random: give sysctl_random_min_urandom_seed a more sensible value

stable inclusion
from stable-v5.10.119
commit 4c74ca006afe2410a48a7cddf9a3211d325b267a
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I5L6BB

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=4c74ca006afe2410a48a7cddf9a3211d325b267a

--------------------------------

commit d0efdf35 upstream.

This isn't used by anything or anywhere, but we can't delete it due to
compatibility. So at least give it the correct value of what it's
supposed to be instead of a garbage one.

Cc: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: NDominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: NJason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>
Acked-by: NXie XiuQi <xiexiuqi@huawei.com>

drivers/char/random.c

@@ -1619,7 +1619,7 @@ const struct file_operations urandom_fops = {
  *   to avoid breaking old userspaces, but writing to it does not
  *   change any behavior of the RNG.
  *
- * - urandom_min_reseed_secs - fixed to the meaningless value "60".
+ * - urandom_min_reseed_secs - fixed to the value CRNG_RESEED_INTERVAL.
  *   It is writable to avoid breaking old userspaces, but writing
  *   to it does not change any behavior of the RNG.
  *
@@ -1629,7 +1629,7 @@ const struct file_operations urandom_fops = {
 
 #include <linux/sysctl.h>
 
-static int sysctl_random_min_urandom_seed = 60;
+static int sysctl_random_min_urandom_seed = CRNG_RESEED_INTERVAL / HZ;
 static int sysctl_random_write_wakeup_bits = POOL_MIN_BITS;
 static int sysctl_poolsize = POOL_BITS;
 static u8 sysctl_bootid[UUID_SIZE];