!874 Support check duplicate so name for system app

Merge pull request !874 from yinchuang/support_same_so

porting/linux/user/include/dlfcn.h

@@ -24,6 +24,7 @@ extern "C" {
 /* create flags for dlns_create */
 #define CREATE_INHERIT_DEFAULT 0x1
 #define CREATE_INHERIT_CURRENT 0x2
+#define LOCAL_NS_PREFERED 0x4 /* Use app's library when app's library has same name as system library. */
 
 int    dlclose(void *);
 char  *dlerror(void);

porting/linux/user/ldso/dynlink.c

@@ -1714,6 +1714,18 @@ static struct dso *search_dso_by_fstat(const struct stat *st, const ns_t *ns, ui
 	}
 	return NULL;
 }
+
+static inline int app_has_same_name_so(const char *so_name, const ns_t *ns)
+{
+   int fd = -1;
+   /* Only check system app. */
+   if (((ns->flag & LOCAL_NS_PREFERED) != 0) && ns->lib_paths) {
+       char tmp_buf[PATH_MAX+1];
+       fd = path_open(so_name, ns->lib_paths, tmp_buf, sizeof tmp_buf);
+   }
+   return fd;
+}
+
 /* Find loaded so by name */
 static struct dso *find_library_by_name(const char *name, const ns_t *ns, bool check_inherited)
 {
@@ -1727,7 +1739,12 @@ static struct dso *find_library_by_name(const char *name, const ns_t *ns, bool c
 		for (size_t i = 0; i < ns->ns_inherits->num; i++){
 			ns_inherit * inherit = ns->ns_inherits->inherits[i];
 			p = search_dso_by_name(name, inherit->inherited_ns);
-			if (p && is_sharable(inherit, name)) return p;
+			if (p && is_sharable(inherit, name)) {
+			    if (app_has_same_name_so(name, ns) != -1) {
+			        return NULL;
+			    }
+			    return p;
+			}
 		}
 	}
 	return NULL;
@@ -3387,6 +3404,7 @@ int dlns_create2(Dl_namespace *dlns, const char *lib_path, int flags)
 		return ENOMEM;
 	}
 	ns_set_name(ns, dlns->name);
+	ns_set_flag(ns, flags);
 	ns_add_dso(ns, get_default_ns()->ns_dsos->dsos[0]); /* add main app to this namespace*/
 	nslist_add_ns(ns); /* add ns to list*/
 	ns_set_lib_paths(ns, lib_path);

porting/linux/user/ldso/namespace.c

@@ -602,3 +602,12 @@ bool is_sharable(ns_inherit *inherit, const char *lib_name)
     LD_LOGD("is_sharable shared_libs not config, return true.");
     return true;
 }
+
+void ns_set_flag(ns_t *ns, int flag)
+{
+    if (!ns) {
+        return;
+    }
+    ns->flag = flag;
+    LD_LOGD("ns_set_flag ns[%{public}s] flag:%{public}d.", ns->ns_name, ns->flag);
+}
\ No newline at end of file

porting/linux/user/ldso/namespace.h

@@ -47,6 +47,7 @@ typedef struct _namespace_t_ {
     strlist *allowed_libs;       /* when separated, allowed library names splited by ':'. */
     dsolist *ns_dsos;         /* dso list in this namespace */
     struct _ns_inherit_list_ *ns_inherits;   /* inherit list in this namespace */
+    int flag;
 } ns_t;
 /* define namespace list */
 typedef struct _namespaces_list_ {
@@ -83,6 +84,7 @@ void ns_set_allowed_libs(ns_t *ns, const char *allowed_libs);
 void ns_add_dso(ns_t *ns, struct dso *dso);
 void nslist_add_ns(ns_t *ns);
 void ns_add_inherit(ns_t *ns,ns_t *inherited, const char *shared_libs);
+void ns_set_flag(ns_t *ns, int flag);
 
 /* get default namespace */
 ns_t *get_default_ns();