ust: allow tracing of dynamically linked libraries

- this also includes being able to link libmarkers dynamically
- a special init function must be added via the MARKER_LIB macro

diff --git a/hello/Makefile b/hello/Makefile
index eeb43fdb1d1a9cdde578c92cb2e548061711a655..57cc8f2be33567a34a4f3534d73da0000527a0ef 100644 (file)
--- a/hello/Makefile
+++ b/hello/Makefile
@@ -2,9 +2,9 @@ all: hello
 
 hello: hello.c
 #dynamic version
-#      gcc -g -I../libmarkers -I../share -I../libtracing -L../libmarkers -lmarkers -L../libtracectl -ltracectl -L../libtracing -ltracing -o hello hello.c marker-control.c serialize.c -static
+       gcc -g -Wl,--print-map -I../libmarkers -I../share -I../libtracing -L../libmarkers -lmarkers -L../libtracectl -ltracectl -L../libtracing -ltracing -o hello hello.c marker-control.c serialize.c
 #static version
-       gcc -g -I../libmarkers -I../share -I../libtracing -L../libmarkers -o hello hello.c marker-control.c serialize.c ../libtracing/*.c ../libmarkers/*.c ../libtracectl/*.c ../share/*.c
+#      gcc -g -I../libmarkers -I../share -I../libtracing -L../libmarkers -o hello hello.c marker-control.c serialize.c ../libtracing/*.c ../libmarkers/*.c ../libtracectl/*.c ../share/*.c
 
 clean:
        rm -rf hello *.o

diff --git a/hello/hello.c b/hello/hello.c
index d6750d061d349dee41628d3c671aef6d6389708f..ee7992b00d006aa9d264a634b268b30680a55d52 100644 (file)
--- a/hello/hello.c
+++ b/hello/hello.c
@@ -204,6 +204,11 @@ int main()
 
        printf("page size is %d\n", sysconf(_SC_PAGE_SIZE));
 
+//     extern struct marker __start___markers[] __attribute__((visibility("hidden")));
+//     extern struct marker __stop___markers[] __attribute__((visibility("hidden")));
+//
+//     printf("the executable's markers start at %lx and end at %lx, the size of a marker is %d\n", __start___markers, __stop___markers, sizeof(struct marker));
+
        marker_control_init();
 
        //marker_probe_register("abc", "testmark", "", probe, NULL);
@@ -268,3 +273,5 @@ int main()
 
        return 0;
 }
+
+MARKER_LIB

diff --git a/libmarkers/marker.c b/libmarkers/marker.c
index d31f2cfa97ebaaef8ca4c7ae4ef5ef0c78c8bc2c..139b4327084528e2eb8e99f81eecfe30d1e43cf3 100644 (file)
--- a/libmarkers/marker.c
+++ b/libmarkers/marker.c
@@ -37,8 +37,8 @@
 #include "tracercore.h"
 #include "tracer.h"
 
-extern struct marker __start___markers[];
-extern struct marker __stop___markers[];
+extern struct marker __start___markers[] __attribute__((visibility("hidden")));
+extern struct marker __stop___markers[] __attribute__((visibility("hidden")));
 
 /* Set to 1 to enable marker debug output */
 static const int marker_debug;
@@ -705,9 +705,10 @@ void marker_update_probe_range(struct marker *begin,
 static void marker_update_probes(void)
 {
        /* Core kernel markers */
-       marker_update_probe_range(__start___markers, __stop___markers);
+//ust//        marker_update_probe_range(__start___markers, __stop___markers);
        /* Markers in modules. */
 //ust//        module_update_markers();
+       lib_update_markers();
 //ust//        tracepoint_probe_update_all();
        /* Update immediate values */
        core_imv_update();
@@ -1062,6 +1063,7 @@ static void marker_get_iter(struct marker_iter *iter)
 
        /* Core kernel markers */
        if (!iter->lib) {
+               /* ust FIXME: how come we cannot disable the following line? we shouldn't need core stuff */
                found = marker_get_iter_range(&iter->marker,
                                __start___markers, __stop___markers);
                if (found)
@@ -1443,6 +1445,17 @@ int lib_get_iter_markers(struct marker_iter *iter)
        return found;
 }
 
+void lib_update_markers(void)
+{
+       struct lib *lib;
+
+//ust//        mutex_lock(&module_mutex);
+       list_for_each_entry(lib, &libs, list)
+               marker_update_probe_range(lib->markers_start,
+                               lib->markers_start + lib->markers_count);
+//ust//        mutex_unlock(&module_mutex);
+}
+
 int marker_register_lib(struct marker *markers_start, int markers_count)
 {
        struct lib *pl;
@@ -1458,3 +1471,9 @@ int marker_register_lib(struct marker *markers_start, int markers_count)
        
        return 0;
 }
+
+static void __attribute__((constructor)) __markers__init(void)
+{
+       marker_register_lib(__start___markers, (((long)__stop___markers)-((long)__start___markers))/sizeof(struct marker));
+       printf("markers_start: %p, markers_stop: %p\n", __start___markers, __stop___markers);
+}

diff --git a/libmarkers/marker.h b/libmarkers/marker.h
index f26bcac033519fad67850a3757da23eb5d03f58e..b83ff65e654328fef1c8ca28d0eee6c01a7e055a 100644 (file)
--- a/libmarkers/marker.h
+++ b/libmarkers/marker.h
@@ -282,5 +282,15 @@ struct lib {
        struct list_head list;
 };
 
+int marker_register_lib(struct marker *markers_start, int markers_count);
+
+#define MARKER_LIB                                             \
+extern struct marker __start___markers[] __attribute__((visibility("hidden")));                        \
+extern struct marker __stop___markers[] __attribute__((visibility("hidden")));                         \
+                                                               \
+static void __attribute__((constructor)) __markers__init(void)         \
+{                                                              \
+       marker_register_lib(__start___markers, (((long)__stop___markers)-((long)__start___markers))/sizeof(struct marker));\
+}
 
 #endif