svn commit: r202342 - in head/sys: i386/ibcs2 kern

[Brooks Davis]

Author: brooks
Date: Fri Jan 15 07:18:46 2010
New Revision: 202342
URL: http://svn.freebsd.org/changeset/base/202342

Log:
  Only allocate the space we need before calling kern_getgroups instead
  of allocating what ever the user asks for up to "ngroups_max + 1".  On
  systems with large values of kern.ngroups this will be more efficient.
  
  The now redundant check that the array is large enough in
  kern_getgroups() is deliberate to allow this change to be merged to
  stable/8 without breaking potential third party consumers of the API.
  
  Reported by:	bde
  MFC after:	28 days

Modified:
  head/sys/i386/ibcs2/ibcs2_misc.c
  head/sys/kern/kern_prot.c

Modified: head/sys/i386/ibcs2/ibcs2_misc.c
==============================================================================
--- head/sys/i386/ibcs2/ibcs2_misc.c	Fri Jan 15 07:05:00 2010	(r202341)
+++ head/sys/i386/ibcs2/ibcs2_misc.c	Fri Jan 15 07:18:46 2010	(r202342)
@@ -663,9 +663,13 @@ ibcs2_getgroups(td, uap)
 	u_int i, ngrp;
 	int error;
 
-	if (uap->gidsetsize < 0)
-		return (EINVAL);
-	ngrp = MIN(uap->gidsetsize, ngroups_max + 1);
+	if (uap->gidsetsize < td->td_ucred->cr_ngroups) {
+		if (uap->gidsetsize == 0)
+			ngrp = 0;
+		else
+			return (EINVAL);
+	} else
+		ngrp = td->td_ucred->cr_ngroups;
 	gp = malloc(ngrp * sizeof(*gp), M_TEMP, M_WAITOK);
 	error = kern_getgroups(td, &ngrp, gp);
 	if (error)

Modified: head/sys/kern/kern_prot.c
==============================================================================
--- head/sys/kern/kern_prot.c	Fri Jan 15 07:05:00 2010	(r202341)
+++ head/sys/kern/kern_prot.c	Fri Jan 15 07:18:46 2010	(r202342)
@@ -283,7 +283,13 @@ getgroups(struct thread *td, register st
 	u_int ngrp;
 	int error;
 
-	ngrp = MIN(uap->gidsetsize, ngroups_max + 1);
+	if (uap->gidsetsize < td->td_ucred->cr_ngroups) {
+		if (uap->gidsetsize == 0)
+			ngrp = 0;
+		else
+			return (EINVAL);
+	} else
+		ngrp = td->td_ucred->cr_ngroups;
 	groups = malloc(ngrp * sizeof(*groups), M_TEMP, M_WAITOK);
 	error = kern_getgroups(td, &ngrp, groups);
 	if (error)