public inbox for linux-next@vger.kernel.org 
 help / color / mirror / Atom feed
From: Mark Rutland <mark.rutland@arm•com>
To: Stephen Rothwell <sfr@canb•auug.org.au>, Theodore Ts'o <tytso@mit•edu>
Cc: Linux Next Mailing List <linux-next@vger•kernel.org>,
	Linux Kernel Mailing List <linux-kernel@vger•kernel.org>
Subject: Re: linux-next: build warning after merge of the random tree
Date: Tue, 10 Mar 2020 12:17:47 +0000	[thread overview]
Message-ID: <20200310121747.GA49602@lakrids.cambridge.arm.com> (raw)
In-Reply-To: <20200306155348.7bdc9622@canb.auug.org.au>

On Fri, Mar 06, 2020 at 03:53:48PM +1100, Stephen Rothwell wrote:
> Hi all,
> 
> On Mon, 2 Mar 2020 14:44:52 +1100 Stephen Rothwell <sfr@canb•auug.org.au> wrote:
> >
> > After merging the random tree, today's linux-next build (x86_64
> > allnoconfig) produced this warning:
> > 
> > drivers/char/random.c:820:13: warning: 'crng_initialize_secondary' defined but not used [-Wunused-function]
> >   820 | static void crng_initialize_secondary(struct crng_state *crng)
> >       |             ^~~~~~~~~~~~~~~~~~~~~~~~~
> > 
> > Introduced by commit
> > 
> >   5cbe0f13b51a ("random: split primary/secondary crng init paths")
> 
> I am still getting this warning.

Sorry, this is my bad.

We only call crng_initialize_secondary() in do_numa_crng_init(), which
is only built for CONFIG_NUMA. We can either drop both
crng_initialize_secondary() and crng_init_try_arch() under the
CONFIG_NUMA ifdef, or add __maybe_unused to crng_initialize_secondary().

Ted, does the below look ok to you? Or would you prefer moving things
under the ifdeffery?

Thanks,
Mark.

---->8----
From 6c3a35cd562d53066e11f5f8a6c3a6f63701d3ed Mon Sep 17 00:00:00 2001
From: Mark Rutland <mark.rutland@arm•com>
Date: Tue, 10 Mar 2020 12:09:12 +0000
Subject: [PATCH] random: avoid warnings for !CONFIG_NUMA builds

As crng_initialize_secondary() is only called by do_numa_crng_init(),
and the latter is under ifdeffery for CONFIG_NUMA, when CONFIG_NUMA is
not selected the compiler will warn that the former is unused:

| drivers/char/random.c:820:13: warning: 'crng_initialize_secondary' defined but not used [-Wunused-function]
|   820 | static void crng_initialize_secondary(struct crng_state *crng)
|       |             ^~~~~~~~~~~~~~~~~~~~~~~~~

Stephen reports that this happens for x86_64 noallconfig builds.

We could move crng_initialize_secondary() and crng_init_try_arch() under
the CONFIG_NUMA ifdeffery, but this has the unfortunate property of
separating them from crng_initialize_primary() and
crng_init_try_arch_early() respectively. Instead, let's mark
crng_initialize_secondary() as __maybe_unused.

Fixes: 5cbe0f13b51a ("random: split primary/secondary crng init paths")
Reported-by: Stephen Rothwell <sfr@canb•auug.org.au>
Signed-off-by: Mark Rutland <mark.rutland@arm•com>
Cc: Theodore Ts'o <tytso@mit•edu>
---
 drivers/char/random.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/char/random.c b/drivers/char/random.c
index f43f65c2195d..0d10e31fd342 100644
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -817,7 +817,7 @@ static bool __init crng_init_try_arch_early(struct crng_state *crng)
 	return arch_init;
 }
 
-static void crng_initialize_secondary(struct crng_state *crng)
+static void __maybe_unused crng_initialize_secondary(struct crng_state *crng)
 {
 	memcpy(&crng->state[0], "expand 32-byte k", 16);
 	_get_random_bytes(&crng->state[4], sizeof(__u32) * 12);
-- 
2.11.0


  reply	other threads:[~2020-03-10 12:17 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-03-02  3:44 linux-next: build warning after merge of the random tree Stephen Rothwell
2020-03-06  4:53 ` Stephen Rothwell
2020-03-10 12:17   ` Mark Rutland [this message]
2020-03-10 14:46     ` Theodore Y. Ts'o
2020-03-16  5:59       ` Stephen Rothwell
2020-03-19  3:30         ` Theodore Y. Ts'o
  -- strict thread matches above, loose matches on Subject: below --
2018-07-16  5:52 Stephen Rothwell
2018-06-08  3:37 Stephen Rothwell
2018-06-18  3:35 ` Stephen Rothwell
2018-06-18  5:29   ` Tobin C. Harding
2018-07-10  7:26     ` Stephen Rothwell
2017-02-01  6:09 Stephen Rothwell
2014-07-21  7:49 Stephen Rothwell
2013-09-23  4:39 Stephen Rothwell
2013-09-23  4:42 ` Stephen Rothwell

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=20200310121747.GA49602@lakrids.cambridge.arm.com \
    --to=mark.rutland@arm$(echo .)com \
    --cc=linux-kernel@vger$(echo .)kernel.org \
    --cc=linux-next@vger$(echo .)kernel.org \
    --cc=sfr@canb$(echo .)auug.org.au \
    --cc=tytso@mit$(echo .)edu \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html
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