From: Lionel Sambuc <lionel@minix3.org>
Date: Tue, 28 May 2013 19:08:15 +0000 (+0000)
Subject: servers/pm: Fix EFAULT check for SETGROUPS
X-Git-Tag: v3.3.0~956
X-Git-Url: http://zhaoyanbai.com/repos/%22http:/www.isc.org/icons/zlib_tech.html?a=commitdiff_plain;h=refs%2Fchanges%2F97%2F597%2F1;p=minix.git

servers/pm: Fix EFAULT check for SETGROUPS

The previous test would return EFAULT as soon as the group pointer
was NULL, while it is sensible when the count is also 0.

In that case, the SETGROUP syscall is expected to clear all the
group entries as the new set is empty.

Change-Id: I07b7e1d1f023a52e3035d53f7d9b42b660e039e8
---

diff --git a/servers/pm/getset.c b/servers/pm/getset.c
index 407a5a63a..9084b4e76 100644
--- a/servers/pm/getset.c
+++ b/servers/pm/getset.c
@@ -141,7 +141,7 @@ int do_set()
 		if (ngroups > NGROUPS_MAX || ngroups < 0) 
 			return(EINVAL);
 
-		if (m_in.groupsp == NULL) 
+		if (m_in.grp_no > 0 && m_in.groupsp == NULL)
 			return(EFAULT);
 
 		r = sys_datacopy(who_e, (vir_bytes) m_in.groupsp, SELF,