[src/trunk]: src/sys 1) On 64bit systems, don't add the 32bit execsw[] to the...

[maxv <maxv%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/42f8eb7e7a45
branches:  trunk
changeset: 797561:42f8eb7e7a45
user:      maxv <maxv%NetBSD.org@localhost>
date:      Tue Jul 22 08:18:33 2014 +0000

description:
1) On 64bit systems, don't add the 32bit execsw[] to the global exec array.
   exec_elf32 works on 32bit systems only, and will crash 32bit binaries on
   64bit systems.
2) Now that exec_elf32 is dormant, we can give the native ELF loaders the
   highest priority.

Binaries will load faster now (system boot, compilation, etc.).

With the help of njloy@. Discussed a bit on tech-kern@, no disagreement.

diffstat:

 sys/compat/linux32/common/linux32_mod.c |   6 +++---
 sys/compat/netbsd32/netbsd32_mod.c      |   6 +++---
 sys/kern/exec_elf32.c                   |  28 +++++++++++++++++++++++++---
 sys/kern/exec_elf64.c                   |   6 +++---
 4 files changed, 34 insertions(+), 12 deletions(-)

diffs (143 lines):

diff -r 9eda27738281 -r 42f8eb7e7a45 sys/compat/linux32/common/linux32_mod.c
--- a/sys/compat/linux32/common/linux32_mod.c   Tue Jul 22 07:38:41 2014 +0000
+++ b/sys/compat/linux32/common/linux32_mod.c   Tue Jul 22 08:18:33 2014 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: linux32_mod.c,v 1.5 2014/03/07 01:33:43 christos Exp $ */
+/*     $NetBSD: linux32_mod.c,v 1.6 2014/07/22 08:18:33 maxv Exp $     */
 
 /*-
  * Copyright (c) 2008 The NetBSD Foundation, Inc.
@@ -30,7 +30,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: linux32_mod.c,v 1.5 2014/03/07 01:33:43 christos Exp $");
+__KERNEL_RCSID(0, "$NetBSD: linux32_mod.c,v 1.6 2014/07/22 08:18:33 maxv Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_execfmt.h"
@@ -67,7 +67,7 @@
                        .elf_probe_func = linux32_elf32_probe, 
                },
                .es_emul = &emul_linux32,
-               .es_prio = EXECSW_PRIO_FIRST, 
+               .es_prio = EXECSW_PRIO_ANY, 
                .es_arglen = LINUX32_ELF_AUX_ARGSIZ,
                .es_copyargs = linux32_elf32_copyargs,
                .es_setregs = NULL,
diff -r 9eda27738281 -r 42f8eb7e7a45 sys/compat/netbsd32/netbsd32_mod.c
--- a/sys/compat/netbsd32/netbsd32_mod.c        Tue Jul 22 07:38:41 2014 +0000
+++ b/sys/compat/netbsd32/netbsd32_mod.c        Tue Jul 22 08:18:33 2014 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: netbsd32_mod.c,v 1.4 2014/07/11 16:22:49 maxv Exp $    */
+/*     $NetBSD: netbsd32_mod.c,v 1.5 2014/07/22 08:18:33 maxv Exp $    */
 
 /*-
  * Copyright (c) 2008 The NetBSD Foundation, Inc.
@@ -30,7 +30,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: netbsd32_mod.c,v 1.4 2014/07/11 16:22:49 maxv Exp $");
+__KERNEL_RCSID(0, "$NetBSD: netbsd32_mod.c,v 1.5 2014/07/22 08:18:33 maxv Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_execfmt.h"
@@ -87,7 +87,7 @@
                        .elf_probe_func = netbsd32_elf32_probe,
                },
                .es_emul = &emul_netbsd32,
-               .es_prio = EXECSW_PRIO_FIRST,
+               .es_prio = EXECSW_PRIO_ANY,
                .es_arglen = ELF32_AUXSIZE,
                .es_copyargs = netbsd32_elf32_copyargs,
                .es_setregs = NULL,
diff -r 9eda27738281 -r 42f8eb7e7a45 sys/kern/exec_elf32.c
--- a/sys/kern/exec_elf32.c     Tue Jul 22 07:38:41 2014 +0000
+++ b/sys/kern/exec_elf32.c     Tue Jul 22 08:18:33 2014 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: exec_elf32.c,v 1.140 2014/04/07 17:02:15 rjs Exp $     */
+/*     $NetBSD: exec_elf32.c,v 1.141 2014/07/22 08:18:33 maxv Exp $    */
 
 /*
  * Copyright (c) 1996 Christopher G. Demetriou
@@ -32,7 +32,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: exec_elf32.c,v 1.140 2014/04/07 17:02:15 rjs Exp $");
+__KERNEL_RCSID(0, "$NetBSD: exec_elf32.c,v 1.141 2014/07/22 08:18:33 maxv Exp $");
 
 #define        ELFSIZE 32
 
@@ -59,7 +59,7 @@
                        .elf_probe_func = netbsd_elf32_probe,
                },
                .es_emul = &emul_netbsd,
-               .es_prio = EXECSW_PRIO_ANY,
+               .es_prio = EXECSW_PRIO_FIRST,
                .es_arglen = ELF32_AUXSIZE,
                .es_copyargs = elf32_copyargs,
                .es_setregs = NULL,
@@ -87,7 +87,28 @@
 static int
 exec_elf32_modcmd(modcmd_t cmd, void *arg)
 {
+#if ARCH_ELFSIZE == 64
+       /*
+        * If we are on a 64bit system, we don't want the 32bit execsw[] to be
+        * added in the global array, because the exec_elf32 module only works
+        * on 32bit systems.
+        *
+        * However, we need the exec_elf32 module, because it will make the 32bit
+        * functions available for netbsd32 and linux32.
+        *
+        * Therefore, allow this module on 64bit systems, but make it dormant.
+        */
 
+       (void)exec_elf32_execsw; /* unused */
+
+       switch (cmd) {
+       case MODULE_CMD_INIT:
+       case MODULE_CMD_FINI:
+               return 0;
+       default:
+               return ENOTTY;
+       }
+#else /* ARCH_ELFSIZE == 64 */
        switch (cmd) {
        case MODULE_CMD_INIT:
                return exec_add(exec_elf32_execsw,
@@ -100,4 +121,5 @@
        default:
                return ENOTTY;
         }
+#endif /* ARCH_ELFSIZE == 64 */
 }
diff -r 9eda27738281 -r 42f8eb7e7a45 sys/kern/exec_elf64.c
--- a/sys/kern/exec_elf64.c     Tue Jul 22 07:38:41 2014 +0000
+++ b/sys/kern/exec_elf64.c     Tue Jul 22 08:18:33 2014 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: exec_elf64.c,v 1.5 2014/03/07 01:34:29 christos Exp $  */
+/*     $NetBSD: exec_elf64.c,v 1.6 2014/07/22 08:18:33 maxv Exp $      */
 
 /*
  * Copyright (c) 1996 Christopher G. Demetriou
@@ -32,7 +32,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: exec_elf64.c,v 1.5 2014/03/07 01:34:29 christos Exp $");
+__KERNEL_RCSID(0, "$NetBSD: exec_elf64.c,v 1.6 2014/07/22 08:18:33 maxv Exp $");
 
 #define        ELFSIZE 64
 
@@ -60,7 +60,7 @@
                        .elf_probe_func = netbsd_elf64_probe,
                },
                .es_emul = &emul_netbsd,
-               .es_prio = EXECSW_PRIO_ANY,
+               .es_prio = EXECSW_PRIO_FIRST,
                .es_arglen = ELF64_AUXSIZE,
                .es_copyargs = elf64_copyargs,
                .es_setregs = NULL,