[PATCH] tracing: ring-buffer: allowlist clang-generated symbols

From: Arnd Bergmann

Date: Tue Jun 16 2026 - 12:50:14 EST


From: Arnd Bergmann <arnd@xxxxxxxx>

In randconfig build testing using clang-22, I came across two
sets of extra symbols in the ring buffer code that may get
inserted by the compiler:

Unexpected symbols in kernel/trace/simple_ring_buffer.o:
U memset

Unexpected symbols in kernel/trace/simple_ring_buffer.o:
U llvm_gcda_emit_arcs
U llvm_gcda_emit_function
U llvm_gcda_end_file
U llvm_gcda_start_file
U llvm_gcda_summary_info
U llvm_gcov_init

Add all of these to the allowlist.

Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
kernel/trace/Makefile | 1 +
1 file changed, 1 insertion(+)

diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile
index f934ff586bd4..aa8564fb8ff4 100644
--- a/kernel/trace/Makefile
+++ b/kernel/trace/Makefile
@@ -146,6 +146,7 @@ KASAN_SANITIZE_undefsyms_base.o := y

UNDEFINED_ALLOWLIST = __asan __gcov __kasan __kcsan __hwasan __sancov __sanitizer __tsan __ubsan __msan \
__aeabi_unwind_cpp __s390_indirect_jump __x86_indirect_thunk simple_ring_buffer \
+ memset llvm_gcda llvm_gcov \
$(shell $(NM) -u $(obj)/undefsyms_base.o 2>/dev/null | awk '{print $$2}')

quiet_cmd_check_undefined = NM $<
--
2.39.5