Differential D15526 Diff 43193 sys/dev/random/random_harvestq.c

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sys/dev/random/random_harvestq.c

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* 'empty' queue.		* 'empty' queue.
*/		*/
#define RANDOM_RING_MAX 1024		#define RANDOM_RING_MAX 1024
#define RANDOM_ACCUM_MAX 8		#define RANDOM_ACCUM_MAX 8

/* 1 to let the kernel thread run, 0 to terminate, -1 to mark completion */		/* 1 to let the kernel thread run, 0 to terminate, -1 to mark completion */
volatile int random_kthread_control;		volatile int random_kthread_control;


		/* Allow the sysadmin to select the broad category of
		* entropy types to harvest.
		*/
		__read_frequently u_int hc_source_mask;

/*		/*
* Put all the harvest queue context stuff in one place.		* Put all the harvest queue context stuff in one place.
* this make is a bit easier to lock and protect.		* this make is a bit easier to lock and protect.
*/		*/
static struct harvest_context {		static struct harvest_context {
/* The harvest mutex protects all of harvest_context and		/* The harvest mutex protects all of harvest_context and
* the related data.		* the related data.
*/		*/
struct mtx hc_mtx;		struct mtx hc_mtx;
/* Round-robin destination cache. */		/* Round-robin destination cache. */
u_int hc_destination[ENTROPYSOURCE];		u_int hc_destination[ENTROPYSOURCE];
/* The context of the kernel thread processing harvested entropy */		/* The context of the kernel thread processing harvested entropy */
struct proc *hc_kthread_proc;		struct proc *hc_kthread_proc;
/* Allow the sysadmin to select the broad category of
* entropy types to harvest.
*/
u_int hc_source_mask;
/*		/*
* Lockless ring buffer holding entropy events		* Lockless ring buffer holding entropy events
* If ring.in == ring.out,		* If ring.in == ring.out,
* the buffer is empty.		* the buffer is empty.
* If ring.in != ring.out,		* If ring.in != ring.out,
* the buffer contains harvested entropy.		* the buffer contains harvested entropy.
* If (ring.in + 1) == ring.out (mod RANDOM_RING_MAX),		* If (ring.in + 1) == ring.out (mod RANDOM_RING_MAX),
* the buffer is full.		* the buffer is full.
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/* ARGSUSED */		/* ARGSUSED */
static int		static int
random_check_uint_harvestmask(SYSCTL_HANDLER_ARGS)		random_check_uint_harvestmask(SYSCTL_HANDLER_ARGS)
{		{
int error;		int error;
u_int value, orig_value;		u_int value, orig_value;

orig_value = value = harvest_context.hc_source_mask;		orig_value = value = hc_source_mask;
error = sysctl_handle_int(oidp, &value, 0, req);		error = sysctl_handle_int(oidp, &value, 0, req);
if (error != 0 \|\| req->newptr == NULL)		if (error != 0 \|\| req->newptr == NULL)
return (error);		return (error);

if (flsl(value) > ENTROPYSOURCE)		if (flsl(value) > ENTROPYSOURCE)
return (EINVAL);		return (EINVAL);

/*		/*
* Disallow userspace modification of pure entropy sources.		* Disallow userspace modification of pure entropy sources.
*/		*/
harvest_context.hc_source_mask = (value & ~RANDOM_HARVEST_PURE_MASK) \|		hc_source_mask = (value & ~RANDOM_HARVEST_PURE_MASK) \|
(orig_value & RANDOM_HARVEST_PURE_MASK);		(orig_value & RANDOM_HARVEST_PURE_MASK);
return (0);		return (0);
}		}

/* ARGSUSED */		/* ARGSUSED */
static int		static int
random_print_harvestmask(SYSCTL_HANDLER_ARGS)		random_print_harvestmask(SYSCTL_HANDLER_ARGS)
{		{
struct sbuf sbuf;		struct sbuf sbuf;
int error, i;		int error, i;

error = sysctl_wire_old_buffer(req, 0);		error = sysctl_wire_old_buffer(req, 0);
if (error == 0) {		if (error == 0) {
sbuf_new_for_sysctl(&sbuf, NULL, 128, req);		sbuf_new_for_sysctl(&sbuf, NULL, 128, req);
for (i = ENTROPYSOURCE - 1; i >= 0; i--)		for (i = ENTROPYSOURCE - 1; i >= 0; i--)
sbuf_cat(&sbuf, (harvest_context.hc_source_mask & (1 << i)) ? "1" : "0");		sbuf_cat(&sbuf, (hc_source_mask & (1 << i)) ? "1" : "0");
error = sbuf_finish(&sbuf);		error = sbuf_finish(&sbuf);
sbuf_delete(&sbuf);		sbuf_delete(&sbuf);
}		}
return (error);		return (error);
}		}

static const char *random_source_descr[ENTROPYSOURCE] = {		static const char *random_source_descr[ENTROPYSOURCE] = {
[RANDOM_CACHED] = "CACHED",		[RANDOM_CACHED] = "CACHED",
Show All 30 Lines	random_print_harvestmask_symbolic(SYSCTL_HANDLER_ARGS)
bool first;		bool first;

first = true;		first = true;
error = sysctl_wire_old_buffer(req, 0);		error = sysctl_wire_old_buffer(req, 0);
if (error == 0) {		if (error == 0) {
sbuf_new_for_sysctl(&sbuf, NULL, 128, req);		sbuf_new_for_sysctl(&sbuf, NULL, 128, req);
for (i = ENTROPYSOURCE - 1; i >= 0; i--) {		for (i = ENTROPYSOURCE - 1; i >= 0; i--) {
if (i >= RANDOM_PURE_START &&		if (i >= RANDOM_PURE_START &&
(harvest_context.hc_source_mask & (1 << i)) == 0)		(hc_source_mask & (1 << i)) == 0)
continue;		continue;
if (!first)		if (!first)
sbuf_cat(&sbuf, ",");		sbuf_cat(&sbuf, ",");
sbuf_cat(&sbuf, !(harvest_context.hc_source_mask & (1 << i)) ? "[" : "");		sbuf_cat(&sbuf, !(hc_source_mask & (1 << i)) ? "[" : "");
sbuf_cat(&sbuf, random_source_descr[i]);		sbuf_cat(&sbuf, random_source_descr[i]);
sbuf_cat(&sbuf, !(harvest_context.hc_source_mask & (1 << i)) ? "]" : "");		sbuf_cat(&sbuf, !(hc_source_mask & (1 << i)) ? "]" : "");
first = false;		first = false;
}		}
error = sbuf_finish(&sbuf);		error = sbuf_finish(&sbuf);
sbuf_delete(&sbuf);		sbuf_delete(&sbuf);
}		}
return (error);		return (error);
}		}

/* ARGSUSED */		/* ARGSUSED */
static void		static void
random_harvestq_init(void *unused __unused)		random_harvestq_init(void *unused __unused)
{		{
struct sysctl_oid *random_sys_o;		struct sysctl_oid *random_sys_o;

random_sys_o = SYSCTL_ADD_NODE(&random_clist,		random_sys_o = SYSCTL_ADD_NODE(&random_clist,
SYSCTL_STATIC_CHILDREN(_kern_random),		SYSCTL_STATIC_CHILDREN(_kern_random),
OID_AUTO, "harvest", CTLFLAG_RW, 0,		OID_AUTO, "harvest", CTLFLAG_RW, 0,
"Entropy Device Parameters");		"Entropy Device Parameters");
harvest_context.hc_source_mask = RANDOM_HARVEST_EVERYTHING_MASK;		hc_source_mask = RANDOM_HARVEST_EVERYTHING_MASK;
SYSCTL_ADD_PROC(&random_clist,		SYSCTL_ADD_PROC(&random_clist,
SYSCTL_CHILDREN(random_sys_o),		SYSCTL_CHILDREN(random_sys_o),
OID_AUTO, "mask", CTLTYPE_UINT \| CTLFLAG_RW,		OID_AUTO, "mask", CTLTYPE_UINT \| CTLFLAG_RW,
NULL, 0, random_check_uint_harvestmask, "IU",		NULL, 0, random_check_uint_harvestmask, "IU",
"Entropy harvesting mask");		"Entropy harvesting mask");
SYSCTL_ADD_PROC(&random_clist,		SYSCTL_ADD_PROC(&random_clist,
SYSCTL_CHILDREN(random_sys_o),		SYSCTL_CHILDREN(random_sys_o),
OID_AUTO, "mask_bin", CTLTYPE_STRING \| CTLFLAG_RD,		OID_AUTO, "mask_bin", CTLTYPE_STRING \| CTLFLAG_RD,
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* check a few lines below. This includes the "always-on" sources		* check a few lines below. This includes the "always-on" sources
* like the Intel "rdrand" or the VIA Nehamiah "xstore" sources.		* like the Intel "rdrand" or the VIA Nehamiah "xstore" sources.
*/		*/
/* XXXRW: get_cyclecount() is cheap on most modern hardware, where cycle		/* XXXRW: get_cyclecount() is cheap on most modern hardware, where cycle
* counters are built in, but on older hardware it will do a real time clock		* counters are built in, but on older hardware it will do a real time clock
* read which can be quite expensive.		* read which can be quite expensive.
*/		*/
void		void
random_harvest_queue(const void *entropy, u_int size, u_int bits, enum random_entropy_source origin)		random_harvest_queue_(const void *entropy, u_int size, u_int bits,
		enum random_entropy_source origin)
{		{
struct harvest_event *event;		struct harvest_event *event;
u_int ring_in;		u_int ring_in;

KASSERT(origin >= RANDOM_START && origin < ENTROPYSOURCE, ("%s: origin %d invalid\n", __func__, origin));		KASSERT(origin >= RANDOM_START && origin < ENTROPYSOURCE, ("%s: origin %d invalid\n", __func__, origin));
if (!(harvest_context.hc_source_mask & (1 << origin)))
return;
RANDOM_HARVEST_LOCK();		RANDOM_HARVEST_LOCK();
ring_in = (harvest_context.hc_entropy_ring.in + 1)%RANDOM_RING_MAX;		ring_in = (harvest_context.hc_entropy_ring.in + 1)%RANDOM_RING_MAX;
if (ring_in != harvest_context.hc_entropy_ring.out) {		if (ring_in != harvest_context.hc_entropy_ring.out) {
/* The ring is not full */		/* The ring is not full */
event = harvest_context.hc_entropy_ring.ring + ring_in;		event = harvest_context.hc_entropy_ring.ring + ring_in;
event->he_somecounter = (uint32_t)get_cyclecount();		event->he_somecounter = (uint32_t)get_cyclecount();
event->he_source = origin;		event->he_source = origin;
event->he_destination = harvest_context.hc_destination[origin]++;		event->he_destination = harvest_context.hc_destination[origin]++;
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/*-		/*-
* Entropy harvesting fast routine.		* Entropy harvesting fast routine.
*		*
* This is supposed to be very fast; do not do anything slow in here!		* This is supposed to be very fast; do not do anything slow in here!
* This is the right place for high-rate harvested data.		* This is the right place for high-rate harvested data.
*/		*/
void		void
random_harvest_fast(const void *entropy, u_int size, u_int bits, enum random_entropy_source origin)		random_harvest_fast_(const void *entropy, u_int size, u_int bits)
{		{
u_int pos;		u_int pos;

KASSERT(origin >= RANDOM_START && origin < ENTROPYSOURCE, ("%s: origin %d invalid\n", __func__, origin));
/* XXX: FIX!! The above KASSERT is BS. Right now we ignore most structure and just accumulate the supplied data */
if (!(harvest_context.hc_source_mask & (1 << origin)))
return;
pos = harvest_context.hc_entropy_fast_accumulator.pos;		pos = harvest_context.hc_entropy_fast_accumulator.pos;
		cemUnsubmitted Not Done Inline Actions KASSERT references removed parameter cem: KASSERT references removed parameter
harvest_context.hc_entropy_fast_accumulator.buf[pos] ^= jenkins_hash(entropy, size, (uint32_t)get_cyclecount());		harvest_context.hc_entropy_fast_accumulator.buf[pos] ^= jenkins_hash(entropy, size, (uint32_t)get_cyclecount());
harvest_context.hc_entropy_fast_accumulator.pos = (pos + 1)%RANDOM_ACCUM_MAX;		harvest_context.hc_entropy_fast_accumulator.pos = (pos + 1)%RANDOM_ACCUM_MAX;
}		}

/*-		/*-
* Entropy harvesting direct routine.		* Entropy harvesting direct routine.
*		*
* This is not supposed to be fast, but will only be used during		* This is not supposed to be fast, but will only be used during
* (e.g.) booting when initial entropy is being gathered.		* (e.g.) booting when initial entropy is being gathered.
*/		*/
void		void
random_harvest_direct(const void *entropy, u_int size, u_int bits, enum random_entropy_source origin)		random_harvest_direct_(const void *entropy, u_int size, u_int bits, enum random_entropy_source origin)
{		{
struct harvest_event event;		struct harvest_event event;

KASSERT(origin >= RANDOM_START && origin < ENTROPYSOURCE, ("%s: origin %d invalid\n", __func__, origin));		KASSERT(origin >= RANDOM_START && origin < ENTROPYSOURCE, ("%s: origin %d invalid\n", __func__, origin));
if (!(harvest_context.hc_source_mask & (1 << origin)))
return;
size = MIN(size, sizeof(event.he_entropy));		size = MIN(size, sizeof(event.he_entropy));
event.he_somecounter = (uint32_t)get_cyclecount();		event.he_somecounter = (uint32_t)get_cyclecount();
event.he_size = size;		event.he_size = size;
event.he_bits = bits;		event.he_bits = bits;
event.he_source = origin;		event.he_source = origin;
event.he_destination = harvest_context.hc_destination[origin]++;		event.he_destination = harvest_context.hc_destination[origin]++;
memcpy(event.he_entropy, entropy, size);		memcpy(event.he_entropy, entropy, size);
random_harvestq_fast_process_event(&event);		random_harvestq_fast_process_event(&event);
explicit_bzero(&event, sizeof(event));		explicit_bzero(&event, sizeof(event));
}		}

void		void
random_harvest_register_source(enum random_entropy_source source)		random_harvest_register_source(enum random_entropy_source source)
{		{

harvest_context.hc_source_mask \|= (1 << source);		hc_source_mask \|= (1 << source);
}		}

void		void
random_harvest_deregister_source(enum random_entropy_source source)		random_harvest_deregister_source(enum random_entropy_source source)
{		{

harvest_context.hc_source_mask &= ~(1 << source);		hc_source_mask &= ~(1 << source);
}		}

MODULE_VERSION(random_harvestq, 1);		MODULE_VERSION(random_harvestq, 1);