diff mbox series

random32: Restore __latent_entropy attribute on net_rand_state

Message ID 20201002151610.24258-1-thibaut.sautereau@clip-os.org
State New, archived
Headers show
Series random32: Restore __latent_entropy attribute on net_rand_state | expand

Commit Message

Thibaut Sautereau Oct. 2, 2020, 3:16 p.m. UTC
From: Thibaut Sautereau <thibaut.sautereau@ssi.gouv.fr>

Commit f227e3ec3b5c ("random32: update the net random state on interrupt
and activity") broke compilation and was temporarily fixed by Linus in
83bdc7275e62 ("random32: remove net_rand_state from the latent entropy
gcc plugin") by entirely moving net_rand_state out of the things handled
by the latent_entropy GCC plugin.

From what I understand when reading the plugin code, using the
__latent_entropy attribute on a declaration was the wrong part and
simply keeping the __latent_entropy attribute on the variable definition
was the correct fix.

Fixes: 83bdc7275e62 ("random32: remove net_rand_state from the latent entropy gcc plugin")
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Willy Tarreau <w@1wt.eu>
Cc: Emese Revfy <re.emese@gmail.com>
Signed-off-by: Thibaut Sautereau <thibaut.sautereau@ssi.gouv.fr>
---
 lib/random32.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Willy Tarreau Oct. 2, 2020, 3:22 p.m. UTC | #1
On Fri, Oct 02, 2020 at 05:16:11PM +0200, Thibaut Sautereau wrote:
> From: Thibaut Sautereau <thibaut.sautereau@ssi.gouv.fr>
> 
> Commit f227e3ec3b5c ("random32: update the net random state on interrupt
> and activity") broke compilation and was temporarily fixed by Linus in
> 83bdc7275e62 ("random32: remove net_rand_state from the latent entropy
> gcc plugin") by entirely moving net_rand_state out of the things handled
> by the latent_entropy GCC plugin.
> 
> From what I understand when reading the plugin code, using the
> __latent_entropy attribute on a declaration was the wrong part and
> simply keeping the __latent_entropy attribute on the variable definition
> was the correct fix.

Ah thank you, this is what I tried to figure and failed to! Spender
mentioned that a one-liner was all that was needed to fix this but
never responded to my request asking about it.

Willy
Kees Cook Oct. 6, 2020, 2:12 a.m. UTC | #2
On Fri, Oct 02, 2020 at 05:16:11PM +0200, Thibaut Sautereau wrote:
> From: Thibaut Sautereau <thibaut.sautereau@ssi.gouv.fr>
> 
> Commit f227e3ec3b5c ("random32: update the net random state on interrupt
> and activity") broke compilation and was temporarily fixed by Linus in
> 83bdc7275e62 ("random32: remove net_rand_state from the latent entropy
> gcc plugin") by entirely moving net_rand_state out of the things handled
> by the latent_entropy GCC plugin.
> 
> From what I understand when reading the plugin code, using the
> __latent_entropy attribute on a declaration was the wrong part and
> simply keeping the __latent_entropy attribute on the variable definition
> was the correct fix.
> 
> Fixes: 83bdc7275e62 ("random32: remove net_rand_state from the latent entropy gcc plugin")
> Cc: Linus Torvalds <torvalds@linux-foundation.org>
> Cc: Willy Tarreau <w@1wt.eu>
> Cc: Emese Revfy <re.emese@gmail.com>
> Signed-off-by: Thibaut Sautereau <thibaut.sautereau@ssi.gouv.fr>

Yes, that looks correct. Thank you!

Acked-by: Kees Cook <keescook@chromium.org>

I'm not sure the best tree for this. Ted, Andrew, Linus? I'll take it
via my gcc plugin tree if no one else takes it. :)
Willy Tarreau Oct. 6, 2020, 2:28 a.m. UTC | #3
Hi Kees,

On Mon, Oct 05, 2020 at 07:12:29PM -0700, Kees Cook wrote:
> On Fri, Oct 02, 2020 at 05:16:11PM +0200, Thibaut Sautereau wrote:
> > From: Thibaut Sautereau <thibaut.sautereau@ssi.gouv.fr>
> > 
> > Commit f227e3ec3b5c ("random32: update the net random state on interrupt
> > and activity") broke compilation and was temporarily fixed by Linus in
> > 83bdc7275e62 ("random32: remove net_rand_state from the latent entropy
> > gcc plugin") by entirely moving net_rand_state out of the things handled
> > by the latent_entropy GCC plugin.
> > 
> > From what I understand when reading the plugin code, using the
> > __latent_entropy attribute on a declaration was the wrong part and
> > simply keeping the __latent_entropy attribute on the variable definition
> > was the correct fix.
> > 
> > Fixes: 83bdc7275e62 ("random32: remove net_rand_state from the latent entropy gcc plugin")
> > Cc: Linus Torvalds <torvalds@linux-foundation.org>
> > Cc: Willy Tarreau <w@1wt.eu>
> > Cc: Emese Revfy <re.emese@gmail.com>
> > Signed-off-by: Thibaut Sautereau <thibaut.sautereau@ssi.gouv.fr>
> 
> Yes, that looks correct. Thank you!
> 
> Acked-by: Kees Cook <keescook@chromium.org>
> 
> I'm not sure the best tree for this. Ted, Andrew, Linus? I'll take it
> via my gcc plugin tree if no one else takes it. :)

It was already merged as commit 09a6b0bc3be79 and queued for -stable.

Cheers,
Willy
Kees Cook Oct. 6, 2020, 5:57 a.m. UTC | #4
On Tue, Oct 06, 2020 at 04:28:09AM +0200, Willy Tarreau wrote:
> Hi Kees,
> 
> On Mon, Oct 05, 2020 at 07:12:29PM -0700, Kees Cook wrote:
> > On Fri, Oct 02, 2020 at 05:16:11PM +0200, Thibaut Sautereau wrote:
> > > From: Thibaut Sautereau <thibaut.sautereau@ssi.gouv.fr>
> > > 
> > > Commit f227e3ec3b5c ("random32: update the net random state on interrupt
> > > and activity") broke compilation and was temporarily fixed by Linus in
> > > 83bdc7275e62 ("random32: remove net_rand_state from the latent entropy
> > > gcc plugin") by entirely moving net_rand_state out of the things handled
> > > by the latent_entropy GCC plugin.
> > > 
> > > From what I understand when reading the plugin code, using the
> > > __latent_entropy attribute on a declaration was the wrong part and
> > > simply keeping the __latent_entropy attribute on the variable definition
> > > was the correct fix.
> > > 
> > > Fixes: 83bdc7275e62 ("random32: remove net_rand_state from the latent entropy gcc plugin")
> > > Cc: Linus Torvalds <torvalds@linux-foundation.org>
> > > Cc: Willy Tarreau <w@1wt.eu>
> > > Cc: Emese Revfy <re.emese@gmail.com>
> > > Signed-off-by: Thibaut Sautereau <thibaut.sautereau@ssi.gouv.fr>
> > 
> > Yes, that looks correct. Thank you!
> > 
> > Acked-by: Kees Cook <keescook@chromium.org>
> > 
> > I'm not sure the best tree for this. Ted, Andrew, Linus? I'll take it
> > via my gcc plugin tree if no one else takes it. :)
> 
> It was already merged as commit 09a6b0bc3be79 and queued for -stable.

Ah, perfect! Thanks.
diff mbox series

Patch

diff --git a/lib/random32.c b/lib/random32.c
index 932345323af0..dfb9981ab798 100644
--- a/lib/random32.c
+++ b/lib/random32.c
@@ -49,7 +49,7 @@  static inline void prandom_state_selftest(void)
 }
 #endif
 
-DEFINE_PER_CPU(struct rnd_state, net_rand_state);
+DEFINE_PER_CPU(struct rnd_state, net_rand_state)  __latent_entropy;
 
 /**
  *	prandom_u32_state - seeded pseudo-random number generator.