ldso: Rework global scope handling and symbol lookup mechanism

Global symbol scope is implemented as a linked list of
local scope, that dynamically grows and shrinks when dlopen/
dlclose are called. Each local scope is implemented as an array
of pointer to struct elf_resolve.
This will help to detect conflict when LD_TRACE_PRELINKING option
will be implemented.

Signed-off-by: Filippo Arcidiacono <filippo.arcidiacono@st.com>
Signed-off-by: Carmelo Amoroso <carmelo.amoroso@st.com>

1 files changed, 44 insertions, 39 deletions

diff --git a/ldso/ldso/dl-hash.c b/ldso/ldso/dl-hash.c
index 0048734ba..2c4571f20 100644
--- a/ldso/ldso/dl-hash.c
+++ b/ldso/ldso/dl-hash.c
@@ -268,70 +268,75 @@ _dl_lookup_sysv_hash(struct elf_resolve *tpnt, ElfW(Sym) *symtab, unsigned long
  * This function resolves externals, and this is either called when we process
  * relocations or when we call an entry in the PLT table for the first time.
  */
-char *_dl_lookup_hash(const char *name, struct dyn_elf *rpnt, struct elf_resolve *mytpnt,
+char *_dl_lookup_hash(const char *name, struct r_scope_elem *scope, struct elf_resolve *mytpnt,
 	int type_class, struct elf_resolve **tpntp)
 {
 	struct elf_resolve *tpnt = NULL;
 	ElfW(Sym) *symtab;
+	int i = 0;
 
 	unsigned long elf_hash_number = 0xffffffff;
 	const ElfW(Sym) *sym = NULL;
 
 	char *weak_result = NULL;
+	struct r_scope_elem *loop_scope;
 
 #ifdef __LDSO_GNU_HASH_SUPPORT__
 	unsigned long gnu_hash_number = _dl_gnu_hash((const unsigned char *)name);
 #endif
 
-	for (; rpnt; rpnt = rpnt->next) {
-		tpnt = rpnt->dyn;
-
-		if (!(tpnt->rtld_flags & RTLD_GLOBAL) && mytpnt) {
-			if (mytpnt == tpnt)
-				;
-			else {
-				struct init_fini_list *tmp;
-
-				for (tmp = mytpnt->rtld_local; tmp; tmp = tmp->next) {
-					if (tmp->tpnt == tpnt)
-						break;
+	for (loop_scope = scope; loop_scope && !sym; loop_scope = loop_scope->next) {
+		for (i = 0; i < loop_scope->r_nlist; i++) {
+			tpnt = loop_scope->r_list[i];
+
+			if (!(tpnt->rtld_flags & RTLD_GLOBAL) && mytpnt) {
+				if (mytpnt == tpnt)
+					;
+				else {
+					struct init_fini_list *tmp;
+
+					for (tmp = mytpnt->rtld_local; tmp; tmp = tmp->next) {
+						if (tmp->tpnt == tpnt)
+							break;
+					}
+					if (!tmp)
+						continue;
 				}
-				if (!tmp)
-					continue;
 			}
-		}
-		/* Don't search the executable when resolving a copy reloc. */
-		if ((type_class &  ELF_RTYPE_CLASS_COPY) && tpnt->libtype == elf_executable)
-			continue;
+			/* Don't search the executable when resolving a copy reloc. */
+			if ((type_class &  ELF_RTYPE_CLASS_COPY) && tpnt->libtype == elf_executable)
+				continue;
 
-		/* If the hash table is empty there is nothing to do here.  */
-		if (tpnt->nbucket == 0)
-			continue;
+			/* If the hash table is empty there is nothing to do here.  */
+			if (tpnt->nbucket == 0)
+				continue;
 
-		symtab = (ElfW(Sym) *) (intptr_t) (tpnt->dynamic_info[DT_SYMTAB]);
+			symtab = (ElfW(Sym) *) (intptr_t) (tpnt->dynamic_info[DT_SYMTAB]);
 
 #ifdef __LDSO_GNU_HASH_SUPPORT__
-		/* Prefer GNU hash style, if any */
-		if (tpnt->l_gnu_bitmask) {
-			sym = _dl_lookup_gnu_hash(tpnt, symtab, gnu_hash_number, name, type_class);
-			if (sym != NULL)
-				/* If sym has been found, do not search further */
-				break;
-		} else {
+			/* Prefer GNU hash style, if any */
+			if (tpnt->l_gnu_bitmask) {
+				sym = _dl_lookup_gnu_hash(tpnt, symtab, gnu_hash_number, name, type_class);
+				if (sym != NULL)
+					/* If sym has been found, do not search further */
+					break;
+			} else {
 #endif
-		/* Use the old SysV-style hash table */
+				/* Use the old SysV-style hash table */
 
-		/* Calculate the old sysv hash number only once */
-		if (elf_hash_number == 0xffffffff)
-			elf_hash_number = _dl_elf_hash((const unsigned char *)name);
+				/* Calculate the old sysv hash number only once */
+				if (elf_hash_number == 0xffffffff)
+					elf_hash_number = _dl_elf_hash((const unsigned char *)name);
 
-		sym = _dl_lookup_sysv_hash(tpnt, symtab, elf_hash_number, name, type_class);
-		if (sym != NULL)
-			break;
+				sym = _dl_lookup_sysv_hash(tpnt, symtab, elf_hash_number, name, type_class);
+				if (sym != NULL)
+					/* If sym has been found, do not search further */
+					break;
 #ifdef __LDSO_GNU_HASH_SUPPORT__
-		}
+			}
 #endif
-	} /* end of for (; rpnt; rpnt = rpnt->next) { */
+		} /* End of inner for */
+	}
 
 	if (sym) {
 		/* At this point we have found the requested symbol, do binding */