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authorLinus Walleij <linus.walleij@linaro.org>2015-12-21 09:36:21 +0100
committerLinus Walleij <linus.walleij@linaro.org>2015-12-21 09:36:21 +0100
commit0529357f102b96f68bc199f858d1c3b07f4b674c (patch)
treeeaa047952a768099e00a5245afa0d84799df6990 /drivers/block/xen-blkback/blkback.c
parenta9f1a3e4c1c7dc82711bc22dc52c7b0d6912ed56 (diff)
parent4ef7675344d687a0ef5b0d7c0cee12da005870c0 (diff)
downloadop-kernel-dev-0529357f102b96f68bc199f858d1c3b07f4b674c.zip
op-kernel-dev-0529357f102b96f68bc199f858d1c3b07f4b674c.tar.gz
Merge tag 'v4.4-rc6' into devel
Linux 4.4-rc6
Diffstat (limited to 'drivers/block/xen-blkback/blkback.c')
-rw-r--r--drivers/block/xen-blkback/blkback.c15
1 files changed, 10 insertions, 5 deletions
diff --git a/drivers/block/xen-blkback/blkback.c b/drivers/block/xen-blkback/blkback.c
index f909994..41fb1a9 100644
--- a/drivers/block/xen-blkback/blkback.c
+++ b/drivers/block/xen-blkback/blkback.c
@@ -950,6 +950,8 @@ static int xen_blkbk_parse_indirect(struct blkif_request *req,
goto unmap;
for (n = 0, i = 0; n < nseg; n++) {
+ uint8_t first_sect, last_sect;
+
if ((n % SEGS_PER_INDIRECT_FRAME) == 0) {
/* Map indirect segments */
if (segments)
@@ -957,15 +959,18 @@ static int xen_blkbk_parse_indirect(struct blkif_request *req,
segments = kmap_atomic(pages[n/SEGS_PER_INDIRECT_FRAME]->page);
}
i = n % SEGS_PER_INDIRECT_FRAME;
+
pending_req->segments[n]->gref = segments[i].gref;
- seg[n].nsec = segments[i].last_sect -
- segments[i].first_sect + 1;
- seg[n].offset = (segments[i].first_sect << 9);
- if ((segments[i].last_sect >= (XEN_PAGE_SIZE >> 9)) ||
- (segments[i].last_sect < segments[i].first_sect)) {
+
+ first_sect = READ_ONCE(segments[i].first_sect);
+ last_sect = READ_ONCE(segments[i].last_sect);
+ if (last_sect >= (XEN_PAGE_SIZE >> 9) || last_sect < first_sect) {
rc = -EINVAL;
goto unmap;
}
+
+ seg[n].nsec = last_sect - first_sect + 1;
+ seg[n].offset = first_sect << 9;
preq->nr_sects += seg[n].nsec;
}
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