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author | Ian Jackson <ian.jackson@eu.citrix.com> | 2013-06-14 16:43:16 +0100 |
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committer | Ian Jackson <Ian.Jackson@eu.citrix.com> | 2013-06-14 16:43:16 +0100 |
commit | a672da4b2d58ef12be9d7407160e9fb43cac75d9 (patch) | |
tree | 29587c7a1b5638d439947c62df32c0f8ac5381b9 | |
parent | 9737484becab4a25159f1e985700eaee89690d34 (diff) | |
download | xen-a672da4b2d58ef12be9d7407160e9fb43cac75d9.tar.gz xen-a672da4b2d58ef12be9d7407160e9fb43cac75d9.tar.bz2 xen-a672da4b2d58ef12be9d7407160e9fb43cac75d9.zip |
libxc: introduce xc_dom_seg_to_ptr_pages
Provide a version of xc_dom_seg_to_ptr which returns the number of
guest pages it has actually mapped. This is useful for callers who
want to do range checking; we will use this later in this series.
This is part of the fix to a security issue, XSA-55.
Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
-rw-r--r-- | tools/libxc/xc_dom.h | 19 |
1 files changed, 16 insertions, 3 deletions
diff --git a/tools/libxc/xc_dom.h b/tools/libxc/xc_dom.h index 6a72aa93f5..9af2195748 100644 --- a/tools/libxc/xc_dom.h +++ b/tools/libxc/xc_dom.h @@ -278,14 +278,27 @@ void *xc_dom_pfn_to_ptr(struct xc_dom_image *dom, xen_pfn_t first, void xc_dom_unmap_one(struct xc_dom_image *dom, xen_pfn_t pfn); void xc_dom_unmap_all(struct xc_dom_image *dom); -static inline void *xc_dom_seg_to_ptr(struct xc_dom_image *dom, - struct xc_dom_seg *seg) +static inline void *xc_dom_seg_to_ptr_pages(struct xc_dom_image *dom, + struct xc_dom_seg *seg, + xen_pfn_t *pages_out) { xen_vaddr_t segsize = seg->vend - seg->vstart; unsigned int page_size = XC_DOM_PAGE_SIZE(dom); xen_pfn_t pages = (segsize + page_size - 1) / page_size; + void *retval; + + retval = xc_dom_pfn_to_ptr(dom, seg->pfn, pages); + + *pages_out = retval ? pages : 0; + return retval; +} + +static inline void *xc_dom_seg_to_ptr(struct xc_dom_image *dom, + struct xc_dom_seg *seg) +{ + xen_pfn_t dummy; - return xc_dom_pfn_to_ptr(dom, seg->pfn, pages); + return xc_dom_seg_to_ptr_pages(dom, seg, &dummy); } static inline void *xc_dom_vaddr_to_ptr(struct xc_dom_image *dom, |