Add support such that if LD_TRACE_LOADED_OBJECTS_ALL is defined to a

non-empty string in the environment; we indicate which objects caused
each object to be loaded.

PR:		30908
Submitted-by:	Mike Meyer <mwm@mired.org>

4 files changed, 30 insertions, 7 deletions

diff --git a/libexec/rtld-elf/rtld.1 b/libexec/rtld-elf/rtld.1
index b32b08d..dad1a63 100644
--- a/libexec/rtld-elf/rtld.1
+++ b/libexec/rtld-elf/rtld.1
@@ -107,6 +107,11 @@ When set to a nonempty string, causes
 .Nm
 to exit after loading the shared objects and printing a summary which includes
 the absolute pathnames of all objects, to standard output.
+.It Ev LD_TRACE_LOADED_OBJECTS_ALL
+When set to a nonempty string, causes
+.Nm
+to expand the summary to indicate which objects caused each object to
+be loaded.
 .It Ev LD_TRACE_LOADED_OBJECTS_FMT1
 .It Ev LD_TRACE_LOADED_OBJECTS_FMT2
 When set, these variables are interpreted as format strings a la
diff --git a/libexec/rtld-elf/rtld.c b/libexec/rtld-elf/rtld.c
index 100f011..abc95e8 100644
--- a/libexec/rtld-elf/rtld.c
+++ b/libexec/rtld-elf/rtld.c
@@ -2010,7 +2010,7 @@ symlook_obj(const char *name, unsigned long hash, const Obj_Entry *obj,
 static void
 trace_loaded_objects(Obj_Entry *obj)
 {
-    char	*fmt1, *fmt2, *fmt, *main_local;
+    char	*fmt1, *fmt2, *fmt, *main_local, *list_containers;
     int		c;
 
     if ((main_local = getenv("LD_TRACE_LOADED_OBJECTS_PROGNAME")) == NULL)
@@ -2022,14 +2022,18 @@ trace_loaded_objects(Obj_Entry *obj)
     if ((fmt2 = getenv("LD_TRACE_LOADED_OBJECTS_FMT2")) == NULL)
 	fmt2 = "\t%o (%x)\n";
 
+    list_containers = getenv("LD_TRACE_LOADED_OBJECTS_ALL");
+
     for (; obj; obj = obj->next) {
 	Needed_Entry		*needed;
 	char			*name, *path;
 	bool			is_lib;
 
+	if (list_containers && obj->needed != NULL)
+	    printf("%s:\n", obj->path);
 	for (needed = obj->needed; needed; needed = needed->next) {
 	    if (needed->obj != NULL) {
-		if (needed->obj->traced)
+		if (needed->obj->traced && !list_containers)
 		    continue;
 		needed->obj->traced = true;
 		path = needed->obj->path;
diff --git a/usr.bin/ldd/ldd.1 b/usr.bin/ldd/ldd.1
index 470fd42..a631df2 100644
--- a/usr.bin/ldd/ldd.1
+++ b/usr.bin/ldd/ldd.1
@@ -8,6 +8,7 @@
 .Nd list dynamic object dependencies
 .Sh SYNOPSIS
 .Nm
+.Op Fl a
 .Op Fl v
 .Op Fl f Ar format
 .Ar program ...
@@ -35,6 +36,13 @@ See
 for a list of recognized conversion characters.
 .Pp
 The
+.Fl a
+option displays the list of all objects that are needed by each loaded
+object. This option does not work with
+.Xr a.out 5
+binaries.
+.Pp
+The
 .Fl v
 option displays an verbose listing of the dynamic linking headers
 encoded in the executable.  See the source code and include
diff --git a/usr.bin/ldd/ldd.c b/usr.bin/ldd/ldd.c
index fc20467..19db2f1 100644
--- a/usr.bin/ldd/ldd.c
+++ b/usr.bin/ldd/ldd.c
@@ -49,7 +49,7 @@ extern int	error_count;
 void
 usage()
 {
-	fprintf(stderr, "usage: ldd [-v] [-f format] program ...\n");
+	fprintf(stderr, "usage: ldd [-a] [-v] [-f format] program ...\n");
 	exit(1);
 }
 
@@ -61,10 +61,15 @@ char	*argv[];
 	char		*fmt1 = NULL, *fmt2 = NULL;
 	int		rval;
 	int		c;
-	int		vflag = 0;
+	int		aflag, vflag;
 
-	while ((c = getopt(argc, argv, "vf:")) != -1) {
+	aflag = vflag = 0;
+
+	while ((c = getopt(argc, argv, "avf:")) != -1) {
 		switch (c) {
+		case 'a':
+			aflag++;
+			break;
 		case 'v':
 			vflag++;
 			break;
@@ -101,7 +106,7 @@ char	*argv[];
 #endif
 
 	/* ld.so magic */
-	setenv("LD_TRACE_LOADED_OBJECTS", "1", 1);
+	setenv("LD_TRACE_LOADED_OBJECTS", "yes", 1);
 	if (fmt1)
 		setenv("LD_TRACE_LOADED_OBJECTS_FMT1", fmt1, 1);
 	if (fmt2)
@@ -190,7 +195,8 @@ char	*argv[];
 		}
 
 		setenv("LD_TRACE_LOADED_OBJECTS_PROGNAME", *argv, 1);
-		if (fmt1 == NULL && fmt2 == NULL)
+		if (aflag) setenv("LD_TRACE_LOADED_OBJECTS_ALL", "1", 1);
+		else if (fmt1 == NULL && fmt2 == NULL)
 			/* Default formats */
 			printf("%s:\n", *argv);