diff options
Diffstat (limited to 'sys/dev/random/ivy.c')
| -rw-r--r-- | sys/dev/random/ivy.c | 69 |
1 files changed, 19 insertions, 50 deletions
diff --git a/sys/dev/random/ivy.c b/sys/dev/random/ivy.c index fa1e4831f1b9..3eb0f261e6dc 100644 --- a/sys/dev/random/ivy.c +++ b/sys/dev/random/ivy.c @@ -1,6 +1,6 @@ /*- + * Copyright (c) 2013, 2025, David E. O'Brien <deo@NUXI.org> * Copyright (c) 2013 The FreeBSD Foundation - * Copyright (c) 2013 David E. O'Brien <obrien@NUXI.org> * Copyright (c) 2012 Konstantin Belousov <kib@FreeBSD.org> * All rights reserved. * @@ -48,7 +48,6 @@ #define RETRY_COUNT 10 -static bool has_rdrand, has_rdseed; static u_int random_ivy_read(void *, u_int); static const struct random_source random_ivy = { @@ -57,13 +56,7 @@ static const struct random_source random_ivy = { .rs_read = random_ivy_read }; -SYSCTL_NODE(_kern_random, OID_AUTO, rdrand, CTLFLAG_RW | CTLFLAG_MPSAFE, 0, - "rdrand (ivy) entropy source"); static bool acquire_independent_seed_samples = false; -SYSCTL_BOOL(_kern_random_rdrand, OID_AUTO, rdrand_independent_seed, - CTLFLAG_RWTUN, &acquire_independent_seed_samples, 0, - "If non-zero, use more expensive and slow, but safer, seeded samples " - "where RDSEED is not present."); static bool x86_rdrand_store(u_long *buf) @@ -99,45 +92,6 @@ x86_rdrand_store(u_long *buf) return (true); } -static bool -x86_rdseed_store(u_long *buf) -{ - u_long rndval; - int retry; - - retry = RETRY_COUNT; - __asm __volatile( - "1:\n\t" - "rdseed %1\n\t" /* read randomness into rndval */ - "jc 2f\n\t" /* CF is set on success, exit retry loop */ - "dec %0\n\t" /* otherwise, retry-- */ - "jne 1b\n\t" /* and loop if retries are not exhausted */ - "2:" - : "+r" (retry), "=r" (rndval) : : "cc"); - *buf = rndval; - return (retry != 0); -} - -static bool -x86_unimpl_store(u_long *buf __unused) -{ - - panic("%s called", __func__); -} - -DEFINE_IFUNC(static, bool, x86_rng_store, (u_long *buf)) -{ - has_rdrand = (cpu_feature2 & CPUID2_RDRAND); - has_rdseed = (cpu_stdext_feature & CPUID_STDEXT_RDSEED); - - if (has_rdseed) - return (x86_rdseed_store); - else if (has_rdrand) - return (x86_rdrand_store); - else - return (x86_unimpl_store); -} - /* It is required that buf length is a multiple of sizeof(u_long). */ static u_int random_ivy_read(void *buf, u_int c) @@ -148,7 +102,7 @@ random_ivy_read(void *buf, u_int c) KASSERT(c % sizeof(*b) == 0, ("partial read %d", c)); b = buf; for (count = c; count > 0; count -= sizeof(*b)) { - if (!x86_rng_store(&rndval)) + if (!x86_rdrand_store(&rndval)) break; *b++ = rndval; } @@ -158,18 +112,33 @@ random_ivy_read(void *buf, u_int c) static int rdrand_modevent(module_t mod, int type, void *unused) { + struct sysctl_ctx_list ctx; + struct sysctl_oid *o; + bool has_rdrand, has_rdseed; int error = 0; + has_rdrand = (cpu_feature2 & CPUID2_RDRAND); + has_rdseed = (cpu_stdext_feature & CPUID_STDEXT_RDSEED); + switch (type) { case MOD_LOAD: - if (has_rdrand || has_rdseed) { + if (has_rdrand && !has_rdseed) { + sysctl_ctx_init(&ctx); + o = SYSCTL_ADD_NODE(&ctx, SYSCTL_STATIC_CHILDREN(_kern_random), + OID_AUTO, "rdrand", CTLFLAG_RW | CTLFLAG_MPSAFE, 0, + "rdrand (ivy) entropy source"); + SYSCTL_ADD_BOOL(&ctx, SYSCTL_CHILDREN(o), OID_AUTO, + "rdrand_independent_seed", CTLFLAG_RDTUN, + &acquire_independent_seed_samples, 0, + "If non-zero, use more expensive and slow, but safer, seeded samples " + "where RDSEED is not present."); random_source_register(&random_ivy); printf("random: fast provider: \"%s\"\n", random_ivy.rs_ident); } break; case MOD_UNLOAD: - if (has_rdrand || has_rdseed) + if (has_rdrand && !has_rdseed) random_source_deregister(&random_ivy); break; |