X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=mm%2Fswapfile.c;h=ecf2702595b234a36d6f63a7d6d87726d234dc7e;hb=4cecd7e369e1b252db1d64451462221b362eed1c;hp=221c4c77bb7c2fd18b73de780205c34caf3dee6a;hpb=50d8b1519232c2da309bce29ec1612edbe1eacce;p=pandora-kernel.git

diff --git a/mm/swapfile.c b/mm/swapfile.c
index 221c4c77bb7c..ecf2702595b2 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -1649,7 +1649,6 @@ SYSCALL_DEFINE1(swapoff, const char __user *, specialfile)
 	p->max = 0;
 	swap_map = p->swap_map;
 	p->swap_map = NULL;
-	p->flags = 0;
 	spin_unlock(&swap_lock);
 	mutex_unlock(&swapon_mutex);
 	vfree(swap_map);
@@ -1667,6 +1666,16 @@ SYSCALL_DEFINE1(swapoff, const char __user *, specialfile)
 		mutex_unlock(&inode->i_mutex);
 	}
 	filp_close(swap_file, NULL);
+
+	/*
+	 * Clear the SWP_USED flag after all resources are freed so that swapon
+	 * can reuse this swap_info in alloc_swap_info() safely.  It is ok to
+	 * not hold p->lock after we cleared its SWP_WRITEOK.
+	 */
+	spin_lock(&swap_lock);
+	p->flags = 0;
+	spin_unlock(&swap_lock);
+
 	err = 0;
 	atomic_inc(&proc_poll_event);
 	wake_up_interruptible(&proc_poll_wait);
@@ -1904,6 +1913,8 @@ static unsigned long read_swap_header(struct swap_info_struct *p,
 		swab32s(&swap_header->info.version);
 		swab32s(&swap_header->info.last_page);
 		swab32s(&swap_header->info.nr_badpages);
+		if (swap_header->info.nr_badpages > MAX_SWAP_BADPAGES)
+			return 0;
 		for (i = 0; i < swap_header->info.nr_badpages; i++)
 			swab32s(&swap_header->info.badpages[i]);
 	}