lkml.org 
[lkml]   [2017]   [Dec]   [19]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[RFC PATCH 32/60] hyper_dmabuf: make all shared pages read-only
Date
All shared pages need to be read-only from importer's
point of view to prevent the buffer from being corrupted.

This patch may need to be reverted if we find a better
way to protect the original content in this sharing
model.

Signed-off-by: Dongwon Kim <dongwon.kim@intel.com>
---
drivers/xen/hyper_dmabuf/xen/hyper_dmabuf_xen_shm.c | 16 ++++++++--------
1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/drivers/xen/hyper_dmabuf/xen/hyper_dmabuf_xen_shm.c b/drivers/xen/hyper_dmabuf/xen/hyper_dmabuf_xen_shm.c
index c6a2993..1416a69 100644
--- a/drivers/xen/hyper_dmabuf/xen/hyper_dmabuf_xen_shm.c
+++ b/drivers/xen/hyper_dmabuf/xen/hyper_dmabuf_xen_shm.c
@@ -104,24 +104,24 @@ int hyper_dmabuf_xen_share_pages(struct page **pages, int domid, int nents,

*refs_info = (void *)sh_pages_info;

- /* share data pages in rw mode*/
+ /* share data pages in readonly mode for security */
for (i=0; i<nents; i++) {
lvl2_table[i] = gnttab_grant_foreign_access(domid,
pfn_to_mfn(page_to_pfn(pages[i])),
- 0);
+ true /* read-only from remote domain */);
}

/* Share 2nd level addressing pages in readonly mode*/
for (i=0; i< n_lvl2_grefs; i++) {
lvl3_table[i] = gnttab_grant_foreign_access(domid,
virt_to_mfn((unsigned long)lvl2_table+i*PAGE_SIZE ),
- 1);
+ true);
}

/* Share lvl3_table in readonly mode*/
lvl3_gref = gnttab_grant_foreign_access(domid,
virt_to_mfn((unsigned long)lvl3_table),
- 1);
+ true);


/* Store lvl3_table page to be freed later */
@@ -317,12 +317,12 @@ struct page ** hyper_dmabuf_xen_map_shared_pages(int lvl3_gref, int domid, int n
for (j = 0; j < REFS_PER_PAGE; j++) {
gnttab_set_map_op(&data_map_ops[k],
(unsigned long)pfn_to_kaddr(page_to_pfn(data_pages[k])),
- GNTMAP_host_map,
+ GNTMAP_host_map | GNTMAP_readonly,
lvl2_table[j], domid);

gnttab_set_unmap_op(&data_unmap_ops[k],
(unsigned long)pfn_to_kaddr(page_to_pfn(data_pages[k])),
- GNTMAP_host_map, -1);
+ GNTMAP_host_map | GNTMAP_readonly, -1);
k++;
}
}
@@ -333,12 +333,12 @@ struct page ** hyper_dmabuf_xen_map_shared_pages(int lvl3_gref, int domid, int n
for (j = 0; j < nents_last; j++) {
gnttab_set_map_op(&data_map_ops[k],
(unsigned long)pfn_to_kaddr(page_to_pfn(data_pages[k])),
- GNTMAP_host_map,
+ GNTMAP_host_map | GNTMAP_readonly,
lvl2_table[j], domid);

gnttab_set_unmap_op(&data_unmap_ops[k],
(unsigned long)pfn_to_kaddr(page_to_pfn(data_pages[k])),
- GNTMAP_host_map, -1);
+ GNTMAP_host_map | GNTMAP_readonly, -1);
k++;
}

--
2.7.4
\
 
 \ /
  Last update: 2017-12-19 20:46    [W:0.317 / U:0.488 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site