From: "Jason A. Donenfeld" Jason@zx2c4.com
commit 0deff3c43206c24e746b1410f11125707ad3040e upstream.
This pulls all of the sysctl-focused functions into the sixth labeled section.
No functional changes.
Cc: Theodore Ts'o tytso@mit.edu Reviewed-by: Dominik Brodowski linux@dominikbrodowski.net Signed-off-by: Jason A. Donenfeld Jason@zx2c4.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/char/random.c | 35 ++++++++++++++++++++++++++++++----- 1 file changed, 30 insertions(+), 5 deletions(-)
--- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -1693,9 +1693,34 @@ const struct file_operations urandom_fop .llseek = noop_llseek, };
+ /******************************************************************** * - * Sysctl interface + * Sysctl interface. + * + * These are partly unused legacy knobs with dummy values to not break + * userspace and partly still useful things. They are usually accessible + * in /proc/sys/kernel/random/ and are as follows: + * + * - boot_id - a UUID representing the current boot. + * + * - uuid - a random UUID, different each time the file is read. + * + * - poolsize - the number of bits of entropy that the input pool can + * hold, tied to the POOL_BITS constant. + * + * - entropy_avail - the number of bits of entropy currently in the + * input pool. Always <= poolsize. + * + * - write_wakeup_threshold - the amount of entropy in the input pool + * below which write polls to /dev/random will unblock, requesting + * more entropy, tied to the POOL_MIN_BITS constant. It is writable + * 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". + * It is writable to avoid breaking old userspaces, but writing + * to it does not change any behavior of the RNG. * ********************************************************************/
@@ -1703,8 +1728,8 @@ const struct file_operations urandom_fop
#include <linux/sysctl.h>
-static int random_min_urandom_seed = 60; -static int random_write_wakeup_bits = POOL_MIN_BITS; +static int sysctl_random_min_urandom_seed = 60; +static int sysctl_random_write_wakeup_bits = POOL_MIN_BITS; static int sysctl_poolsize = POOL_BITS; static char sysctl_bootid[16];
@@ -1762,14 +1787,14 @@ struct ctl_table random_table[] = { }, { .procname = "write_wakeup_threshold", - .data = &random_write_wakeup_bits, + .data = &sysctl_random_write_wakeup_bits, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec, }, { .procname = "urandom_min_reseed_secs", - .data = &random_min_urandom_seed, + .data = &sysctl_random_min_urandom_seed, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec,