From: David van Moolenbroek <david@minix3.org>
Date: Fri, 19 Dec 2014 15:35:31 +0000 (+0000)
Subject: procfs: do not list inactive services
X-Git-Url: http://zhaoyanbai.com/repos/%22http:/www.isc.org/icons/zpipe.c?a=commitdiff_plain;h=refs%2Fchanges%2F10%2F3010%2F1;p=minix.git

procfs: do not list inactive services

Each /proc/service entry must have a unique label.  With cloning,
multiple RS services may have the same label.  Since we are not
actually interested in inactive services (for now), eliminate those
entries, leaving only the active service which will then indeed have
a unique label in the list.  This resolves a procfs crash.

Change-Id: I0de7ef8fd186ab13f3e22e46416504fd981c09aa
---

diff --git a/minix/fs/procfs/service.c b/minix/fs/procfs/service.c
index 576472105..0dc2f6a19 100644
--- a/minix/fs/procfs/service.c
+++ b/minix/fs/procfs/service.c
@@ -142,7 +142,8 @@ service_get_policies(struct policies * pol, index_t slot)
 	memset(pol[slot].formatted, 0, MAX_POL_FORMAT_SZ);
 	for(pos = 0; pos < (sizeof(def_pol) / sizeof(def_pol[0])); pos++) {
 		if (0 == strcmp(ref_label, def_pol[pos].label)) {
-			(void)strncpy(pol[slot].formatted, def_pol[pos].policy_str, MAX_POL_FORMAT_SZ);
+			(void)strncpy(pol[slot].formatted,
+			    def_pol[pos].policy_str, MAX_POL_FORMAT_SZ);
 			pol[slot].formatted[MAX_POL_FORMAT_SZ-1] = '\0';
 			break;
 		}
@@ -154,6 +155,19 @@ service_get_policies(struct policies * pol, index_t slot)
 	return pol[slot].formatted;
 }
 
+/*
+ * Return whether a slot is in use and active.  The purpose of this check is
+ * to ensure that after eliminating all slots that do not pass this check, we
+ * are left with a set of live services each with a unique label.
+ */
+static int
+service_active(index_t slot)
+{
+
+	return ((rproc.proc[slot].r_flags & (RS_IN_USE | RS_ACTIVE)) ==
+	    (RS_IN_USE | RS_ACTIVE));
+}
+
 /*
  * Update the contents of the service directory, by first updating the RS
  * tables and then updating the directory contents.
@@ -187,7 +201,7 @@ service_update(void)
 		 * If the slot is no longer in use, or the label name does not
 		 * match, the node must be deleted.
 		 */
-		if (!(rproc.proc[slot].r_flags & RS_IN_USE) ||
+		if (!service_active(slot) ||
 		    strcmp(get_inode_name(node), rproc.pub[slot].label))
 			delete_inode(node);
 	}
@@ -198,7 +212,7 @@ service_update(void)
 	stat.gid = SUPER_USER;
 
 	for (slot = 0; slot < NR_SYS_PROCS; slot++) {
-		if (!(rproc.proc[slot].r_flags & RS_IN_USE) ||
+		if (!service_active(slot) ||
 		    get_inode_by_index(service_node, slot) != NULL)
 			continue;