bsearch(3): support arrays with more than INT_MAX elements

The "lim" variable needs to be a size_t to match nmemb, otherwise we
get undefined behavior when nmemb exceeds INT_MAX.

Prompted by a blog post by Joshua Bloch:

https://ai.googleblog.com/2006/06/extra-extra-read-all-about-it-nearly.html

Fixed by Chris Torek a long time ago:

https://svnweb.freebsd.org/csrg/lib/libc/stdlib/bsearch.c?revision=51742&view=markup

ok millert@

diff --git a/lib/libc/stdlib/bsearch.c b/lib/libc/stdlib/bsearch.c
index 59d478e..6df44d6 100644 (file)
--- a/lib/libc/stdlib/bsearch.c
+++ b/lib/libc/stdlib/bsearch.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: bsearch.c,v 1.8 2016/10/22 19:19:34 tb Exp $ */
+/*     $OpenBSD: bsearch.c,v 1.9 2021/12/02 20:58:01 cheloha Exp $ */
 /*
  * Copyright (c) 1990 Regents of the University of California.
  * All rights reserved.
@@ -51,8 +51,9 @@ bsearch(const void *key, const void *base0, size_t nmemb, size_t size,
     int (*compar)(const void *, const void *))
 {
        const char *base = base0;
-       int lim, cmp;
        const void *p;
+       size_t lim;
+       int cmp;
 
        for (lim = nmemb; lim != 0; lim >>= 1) {
                p = base + (lim >> 1) * size;