[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH 02/22] 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@xxxxxxxxxxxxx> v5: xc_dom_seg_to_ptr_pages sets *pages_out=0 if it returns NULL. v4 was: Acked-by: Ian Campbell <ian.campbell@xxxxxxxxxx> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx> --- tools/libxc/xc_dom.h | 18 +++++++++++++++--- 1 files changed, 15 insertions(+), 3 deletions(-) diff --git a/tools/libxc/xc_dom.h b/tools/libxc/xc_dom.h index ac36600..da0598c 100644 --- a/tools/libxc/xc_dom.h +++ b/tools/libxc/xc_dom.h @@ -294,14 +294,26 @@ 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); + + if ( pages_out != NULL ) + *pages_out = retval ? pages : 0; + return retval; +} - return xc_dom_pfn_to_ptr(dom, seg->pfn, pages); +static inline void *xc_dom_seg_to_ptr(struct xc_dom_image *dom, + struct xc_dom_seg *seg) +{ + return xc_dom_seg_to_ptr_pages(dom, seg, NULL); } static inline void *xc_dom_vaddr_to_ptr(struct xc_dom_image *dom, -- 1.7.2.5 _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx http://lists.xen.org/xen-devel
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