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reorder addend handling before symbol lookup in relocation code

these two tasks are independent now, but in order to support lazy
relocations, the failure path for symbol lookup may want the addend to
be available.
Rich Felker 8 年之前
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4823b13a75
共有 1 个文件被更改,包括 17 次插入16 次删除
  1. 17 16
      ldso/dynlink.c

+ 17 - 16
ldso/dynlink.c

@@ -323,8 +323,24 @@ static void do_relocs(struct dso *dso, size_t *rel, size_t rel_size, size_t stri
 		if (skip_relative && IS_RELATIVE(rel[1], dso->syms)) continue;
 		type = R_TYPE(rel[1]);
 		if (type == REL_NONE) continue;
-		sym_index = R_SYM(rel[1]);
 		reloc_addr = laddr(dso, rel[0]);
+
+		if (stride > 2) {
+			addend = rel[2];
+		} else if (type==REL_GOT || type==REL_PLT|| type==REL_COPY) {
+			addend = 0;
+		} else if (reuse_addends) {
+			/* Save original addend in stage 2 where the dso
+			 * chain consists of just ldso; otherwise read back
+			 * saved addend since the inline one was clobbered. */
+			if (head==&ldso)
+				saved_addends[save_slot] = *reloc_addr;
+			addend = saved_addends[save_slot++];
+		} else {
+			addend = *reloc_addr;
+		}
+
+		sym_index = R_SYM(rel[1]);
 		if (sym_index) {
 			sym = syms + sym_index;
 			name = strings + sym->st_name;
@@ -345,21 +361,6 @@ static void do_relocs(struct dso *dso, size_t *rel, size_t rel_size, size_t stri
 			def.dso = dso;
 		}
 
-		if (stride > 2) {
-			addend = rel[2];
-		} else if (type==REL_GOT || type==REL_PLT|| type==REL_COPY) {
-			addend = 0;
-		} else if (reuse_addends) {
-			/* Save original addend in stage 2 where the dso
-			 * chain consists of just ldso; otherwise read back
-			 * saved addend since the inline one was clobbered. */
-			if (head==&ldso)
-				saved_addends[save_slot] = *reloc_addr;
-			addend = saved_addends[save_slot++];
-		} else {
-			addend = *reloc_addr;
-		}
-
 		sym_val = def.sym ? (size_t)laddr(def.dso, def.sym->st_value) : 0;
 		tls_val = def.sym ? def.sym->st_value : 0;