From: Joe Perches <joe@perches.com>
To: "Ingo Molnar" <mingo@kernel.org>, "Måns Rullgård" <mans@mansr.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Colin King <colin.king@canonical.com>,
Ingo Molnar <mingo@redhat.com>,
linux-kernel@vger.kernel.org, Richard Henderson <rth@twiddle.net>,
Jakub Jelinek <jakub@redhat.com>,
Dan Carpenter <dan.carpenter@oracle.com>
Subject: Re: Q: why didn't GCC warn about this uninitialized variable?
Date: Thu, 03 Mar 2016 04:49:25 -0800 [thread overview]
Message-ID: <1457009365.4044.115.camel@perches.com> (raw)
In-Reply-To: <20160303124319.GA8781@gmail.com>
On Thu, 2016-03-03 at 13:43 +0100, Ingo Molnar wrote:
> it would be absolutely fantastic if one of these solutions existed on GCC:>
>
> - emit a warning if a structure is passed around uninitialized. A new GCC
> __attribute__((struct_fully_initialized)) could be used to annotate extern
> function arguments which fully initialize input arguments.
>
> (I'd personally migrate both tools/perf and kernel side code to use it, module
> by module.)
>
> - or memset() to zero all on-stack structures that GCC cannot prove are
> initialized fully.
>
> The first solution takes extra work on the source level, the latter takes extra
> runtime profiling to find where the extra memset()s matter to performance. Any of
> these would be fantastic tools for C robustness and security.
Maybe memset any alignment padding between automatic variables too.
next prev parent reply other threads:[~2016-03-03 12:49 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-03-02 12:55 [PATCH] perf tests: initialize sa.sa_flags Colin King
2016-03-02 12:59 ` Peter Zijlstra
2016-03-02 13:03 ` Arnaldo Carvalho de Melo
2016-03-02 13:21 ` Peter Zijlstra
2016-03-02 13:23 ` Arnaldo Carvalho de Melo
2016-03-03 12:19 ` Q: why didn't GCC warn about this uninitialized variable? (was: Re: [PATCH] perf tests: initialize sa.sa_flags) Ingo Molnar
2016-03-03 12:25 ` Q: why didn't GCC warn about this uninitialized variable? Colin Ian King
2016-03-03 12:31 ` Måns Rullgård
2016-03-03 12:43 ` Ingo Molnar
2016-03-03 12:49 ` Joe Perches [this message]
2016-03-03 12:55 ` Q: why didn't GCC warn about this uninitialized variable? (was: Re: [PATCH] perf tests: initialize sa.sa_flags) Jakub Jelinek
2016-03-03 13:24 ` Ingo Molnar
2016-03-03 13:46 ` Jakub Jelinek
2016-03-03 14:04 ` Ingo Molnar
2016-03-03 13:47 ` Ingo Molnar
2016-03-03 14:19 ` Jakub Jelinek
2016-03-03 14:40 ` Ingo Molnar
2016-03-03 14:53 ` Ingo Molnar
2016-03-03 15:04 ` Ingo Molnar
2016-03-02 13:02 ` [PATCH] perf tests: initialize sa.sa_flags Arnaldo Carvalho de Melo
2016-03-05 8:20 ` [tip:perf/core] perf tests: Initialize sa.sa_flags tip-bot for Colin Ian King
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=1457009365.4044.115.camel@perches.com \
--to=joe@perches.com \
--cc=acme@kernel.org \
--cc=colin.king@canonical.com \
--cc=dan.carpenter@oracle.com \
--cc=jakub@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mans@mansr.com \
--cc=mingo@kernel.org \
--cc=mingo@redhat.com \
--cc=peterz@infradead.org \
--cc=rth@twiddle.net \
/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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.