[src/netbsd-7]: src/sys/crypto/cprng_fast Pull up following revision(s) (requ...

[martin <martin%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/6fd99de056bc
branches:  netbsd-7
changeset: 798246:6fd99de056bc
user:      martin <martin%NetBSD.org@localhost>
date:      Fri Aug 15 09:53:48 2014 +0000

description:
Pull up following revision(s) (requested by riastradh in ticket #16):
        sys/crypto/cprng_fast/cprng_fast.c: revision 1.7
        sys/crypto/cprng_fast/cprng_fast.c: revision 1.8
        sys/crypto/cprng_fast/cprng_fast.c: revision 1.9
        sys/crypto/cprng_fast/cprng_fast.c: revision 1.10
Access to struct cprng_fast must be consistently at IPL_VM.
Use percpu_foreach instead of manual iteration.
Move initial entropy bookkeeping out of the fast path.
Tweak cprng_fast_buf to use 32-bit unaligned writes if possible.

diffstat:

 sys/crypto/cprng_fast/cprng_fast.c |  75 ++++++++++++++++++++-----------------
 1 files changed, 40 insertions(+), 35 deletions(-)

diffs (155 lines):

diff -r ae70996561e5 -r 6fd99de056bc sys/crypto/cprng_fast/cprng_fast.c
--- a/sys/crypto/cprng_fast/cprng_fast.c        Thu Aug 14 06:58:39 2014 +0000
+++ b/sys/crypto/cprng_fast/cprng_fast.c        Fri Aug 15 09:53:48 2014 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: cprng_fast.c,v 1.6 2014/08/11 03:50:29 riastradh Exp $ */
+/*     $NetBSD: cprng_fast.c,v 1.6.2.1 2014/08/15 09:53:48 martin Exp $        */
 
 /*-
  * Copyright (c) 2014 The NetBSD Foundation, Inc.
@@ -30,7 +30,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: cprng_fast.c,v 1.6 2014/08/11 03:50:29 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: cprng_fast.c,v 1.6.2.1 2014/08/15 09:53:48 martin Exp $");
 
 #include <sys/types.h>
 #include <sys/param.h>
@@ -203,6 +203,7 @@
 
 __CTASSERT(sizeof ((struct cprng_fast *)0)->key == CPRNG_FAST_SEED_BYTES);
 
+static void    cprng_fast_init_cpu(void *, void *, struct cpu_info *);
 static void    cprng_fast_schedule_reseed(struct cprng_fast *);
 static void    cprng_fast_intr(void *);
 
@@ -218,33 +219,39 @@
 void
 cprng_fast_init(void)
 {
-       struct cpu_info *ci;
-       CPU_INFO_ITERATOR cii;
 
        crypto_core_selftest();
        cprng_fast_percpu = percpu_alloc(sizeof(struct cprng_fast));
-       for (CPU_INFO_FOREACH(cii, ci)) {
-               struct cprng_fast *cprng;
-               uint8_t seed[CPRNG_FAST_SEED_BYTES];
-
-               percpu_traverse_enter();
-               cprng = percpu_getptr_remote(cprng_fast_percpu, ci);
-               cprng_strong(kern_cprng, seed, sizeof(seed), FASYNC);
-               /* Can't do anything about it if not full entropy.  */
-               cprng_fast_seed(cprng, seed);
-               explicit_memset(seed, 0, sizeof(seed));
-               percpu_traverse_exit();
-       }
+       percpu_foreach(cprng_fast_percpu, &cprng_fast_init_cpu, NULL);
        cprng_fast_softint = softint_establish(SOFTINT_SERIAL|SOFTINT_MPSAFE,
            &cprng_fast_intr, NULL);
 }
 
+static void
+cprng_fast_init_cpu(void *p, void *arg __unused, struct cpu_info *ci __unused)
+{
+       struct cprng_fast *const cprng = p;
+       uint8_t seed[CPRNG_FAST_SEED_BYTES];
+
+       cprng_strong(kern_cprng, seed, sizeof seed, FASYNC);
+       cprng_fast_seed(cprng, seed);
+       cprng->have_initial = rnd_initial_entropy;
+       (void)explicit_memset(seed, 0, sizeof seed);
+}
+
 static inline int
 cprng_fast_get(struct cprng_fast **cprngp)
 {
+       struct cprng_fast *cprng;
+       int s;
 
-       *cprngp = percpu_getref(cprng_fast_percpu);
-       return splvm();
+       *cprngp = cprng = percpu_getref(cprng_fast_percpu);
+       s = splvm();
+
+       if (__predict_false(!cprng->have_initial))
+               cprng_fast_schedule_reseed(cprng);
+
+       return s;
 }
 
 static inline void
@@ -256,7 +263,7 @@
        splx(s);
        percpu_putref(cprng_fast_percpu);
 }
-
+
 static inline void
 cprng_fast_schedule_reseed(struct cprng_fast *cprng __unused)
 {
@@ -269,11 +276,15 @@
 {
        struct cprng_fast *cprng;
        uint8_t seed[CPRNG_FAST_SEED_BYTES];
+       int s;
 
        cprng_strong(kern_cprng, seed, sizeof(seed), FASYNC);
 
        cprng = percpu_getref(cprng_fast_percpu);
+       s = splvm();
        cprng_fast_seed(cprng, seed);
+       cprng->have_initial = rnd_initial_entropy;
+       splx(s);
        percpu_putref(cprng_fast_percpu);
 
        explicit_memset(seed, 0, sizeof(seed));
@@ -298,12 +309,6 @@
        (void)memset(cprng->buffer, 0, sizeof cprng->buffer);
        (void)memcpy(cprng->key, seed, sizeof cprng->key);
        (void)memset(cprng->nonce, 0, sizeof cprng->nonce);
-
-       if (__predict_true(rnd_initial_entropy)) {
-               cprng->have_initial = true;
-       } else {
-               cprng->have_initial = false;
-       }
 }
 
 static inline uint32_t
@@ -320,12 +325,6 @@
                if (__predict_false(++cprng->nonce[0] == 0)) {
                        cprng->nonce[1]++;
                        cprng_fast_schedule_reseed(cprng);
-               } else {
-                       if (__predict_false(false == cprng->have_initial)) {
-                               if (rnd_initial_entropy) {
-                                       cprng_fast_schedule_reseed(cprng);
-                               }
-                       }
                }
                v = cprng->buffer[CPRNG_FAST_BUFIDX];
                cprng->buffer[CPRNG_FAST_BUFIDX] = CPRNG_FAST_BUFIDX;
@@ -339,11 +338,17 @@
 {
        uint8_t *p = buf;
        uint32_t v;
-       unsigned r;
+       unsigned w, r;
 
-       while (n) {
-               r = MIN(n, 4);
-               n -= r;
+       w = n / sizeof(uint32_t);
+       while (w--) {
+               v = cprng_fast_word(cprng);
+               (void)memcpy(p, &v, 4);
+               p += 4;
+       }
+
+       r = n % sizeof(uint32_t);
+       if (r) {
                v = cprng_fast_word(cprng);
                while (r--) {
                        *p++ = (v & 0xff);