From: "Theodore Y. Ts'o" <tytso@mit.edu>
To: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
Linux-Next Mailing List <linux-next@vger.kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: linux-next: build warnings from Linus' tree
Date: Sun, 19 Aug 2018 20:02:18 -0400 [thread overview]
Message-ID: <20180820000218.GE19200@thunk.org> (raw)
In-Reply-To: <20180820081323.23a47af3@canb.auug.org.au>
On Mon, Aug 20, 2018 at 08:13:23AM +1000, Stephen Rothwell wrote:
> fs/ext4/super.c: In function '__save_error_info':
> fs/ext4/super.c:344:2: warning: 'strncpy' specified bound 32 equals destination size [-Wstringop-truncation]
> strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> fs/ext4/super.c:349:3: warning: 'strncpy' specified bound 32 equals destination size [-Wstringop-truncation]
> strncpy(es->s_first_error_func, func,
> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> sizeof(es->s_first_error_func));
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
All of ext4 superblock char[] fields are not necessarily null
terminated, so this is a false positive. I suppose we could do
something like this:
inline char *
strncpy_I_solemnly_swear_I_know_what_I_am_doing(char *dest,
const char *src, size_t n)
{
#if __GNUC_PREREQ (8, 2)
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wstringop-truncate"
#endif
return strncpy(dest, src, n);
#if __GNUC_PREREQ (8, 2)
#pragma GCC diagnostic pop
#endif
}
(if we really think this warning is worthwhile enough that we don't
just want to globally disable it, of course)
- Ted
P.S. It's really, really too bad there isn't a simpler way to shut up
gcc. You need the #ifdef __GNUC_PREREQ nonsense because otherwise
older versions of gcc that don't understand the particular warning
you're trying to suppress will complain loudly. (Ask me how I
know....)
next prev parent reply other threads:[~2018-08-20 0:02 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-08-19 22:13 linux-next: build warnings from Linus' tree Stephen Rothwell
2018-08-19 22:16 ` Stephen Rothwell
2018-08-19 22:40 ` Stephen Rothwell
2018-08-19 23:21 ` Linus Torvalds
2018-08-20 1:33 ` Adam Borowski
2018-08-20 2:53 ` Theodore Y. Ts'o
2018-08-20 0:02 ` Theodore Y. Ts'o [this message]
2018-08-20 17:47 ` Miguel Ojeda
-- strict thread matches above, loose matches on Subject: below --
2019-08-29 21:59 Stephen Rothwell
2018-06-11 22:14 Stephen Rothwell
2018-11-14 4:54 ` Joel Stanley
2018-11-14 10:20 ` Michael Ellerman
2018-11-18 11:22 ` Alan Modra
2018-12-03 23:24 ` Joel Stanley
2010-10-28 0:27 Stephen Rothwell
2010-10-28 3:04 ` Mark Brown
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=20180820000218.GE19200@thunk.org \
--to=tytso@mit.edu \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-next@vger.kernel.org \
--cc=sfr@canb.auug.org.au \
--cc=torvalds@linux-foundation.org \
/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).