Differential D22839 Diff 78075 sys/dev/random/fenestrasX/fx_brng.c

Changeset View

Standalone View

sys/dev/random/fenestrasX/fx_brng.c

Show All 33 Lines
#include <sys/lock.h>		#include <sys/lock.h>
#include <sys/kernel.h>		#include <sys/kernel.h>
#include <sys/malloc.h>		#include <sys/malloc.h>
#include <sys/mutex.h>		#include <sys/mutex.h>
#include <sys/random.h>		#include <sys/random.h>
#include <sys/sdt.h>		#include <sys/sdt.h>
#include <sys/sysctl.h>		#include <sys/sysctl.h>
#include <sys/systm.h>		#include <sys/systm.h>
		#include <sys/vdso.h>

#include <machine/cpu.h>		#include <machine/cpu.h>

#include <dev/random/randomdev.h>		#include <dev/random/randomdev.h>
#include <dev/random/random_harvestq.h>		#include <dev/random/random_harvestq.h>
#include <dev/random/uint128.h>		#include <dev/random/uint128.h>

#include <dev/random/fenestrasX/fx_brng.h>		#include <dev/random/fenestrasX/fx_brng.h>
▲ Show 20 Lines • Show All 53 Lines • ▼ Show 20 Lines	fxrng_brng_src_reseed(const struct harvest_event *event)
* Bump root generation (which is costly) to force downstream BRNGs to		* Bump root generation (which is costly) to force downstream BRNGs to
* reseed and quickly incorporate the new entropy. The intuition is		* reseed and quickly incorporate the new entropy. The intuition is
* that this tradeoff is worth it because new sources show up extremely		* that this tradeoff is worth it because new sources show up extremely
* rarely (limiting cost) and if they can contribute any entropy to a		* rarely (limiting cost) and if they can contribute any entropy to a
* weak state, we want to propagate it to all generators ASAP.		* weak state, we want to propagate it to all generators ASAP.
*/		*/
rng->brng_generation++;		rng->brng_generation++;
atomic_store_rel_64(&fxrng_root_generation, rng->brng_generation);		atomic_store_rel_64(&fxrng_root_generation, rng->brng_generation);
		/* Update VDSO version. */
		fxrng_push_seed_generation(rng->brng_generation);
FXRNG_BRNG_UNLOCK(rng);		FXRNG_BRNG_UNLOCK(rng);
}		}

/*		/*
* Reseed a brng from some amount of pooled entropy (determined in fx_pool.c by		* Reseed a brng from some amount of pooled entropy (determined in fx_pool.c by
* fxent_timer_reseed_npools). For initial seeding, we pool entropy in a		* fxent_timer_reseed_npools). For initial seeding, we pool entropy in a
* single pool and use this API as well (fxrng_alg_seeded).		* single pool and use this API as well (fxrng_alg_seeded).
*/		*/
void		void
fxrng_brng_reseed(const void *entr, size_t sz)		fxrng_brng_reseed(const void *entr, size_t sz)
{		{
struct fxrng_buffered_rng *rng;		struct fxrng_buffered_rng *rng;

rng = &fxrng_root;		rng = &fxrng_root;
FXRNG_BRNG_LOCK(rng);		FXRNG_BRNG_LOCK(rng);

fxrng_rng_reseed(&rng->brng_rng, (rng->brng_generation > 0), entr, sz);		fxrng_rng_reseed(&rng->brng_rng, (rng->brng_generation > 0), entr, sz);
FXRNG_BRNG_ASSERT(rng);		FXRNG_BRNG_ASSERT(rng);

rng->brng_generation++;		rng->brng_generation++;
atomic_store_rel_64(&fxrng_root_generation, rng->brng_generation);		atomic_store_rel_64(&fxrng_root_generation, rng->brng_generation);
		/* Update VDSO version. */
		fxrng_push_seed_generation(rng->brng_generation);
FXRNG_BRNG_UNLOCK(rng);		FXRNG_BRNG_UNLOCK(rng);
}		}

		/*
		* Sysentvec and VDSO are initialized much later than SI_SUB_RANDOM. When
		* they're online, go ahead and push an initial root seed version.
		* INIT_SYSENTVEC runs at SI_SUB_EXEC:SI_ORDER_ANY, and SI_ORDER_ANY is the
		* maximum value, so we must run at SI_SUB_EXEC+1.
		*/
		static void
		fxrng_vdso_sysinit(void *dummy __unused)
		{
		FXRNG_BRNG_LOCK(&fxrng_root);
		fxrng_push_seed_generation(fxrng_root.brng_generation);
		FXRNG_BRNG_UNLOCK(&fxrng_root);
		}
		SYSINIT(fxrng_vdso, SI_SUB_EXEC + 1, SI_ORDER_ANY, fxrng_vdso_sysinit, NULL);

/*		/*
* Grab some bytes off an initialized, current generation RNG.		* Grab some bytes off an initialized, current generation RNG.
*		*
* (Does not handle reseeding if our generation is stale.)		* (Does not handle reseeding if our generation is stale.)
*		*
* Locking protocol is a bit odd. The RNG is locked on entrance, but the lock		* Locking protocol is a bit odd. The RNG is locked on entrance, but the lock
* is dropped on exit. This avoids holding a lock during expensive and slow		* is dropped on exit. This avoids holding a lock during expensive and slow
▲ Show 20 Lines • Show All 155 Lines • Show Last 20 Lines