Module Name: src
Committed By: kre
Date: Tue Mar 12 00:25:44 UTC 2019
Modified Files:
src/sys/kern: subr_humanize.c
Log Message:
This had a similar problem to that reported in PR lib/54053
for the userland (libc) version of humanize_number(),
except in a much more limited, and less harmful, way ...
If the value to be printed was > ~0/10 (eg ~0 itself) and
the buffer given was big enough to hold it, "umax" would overflow,
and the expected result was not produced (here at least the effect was
simply to scale the result for huge values by one unnecessary step,
rather than maximally scale all values usually generating 0E, but
incorrect nonetheless.)
To generate a diff of this commit:
cvs rdiff -u -r1.1 -r1.2 src/sys/kern/subr_humanize.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/kern/subr_humanize.c
diff -u src/sys/kern/subr_humanize.c:1.1 src/sys/kern/subr_humanize.c:1.2
--- src/sys/kern/subr_humanize.c:1.1 Fri Oct 2 15:48:41 2009
+++ src/sys/kern/subr_humanize.c Tue Mar 12 00:25:44 2019
@@ -1,4 +1,4 @@
-/* $NetBSD: subr_humanize.c,v 1.1 2009/10/02 15:48:41 pooka Exp $ */
+/* $NetBSD: subr_humanize.c,v 1.2 2019/03/12 00:25:44 kre Exp $ */
/*-
* Copyright (c) 1997, 1998, 1999, 2002, 2007, 2008 The NetBSD Foundation, Inc.
@@ -30,7 +30,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: subr_humanize.c,v 1.1 2009/10/02 15:48:41 pooka Exp $");
+__KERNEL_RCSID(0, "$NetBSD: subr_humanize.c,v 1.2 2019/03/12 00:25:44 kre Exp $");
#include <sys/types.h>
#include <sys/systm.h>
@@ -55,7 +55,7 @@ humanize_number(char *buf, size_t len, u
/* prefixes are: (none), kilo, Mega, Giga, Tera, Peta, Exa */
const char *prefixes;
int r;
- uint64_t umax;
+ uint64_t umax, b10;
size_t i, suffixlen;
if (buf == NULL || suffix == NULL)
@@ -77,14 +77,23 @@ humanize_number(char *buf, size_t len, u
prefixes = " kMGTPE"; /* SI for decimal multiplies */
umax = 1;
+ b10 = bytes/10;
for (i = 0; i < len - suffixlen - 3; i++) {
+ if (umax > b10) {
+ /*
+ * there is space for the unscaled number
+ * but bytes might be ~0 - there is no bigger
+ * value available for umax, so we must skip
+ * the "bytes >= umax" test below
+ */
+ i = 0;
+ goto nodiv;
+ }
umax *= 10;
- if (umax > bytes)
- break;
}
for (i = 0; bytes >= umax && prefixes[i + 1]; i++)
bytes /= divisor;
-
+ nodiv:
r = snprintf(buf, len, "%qu%s%c%s", (unsigned long long)bytes,
i == 0 ? "" : " ", prefixes[i], suffix);
