Merge branch 'ease-bpf-signing-build-requirements'

Alan Maguire says:

====================
Ease BPF signing build requirements

This series makes it easier to build bpftool and selftests with
signing support, removing reliance on >= openssl v3 (supporting
openssl v1) to build bpftool and not requiring latest xxd to
build verification cert header in selftests.

Changes since v1 [1]:

- Updated patch 2 to add symlink test_progs_verification_cert to .gitignore,
  EXTRA_CLEANFILES (AI review bot)
- Added acks to patch 1 (Song, Quentin)

[1] https://lore.kernel.org/bpf/20251114222249.30122-1-alan.maguire@oracle.com/
====================

Link: https://patch.msgid.link/20251120084754.640405-1-alan.maguire@oracle.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

Author: Alexei Starovoitov

tools/bpf/bpftool/sign.c

@@ -28,6 +28,12 @@
 
 #define OPEN_SSL_ERR_BUF_LEN 256
 
+/* Use deprecated in 3.0 ERR_get_error_line_data for openssl < 3 */
+#if !defined(OPENSSL_VERSION_MAJOR) || (OPENSSL_VERSION_MAJOR < 3)
+#define ERR_get_error_all(file, line, func, data, flags) \
+	ERR_get_error_line_data(file, line, data, flags)
+#endif
+
 static void display_openssl_errors(int l)
 {
 	char buf[OPEN_SSL_ERR_BUF_LEN];

tools/testing/selftests/bpf/.gitignore

@@ -23,6 +23,7 @@ test_tcpnotify_user
 test_libbpf
 xdping
 test_cpp
+test_progs_verification_cert
 *.d
 *.subskel.h
 *.skel.h

tools/testing/selftests/bpf/Makefile

@@ -731,7 +731,8 @@ $(VERIFICATION_CERT) $(PRIVATE_KEY): $(VERIFY_SIG_SETUP)
 	$(Q)$(VERIFY_SIG_SETUP) genkey $(BUILD_DIR)
 
 $(VERIFY_SIG_HDR): $(VERIFICATION_CERT)
-	$(Q)xxd -i -n test_progs_verification_cert $< > $@
+	$(Q)ln -fs $< test_progs_verification_cert && \
+	xxd -i test_progs_verification_cert > $@
 
 # Define test_progs test runner.
 TRUNNER_TESTS_DIR := prog_tests
@@ -905,7 +906,8 @@ EXTRA_CLEAN := $(SCRATCH_DIR) $(HOST_SCRATCH_DIR)			\
 	$(addprefix $(OUTPUT)/,*.o *.d *.skel.h *.lskel.h *.subskel.h	\
 			       no_alu32 cpuv4 bpf_gcc			\
 			       liburandom_read.so)			\
-	$(OUTPUT)/FEATURE-DUMP.selftests
+	$(OUTPUT)/FEATURE-DUMP.selftests				\
+	test_progs_verification_cert
 
 .PHONY: docs docs-clean