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Date:      Tue, 1 Jul 2014 09:21:33 +0000 (UTC)
From:      Mateusz Guzik <mjg@FreeBSD.org>
To:        src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org
Subject:   svn commit: r268087 - head/sys/kern
Message-ID:  <201407010921.s619LXHL063077@svn.freebsd.org>
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Author: mjg
Date: Tue Jul  1 09:21:32 2014
New Revision: 268087
URL: http://svnweb.freebsd.org/changeset/base/268087

Log:
  Don't call crcopysafe or uifind unnecessarily in execve.
  
  MFC after:	1 week

Modified:
  head/sys/kern/kern_exec.c

Modified: head/sys/kern/kern_exec.c
==============================================================================
--- head/sys/kern/kern_exec.c	Tue Jul  1 08:36:56 2014	(r268086)
+++ head/sys/kern/kern_exec.c	Tue Jul  1 09:21:32 2014	(r268087)
@@ -336,7 +336,7 @@ do_execve(td, args, mac_p)
 	struct proc *p = td->td_proc;
 	struct nameidata nd;
 	struct ucred *newcred = NULL, *oldcred;
-	struct uidinfo *euip;
+	struct uidinfo *euip = NULL;
 	register_t *stack_base;
 	int error, i;
 	struct image_params image_params, *imgp;
@@ -601,8 +601,6 @@ interpret:
 	/*
 	 * Malloc things before we need locks.
 	 */
-	newcred = crget();
-	euip = uifind(attr.va_uid);
 	i = imgp->args->begin_envv - imgp->args->begin_argv;
 	/* Cache arguments if they fit inside our allowance */
 	if (ps_arg_cache_limit >= i + sizeof(struct pargs)) {
@@ -631,7 +629,7 @@ interpret:
 	PROC_LOCK(p);
 	if (oldsigacts)
 		p->p_sigacts = newsigacts;
-	oldcred = crcopysafe(p, newcred);
+	oldcred = p->p_ucred;
 	/* Stop profiling */
 	stopprofclock(p);
 
@@ -721,6 +719,8 @@ interpret:
 		vn_lock(imgp->vp, LK_SHARED | LK_RETRY);
 		if (error != 0)
 			goto done1;
+		newcred = crdup(oldcred);
+		euip = uifind(attr.va_uid);
 		PROC_LOCK(p);
 		/*
 		 * Set the new credentials.
@@ -745,7 +745,6 @@ interpret:
 		change_svuid(newcred, newcred->cr_uid);
 		change_svgid(newcred, newcred->cr_gid);
 		p->p_ucred = newcred;
-		newcred = NULL;
 	} else {
 		if (oldcred->cr_uid == oldcred->cr_ruid &&
 		    oldcred->cr_gid == oldcred->cr_rgid)
@@ -764,10 +763,12 @@ interpret:
 		 */
 		if (oldcred->cr_svuid != oldcred->cr_uid ||
 		    oldcred->cr_svgid != oldcred->cr_gid) {
+			PROC_UNLOCK(p);
+			newcred = crdup(oldcred);
+			PROC_LOCK(p);
 			change_svuid(newcred, newcred->cr_uid);
 			change_svgid(newcred, newcred->cr_gid);
 			p->p_ucred = newcred;
-			newcred = NULL;
 		}
 	}
 
@@ -844,11 +845,10 @@ done1:
 	/*
 	 * Free any resources malloc'd earlier that we didn't use.
 	 */
-	uifree(euip);
-	if (newcred == NULL)
+	if (euip != NULL)
+		uifree(euip);
+	if (newcred != NULL)
 		crfree(oldcred);
-	else
-		crfree(newcred);
 	VOP_UNLOCK(imgp->vp, 0);
 
 	/*

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