From: Keir Fraser <keir.fraser@citrix.com>
Date: Wed, 18 Jun 2008 08:38:11 +0000 (+0100)
Subject: minios: fix gnttab allocation boundary
X-Git-Tag: archive/raspbian/4.8.0-1+rpi1~1^2~14192^2~52
X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=030c31dd18ad7dc1c71d6502c577762e467cdb92;p=xen.git

minios: fix gnttab allocation boundary

The gnttab_sem is already fed during initialization's put_free_entry
loop.

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

diff --git a/extras/mini-os/gnttab.c b/extras/mini-os/gnttab.c
index d94c28b815..18fd87e29c 100644
--- a/extras/mini-os/gnttab.c
+++ b/extras/mini-os/gnttab.c
@@ -35,7 +35,7 @@ static grant_ref_t gnttab_list[NR_GRANT_ENTRIES];
 #ifdef GNT_DEBUG
 static char inuse[NR_GRANT_ENTRIES];
 #endif
-static __DECLARE_SEMAPHORE_GENERIC(gnttab_sem, NR_GRANT_ENTRIES);
+static __DECLARE_SEMAPHORE_GENERIC(gnttab_sem, 0);
 
 static void
 put_free_entry(grant_ref_t ref)
@@ -60,6 +60,7 @@ get_free_entry(void)
     down(&gnttab_sem);
     local_irq_save(flags);
     ref = gnttab_list[0];
+    BUG_ON(ref < NR_RESERVED_ENTRIES || ref >= NR_GRANT_ENTRIES);
     gnttab_list[0] = gnttab_list[ref];
 #ifdef GNT_DEBUG
     BUG_ON(inuse[ref]);