From: Keir Fraser <keir.fraser@citrix.com>
Date: Thu, 24 Jul 2008 13:11:47 +0000 (+0100)
Subject: mini-os: select call incorrectly reports xce_handle as ready
X-Git-Tag: archive/raspbian/4.8.0-1+rpi1~1^2~14165^2~133
X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=597e548eef7de6cba2f30f47a7f3177e31cadbeb;p=xen.git

mini-os: select call incorrectly reports xce_handle as ready

The current implementation in minios of xc_evtchn_pending doesn't set
read=0 when there is exactly one port pending. This resulted in
select() incorrectly reporting the file descriptor as ready.

Signed-off-by: Diego Ongaro <diego.ongaro@citrix.com>
Signed-off-by: Samuel Thibault <samuel.thibault@eu.citrix.com>
---

diff --git a/tools/libxc/xc_minios.c b/tools/libxc/xc_minios.c
index 4a5a351aeb..a07b17dd6f 100644
--- a/tools/libxc/xc_minios.c
+++ b/tools/libxc/xc_minios.c
@@ -292,18 +292,24 @@ evtchn_port_or_error_t xc_evtchn_pending(int xce_handle)
 {
     int i;
     unsigned long flags;
+    evtchn_port_t ret = -1;
+
     local_irq_save(flags);
+    files[xce_handle].read = 0;
     for (i = 0; i < MAX_EVTCHN_PORTS; i++) {
-	evtchn_port_t port = files[xce_handle].evtchn.ports[i].port;
-	if (port != -1 && files[xce_handle].evtchn.ports[i].pending) {
-	    files[xce_handle].evtchn.ports[i].pending = 0;
-	    local_irq_restore(flags);
-	    return port;
-	}
+        evtchn_port_t port = files[xce_handle].evtchn.ports[i].port;
+        if (port != -1 && files[xce_handle].evtchn.ports[i].pending) {
+            if (ret == -1) {
+                ret = port;
+                files[xce_handle].evtchn.ports[i].pending = 0;
+            } else {
+                files[xce_handle].read = 1;
+                break;
+            }
+        }
     }
-    files[xce_handle].read = 0;
     local_irq_restore(flags);
-    return -1;
+    return ret;
 }
 
 int xc_evtchn_unmask(int xce_handle, evtchn_port_t port)