svn commit: r273685 - head/sys/kern

[Mateusz Guzik]

Author: mjg
Date: Sun Oct 26 06:04:09 2014
New Revision: 273685
URL: https://svnweb.freebsd.org/changeset/base/273685

Log:
  Tidy up sys_setgroups and kern_setgroups.
  
  - 'groups' initialization to NULL is always ovewrwriten before use, so plug it
  - get rid of 'goto out'
  - kern_setgroups's callers already validate ngrp, so only assert the condition
  - ngrp  is an u_int, so 'ngrp < 1' is more readable as 'ngrp == 0'
  
  No functional changes.

Modified:
  head/sys/kern/kern_prot.c

Modified: head/sys/kern/kern_prot.c
==============================================================================
--- head/sys/kern/kern_prot.c	Sun Oct 26 05:39:42 2014	(r273684)
+++ head/sys/kern/kern_prot.c	Sun Oct 26 06:04:09 2014	(r273685)
@@ -805,23 +805,24 @@ struct setgroups_args {
 int
 sys_setgroups(struct thread *td, struct setgroups_args *uap)
 {
-	gid_t *groups = NULL;
 	gid_t smallgroups[XU_NGROUPS];
+	gid_t *groups;
 	u_int gidsetsize;
 	int error;
 
 	gidsetsize = uap->gidsetsize;
 	if (gidsetsize > ngroups_max + 1)
 		return (EINVAL);
+
 	if (gidsetsize > XU_NGROUPS)
 		groups = malloc(gidsetsize * sizeof(gid_t), M_TEMP, M_WAITOK);
 	else
 		groups = smallgroups;
+
 	error = copyin(uap->gidset, groups, gidsetsize * sizeof(gid_t));
-	if (error)
-		goto out;
-	error = kern_setgroups(td, gidsetsize, groups);
-out:
+	if (error == 0)
+		error = kern_setgroups(td, gidsetsize, groups);
+
 	if (gidsetsize > XU_NGROUPS)
 		free(groups, M_TEMP);
 	return (error);
@@ -834,8 +835,7 @@ kern_setgroups(struct thread *td, u_int 
 	struct ucred *newcred, *oldcred;
 	int error;
 
-	if (ngrp > ngroups_max + 1)
-		return (EINVAL);
+	MPASS(ngrp <= ngroups_max);
 	AUDIT_ARG_GROUPSET(groups, ngrp);
 	newcred = crget();
 	crextend(newcred, ngrp);
@@ -852,7 +852,7 @@ kern_setgroups(struct thread *td, u_int 
 	if (error)
 		goto fail;
 
-	if (ngrp < 1) {
+	if (ngrp == 0) {
 		/*
 		 * setgroups(0, NULL) is a legitimate way of clearing the
 		 * groups vector on non-BSD systems (which generally do not