Aren
/
NetBSD
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Print `entropy: ready' only when we first have full entropy. 

Now that we consolidate entropy in rndctl -L and equivalent, not just
when the operator chooses, epoch != -1 no longer necessarily means
full entropy -- it just means `time to (re)seed, whether justified by
entropy accounting or by explicit consolidation'.

There is a bug on x86 systems with RDRAND/RDSEED that prevents this
message from appearing at all: it happens so early that consinit has
not run yet, so it just goes into oblivion.  Need to fix that some
other way!
This commit is contained in:
riastradh 2020-05-07 19:07:29 +00:00
parent bbed174793
commit e0635d720d
1 changed files with 10 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

19
sys/kern/kern_entropy.c
View File

@ -1,4 +1,4 @@
/* $NetBSD: kern_entropy.c,v 1.13 2020/05/07 19:05:51 riastradh Exp $ */
/* $NetBSD: kern_entropy.c,v 1.14 2020/05/07 19:07:29 riastradh Exp $ */
/*-
* Copyright (c) 2019 The NetBSD Foundation, Inc.
@ -75,7 +75,7 @@
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: kern_entropy.c,v 1.13 2020/05/07 19:05:51 riastradh Exp $");
__KERNEL_RCSID(0, "$NetBSD: kern_entropy.c,v 1.14 2020/05/07 19:07:29 riastradh Exp $");
#include <sys/param.h>
#include <sys/types.h>
@ -172,7 +172,7 @@ struct {
} entropy_global __cacheline_aligned = {
/* Fields that must be initialized when the kernel is loaded. */
.needed = ENTROPY_CAPACITY*NBBY,
.epoch = (unsigned)-1, /* -1 means not yet full entropy */
.epoch = (unsigned)-1, /* -1 means entropy never consolidated */
.sources = LIST_HEAD_INITIALIZER(entropy_global.sources),
.stage = ENTROPY_COLD,
};
@ -596,10 +596,10 @@ entropy_bootrequest(void)
* entropy_epoch()
*
* Returns the current entropy epoch. If this changes, you should
* reseed. If -1, means the system has not yet reached full
* entropy; never reverts back to -1 after full entropy has been
* reached. Never zero, so you can always use zero as an
* uninitialized sentinel value meaning `reseed ASAP'.
* reseed. If -1, means system entropy has not yet reached full
* entropy or been explicitly consolidated; never reverts back to
* -1. Never zero, so you can always use zero as an uninitialized
* sentinel value meaning `reseed ASAP'.
*
* Usage model:
*
@ -1118,11 +1118,12 @@ entropy_notify(void)
* that we're ready so operators can compare it to the timing
* of other events.
*/
if (E->epoch == (unsigned)-1)
if (__predict_false(!rnd_initial_entropy) && E->needed == 0) {
printf("entropy: ready\n");
rnd_initial_entropy = 1;
}
/* Set the epoch; roll over from UINTMAX-1 to 1. */
rnd_initial_entropy = 1; /* XXX legacy */
if (__predict_true(!atomic_load_relaxed(&entropy_depletion)) ||
ratecheck(&lasttime, &interval)) {
epoch = E->epoch + 1;