUTPUT)/urandom_read: urandom_read.c
$(OUTPUT)/bpf_testmod.ko: $(VMLINUX_BTF) $(wildcard bpf_testmod/Makefile bpf_testmod/*.[ch]) $(call msg,MOD,,$@) + $(Q)$(RM) bpf_testmod/bpf_testmod.ko # force re-compilation $(Q)$(MAKE) $(submake_extras) -C bpf_testmod $(Q)cp bpf_testmod/bpf_testmod.ko $@
@@ -147,16 +158,6 @@ $(OUTPUT)/test_stub.o: test_stub.c $(BPFOBJ) $(call msg,CC,,$@) $(Q)$(CC) -c $(CFLAGS) -o $@ $<
-VMLINUX_BTF_PATHS ?= $(if $(O),$(O)/vmlinux) \ - $(if $(KBUILD_OUTPUT),$(KBUILD_OUTPUT)/vmlinux) \ - ../../../../vmlinux \ - /sys/kernel/btf/vmlinux \ - /boot/vmlinux-$(shell uname -r) -VMLINUX_BTF ?= $(abspath $(firstword $(wildcard $(VMLINUX_BTF_PATHS)))) -ifeq ($(VMLINUX_BTF),) -$(error Cannot find a vmlinux for VMLINUX_BTF at any of "$(VMLINUX_BTF_PATHS)") -endif - DEFAULT_BPFTOOL := $(SCRATCH_DIR)/sbin/bpftool
$(OUTPUT)/runqslower: $(BPFOBJ) | $(DEFAULT_BPFTOOL)