Changeset: 3994b577f3c4 for MonetDB
URL: http://dev.monetdb.org/hg/MonetDB?cmd=changeset;node=3994b577f3c4
Modified Files:
MonetDB/src/gdk/gdk_storage.mx
Branch: Jun2010
Log Message:
detect address underrun to prevent segfaults in access_heap()
diffs (50 lines):
diff -r fcc6c41c10b6 -r 3994b577f3c4 MonetDB/src/gdk/gdk_storage.mx
--- a/MonetDB/src/gdk/gdk_storage.mx Wed Aug 11 01:11:57 2010 +0200
+++ b/MonetDB/src/gdk/gdk_storage.mx Wed Aug 11 01:27:21 2010 +0200
@@ -761,25 +761,31 @@
view and heap.base of views are not necessarily
aligned */
size_t *lo = (size_t *) (((size_t) base + sizeof(size_t) - 1) &
(~(sizeof(size_t) - 1)));
- size_t *hi = (size_t *) (base + touch);
+ size_t *hi = (size_t *) (base + touch), *hi8 = NULL, hi1 = NULL;
/* page size: [bytes] -> [sizeof(size_t)]
* to make sure we touch each page,
* not only 1 in sizeof(size_t) pages */
page /= sizeof(size_t);
- for (hi -= 8 * page; lo <= hi; lo += 8 * page) {
- /* try to trigger loading of multiple pages
- without blocking */
- v0 += lo[0 * page];
- v1 += lo[1 * page];
- v2 += lo[2 * page];
- v3 += lo[3 * page];
- v4 += lo[4 * page];
- v5 += lo[5 * page];
- v6 += lo[6 * page];
- v7 += lo[7 * page];
- }
- for (hi += 7 * page; lo <= hi; lo += page)
- v0 += *lo;
+ hi8 = hi - 8 * page;
+ hi1 = hi - page;
+ /* detect address underrun */
+ if (hi8 < hi)
+ for (; lo <= hi8; lo += 8 * page) {
+ /* try to trigger loading of multiple pages
+ without blocking */
+ v0 += lo[0 * page];
+ v1 += lo[1 * page];
+ v2 += lo[2 * page];
+ v3 += lo[3 * page];
+ v4 += lo[4 * page];
+ v5 += lo[5 * page];
+ v6 += lo[6 * page];
+ v7 += lo[7 * page];
+ }
+ /* detect address underrun */
+ if (hi1 < hi)
+ for (; lo <= hi1; lo += page)
+ v0 += *lo;
}
IODEBUG THRprintf(GDKout,
"#BATpreload(%s->%s,preload=%d,sz=%dMB,touch=%dMB,%s)
= %dms \n",
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