diff options
| author | Peter Maydell <peter.maydell@linaro.org> | 2015-12-18 15:32:32 +0000 |
|---|---|---|
| committer | Peter Maydell <peter.maydell@linaro.org> | 2015-12-18 15:32:32 +0000 |
| commit | 6126bc55220f7cde3392ef1fbbffcbc67240d4f0 (patch) | |
| tree | 64f99103ff5838afd549d7edc7da01dc6032f23c | |
| parent | 18f49881cf8359e89396aac12f5d3cf3f8a632ba (diff) | |
| parent | 7ea11bf376aea4bf8340eb363de9777c7f93e556 (diff) | |
Merge remote-tracking branch 'remotes/sstabellini/tags/xsa155' into staging
XSA-155 fixes
# gpg: Signature made Fri 18 Dec 2015 15:16:18 GMT using RSA key ID 70E1AE90
# gpg: Good signature from "Stefano Stabellini <stefano.stabellini@eu.citrix.com>"
* remotes/sstabellini/tags/xsa155:
xenfb: avoid reading twice the same fields from the shared page
xen/blkif: Avoid double access to src->nr_segments
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
| -rw-r--r-- | hw/block/xen_blkif.h | 12 | ||||
| -rw-r--r-- | hw/display/xenfb.c | 10 |
2 files changed, 14 insertions, 8 deletions
diff --git a/hw/block/xen_blkif.h b/hw/block/xen_blkif.h index 711b692742..c68487cb31 100644 --- a/hw/block/xen_blkif.h +++ b/hw/block/xen_blkif.h @@ -85,8 +85,10 @@ static inline void blkif_get_x86_32_req(blkif_request_t *dst, blkif_x86_32_reque d->nr_sectors = s->nr_sectors; return; } - if (n > src->nr_segments) - n = src->nr_segments; + /* prevent the compiler from optimizing the code and using src->nr_segments instead */ + barrier(); + if (n > dst->nr_segments) + n = dst->nr_segments; for (i = 0; i < n; i++) dst->seg[i] = src->seg[i]; } @@ -106,8 +108,10 @@ static inline void blkif_get_x86_64_req(blkif_request_t *dst, blkif_x86_64_reque d->nr_sectors = s->nr_sectors; return; } - if (n > src->nr_segments) - n = src->nr_segments; + /* prevent the compiler from optimizing the code and using src->nr_segments instead */ + barrier(); + if (n > dst->nr_segments) + n = dst->nr_segments; for (i = 0; i < n; i++) dst->seg[i] = src->seg[i]; } diff --git a/hw/display/xenfb.c b/hw/display/xenfb.c index 5e324ef62d..4e2a27a3d6 100644 --- a/hw/display/xenfb.c +++ b/hw/display/xenfb.c @@ -784,18 +784,20 @@ static void xenfb_invalidate(void *opaque) static void xenfb_handle_events(struct XenFB *xenfb) { - uint32_t prod, cons; + uint32_t prod, cons, out_cons; struct xenfb_page *page = xenfb->c.page; prod = page->out_prod; - if (prod == page->out_cons) + out_cons = page->out_cons; + if (prod == out_cons) return; xen_rmb(); /* ensure we see ring contents up to prod */ - for (cons = page->out_cons; cons != prod; cons++) { + for (cons = out_cons; cons != prod; cons++) { union xenfb_out_event *event = &XENFB_OUT_RING_REF(page, cons); + uint8_t type = event->type; int x, y, w, h; - switch (event->type) { + switch (type) { case XENFB_TYPE_UPDATE: if (xenfb->up_count == UP_QUEUE) xenfb->up_fullscreen = 1; |