linux-next: build warning after merge of the random tree

linux-next: build warning after merge of the random tree

[Stephen Rothwell]

Hi Ted,

[This actually appeared yesterday, but I missed it, sorry.]

After merging the random tree, today's linux-next build (x86_64
allnoconfig) produced this warning:

drivers/char/random.c:318:12: warning: 'random_min_urandom_seed' defined but not used [-Wunused-variable]
 static int random_min_urandom_seed = 60;
            ^

Introduced by commit

  43d8a72cd985 ("random: remove variable limit")

I understand why it is left there, but it would be nice if this warning
could be removed.

-- 
Cheers,
Stephen Rothwell

linux-next: build warning after merge of the random tree

[Stephen Rothwell]

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Hi all,

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")

-- 
Cheers,
Stephen Rothwell

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Re: linux-next: build warning after merge of the random tree

[Stephen Rothwell]

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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.
-- 
Cheers,
Stephen Rothwell

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Re: linux-next: build warning after merge of the random tree

[Mark Rutland]

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

Re: linux-next: build warning after merge of the random tree

[Theodore Y. Ts'o]

On Tue, Mar 10, 2020 at 12:17:47PM +0000, Mark Rutland wrote:
> 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?

Yes, that looks fine.  Reordering the functions to move them under the
#ifdefs will make the code less readable, and adding extra
#ifdef/#endif would also make things less readable.

Thanks for the patch, will apply.

						- Ted

Re: linux-next: build warning after merge of the random tree

[Stephen Rothwell]

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Hi all,

On Tue, 10 Mar 2020 10:46:18 -0400 "Theodore Y. Ts'o" <tytso@mit.edu> wrote:
>
> On Tue, Mar 10, 2020 at 12:17:47PM +0000, Mark Rutland wrote:
> > 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?  
> 
> Yes, that looks fine.  Reordering the functions to move them under the
> #ifdefs will make the code less readable, and adding extra
> #ifdef/#endif would also make things less readable.
> 
> Thanks for the patch, will apply.

How are we going with this?

-- 
Cheers,
Stephen Rothwell

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Re: linux-next: build warning after merge of the random tree

[Theodore Y. Ts'o]

On Mon, Mar 16, 2020 at 04:59:23PM +1100, Stephen Rothwell wrote:
> > Yes, that looks fine.  Reordering the functions to move them under the
> > #ifdefs will make the code less readable, and adding extra
> > #ifdef/#endif would also make things less readable.
> > 
> > Thanks for the patch, will apply.
> 
> How are we going with this?

I've applied and pushed out Mark's patch.

     	     	 	    	   - Ted

linux-next: build warning after merge of the random tree

[Stephen Rothwell]

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Hi Ted,

After merging the random tree, today's linux-next build (arm
multi_v7_defconfig) produced this warning:

drivers/char/random.c: In function 'write_pool.constprop':
drivers/char/random.c:1912:11: warning: 't' may be used uninitialized in this function [-Wmaybe-uninitialized]
    buf[i] ^= t;
           ^~

Introduced by commit

  349ddb707fb7 ("random: mix rdrand with entropy sent in from userspace")

-- 
Cheers,
Stephen Rothwell

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linux-next: build warning after merge of the random tree

[Stephen Rothwell]

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Hi Theodore,

After merging the random tree, today's linux-next build (arm
multi_v7_defconfig) produced this warning:

lib/vsprintf.c:1668:13: warning: 'have_filled_random_ptr_key' defined but not used [-Wunused-variable]
 static bool have_filled_random_ptr_key __read_mostly;
             ^~~~~~~~~~~~~~~~~~~~~~~~~~

Introduced by commit

  bfe80ed3d7c7 ("vsprintf: add command line option debug_boot_weak_hash")

-- 
Cheers,
Stephen Rothwell

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Re: linux-next: build warning after merge of the random tree

[Stephen Rothwell]

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Hi all,

On Fri, 8 Jun 2018 13:37:48 +1000 Stephen Rothwell <sfr@canb.auug.org.au> wrote:
>
> After merging the random tree, today's linux-next build (arm
> multi_v7_defconfig) produced this warning:
> 
> lib/vsprintf.c:1668:13: warning: 'have_filled_random_ptr_key' defined but not used [-Wunused-variable]
>  static bool have_filled_random_ptr_key __read_mostly;
>              ^~~~~~~~~~~~~~~~~~~~~~~~~~
> 
> Introduced by commit
> 
>   bfe80ed3d7c7 ("vsprintf: add command line option debug_boot_weak_hash")

I am still getting this ...
-- 
Cheers,
Stephen Rothwell

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Re: linux-next: build warning after merge of the random tree

[Tobin C. Harding]

On Mon, Jun 18, 2018 at 01:35:23PM +1000, Stephen Rothwell wrote:
> Hi all,
> 
> On Fri, 8 Jun 2018 13:37:48 +1000 Stephen Rothwell <sfr@canb.auug.org.au> wrote:
> >
> > After merging the random tree, today's linux-next build (arm
> > multi_v7_defconfig) produced this warning:
> > 
> > lib/vsprintf.c:1668:13: warning: 'have_filled_random_ptr_key' defined but not used [-Wunused-variable]
> >  static bool have_filled_random_ptr_key __read_mostly;
> >              ^~~~~~~~~~~~~~~~~~~~~~~~~~
> > 
> > Introduced by commit
> > 
> >   bfe80ed3d7c7 ("vsprintf: add command line option debug_boot_weak_hash")
> 
> I am still getting this ...

This is fixed in:

	[PATCH v7 0/4] enable early printing of hashed pointers


FYI v8 to come with unrelated change removing EXPORT_SYMBOL() (as suggested
on LKML in response to v7)



thanks,
Tobin.

Re: linux-next: build warning after merge of the random tree

[Stephen Rothwell]

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Hi all,

On Mon, 18 Jun 2018 15:29:00 +1000 "Tobin C. Harding" <me@tobin.cc> wrote:
>
> On Mon, Jun 18, 2018 at 01:35:23PM +1000, Stephen Rothwell wrote:
> > 
> > On Fri, 8 Jun 2018 13:37:48 +1000 Stephen Rothwell <sfr@canb.auug.org.au> wrote:  
> > >
> > > After merging the random tree, today's linux-next build (arm
> > > multi_v7_defconfig) produced this warning:
> > > 
> > > lib/vsprintf.c:1668:13: warning: 'have_filled_random_ptr_key' defined but not used [-Wunused-variable]
> > >  static bool have_filled_random_ptr_key __read_mostly;
> > >              ^~~~~~~~~~~~~~~~~~~~~~~~~~
> > > 
> > > Introduced by commit
> > > 
> > >   bfe80ed3d7c7 ("vsprintf: add command line option debug_boot_weak_hash")  
> > 
> > I am still getting this ...  
> 
> This is fixed in:
> 
> 	[PATCH v7 0/4] enable early printing of hashed pointers
> 
> 
> FYI v8 to come with unrelated change removing EXPORT_SYMBOL() (as suggested
> on LKML in response to v7)

Still getting this warning ...

-- 
Cheers,
Stephen Rothwell

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linux-next: build warning after merge of the random tree

[Stephen Rothwell]

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Hi Ted,

After merging the random tree, today's linux-next build (x86_64
allmodconfig) produced this warning:

drivers/char/random.c: In function 'SYSC_getrandom':
drivers/char/random.c:1526:6: warning: unused variable 'r' [-Wunused-variable]
  int r;
      ^

Introduced by commit 386474e168a8 ("random: introduce getrandom(2) system call").

-- 
Cheers,
Stephen Rothwell                    sfr@canb.auug.org.au

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linux-next: build warning after merge of the random tree

[Stephen Rothwell]

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Hi Ted,

After merging the random tree, today's linux-next build (powerpc64
allnoconfig) produced this warning:

In file included from include/linux/kernel.h:10:0,
                 from include/linux/sched.h:15,
                 from include/linux/utsname.h:5,
                 from drivers/char/random.c:238:
drivers/char/random.c: In function 'add_interrupt_randomness':
include/linux/bitops.h:96:2: warning: 'input[3]' may be used uninitialized in this function [-Wmaybe-uninitialized]
  return (word << shift) | (word >> (32 - shift));
  ^
drivers/char/random.c:827:10: note: 'input[3]' was declared here
  __u32   input[4], cycles = random_get_entropy();
          ^
In file included from include/linux/kernel.h:10:0,
                 from include/linux/sched.h:15,
                 from include/linux/utsname.h:5,
                 from drivers/char/random.c:238:
include/linux/bitops.h:96:2: warning: 'input[2]' may be used uninitialized in this function [-Wmaybe-uninitialized]
  return (word << shift) | (word >> (32 - shift));
  ^
drivers/char/random.c:827:10: note: 'input[2]' was declared here
  __u32   input[4], cycles = random_get_entropy();
          ^

Probably introduced by commit d5693ae494f2 ("random: speed up the
fast_mix function by a factor of four").

-- 
Cheers,
Stephen Rothwell                    sfr@canb.auug.org.au

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Re: linux-next: build warning after merge of the random tree

[Stephen Rothwell]

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Hi Ted,

On Mon, 23 Sep 2013 14:39:24 +1000 Stephen Rothwell <sfr@canb.auug.org.au> wrote:
>
> After merging the random tree, today's linux-next build (powerpc64
> allnoconfig) produced this warning:
> 
> In file included from include/linux/kernel.h:10:0,
>                  from include/linux/sched.h:15,
>                  from include/linux/utsname.h:5,
>                  from drivers/char/random.c:238:
> drivers/char/random.c: In function 'add_interrupt_randomness':
> include/linux/bitops.h:96:2: warning: 'input[3]' may be used uninitialized in this function [-Wmaybe-uninitialized]
>   return (word << shift) | (word >> (32 - shift));
>   ^
> drivers/char/random.c:827:10: note: 'input[3]' was declared here
>   __u32   input[4], cycles = random_get_entropy();
>           ^
> In file included from include/linux/kernel.h:10:0,
>                  from include/linux/sched.h:15,
>                  from include/linux/utsname.h:5,
>                  from drivers/char/random.c:238:
> include/linux/bitops.h:96:2: warning: 'input[2]' may be used uninitialized in this function [-Wmaybe-uninitialized]
>   return (word << shift) | (word >> (32 - shift));
>   ^
> drivers/char/random.c:827:10: note: 'input[2]' was declared here
>   __u32   input[4], cycles = random_get_entropy();
>           ^
> 
> Probably introduced by commit d5693ae494f2 ("random: speed up the
> fast_mix function by a factor of four").

i386 defconfig produces similar (to make testing easier).

-- 
Cheers,
Stephen Rothwell                    sfr@canb.auug.org.au

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