korg/linux
0
0
Fork 0
mirror of https://mirrors.bfsu.edu.cn/git/linux.git synced 2024-11-17 09:14:19 +08:00
Code Issues Packages Projects Releases Wiki Activity

random: throttle hwrng writes if no entropy is credited

Browse Source 
If a hwrng source does not provide an entropy estimate, it currently
does not contribute at all to the CRNG. In order to help fix this, in
case add_hwgenerator_randomness() is called with the entropy parameter
set to zero, go to sleep until one reseed interval has passed.

While the hwrng thread currently only runs under conditions where this
is non-zero, this change is not harmful and prepares for future updates
to the hwrng core.

Cc: Herbert Xu <herbert@gondor.apana.org.au>
Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
This commit is contained in:
Jason A. Donenfeld 2022-09-20 16:12:00 +02:00
parent 745558f958
commit d775335e35
1 changed files with 2 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
drivers/char/random.c
View File

@ -865,9 +865,9 @@ void add_hwgenerator_randomness(const void *buf, size_t len, size_t entropy)
/*
* Throttle writing to once every reseed interval, unless we're not yet
* initialized.
* initialized or no entropy is credited.
*/
if (!kthread_should_stop() && crng_ready())
if (!kthread_should_stop() && (crng_ready() || !entropy))
schedule_timeout_interruptible(crng_reseed_interval());
}
EXPORT_SYMBOL_GPL(add_hwgenerator_randomness);