do not load unneeded stringtab sections; avoids backward seeking; from netbsd; tested by miod@ and martin@; deraadt@ ok

1 files changed, 20 insertions, 13 deletions

diff --git a/sys/lib/libsa/loadfile.c b/sys/lib/libsa/loadfile.c
index 1da87241d1e..7c3b8545718 100644
--- a/sys/lib/libsa/loadfile.c
+++ b/sys/lib/libsa/loadfile.c
@@ -1,5 +1,5 @@
 /* $NetBSD: loadfile.c,v 1.10 2000/12/03 02:53:04 tsutsui Exp $ */
-/* $OpenBSD: loadfile.c,v 1.10 2005/07/13 21:28:02 mickey Exp $ */
+/* $OpenBSD: loadfile.c,v 1.11 2006/12/30 18:31:39 mickey Exp $ */
 
 /*-
  * Copyright (c) 1997 The NetBSD Foundation, Inc.
@@ -261,10 +261,8 @@ elf_exec(int fd, Elf_Ehdr *elf, u_long *marks, int flags)
 	Elf_Shdr *shp;
 	Elf_Phdr *phdr;
 	Elf_Off off;
-	int i;
 	size_t sz;
-	int first;
-	int havesyms;
+	int first, i, j;
 	paddr_t minp = ~0, maxp = 0, pos = 0;
 	paddr_t offset = marks[MARK_START], shpp, elfp;
 
@@ -370,15 +368,21 @@ elf_exec(int fd, Elf_Ehdr *elf, u_long *marks, int flags)
 		 * there are no symbol sections.
 		 */
 		off = roundup((sizeof(Elf_Ehdr) + sz), sizeof(long));
-
-		for (havesyms = i = 0; i < elf->e_shnum; i++)
-			if (shp[i].sh_type == SHT_SYMTAB)
-				havesyms = 1;
-
 		for (first = 1, i = 0; i < elf->e_shnum; i++) {
-			if (shp[i].sh_type == SHT_SYMTAB ||
-			    shp[i].sh_type == SHT_STRTAB) {
-				if (havesyms && (flags & LOAD_SYM)) {
+			switch (shp[i].sh_type) {
+			case SHT_STRTAB:
+				for (j = 0; j < elf->e_shnum; j++)
+					if (shp[j].sh_type == SHT_SYMTAB &&
+					    shp[j].sh_link == (unsigned)i)
+						goto havesym;
+				/* FALLTHROUGH */
+			default:
+				/* Not loading this, so zero out the offset. */
+				shp[i].sh_offset = 0;
+				break;
+			havesym:
+			case SHT_SYMTAB:
+				if (flags & LOAD_SYM) {
 					PROGRESS(("%s%ld", first ? " [" : "+",
 					    (u_long)shp[i].sh_size));
 					if (lseek(fd, shp[i].sh_offset,
@@ -387,6 +391,7 @@ elf_exec(int fd, Elf_Ehdr *elf, u_long *marks, int flags)
 						FREE(shp, sz);
 						return 1;
 					}
+printf("*");
 					if (READ(fd, maxp, shp[i].sh_size) !=
 					    shp[i].sh_size) {
 						WARN(("read symbols"));
@@ -400,11 +405,13 @@ elf_exec(int fd, Elf_Ehdr *elf, u_long *marks, int flags)
 				off += roundup(shp[i].sh_size, sizeof(long));
 				first = 0;
 			}
+			/* Since we don't load .shstrtab, zero the name. */
+			shp[i].sh_name = 0;
 		}
 		if (flags & LOAD_SYM) {
 			BCOPY(shp, shpp, sz);
 
-			if (havesyms && first == 0)
+			if (first == 0)
 				PROGRESS(("]"));
 		}
 		FREE(shp, sz);