From 55ffbe8a15b1254f44d56952fb425a10e3f15c31 Mon Sep 17 00:00:00 2001 From: Leo Yan Date: Tue, 2 Jun 2026 15:47:15 +0100 Subject: selftests/bpf: Initialize operation name before use ASAN reports stack-buffer-overflow due to the uninitialized op_name. Initialize it to fix the issue. Fixes: 054b6c7866c7 ("selftests/bpf: Add verifier log tests for BPF_BTF_LOAD command") Signed-off-by: Leo Yan Acked-by: Ihor Solodrai Link: https://lore.kernel.org/r/20260602-tools_build_fix_zero_init_bpf_only-v2-6-c76e5250ea1c@arm.com Signed-off-by: Alexei Starovoitov --- tools/testing/selftests/bpf/prog_tests/verifier_log.c | 1 + 1 file changed, 1 insertion(+) (limited to 'tools/testing') diff --git a/tools/testing/selftests/bpf/prog_tests/verifier_log.c b/tools/testing/selftests/bpf/prog_tests/verifier_log.c index c01c0114af1b..4542bb586d72 100644 --- a/tools/testing/selftests/bpf/prog_tests/verifier_log.c +++ b/tools/testing/selftests/bpf/prog_tests/verifier_log.c @@ -317,6 +317,7 @@ static void verif_btf_log_subtest(bool bad_btf) res = load_btf(&opts, true); ASSERT_EQ(res, -ENOSPC, "half_log_fd"); ASSERT_EQ(strlen(logs.buf), 24, "log_fixed_25"); + strscpy(op_name, "log_fixed", sizeof(op_name)); ASSERT_STRNEQ(logs.buf, logs.reference, 24, op_name); /* validate rolling verifier log logic: try all variations of log buf -- cgit v1.2.3 From 584f3b7a352586ddf9464faaedea57ac880e0e6d Mon Sep 17 00:00:00 2001 From: Leo Yan Date: Tue, 2 Jun 2026 15:47:16 +0100 Subject: selftests/bpf: Use common CFLAGS for urandom_read The urandom_read helper and its shared library are built with $(CLANG) directly rather than through the normal selftest $(CC) rules. The CFLAGS variable can contain specific flags only for $(CC) but might be imcompatible for $(CLANG) and those flags are not necessarily valid for the clang-only urandom_read build. Split the BPF selftest local flags into COMMON_CFLAGS and append them to CFLAGS for the normal build path. Use COMMON_CFLAGS directly for urandom_read and liburandom_read.so, while still filtering out -static as before. Signed-off-by: Leo Yan Link: https://lore.kernel.org/r/20260602-tools_build_fix_zero_init_bpf_only-v2-7-c76e5250ea1c@arm.com Signed-off-by: Alexei Starovoitov --- tools/testing/selftests/bpf/Makefile | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'tools/testing') diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile index d53b7e496ac9..302a8aed3bf9 100644 --- a/tools/testing/selftests/bpf/Makefile +++ b/tools/testing/selftests/bpf/Makefile @@ -57,7 +57,7 @@ srctree := $(patsubst %/,%,$(dir $(srctree))) srctree := $(patsubst %/,%,$(dir $(srctree))) endif -CFLAGS += -g $(OPT_FLAGS) -rdynamic -std=gnu11 \ +COMMON_CFLAGS = -g $(OPT_FLAGS) -rdynamic -std=gnu11 \ -Wall -Werror -fno-omit-frame-pointer \ -Wno-unused-but-set-variable \ $(GENFLAGS) $(SAN_CFLAGS) $(LIBELF_CFLAGS) \ @@ -70,7 +70,7 @@ LDLIBS += $(LIBELF_LIBS) -lz -lrt -lpthread PCAP_CFLAGS := $(shell $(PKG_CONFIG) --cflags libpcap 2>/dev/null && echo "-DTRAFFIC_MONITOR=1") PCAP_LIBS := $(shell $(PKG_CONFIG) --libs libpcap 2>/dev/null) LDLIBS += $(PCAP_LIBS) -CFLAGS += $(PCAP_CFLAGS) +CFLAGS += $(COMMON_CFLAGS) $(PCAP_CFLAGS) # Some utility functions use LLVM libraries jit_disasm_helpers.c-CFLAGS = $(LLVM_CFLAGS) @@ -267,7 +267,7 @@ endif $(OUTPUT)/liburandom_read.so: urandom_read_lib1.c urandom_read_lib2.c liburandom_read.map $(call msg,LIB,,$@) $(Q)$(CLANG) $(CLANG_TARGET_ARCH) \ - $(filter-out -static,$(CFLAGS) $(LDFLAGS)) \ + $(filter-out -static,$(COMMON_CFLAGS) $(LDFLAGS)) \ $(filter %.c,$^) $(filter-out -static,$(LDLIBS)) \ -Wno-unused-command-line-argument \ -fuse-ld=$(LLD) -Wl,-znoseparate-code -Wl,--build-id=sha1 \ @@ -277,7 +277,7 @@ $(OUTPUT)/liburandom_read.so: urandom_read_lib1.c urandom_read_lib2.c liburandom $(OUTPUT)/urandom_read: urandom_read.c urandom_read_aux.c $(OUTPUT)/liburandom_read.so $(call msg,BINARY,,$@) $(Q)$(CLANG) $(CLANG_TARGET_ARCH) \ - $(filter-out -static,$(CFLAGS) $(LDFLAGS)) $(filter %.c,$^) \ + $(filter-out -static,$(COMMON_CFLAGS) $(LDFLAGS)) $(filter %.c,$^) \ -Wno-unused-command-line-argument \ -lurandom_read $(filter-out -static,$(LDLIBS)) -L$(OUTPUT) \ -fuse-ld=$(LLD) -Wl,-znoseparate-code -Wl,--build-id=sha1 \ -- cgit v1.2.3 From 62617d28d9ae123c0d6ba51035caa3ca52b94f7a Mon Sep 17 00:00:00 2001 From: Leo Yan Date: Tue, 2 Jun 2026 15:47:17 +0100 Subject: selftests/bpf: Avoid static LLVM linking for cross builds The BPF selftests prefer static LLVM linking, which works for native builds but can break cross builds. Its --link-static output may include host-only libraries that are unavailable for the cross compilation, causing link failures. Avoid static LLVM linking for cross builds and use shared LLVM libraries instead. Native builds keep the existing behavior. Signed-off-by: Leo Yan Link: https://lore.kernel.org/r/20260602-tools_build_fix_zero_init_bpf_only-v2-8-c76e5250ea1c@arm.com Signed-off-by: Alexei Starovoitov --- tools/testing/selftests/bpf/Makefile | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) (limited to 'tools/testing') diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile index 302a8aed3bf9..b642ee489ea6 100644 --- a/tools/testing/selftests/bpf/Makefile +++ b/tools/testing/selftests/bpf/Makefile @@ -194,8 +194,15 @@ ifeq ($(feature-llvm),1) LLVM_CONFIG_LIB_COMPONENTS := mcdisassembler all-targets # both llvm-config and lib.mk add -D_GNU_SOURCE, which ends up as conflict LLVM_CFLAGS += $(filter-out -D_GNU_SOURCE,$(shell $(LLVM_CONFIG) --cflags)) - # Prefer linking statically if it's available, otherwise fallback to shared - ifeq ($(shell $(LLVM_CONFIG) --link-static --libs >/dev/null 2>&1 && echo static),static) + # Cross compilation must use dynamic linking to avoid unresolved library + # dependencies. For native build, prefer linking statically if it's + # available, otherwise fallback to shared. + ifneq ($(ARCH), $(HOSTARCH)) + LLVM_LINK_STATIC := + else + LLVM_LINK_STATIC := $(shell $(LLVM_CONFIG) --link-static --libs >/dev/null 2>&1 && echo y) + endif + ifeq ($(LLVM_LINK_STATIC),y) LLVM_LDLIBS += $(shell $(LLVM_CONFIG) --link-static --libs $(LLVM_CONFIG_LIB_COMPONENTS)) LLVM_LDLIBS += $(filter-out -lxml2,$(shell $(LLVM_CONFIG) --link-static --system-libs $(LLVM_CONFIG_LIB_COMPONENTS))) LLVM_LDLIBS += -lstdc++ -- cgit v1.2.3