From: Ben Pfaff <blp@cs.stanford.edu>
Date: Fri, 5 Nov 2004 23:12:11 +0000 (+0000)
Subject: Prevent bitmap_scan() from assert-failing if CNT is greater than the
X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;ds=sidebyside;h=fc637378f55d2e5d39ef4ebd58e3a3b1a13a4fa9;p=pintos-anon

Prevent bitmap_scan() from assert-failing if CNT is greater than the
bitmap's size.
---

diff --git a/src/lib/kernel/bitmap.c b/src/lib/kernel/bitmap.c
index cacc263..95d6890 100644
--- a/src/lib/kernel/bitmap.c
+++ b/src/lib/kernel/bitmap.c
@@ -216,9 +216,10 @@ bitmap_scan (const struct bitmap *b, size_t start, size_t cnt, bool value)
   ASSERT (b != NULL);
   ASSERT (start <= b->bit_cnt);
 
-  for (idx = start, last = b->bit_cnt - cnt; idx <= last; idx++)
-    if (!contains (b, idx, idx + cnt, !value))
-      return idx;
+  if (cnt <= b->bit_cnt)
+    for (idx = start, last = b->bit_cnt - cnt; idx <= last; idx++)
+      if (!contains (b, idx, idx + cnt, !value))
+        return idx;
   return BITMAP_ERROR;
 }