From: "J. Bruce Fields" <bfields@fieldses.org>
To: linux-kernel@vger.kernel.org
Cc: Jim Rees <rees@umich.edu>
Subject: [PATCH] strings: helper for maximum decimal encoding of an unsigned integer
Date: Tue, 21 Aug 2012 17:29:10 -0400 [thread overview]
Message-ID: <20120821212910.GD18637@fieldses.org> (raw)
From: "J. Bruce Fields" <bfields@redhat.com>
I've seen a couple examples recently where we've gotten this wrong.
Maybe something like this would help? Is there some better way?
(Approximation due to Jim Rees).
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
---
include/linux/string.h | 6 ++++++
net/sunrpc/cache.c | 2 +-
2 files changed, 7 insertions(+), 1 deletion(-)
diff --git a/include/linux/string.h b/include/linux/string.h
index ffe0442..d4809b7 100644
--- a/include/linux/string.h
+++ b/include/linux/string.h
@@ -126,6 +126,12 @@ extern void argv_free(char **argv);
extern bool sysfs_streq(const char *s1, const char *s2);
extern int strtobool(const char *s, bool *res);
+/*
+ * length of the decimal representation of an unsigned integer. Just an
+ * approximation, but it's right for types of size 1 to 36 bytes:
+ */
+#define base10len(i) (sizeof(i) * 24 / 10 + 1)
+
#ifdef CONFIG_BINARY_PRINTF
int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args);
int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf);
diff --git a/net/sunrpc/cache.c b/net/sunrpc/cache.c
index 2afd2a8..1dcd2b3 100644
--- a/net/sunrpc/cache.c
+++ b/net/sunrpc/cache.c
@@ -1409,7 +1409,7 @@ static ssize_t read_flush(struct file *file, char __user *buf,
size_t count, loff_t *ppos,
struct cache_detail *cd)
{
- char tbuf[20];
+ char tbuf[base10len(long) + 2];
unsigned long p = *ppos;
size_t len;
--
1.7.9.5
next reply other threads:[~2012-08-21 21:29 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-08-21 21:29 J. Bruce Fields [this message]
2012-08-21 21:22 ` [PATCH] strings: helper for maximum decimal encoding of an unsigned integer Jim Rees
2012-08-21 22:06 ` Al Viro
2012-08-21 22:19 ` J. Bruce Fields
2012-08-22 0:03 ` Jim Rees
2012-09-10 6:19 ` Jan Engelhardt
2012-09-14 9:17 ` Bernd Petrovitsch
2012-09-14 12:30 ` Jim Rees
2012-09-14 13:14 ` J. Bruce Fields
2012-09-14 13:18 ` Bernd Petrovitsch
2012-09-14 13:51 ` Jim Rees
2012-09-14 13:37 ` Jan Engelhardt
2012-09-14 13:54 ` Jim Rees
2012-09-14 12:59 ` Jan Engelhardt
2012-09-14 13:46 ` Jim Rees
2012-09-14 14:25 ` Jan Engelhardt
2012-09-14 15:00 ` Bernd Petrovitsch
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20120821212910.GD18637@fieldses.org \
--to=bfields@fieldses.org \
--cc=linux-kernel@vger.kernel.org \
--cc=rees@umich.edu \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).