From 0193c62c94643a837832f2b5ccc133434ee740cb Mon Sep 17 00:00:00 2001 From: Stefano Stabellini Date: Fri, 17 Jan 2014 15:28:18 +0000 Subject: xenfb: map framebuffer read-only and handle unmap errors The framebuffer is needlessly mapped (PROT_READ | PROT_WRITE), map it PROT_READ instead. The framebuffer is unmapped by replacing the framebuffer pages with anonymous shared memory, calling mmap. Check for return errors and print a warning. Signed-off-by: Stefano Stabellini --- hw/display/xenfb.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'hw') diff --git a/hw/display/xenfb.c b/hw/display/xenfb.c index f0333a0cad..cb9d456814 100644 --- a/hw/display/xenfb.c +++ b/hw/display/xenfb.c @@ -495,7 +495,7 @@ static int xenfb_map_fb(struct XenFB *xenfb) munmap(map, n_fbdirs * XC_PAGE_SIZE); xenfb->pixels = xc_map_foreign_pages(xen_xc, xenfb->c.xendev.dom, - PROT_READ | PROT_WRITE, fbmfns, xenfb->fbpages); + PROT_READ, fbmfns, xenfb->fbpages); if (xenfb->pixels == NULL) goto out; @@ -903,6 +903,11 @@ static void fb_disconnect(struct XenDevice *xendev) fb->pixels = mmap(fb->pixels, fb->fbpages * XC_PAGE_SIZE, PROT_READ | PROT_WRITE, MAP_SHARED | MAP_ANON, -1, 0); + if (fb->pixels == MAP_FAILED) { + xen_be_printf(xendev, 0, + "Couldn't replace the framebuffer with anonymous memory errno=%d\n", + errno); + } common_unbind(&fb->c); fb->feature_update = 0; fb->bug_trigger = 0; -- cgit v1.2.1