[PATCH] backports: random: add prandom_bytes macro for pre-3.8 kernels

[PATCH] backports: random: add prandom_bytes macro for pre-3.8 kernels

[Arend van Spriel]

Map prandom_bytes() calls to get_random_bytes() for kernels before
3.8 kernel. This patch is needed by mac80211 rate control code
since following:

commit f7d8ad81ca8c447124821e58f876d1aff996c85f
Author: Karl Beldan <karl.beldan@rivierawaves.com>
Date:   Wed Nov 13 10:54:19 2013 +0100

    mac80211: minstrels: spare numerous useless calls to get_random_bytes

Signed-off-by: Arend van Spriel <arend@broadcom.com>
---
 backport/backport-include/linux/random.h |    2 ++
 1 file changed, 2 insertions(+)

diff --git a/backport/backport-include/linux/random.h b/backport/backport-include/linux/random.h
index 812ce7f..3adde28 100644
--- a/backport/backport-include/linux/random.h
+++ b/backport/backport-include/linux/random.h
@@ -8,6 +8,8 @@
 #define prandom_seed(_seed)		srandom32(_seed)
 #define prandom_u32()			random32()
 #define prandom_u32_state(_state)	prandom32(_state)
+/* use get_random_bytes() for lack of prandom_bytes() */
+#define prandom_bytes(a, b)		get_random_bytes(a, b)
 #endif
 
 #endif /* __BACKPORT_RANDOM_H */
-- 
1.7.10.4

Re: [PATCH] backports: random: add prandom_bytes macro for pre-3.8 kernels

[Johannes Berg]

On Sun, 2013-12-22 at 12:57 +0100, Arend van Spriel wrote:
> Map prandom_bytes() calls to get_random_bytes() for kernels before
> 3.8 kernel. This patch is needed by mac80211 rate control code
> since following:

> +/* use get_random_bytes() for lack of prandom_bytes() */
> +#define prandom_bytes(a, b)		get_random_bytes(a, b)

I don't think this is a good idea, it's a completely different interface
(get_random_bytes is much higher "quality".)

We had a different patch for this fairly recently and I thought Luis
applied it?

johannes

Re: [PATCH] backports: random: add prandom_bytes macro for pre-3.8 kernels

[Hauke Mehrtens]

On 12/22/2013 01:28 PM, Johannes Berg wrote:
> On Sun, 2013-12-22 at 12:57 +0100, Arend van Spriel wrote:
>> Map prandom_bytes() calls to get_random_bytes() for kernels before
>> 3.8 kernel. This patch is needed by mac80211 rate control code
>> since following:
> 
>> +/* use get_random_bytes() for lack of prandom_bytes() */
>> +#define prandom_bytes(a, b)		get_random_bytes(a, b)
> 
> I don't think this is a good idea, it's a completely different interface
> (get_random_bytes is much higher "quality".)
> 
> We had a different patch for this fairly recently and I thought Luis
> applied it?

Yes a different patch is already in backports:
https://git.kernel.org/cgit/linux/kernel/git/backports/backports.git/commit/?id=40ab1bac8c3680d726ee31fbdb590584ae99756f

Hauke

Re: [PATCH] backports: random: add prandom_bytes macro for pre-3.8 kernels

[Arend van Spriel]

On 12/22/2013 06:15 PM, Hauke Mehrtens wrote:
> On 12/22/2013 01:28 PM, Johannes Berg wrote:
>> On Sun, 2013-12-22 at 12:57 +0100, Arend van Spriel wrote:
>>> Map prandom_bytes() calls to get_random_bytes() for kernels before
>>> 3.8 kernel. This patch is needed by mac80211 rate control code
>>> since following:
>>
>>> +/* use get_random_bytes() for lack of prandom_bytes() */
>>> +#define prandom_bytes(a, b)		get_random_bytes(a, b)
>>
>> I don't think this is a good idea, it's a completely different interface
>> (get_random_bytes is much higher "quality".)
>>
>> We had a different patch for this fairly recently and I thought Luis
>> applied it?
> 
> Yes a different patch is already in backports:
> https://git.kernel.org/cgit/linux/kernel/git/backports/backports.git/commit/?id=40ab1bac8c3680d726ee31fbdb590584ae99756f

I was looking at your github repo, because kernel.org did not work for
3.13 a while ago. Distributed version control can be a curse as well as
a blessing.

Gr. AvS