From 5396f730d7f77c572a67993ef139ed735650398f Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Alexis=20Lothor=C3=A9?= Date: Wed, 9 Jul 2025 17:04:14 +0200 Subject: [PATCH] package/linux-tools: perf: build with libtraceevent support when it is selected MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit When trying to perform a custom uprobe recording on a target with perf built by buildroot, the recording step fails as perf can not record uprobes without libtraceevent support: $ perf probe -x linked_list insert_name index Target program is compiled without optimization. Skipping prologue. Probe on address 0x808 to force probing at the function entry. Added new event: probe_linked_list:insert_name (on insert_name in /root/gdb/linked_list with index) perf is not linked with libtraceevent, to use the new probe you can use tracefs: cd /sys/kernel/tracing/ echo 1 > events/probe_linked_list/insert_name/enable echo 1 > tracing_on cat trace_pipe Before removing the probe, echo 0 > events/probe_linked_list/insert_name/enable $ perf record -e probe_linked_list:insert_name ./linked_list event syntax error: 'probe_linked_list:insert_name' \___ unsupported tracepoint libtraceevent is necessary for tracepoint support Run 'perf list' for a list of valid events Usage: perf record [] [] or: perf record [] -- [] -e, --event event selector. use 'perf list' to list available events libtraceevent support for perf has been disabled with commit b4ab45a5c1db ("package/linux-tools: disable libtracevent detection") because there was no libtraceevent package in buildroot to replace the former libtraceevent removed from the kernel sources. Since then, commit 1474f1b34b17 ("package/libtraceevent: new package") has introduced a libtraceevent package. We can then expose again the possibility to build perf with libtraceevent support. Make buildroot perf makefile detect if libtraceevent package has been enabled, and if so, allow to build perf with libtraceevent support. Signed-off-by: Alexis Lothoré Reviewed-by: Luca Ceresoli Tested-by: Luca Ceresoli Signed-off-by: Julien Olivain --- package/linux-tools/linux-tool-perf.mk.in | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/package/linux-tools/linux-tool-perf.mk.in b/package/linux-tools/linux-tool-perf.mk.in index d67318571a..1e19ee7f1c 100644 --- a/package/linux-tools/linux-tool-perf.mk.in +++ b/package/linux-tools/linux-tool-perf.mk.in @@ -28,7 +28,6 @@ PERF_MAKE_FLAGS = \ NO_LIBPERL=1 \ NO_LIBPYTHON=1 \ NO_LIBBIONIC=1 \ - NO_LIBTRACEEVENT=1 \ NO_SHELLCHECK=1 # We need to pass an argument to ld for setting the emulation when @@ -128,6 +127,12 @@ PERF_MAKE_FLAGS += CORESIGHT=1 # bare "ifdef CORESIGHT" constructs. endif +ifeq ($(BR2_PACKAGE_LIBTRACEEVENT),y) +PERF_DEPENDENCIES += libtraceevent +else +PERF_MAKE_FLAGS += NO_LIBTRACEEVENT=1 +endif + # We really do not want to build the perf documentation, because it # has stringent requirement on the documentation generation tools, # like xmlto and asciidoc), which may be lagging behind on some