From: Pierre Pfister <ppfister@cisco.com>
Date: Thu, 20 Apr 2017 13:34:00 +0000 (+0200)
Subject: vhost: Fix mmap size calculation
X-Git-Tag: v17.07-rc1~271
X-Git-Url: https://gerrit.fd.io/r/gitweb?a=commitdiff_plain;h=bed5489a4eb109efe91dac8d259a03b1834b0db8;p=vpp.git

vhost: Fix mmap size calculation

I had a bug where a requested size of 1G was resulting in
an aligned size of '1G + 2M', resulting in an OOM error.

Previous code was adding one huge page size
when memory is already aligned.

Change-Id: Idd3aa0e9b893fb3efccba6ae1c7161e26d3f9456
Signed-off-by: Pierre Pfister <ppfister@cisco.com>
---

diff --git a/src/vnet/devices/virtio/vhost-user.c b/src/vnet/devices/virtio/vhost-user.c
index bcfef9f5aee..3ac76977099 100644
--- a/src/vnet/devices/virtio/vhost-user.c
+++ b/src/vnet/devices/virtio/vhost-user.c
@@ -303,7 +303,7 @@ unmap_all_mem_regions (vhost_user_intf_t * vui)
 
 	  ssize_t map_sz = (vui->regions[i].memory_size +
 			    vui->regions[i].mmap_offset +
-			    page_sz) & ~(page_sz - 1);
+			    page_sz - 1) & ~(page_sz - 1);
 
 	  r =
 	    munmap (vui->region_mmap_addr[i] - vui->regions[i].mmap_offset,
@@ -917,7 +917,7 @@ vhost_user_socket_read (unix_file_t * uf)
 	  /* align size to 2M page */
 	  ssize_t map_sz = (vui->regions[i].memory_size +
 			    vui->regions[i].mmap_offset +
-			    page_sz) & ~(page_sz - 1);
+			    page_sz - 1) & ~(page_sz - 1);
 
 	  vui->region_mmap_addr[i] = mmap (0, map_sz, PROT_READ | PROT_WRITE,
 					   MAP_SHARED, fds[i], 0);
@@ -1168,7 +1168,7 @@ vhost_user_socket_read (unix_file_t * uf)
 	/* align size to 2M page */
 	long page_sz = get_huge_page_size (fd);
 	ssize_t map_sz =
-	  (msg.log.size + msg.log.offset + page_sz) & ~(page_sz - 1);
+	  (msg.log.size + msg.log.offset + page_sz - 1) & ~(page_sz - 1);
 
 	vui->log_base_addr = mmap (0, map_sz, PROT_READ | PROT_WRITE,
 				   MAP_SHARED, fd, 0);