[PATCH v2 12/13] selftests/bpf: Enable signature verification for all lskel tests
KP Singh
kpsingh at kernel.org
Mon Jul 21 21:19:57 UTC 2025
Convert the kernel's generated verification certificate into a C header
file using xxd. Finally, update the main test runner to load this
certificate into the session keyring via the add_key() syscall before
executing any tests.
The test harness uses the verify_sig_setup.sh to generate the required
key material for program signing.
Signed-off-by: KP Singh <kpsingh at kernel.org>
---
tools/testing/selftests/bpf/.gitignore | 1 +
tools/testing/selftests/bpf/Makefile | 19 +++++++++++++++++--
tools/testing/selftests/bpf/test_progs.c | 13 +++++++++++++
.../testing/selftests/bpf/verify_sig_setup.sh | 13 +++++++++++--
4 files changed, 42 insertions(+), 4 deletions(-)
diff --git a/tools/testing/selftests/bpf/.gitignore b/tools/testing/selftests/bpf/.gitignore
index 3d8378972d26..be1ee7ba7ce0 100644
--- a/tools/testing/selftests/bpf/.gitignore
+++ b/tools/testing/selftests/bpf/.gitignore
@@ -44,3 +44,4 @@ xdp_redirect_multi
xdp_synproxy
xdp_hw_metadata
xdp_features
+verification_cert.h
diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
index 4863106034df..1295ff8f26ff 100644
--- a/tools/testing/selftests/bpf/Makefile
+++ b/tools/testing/selftests/bpf/Makefile
@@ -535,6 +535,7 @@ HEADERS_FOR_BPF_OBJS := $(wildcard $(BPFDIR)/*.bpf.h) \
# $2 - test runner extra "flavor" (e.g., no_alu32, cpuv4, bpf_gcc, etc)
define DEFINE_TEST_RUNNER
+LSKEL_SIGN := -S -k $(PRIVATE_KEY) -i $(VERIFICATION_CERT)
TRUNNER_OUTPUT := $(OUTPUT)$(if $2,/)$2
TRUNNER_BINARY := $1$(if $2,-)$2
TRUNNER_TEST_OBJS := $$(patsubst %.c,$$(TRUNNER_OUTPUT)/%.test.o, \
@@ -601,7 +602,7 @@ $(TRUNNER_BPF_LSKELS): %.lskel.h: %.bpf.o $(BPFTOOL) | $(TRUNNER_OUTPUT)
$(Q)$$(BPFTOOL) gen object $$(<:.o=.llinked2.o) $$(<:.o=.llinked1.o)
$(Q)$$(BPFTOOL) gen object $$(<:.o=.llinked3.o) $$(<:.o=.llinked2.o)
$(Q)diff $$(<:.o=.llinked2.o) $$(<:.o=.llinked3.o)
- $(Q)$$(BPFTOOL) gen skeleton -L $$(<:.o=.llinked3.o) name $$(notdir $$(<:.bpf.o=_lskel)) > $$@
+ $(Q)$$(BPFTOOL) gen skeleton $(LSKEL_SIGN) $$(<:.o=.llinked3.o) name $$(notdir $$(<:.bpf.o=_lskel)) > $$@
$(Q)rm -f $$(<:.o=.llinked1.o) $$(<:.o=.llinked2.o) $$(<:.o=.llinked3.o)
$(LINKED_BPF_OBJS): %: $(TRUNNER_OUTPUT)/%
@@ -667,6 +668,7 @@ $(foreach N,$(patsubst $(TRUNNER_OUTPUT)/%.o,%,$(TRUNNER_EXTRA_OBJS)), \
$(TRUNNER_EXTRA_OBJS): $(TRUNNER_OUTPUT)/%.o: \
%.c \
$(TRUNNER_EXTRA_HDRS) \
+ $(VERIFY_SIG_HDR) \
$(TRUNNER_TESTS_HDR) \
$$(BPFOBJ) | $(TRUNNER_OUTPUT)
$$(call msg,EXT-OBJ,$(TRUNNER_BINARY),$$@)
@@ -697,6 +699,18 @@ $(OUTPUT)/$(TRUNNER_BINARY): $(TRUNNER_TEST_OBJS) \
endef
+VERIFY_SIG_SETUP := $(CURDIR)/verify_sig_setup.sh
+VERIFY_SIG_HDR := verification_cert.h
+VERIFICATION_CERT := $(BUILD_DIR)/signing_key.der
+PRIVATE_KEY := $(BUILD_DIR)/signing_key.pem
+
+$(VERIFICATION_CERT) $(PRIVATE_KEY): $(VERIFY_SIG_SETUP)
+ $(Q)mkdir -p $(BUILD_DIR)
+ $(Q)$(VERIFY_SIG_SETUP) genkey $(BUILD_DIR)
+
+$(VERIFY_SIG_HDR): $(VERIFICATION_CERT)
+ $(Q)xxd -i -n test_progs_verification_cert $< > $@
+
# Define test_progs test runner.
TRUNNER_TESTS_DIR := prog_tests
TRUNNER_BPF_PROGS_DIR := progs
@@ -716,6 +730,7 @@ TRUNNER_EXTRA_SOURCES := test_progs.c \
disasm.c \
disasm_helpers.c \
json_writer.c \
+ $(VERIFY_SIG_HDR) \
flow_dissector_load.h \
ip_check_defrag_frags.h
TRUNNER_EXTRA_FILES := $(OUTPUT)/urandom_read \
@@ -725,7 +740,7 @@ TRUNNER_EXTRA_FILES := $(OUTPUT)/urandom_read \
$(OUTPUT)/uprobe_multi \
$(TEST_KMOD_TARGETS) \
ima_setup.sh \
- verify_sig_setup.sh \
+ $(VERIFY_SIG_SETUP) \
$(wildcard progs/btf_dump_test_case_*.c) \
$(wildcard progs/*.bpf.o)
TRUNNER_BPF_BUILD_RULE := CLANG_BPF_BUILD_RULE
diff --git a/tools/testing/selftests/bpf/test_progs.c b/tools/testing/selftests/bpf/test_progs.c
index 309d9d4a8ace..02a85dda30e6 100644
--- a/tools/testing/selftests/bpf/test_progs.c
+++ b/tools/testing/selftests/bpf/test_progs.c
@@ -14,12 +14,14 @@
#include <netinet/in.h>
#include <sys/select.h>
#include <sys/socket.h>
+#include <linux/keyctl.h>
#include <sys/un.h>
#include <bpf/btf.h>
#include <time.h>
#include "json_writer.h"
#include "network_helpers.h"
+#include "verification_cert.h"
/* backtrace() and backtrace_symbols_fd() are glibc specific,
* use header file when glibc is available and provide stub
@@ -1928,6 +1930,13 @@ static void free_test_states(void)
}
}
+static __u32 register_session_key(const char *key_data, size_t key_data_size)
+{
+ return syscall(__NR_add_key, "asymmetric", "libbpf_session_key",
+ (const void *)key_data, key_data_size,
+ KEY_SPEC_SESSION_KEYRING);
+}
+
int main(int argc, char **argv)
{
static const struct argp argp = {
@@ -1961,6 +1970,10 @@ int main(int argc, char **argv)
/* Use libbpf 1.0 API mode */
libbpf_set_strict_mode(LIBBPF_STRICT_ALL);
libbpf_set_print(libbpf_print_fn);
+ err = register_session_key((const char *)test_progs_verification_cert,
+ test_progs_verification_cert_len);
+ if (err < 0)
+ return err;
traffic_monitor_set_print(traffic_monitor_print_fn);
diff --git a/tools/testing/selftests/bpf/verify_sig_setup.sh b/tools/testing/selftests/bpf/verify_sig_setup.sh
index f2cac42298ba..0834f504f66d 100755
--- a/tools/testing/selftests/bpf/verify_sig_setup.sh
+++ b/tools/testing/selftests/bpf/verify_sig_setup.sh
@@ -32,7 +32,7 @@ usage()
exit 1
}
-setup()
+genkey()
{
local tmp_dir="$1"
@@ -46,8 +46,15 @@ setup()
openssl x509 -in ${tmp_dir}/signing_key.pem -out \
${tmp_dir}/signing_key.der -outform der
- key_id=$(cat ${tmp_dir}/signing_key.der | keyctl padd asymmetric ebpf_testing_key @s)
+}
+setup()
+{
+ local tmp_dir="$1"
+
+ genkey "${tmp_dir}"
+
+ key_id=$(cat ${tmp_dir}/signing_key.der | keyctl padd asymmetric ebpf_testing_key @s)
keyring_id=$(keyctl newring ebpf_testing_keyring @s)
keyctl link $key_id $keyring_id
}
@@ -105,6 +112,8 @@ main()
if [[ "${action}" == "setup" ]]; then
setup "${tmp_dir}"
+ elif [[ "${action}" == "genkey" ]]; then
+ genkey "${tmp_dir}"
elif [[ "${action}" == "cleanup" ]]; then
cleanup "${tmp_dir}"
elif [[ "${action}" == "fsverity-create-sign" ]]; then
--
2.43.0
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