[src/trunk]: src/sys/kern execve_runproc: Move a long code block handling cre...

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

details:   https://anonhg.NetBSD.org/src/rev/27c651e95e53
branches:  trunk
changeset: 328655:27c651e95e53
user:      uebayasi <uebayasi%NetBSD.org@localhost>
date:      Sat Apr 12 06:31:27 2014 +0000

description:
execve_runproc: Move a long code block handling credential into a separate
function.  No functional changes.

diffstat:

 sys/kern/kern_exec.c |  172 +++++++++++++++++++++++++++-----------------------
 1 files changed, 93 insertions(+), 79 deletions(-)

diffs (200 lines):

diff -r 10ca7bac3f7b -r 27c651e95e53 sys/kern/kern_exec.c
--- a/sys/kern/kern_exec.c      Sat Apr 12 05:25:23 2014 +0000
+++ b/sys/kern/kern_exec.c      Sat Apr 12 06:31:27 2014 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: kern_exec.c,v 1.386 2014/04/12 05:25:23 uebayasi Exp $ */
+/*     $NetBSD: kern_exec.c,v 1.387 2014/04/12 06:31:27 uebayasi Exp $ */
 
 /*-
  * Copyright (c) 2008 The NetBSD Foundation, Inc.
@@ -59,7 +59,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: kern_exec.c,v 1.386 2014/04/12 05:25:23 uebayasi Exp $");
+__KERNEL_RCSID(0, "$NetBSD: kern_exec.c,v 1.387 2014/04/12 06:31:27 uebayasi Exp $");
 
 #include "opt_exec.h"
 #include "opt_execfmt.h"
@@ -914,6 +914,94 @@
        PNBUF_PUT(data->ed_resolvedpathbuf);
 }
 
+/* XXX elsewhere */
+static int
+credexec(struct lwp *l, struct vattr *attr)
+{
+       struct proc *p = l->l_proc;
+       int error;
+
+       /*
+        * Deal with set[ug]id.  MNT_NOSUID has already been used to disable
+        * s[ug]id.  It's OK to check for PSL_TRACED here as we have blocked
+        * out additional references on the process for the moment.
+        */
+       if ((p->p_slflag & PSL_TRACED) == 0 &&
+
+           (((attr->va_mode & S_ISUID) != 0 &&
+             kauth_cred_geteuid(l->l_cred) != attr->va_uid) ||
+
+            ((attr->va_mode & S_ISGID) != 0 &&
+             kauth_cred_getegid(l->l_cred) != attr->va_gid))) {
+               /*
+                * Mark the process as SUGID before we do
+                * anything that might block.
+                */
+               proc_crmod_enter();
+               proc_crmod_leave(NULL, NULL, true);
+
+               /* Make sure file descriptors 0..2 are in use. */
+               if ((error = fd_checkstd()) != 0) {
+                       DPRINTF(("%s: fdcheckstd failed %d\n",
+                           __func__, error));
+                       return error;
+               }
+
+               /*
+                * Copy the credential so other references don't see our
+                * changes.
+                */
+               l->l_cred = kauth_cred_copy(l->l_cred);
+#ifdef KTRACE
+               /*
+                * If the persistent trace flag isn't set, turn off.
+                */
+               if (p->p_tracep) {
+                       mutex_enter(&ktrace_lock);
+                       if (!(p->p_traceflag & KTRFAC_PERSISTENT))
+                               ktrderef(p);
+                       mutex_exit(&ktrace_lock);
+               }
+#endif
+               if (attr->va_mode & S_ISUID)
+                       kauth_cred_seteuid(l->l_cred, attr->va_uid);
+               if (attr->va_mode & S_ISGID)
+                       kauth_cred_setegid(l->l_cred, attr->va_gid);
+       } else {
+               if (kauth_cred_geteuid(l->l_cred) ==
+                   kauth_cred_getuid(l->l_cred) &&
+                   kauth_cred_getegid(l->l_cred) ==
+                   kauth_cred_getgid(l->l_cred))
+                       p->p_flag &= ~PK_SUGID;
+       }
+
+       /*
+        * Copy the credential so other references don't see our changes.
+        * Test to see if this is necessary first, since in the common case
+        * we won't need a private reference.
+        */
+       if (kauth_cred_geteuid(l->l_cred) != kauth_cred_getsvuid(l->l_cred) ||
+           kauth_cred_getegid(l->l_cred) != kauth_cred_getsvgid(l->l_cred)) {
+               l->l_cred = kauth_cred_copy(l->l_cred);
+               kauth_cred_setsvuid(l->l_cred, kauth_cred_geteuid(l->l_cred));
+               kauth_cred_setsvgid(l->l_cred, kauth_cred_getegid(l->l_cred));
+       }
+
+       /* Update the master credentials. */
+       if (l->l_cred != p->p_cred) {
+               kauth_cred_t ocred;
+
+               kauth_cred_hold(l->l_cred);
+               mutex_enter(p->p_lock);
+               ocred = p->p_cred;
+               p->p_cred = l->l_cred;
+               mutex_exit(p->p_lock);
+               kauth_cred_free(ocred);
+       }
+
+       return 0;
+}
+
 static int
 execve_runproc(struct lwp *l, struct execve_data * restrict data,
        bool no_local_exec_lock, bool is_spawn)
@@ -1247,83 +1335,9 @@
 #endif
        }
 
-       /*
-        * Deal with set[ug]id.  MNT_NOSUID has already been used to disable
-        * s[ug]id.  It's OK to check for PSL_TRACED here as we have blocked
-        * out additional references on the process for the moment.
-        */
-       if ((p->p_slflag & PSL_TRACED) == 0 &&
-
-           (((data->ed_attr.va_mode & S_ISUID) != 0 &&
-             kauth_cred_geteuid(l->l_cred) != data->ed_attr.va_uid) ||
-
-            ((data->ed_attr.va_mode & S_ISGID) != 0 &&
-             kauth_cred_getegid(l->l_cred) != data->ed_attr.va_gid))) {
-               /*
-                * Mark the process as SUGID before we do
-                * anything that might block.
-                */
-               proc_crmod_enter();
-               proc_crmod_leave(NULL, NULL, true);
-
-               /* Make sure file descriptors 0..2 are in use. */
-               if ((error = fd_checkstd()) != 0) {
-                       DPRINTF(("%s: fdcheckstd failed %d\n",
-                           __func__, error));
-                       goto exec_abort;
-               }
-
-               /*
-                * Copy the credential so other references don't see our
-                * changes.
-                */
-               l->l_cred = kauth_cred_copy(l->l_cred);
-#ifdef KTRACE
-               /*
-                * If the persistent trace flag isn't set, turn off.
-                */
-               if (p->p_tracep) {
-                       mutex_enter(&ktrace_lock);
-                       if (!(p->p_traceflag & KTRFAC_PERSISTENT))
-                               ktrderef(p);
-                       mutex_exit(&ktrace_lock);
-               }
-#endif
-               if (data->ed_attr.va_mode & S_ISUID)
-                       kauth_cred_seteuid(l->l_cred, data->ed_attr.va_uid);
-               if (data->ed_attr.va_mode & S_ISGID)
-                       kauth_cred_setegid(l->l_cred, data->ed_attr.va_gid);
-       } else {
-               if (kauth_cred_geteuid(l->l_cred) ==
-                   kauth_cred_getuid(l->l_cred) &&
-                   kauth_cred_getegid(l->l_cred) ==
-                   kauth_cred_getgid(l->l_cred))
-                       p->p_flag &= ~PK_SUGID;
-       }
-
-       /*
-        * Copy the credential so other references don't see our changes.
-        * Test to see if this is necessary first, since in the common case
-        * we won't need a private reference.
-        */
-       if (kauth_cred_geteuid(l->l_cred) != kauth_cred_getsvuid(l->l_cred) ||
-           kauth_cred_getegid(l->l_cred) != kauth_cred_getsvgid(l->l_cred)) {
-               l->l_cred = kauth_cred_copy(l->l_cred);
-               kauth_cred_setsvuid(l->l_cred, kauth_cred_geteuid(l->l_cred));
-               kauth_cred_setsvgid(l->l_cred, kauth_cred_getegid(l->l_cred));
-       }
-
-       /* Update the master credentials. */
-       if (l->l_cred != p->p_cred) {
-               kauth_cred_t ocred;
-
-               kauth_cred_hold(l->l_cred);
-               mutex_enter(p->p_lock);
-               ocred = p->p_cred;
-               p->p_cred = l->l_cred;
-               mutex_exit(p->p_lock);
-               kauth_cred_free(ocred);
-       }
+       error = credexec(l, &data->ed_attr);
+       if (error)
+               goto exec_abort;
 
 #if defined(__HAVE_RAS)
        /*