implement minimal dlinfo function

include/dlfcn.h

@@ -17,6 +17,8 @@ extern "C" {
 #define RTLD_NEXT    ((void *)-1)
 #define RTLD_DEFAULT ((void *)0)
 
+#define RTLD_DI_LINKMAP 2
+
 int    dlclose(void *);
 char  *dlerror(void);
 void  *dlopen(const char *, int);
@@ -30,6 +32,7 @@ typedef struct {
 	void *dli_saddr;
 } Dl_info;
 int dladdr(void *, Dl_info *);
+int dlinfo(void *, int, void *);
 #endif
 
 #ifdef __cplusplus

src/ldso/dlinfo.c

@@ -0,0 +1,8 @@
+#include <dlfcn.h>
+
+int __dlinfo(void *, int, void *);
+
+int dlinfo(void *dso, int req, void *res)
+{
+	return __dlinfo(dso, req, res);
+}

src/ldso/dynlink.c

@@ -1273,6 +1273,18 @@ int __dladdr (void *addr, Dl_info *info)
 }
 #endif
 
+int __dlinfo(void *dso, int req, void *res)
+{
+	if (invalid_dso_handle(dso)) return -1;
+	if (req != RTLD_DI_LINKMAP) {
+		snprintf(errbuf, sizeof errbuf, "Unsupported request %d", req);
+		errflag = 1;
+		return -1;
+	}
+	*(struct link_map **)res = dso;
+	return 0;
+}
+
 char *dlerror()
 {
 	if (!errflag) return 0;