Weed out duplicates before trying to load libraries.... Delayed

checking for duplicates and returning an alias if an existing lib
is already loaded is still correct for the dlopen case.

3 files changed, 100 insertions, 30 deletions

diff --git a/ldso/ldso/dl-elf.c b/ldso/ldso/dl-elf.c
index 3df8b1461..2f70621d1 100644
--- a/ldso/ldso/dl-elf.c
+++ b/ldso/ldso/dl-elf.c
@@ -166,29 +166,19 @@ search_for_named_library(char *name, int secure, const char *path_list,
 	return NULL;
 }
 
-
-/*
- * Used to return error codes back to dlopen et. al.
- */
-
-unsigned long _dl_error_number;
-unsigned long _dl_internal_error_number;
-extern char *_dl_ldsopath;
-
-struct elf_resolve *_dl_load_shared_library(int secure, struct dyn_elf **rpnt,
-	struct elf_resolve *tpnt, char *full_libname)
+/* Check if the named library is already loaded... */
+struct elf_resolve *_dl_check_if_named_library_is_loaded(const char *full_libname)
 {
-	char *pnt, *pnt1;
+	const char *pnt, *pnt1;
 	struct elf_resolve *tpnt1;
-	char *libname, *libname2;
+	const char *libname, *libname2;
 
-	_dl_internal_error_number = 0;
 	pnt = libname = full_libname;
 
 	/* quick hack to ensure mylibname buffer doesn't overflow.  don't 
 	   allow full_libname or any directory to be longer than 1024. */
 	if (_dl_strlen(full_libname) > 1024)
-		goto goof;
+		return NULL;
 
 	/* Skip over any initial initial './' and '/' stuff to 
 	 * get the short form libname with no path garbage */ 
@@ -215,8 +205,47 @@ struct elf_resolve *_dl_load_shared_library(int secure, struct dyn_elf **rpnt,
 			return tpnt1;
 		}
 	}
+	return NULL;
+}
 	
 
+
+/*
+ * Used to return error codes back to dlopen et. al.
+ */
+
+unsigned long _dl_error_number;
+unsigned long _dl_internal_error_number;
+extern char *_dl_ldsopath;
+
+struct elf_resolve *_dl_load_shared_library(int secure, struct dyn_elf **rpnt,
+	struct elf_resolve *tpnt, char *full_libname)
+{
+	char *pnt, *pnt1;
+	struct elf_resolve *tpnt1;
+	char *libname;
+
+	_dl_internal_error_number = 0;
+	libname = full_libname;
+
+	/* quick hack to ensure mylibname buffer doesn't overflow.  don't 
+	   allow full_libname or any directory to be longer than 1024. */
+	if (_dl_strlen(full_libname) > 1024)
+		goto goof;
+
+	/* Skip over any initial initial './' and '/' stuff to 
+	 * get the short form libname with no path garbage */ 
+	pnt1 = _dl_strrchr(libname, '/');
+	if (pnt1) {
+		libname = pnt1 + 1;
+	}
+
+	/* Critical step!  Weed out duplicates early to avoid
+	 * function aliasing, which wastes memory, and causes
+	 * really bad things to happen with weaks and globals. */
+	if ((tpnt1=_dl_check_if_named_library_is_loaded(libname))!=NULL)
+		return tpnt1;
+
 #if defined (__SUPPORT_LD_DEBUG__)
 	if(_dl_debug) _dl_dprintf(_dl_debug_file, "searching for library: '%s'\n", libname);
 #endif
diff --git a/ldso/ldso/ldso.c b/ldso/ldso/ldso.c
index 2f8e611ba..b6f236d0b 100644
--- a/ldso/ldso/ldso.c
+++ b/ldso/ldso/ldso.c
@@ -902,6 +902,10 @@ static void _dl_get_ready_to_run(struct elf_resolve *tpnt, struct elf_resolve *a
 			*str2 = '\0';
 			if (!_dl_secure || _dl_strchr(str, '/') == NULL) 
 			{
+				if ((tpnt1 = _dl_check_if_named_library_is_loaded(str))) 
+				{
+					continue;
+				}
 				tpnt1 = _dl_load_shared_library(_dl_secure, &rpnt, NULL, str);
 				if (!tpnt1) {
 #ifdef __LDSO_LDD_SUPPORT__
@@ -978,6 +982,10 @@ static void _dl_get_ready_to_run(struct elf_resolve *tpnt, struct elf_resolve *a
 						c = *cp;
 						*cp = '\0';
 
+						if ((tpnt1 = _dl_check_if_named_library_is_loaded(cp2))) 
+						{
+							continue;
+						}
 						tpnt1 = _dl_load_shared_library(0, &rpnt, NULL, cp2);
 						if (!tpnt1) {
 #ifdef __LDSO_LDD_SUPPORT__
@@ -1068,6 +1076,10 @@ static void _dl_get_ready_to_run(struct elf_resolve *tpnt, struct elf_resolve *a
 					tpnt = NULL;
 					continue;
 				}
+				if ((tpnt1 = _dl_check_if_named_library_is_loaded(lpntstr))) 
+				{
+					continue;
+				}
 				if (!(tpnt1 = _dl_load_shared_library(0, &rpnt, tcurr, lpntstr)))
 				{
 #ifdef __LDSO_LDD_SUPPORT__
diff --git a/ldso/ldso/readelflib1.c b/ldso/ldso/readelflib1.c
index 3df8b1461..2f70621d1 100644
--- a/ldso/ldso/readelflib1.c
+++ b/ldso/ldso/readelflib1.c
@@ -166,29 +166,19 @@ search_for_named_library(char *name, int secure, const char *path_list,
 	return NULL;
 }
 
-
-/*
- * Used to return error codes back to dlopen et. al.
- */
-
-unsigned long _dl_error_number;
-unsigned long _dl_internal_error_number;
-extern char *_dl_ldsopath;
-
-struct elf_resolve *_dl_load_shared_library(int secure, struct dyn_elf **rpnt,
-	struct elf_resolve *tpnt, char *full_libname)
+/* Check if the named library is already loaded... */
+struct elf_resolve *_dl_check_if_named_library_is_loaded(const char *full_libname)
 {
-	char *pnt, *pnt1;
+	const char *pnt, *pnt1;
 	struct elf_resolve *tpnt1;
-	char *libname, *libname2;
+	const char *libname, *libname2;
 
-	_dl_internal_error_number = 0;
 	pnt = libname = full_libname;
 
 	/* quick hack to ensure mylibname buffer doesn't overflow.  don't 
 	   allow full_libname or any directory to be longer than 1024. */
 	if (_dl_strlen(full_libname) > 1024)
-		goto goof;
+		return NULL;
 
 	/* Skip over any initial initial './' and '/' stuff to 
 	 * get the short form libname with no path garbage */ 
@@ -215,8 +205,47 @@ struct elf_resolve *_dl_load_shared_library(int secure, struct dyn_elf **rpnt,
 			return tpnt1;
 		}
 	}
+	return NULL;
+}
 	
 
+
+/*
+ * Used to return error codes back to dlopen et. al.
+ */
+
+unsigned long _dl_error_number;
+unsigned long _dl_internal_error_number;
+extern char *_dl_ldsopath;
+
+struct elf_resolve *_dl_load_shared_library(int secure, struct dyn_elf **rpnt,
+	struct elf_resolve *tpnt, char *full_libname)
+{
+	char *pnt, *pnt1;
+	struct elf_resolve *tpnt1;
+	char *libname;
+
+	_dl_internal_error_number = 0;
+	libname = full_libname;
+
+	/* quick hack to ensure mylibname buffer doesn't overflow.  don't 
+	   allow full_libname or any directory to be longer than 1024. */
+	if (_dl_strlen(full_libname) > 1024)
+		goto goof;
+
+	/* Skip over any initial initial './' and '/' stuff to 
+	 * get the short form libname with no path garbage */ 
+	pnt1 = _dl_strrchr(libname, '/');
+	if (pnt1) {
+		libname = pnt1 + 1;
+	}
+
+	/* Critical step!  Weed out duplicates early to avoid
+	 * function aliasing, which wastes memory, and causes
+	 * really bad things to happen with weaks and globals. */
+	if ((tpnt1=_dl_check_if_named_library_is_loaded(libname))!=NULL)
+		return tpnt1;
+
 #if defined (__SUPPORT_LD_DEBUG__)
 	if(_dl_debug) _dl_dprintf(_dl_debug_file, "searching for library: '%s'\n", libname);
 #endif