tracing: Check for undefined symbols in simple_ring_buffer

The simple_ring_buffer implementation must remain simple enough to be
used by the pKVM hypervisor. Prevent the object build if unresolved
symbols are found.

Link: https://patch.msgid.link/20260309162516.2623589-19-vdonnefort@google.com
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
This commit is contained in:
Vincent Donnefort
2026-03-09 16:25:04 +00:00
committed by Steven Rostedt (Google)
parent 635923081c
commit a717943d8e

View File

@@ -132,4 +132,20 @@ obj-$(CONFIG_TRACE_REMOTE) += trace_remote.o
obj-$(CONFIG_SIMPLE_RING_BUFFER) += simple_ring_buffer.o
obj-$(CONFIG_TRACE_REMOTE_TEST) += remote_test.o
#
# simple_ring_buffer is used by the pKVM hypervisor which does not have access
# to all kernel symbols. Fail the build if forbidden symbols are found.
#
UNDEFINED_ALLOWLIST := memset alt_cb_patch_nops __x86 __ubsan __asan __kasan __gcov __aeabi_unwind
UNDEFINED_ALLOWLIST += __stack_chk_fail stackleak_track_stack __ref_stack __sanitizer
UNDEFINED_ALLOWLIST := $(addprefix -e , $(UNDEFINED_ALLOWLIST))
quiet_cmd_check_undefined = NM $<
cmd_check_undefined = test -z "`$(NM) -u $< | grep -v $(UNDEFINED_ALLOWLIST)`"
$(obj)/%.o.checked: $(obj)/%.o FORCE
$(call if_changed,check_undefined)
always-$(CONFIG_SIMPLE_RING_BUFFER) += simple_ring_buffer.o.checked
libftrace-y := ftrace.o