From 1b7157be3a8c4300fc8044d40f4b2e64a152a1b4 Mon Sep 17 00:00:00 2001 From: Josh DuBois Date: Thu, 23 Jul 2020 00:33:59 -0500 Subject: [PATCH 1/2] trace/simple: Allow enabling simple traces from command line The simple trace backend is enabled / disabled with a call to st_set_trace_file_enabled(). When initializing tracing from the command-line, this must be enabled on startup. (Prior to db25d56c014aa1a9, command-line initialization of simple trace worked because every call to st_set_trace_file enabled tracing.) Fixes: db25d56c014aa1a96319c663e0a60346a223b31e Signed-off-by: Josh DuBois Message-id: 20200723053359.256928-1-josh@joshdubois.com Signed-off-by: Stefan Hajnoczi --- trace/control.c | 1 + 1 file changed, 1 insertion(+) diff --git a/trace/control.c b/trace/control.c index 2ffe000818..6558b5c906 100644 --- a/trace/control.c +++ b/trace/control.c @@ -225,6 +225,7 @@ void trace_init_file(const char *file) { #ifdef CONFIG_TRACE_SIMPLE st_set_trace_file(file); + st_set_trace_file_enabled(true); #elif defined CONFIG_TRACE_LOG /* * If both the simple and the log backends are enabled, "--trace file" From 000822441e34916991f7c03217dc24f38be49e50 Mon Sep 17 00:00:00 2001 From: Stefan Hajnoczi Date: Wed, 29 Jul 2020 16:39:26 +0100 Subject: [PATCH 2/2] tracetool: carefully define SDT_USE_VARIADIC The dtrace backend defines SDT_USE_VARIADIC as a workaround for a conflict with a LTTng UST header file, which requires SDT_USE_VARIADIC to be defined. LTTng UST breaks if included after generated dtrace headers because SDT_USE_VARIADIC will already be defined: #ifdef LTTNG_UST_HAVE_SDT_INTEGRATION #define SDT_USE_VARIADIC <-- error, it's already defined #include Be more careful when defining SDT_USE_VARIADIC. This fixes the build when both the dtrace and ust tracers are enabled at the same time. Fixes: 27e08bab94f7c6ebe0b75938c98c394c969e3fd8 ("tracetool: work around ust include conflict") Signed-off-by: Stefan Hajnoczi Message-id: 20200729153926.127083-1-stefanha@redhat.com Signed-off-by: Stefan Hajnoczi --- scripts/tracetool/backend/dtrace.py | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/scripts/tracetool/backend/dtrace.py b/scripts/tracetool/backend/dtrace.py index b7fe4c1b50..fc0c8fc52f 100644 --- a/scripts/tracetool/backend/dtrace.py +++ b/scripts/tracetool/backend/dtrace.py @@ -44,11 +44,15 @@ def generate_h_begin(events, group): # require SDT_USE_VARIADIC to be defined. If dtrace includes # first without defining SDT_USE_VARIADIC then ust breaks because the # STAP_PROBEV() macro is not defined. + out('#ifndef SDT_USE_VARIADIC') out('#define SDT_USE_VARIADIC 1') + out('#endif') out('#include "%s"' % header, '') + out('#undef SDT_USE_VARIADIC') + # SystemTap defines __ENABLED() but other DTrace # implementations might not. for e in events: