Merge tag 'random_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random (d1d9cfc3) · Commits · e / devices / android_kernel_oneplus_sm7250

arch/powerpc/include/asm/archrandom.h

+18 −0

Original line number	Diff line number	Diff line
		@@ -25,8 +25,26 @@ static inline int arch_get_random_int(unsigned int *v)
		return rc;
		}

		static inline int arch_has_random(void)
		{
		return !!ppc_md.get_random_long;
		}

		int powernv_get_random_long(unsigned long *v);

		static inline int arch_get_random_seed_long(unsigned long *v)
		{
		return 0;
		}
		static inline int arch_get_random_seed_int(unsigned int *v)
		{
		return 0;
		}
		static inline int arch_has_random_seed(void)
		{
		return 0;
		}

		#endif /* CONFIG_ARCH_RANDOM */

		#endif /* _ASM_POWERPC_ARCHRANDOM_H */

arch/x86/include/asm/archrandom.h

+41 −1

Original line number	Diff line number	Diff line
		/*
		* This file is part of the Linux kernel.
		*
		* Copyright (c) 2011, Intel Corporation
		* Copyright (c) 2011-2014, Intel Corporation
		* Authors: Fenghua Yu <fenghua.yu@intel.com>,
		* H. Peter Anvin <hpa@linux.intel.com>
		*
		@@ -31,10 +31,13 @@
		#define RDRAND_RETRY_LOOPS 10

		#define RDRAND_INT ".byte 0x0f,0xc7,0xf0"
		#define RDSEED_INT ".byte 0x0f,0xc7,0xf8"
		#ifdef CONFIG_X86_64
		# define RDRAND_LONG ".byte 0x48,0x0f,0xc7,0xf0"
		# define RDSEED_LONG ".byte 0x48,0x0f,0xc7,0xf8"
		#else
		# define RDRAND_LONG RDRAND_INT
		# define RDSEED_LONG RDSEED_INT
		#endif

		#ifdef CONFIG_ARCH_RANDOM
		@@ -53,6 +56,16 @@ static inline int rdrand_long(unsigned long *v)
		return ok;
		}

		/* A single attempt at RDSEED */
		static inline bool rdseed_long(unsigned long *v)
		{
		unsigned char ok;
		asm volatile(RDSEED_LONG "\n\t"
		"setc %0"
		: "=qm" (ok), "=a" (*v));
		return ok;
		}

		#define GET_RANDOM(name, type, rdrand, nop) \
		static inline int name(type *v) \
		{ \
		@@ -70,18 +83,40 @@ static inline int name(type *v) \
		return ok; \
		}

		#define GET_SEED(name, type, rdseed, nop) \
		static inline int name(type *v) \
		{ \
		unsigned char ok; \
		alternative_io("movb $0, %0\n\t" \
		nop, \
		rdseed "\n\t" \
		"setc %0", \
		X86_FEATURE_RDSEED, \
		ASM_OUTPUT2("=q" (ok), "=a" (*v))); \
		return ok; \
		}

		#ifdef CONFIG_X86_64

		GET_RANDOM(arch_get_random_long, unsigned long, RDRAND_LONG, ASM_NOP5);
		GET_RANDOM(arch_get_random_int, unsigned int, RDRAND_INT, ASM_NOP4);

		GET_SEED(arch_get_random_seed_long, unsigned long, RDSEED_LONG, ASM_NOP5);
		GET_SEED(arch_get_random_seed_int, unsigned int, RDSEED_INT, ASM_NOP4);

		#else

		GET_RANDOM(arch_get_random_long, unsigned long, RDRAND_LONG, ASM_NOP3);
		GET_RANDOM(arch_get_random_int, unsigned int, RDRAND_INT, ASM_NOP3);

		GET_SEED(arch_get_random_seed_long, unsigned long, RDSEED_LONG, ASM_NOP4);
		GET_SEED(arch_get_random_seed_int, unsigned int, RDSEED_INT, ASM_NOP4);

		#endif /* CONFIG_X86_64 */

		#define arch_has_random() static_cpu_has(X86_FEATURE_RDRAND)
		#define arch_has_random_seed() static_cpu_has(X86_FEATURE_RDSEED)

		#else

		static inline int rdrand_long(unsigned long *v)
		@@ -89,6 +124,11 @@ static inline int rdrand_long(unsigned long *v)
		return 0;
		}

		static inline bool rdseed_long(unsigned long *v)
		{
		return 0;
		}

		#endif /* CONFIG_ARCH_RANDOM */

		extern void x86_init_rdrand(struct cpuinfo_x86 *c);

drivers/char/random.c

+136 −108

Original line number	Diff line number	Diff line
		@@ -295,17 +295,17 @@
		* The minimum number of bits of entropy before we wake up a read on
		* /dev/random. Should be enough to do a significant reseed.
		*/
		static int random_read_wakeup_thresh = 64;
		static int random_read_wakeup_bits = 64;

		/*
		* If the entropy count falls under this number of bits, then we
		* should wake up processes which are selecting or polling on write
		* access to /dev/random.
		*/
		static int random_write_wakeup_thresh = 28 * OUTPUT_POOL_WORDS;
		static int random_write_wakeup_bits = 28 * OUTPUT_POOL_WORDS;

		/*
		* The minimum number of seconds between urandom pool resending. We
		* The minimum number of seconds between urandom pool reseeding. We
		* do this to limit the amount of entropy that can be drained from the
		* input pool even if there are heavy demands on /dev/urandom.
		*/
		@@ -322,7 +322,7 @@ static int random_min_urandom_seed = 60;
		* Register. (See M. Matsumoto & Y. Kurita, 1992. Twisted GFSR
		* generators. ACM Transactions on Modeling and Computer Simulation
		* 2(3):179-194. Also see M. Matsumoto & Y. Kurita, 1994. Twisted
		* GFSR generators II. ACM Transactions on Mdeling and Computer
		* GFSR generators II. ACM Transactions on Modeling and Computer
		* Simulation 4:254-266)
		*
		* Thanks to Colin Plumb for suggesting this.
		@@ -666,10 +666,10 @@ static void credit_entropy_bits(struct entropy_store *r, int nbits)
		r->entropy_total, _RET_IP_);

		if (r == &input_pool) {
		int entropy_bytes = entropy_count >> ENTROPY_SHIFT;
		int entropy_bits = entropy_count >> ENTROPY_SHIFT;

		/* should we wake readers? */
		if (entropy_bytes >= random_read_wakeup_thresh) {
		if (entropy_bits >= random_read_wakeup_bits) {
		wake_up_interruptible(&random_read_wait);
		kill_fasync(&fasync, SIGIO, POLL_IN);
		}
		@@ -678,9 +678,9 @@ static void credit_entropy_bits(struct entropy_store *r, int nbits)
		* forth between them, until the output pools are 75%
		* full.
		*/
		if (entropy_bytes > random_write_wakeup_thresh &&
		if (entropy_bits > random_write_wakeup_bits &&
		r->initialized &&
		r->entropy_total >= 2*random_read_wakeup_thresh) {
		r->entropy_total >= 2*random_read_wakeup_bits) {
		static struct entropy_store *last = &blocking_pool;
		struct entropy_store *other = &blocking_pool;

		@@ -844,6 +844,8 @@ void add_interrupt_randomness(int irq, int irq_flags)
		cycles_t cycles = random_get_entropy();
		__u32 input[4], c_high, j_high;
		__u64 ip;
		unsigned long seed;
		int credit;

		c_high = (sizeof(cycles) > 4) ? cycles >> 32 : 0;
		j_high = (sizeof(now) > 4) ? now >> 32 : 0;
		@@ -862,20 +864,33 @@ void add_interrupt_randomness(int irq, int irq_flags)

		r = nonblocking_pool.initialized ? &input_pool : &nonblocking_pool;
		__mix_pool_bytes(r, &fast_pool->pool, sizeof(fast_pool->pool), NULL);

		/*
		* If we don't have a valid cycle counter, and we see
		* back-to-back timer interrupts, then skip giving credit for
		* any entropy.
		* any entropy, otherwise credit 1 bit.
		*/
		credit = 1;
		if (cycles == 0) {
		if (irq_flags & __IRQF_TIMER) {
		if (fast_pool->last_timer_intr)
		return;
		credit = 0;
		fast_pool->last_timer_intr = 1;
		} else
		fast_pool->last_timer_intr = 0;
		}
		credit_entropy_bits(r, 1);

		/*
		* If we have architectural seed generator, produce a seed and
		* add it to the pool. For the sake of paranoia count it as
		* 50% entropic.
		*/
		if (arch_get_random_seed_long(&seed)) {
		__mix_pool_bytes(r, &seed, sizeof(seed), NULL);
		credit += sizeof(seed) * 4;
		}

		credit_entropy_bits(r, credit);
		}

		#ifdef CONFIG_BLOCK
		@@ -924,19 +939,19 @@ static void _xfer_secondary_pool(struct entropy_store *r, size_t nbytes)
		{
		__u32 tmp[OUTPUT_POOL_WORDS];

		/* For /dev/random's pool, always leave two wakeup worth's BITS */
		int rsvd = r->limit ? 0 : random_read_wakeup_thresh/4;
		/* For /dev/random's pool, always leave two wakeups' worth */
		int rsvd_bytes = r->limit ? 0 : random_read_wakeup_bits / 4;
		int bytes = nbytes;

		/* pull at least as many as BYTES as wakeup BITS */
		bytes = max_t(int, bytes, random_read_wakeup_thresh / 8);
		/* pull at least as much as a wakeup */
		bytes = max_t(int, bytes, random_read_wakeup_bits / 8);
		/* but never more than the buffer size */
		bytes = min_t(int, bytes, sizeof(tmp));

		trace_xfer_secondary_pool(r->name, bytes * 8, nbytes * 8,
		ENTROPY_BITS(r), ENTROPY_BITS(r->pull));
		bytes = extract_entropy(r->pull, tmp, bytes,
		random_read_wakeup_thresh / 8, rsvd);
		random_read_wakeup_bits / 8, rsvd_bytes);
		mix_pool_bytes(r, tmp, bytes, NULL);
		credit_entropy_bits(r, bytes*8);
		}
		@@ -952,35 +967,22 @@ static void push_to_pool(struct work_struct *work)
		struct entropy_store *r = container_of(work, struct entropy_store,
		push_work);
		BUG_ON(!r);
		_xfer_secondary_pool(r, random_read_wakeup_thresh/8);
		_xfer_secondary_pool(r, random_read_wakeup_bits/8);
		trace_push_to_pool(r->name, r->entropy_count >> ENTROPY_SHIFT,
		r->pull->entropy_count >> ENTROPY_SHIFT);
		}

		/*
		* These functions extracts randomness from the "entropy pool", and
		* returns it in a buffer.
		*
		* The min parameter specifies the minimum amount we can pull before
		* failing to avoid races that defeat catastrophic reseeding while the
		* reserved parameter indicates how much entropy we must leave in the
		* pool after each pull to avoid starving other readers.
		*
		* Note: extract_entropy() assumes that .poolwords is a multiple of 16 words.
		* This function decides how many bytes to actually take from the
		* given pool, and also debits the entropy count accordingly.
		*/

		static size_t account(struct entropy_store *r, size_t nbytes, int min,
		int reserved)
		{
		unsigned long flags;
		int wakeup_write = 0;
		int have_bytes;
		int entropy_count, orig;
		size_t ibytes;

		/* Hold lock while accounting */
		spin_lock_irqsave(&r->lock, flags);

		BUG_ON(r->entropy_count > r->poolinfo->poolfracbits);

		/* Can we pull enough? */
		@@ -988,29 +990,19 @@ static size_t account(struct entropy_store *r, size_t nbytes, int min,
		entropy_count = orig = ACCESS_ONCE(r->entropy_count);
		have_bytes = entropy_count >> (ENTROPY_SHIFT + 3);
		ibytes = nbytes;
		if (have_bytes < min + reserved) {
		ibytes = 0;
		} else {
		/* If limited, never pull more than available */
		if (r->limit && ibytes + reserved >= have_bytes)
		ibytes = have_bytes - reserved;

		if (have_bytes >= ibytes + reserved)
		entropy_count -= ibytes << (ENTROPY_SHIFT + 3);
		else
		entropy_count = reserved << (ENTROPY_SHIFT + 3);

		if (r->limit)
		ibytes = min_t(size_t, ibytes, have_bytes - reserved);
		if (ibytes < min)
		ibytes = 0;
		entropy_count = max_t(int, 0,
		entropy_count - (ibytes << (ENTROPY_SHIFT + 3)));
		if (cmpxchg(&r->entropy_count, orig, entropy_count) != orig)
		goto retry;

		if ((r->entropy_count >> ENTROPY_SHIFT)
		< random_write_wakeup_thresh)
		wakeup_write = 1;
		}
		spin_unlock_irqrestore(&r->lock, flags);

		trace_debit_entropy(r->name, 8 * ibytes);
		if (wakeup_write) {
		if (ibytes &&
		(r->entropy_count >> ENTROPY_SHIFT) < random_write_wakeup_bits) {
		wake_up_interruptible(&random_write_wait);
		kill_fasync(&fasync, SIGIO, POLL_OUT);
		}
		@@ -1018,6 +1010,12 @@ static size_t account(struct entropy_store *r, size_t nbytes, int min,
		return ibytes;
		}

		/*
		* This function does the actual extraction for extract_entropy and
		* extract_entropy_user.
		*
		* Note: we assume that .poolwords is a multiple of 16 words.
		*/
		static void extract_buf(struct entropy_store r, __u8 out)
		{
		int i;
		@@ -1029,23 +1027,23 @@ static void extract_buf(struct entropy_store r, __u8 out)
		__u8 extract[64];
		unsigned long flags;

		/* Generate a hash across the pool, 16 words (512 bits) at a time */
		sha_init(hash.w);
		spin_lock_irqsave(&r->lock, flags);
		for (i = 0; i < r->poolinfo->poolwords; i += 16)
		sha_transform(hash.w, (__u8 *)(r->pool + i), workspace);

		/*
		* If we have a architectural hardware random number
		* generator, mix that in, too.
		* If we have an architectural hardware random number
		* generator, use it for SHA's initial vector
		*/
		sha_init(hash.w);
		for (i = 0; i < LONGS(20); i++) {
		unsigned long v;
		if (!arch_get_random_long(&v))
		break;
		hash.l[i] ^= v;
		hash.l[i] = v;
		}

		/* Generate a hash across the pool, 16 words (512 bits) at a time */
		spin_lock_irqsave(&r->lock, flags);
		for (i = 0; i < r->poolinfo->poolwords; i += 16)
		sha_transform(hash.w, (__u8 *)(r->pool + i), workspace);

		/*
		* We mix the hash back into the pool to prevent backtracking
		* attacks (where the attacker knows the state of the pool
		@@ -1079,6 +1077,15 @@ static void extract_buf(struct entropy_store r, __u8 out)
		memset(&hash, 0, sizeof(hash));
		}

		/*
		* This function extracts randomness from the "entropy pool", and
		* returns it in a buffer.
		*
		* The min parameter specifies the minimum amount we can pull before
		* failing to avoid races that defeat catastrophic reseeding while the
		* reserved parameter indicates how much entropy we must leave in the
		* pool after each pull to avoid starving other readers.
		*/
		static ssize_t extract_entropy(struct entropy_store r, void buf,
		size_t nbytes, int min, int reserved)
		{
		@@ -1129,6 +1136,10 @@ static ssize_t extract_entropy(struct entropy_store r, void buf,
		return ret;
		}

		/*
		* This function extracts randomness from the "entropy pool", and
		* returns it in a userspace buffer.
		*/
		static ssize_t extract_entropy_user(struct entropy_store r, void __user buf,
		size_t nbytes)
		{
		@@ -1170,8 +1181,9 @@ static ssize_t extract_entropy_user(struct entropy_store r, void __user buf,
		/*
		* This function is the exported kernel interface. It returns some
		* number of good random numbers, suitable for key generation, seeding
		* TCP sequence numbers, etc. It does not use the hw random number
		* generator, if available; use get_random_bytes_arch() for that.
		* TCP sequence numbers, etc. It does not rely on the hardware random
		* number generator. For random bytes direct from the hardware RNG
		* (when available), use get_random_bytes_arch().
		*/
		void get_random_bytes(void *buf, int nbytes)
		{
		@@ -1238,7 +1250,8 @@ static void init_std_data(struct entropy_store *r)
		r->last_pulled = jiffies;
		mix_pool_bytes(r, &now, sizeof(now), NULL);
		for (i = r->poolinfo->poolbytes; i > 0; i -= sizeof(rv)) {
		if (!arch_get_random_long(&rv))
		if (!arch_get_random_seed_long(&rv) &&
		!arch_get_random_long(&rv))
		rv = random_get_entropy();
		mix_pool_bytes(r, &rv, sizeof(rv), NULL);
		}
		@@ -1281,56 +1294,71 @@ void rand_initialize_disk(struct gendisk *disk)
		}
		#endif

		static ssize_t
		random_read(struct file file, char __user buf, size_t nbytes, loff_t *ppos)
		/*
		* Attempt an emergency refill using arch_get_random_seed_long().
		*
		* As with add_interrupt_randomness() be paranoid and only
		* credit the output as 50% entropic.
		*/
		static int arch_random_refill(void)
		{
		ssize_t n, retval = 0, count = 0;
		const unsigned int nlongs = 64; /* Arbitrary number */
		unsigned int n = 0;
		unsigned int i;
		unsigned long buf[nlongs];

		if (nbytes == 0)
		if (!arch_has_random_seed())
		return 0;

		while (nbytes > 0) {
		n = nbytes;
		if (n > SEC_XFER_SIZE)
		n = SEC_XFER_SIZE;
		for (i = 0; i < nlongs; i++) {
		if (arch_get_random_seed_long(&buf[n]))
		n++;
		}

		n = extract_entropy_user(&blocking_pool, buf, n);
		if (n) {
		unsigned int rand_bytes = n * sizeof(unsigned long);

		if (n < 0) {
		retval = n;
		break;
		mix_pool_bytes(&input_pool, buf, rand_bytes, NULL);
		credit_entropy_bits(&input_pool, rand_bytes*4);
		}

		return n;
		}

		static ssize_t
		random_read(struct file file, char __user buf, size_t nbytes, loff_t *ppos)
		{
		ssize_t n;

		if (nbytes == 0)
		return 0;

		nbytes = min_t(size_t, nbytes, SEC_XFER_SIZE);
		while (1) {
		n = extract_entropy_user(&blocking_pool, buf, nbytes);
		if (n < 0)
		return n;
		trace_random_read(n8, (nbytes-n)8,
		ENTROPY_BITS(&blocking_pool),
		ENTROPY_BITS(&input_pool));
		if (n > 0)
		return n;

		if (n == 0) {
		if (file->f_flags & O_NONBLOCK) {
		retval = -EAGAIN;
		break;
		}

		wait_event_interruptible(random_read_wait,
		ENTROPY_BITS(&input_pool) >=
		random_read_wakeup_thresh);

		if (signal_pending(current)) {
		retval = -ERESTARTSYS;
		break;
		}
		/* Pool is (near) empty. Maybe wait and retry. */

		/* First try an emergency refill */
		if (arch_random_refill())
		continue;
		}

		count += n;
		buf += n;
		nbytes -= n;
		break; /* This break makes the device work */
		/* like a named pipe */
		}
		if (file->f_flags & O_NONBLOCK)
		return -EAGAIN;

		return (count ? count : retval);
		wait_event_interruptible(random_read_wait,
		ENTROPY_BITS(&input_pool) >=
		random_read_wakeup_bits);
		if (signal_pending(current))
		return -ERESTARTSYS;
		}
		}

		static ssize_t
		@@ -1358,9 +1386,9 @@ random_poll(struct file file, poll_table wait)
		poll_wait(file, &random_read_wait, wait);
		poll_wait(file, &random_write_wait, wait);
		mask = 0;
		if (ENTROPY_BITS(&input_pool) >= random_read_wakeup_thresh)
		if (ENTROPY_BITS(&input_pool) >= random_read_wakeup_bits)
		mask \|= POLLIN \| POLLRDNORM;
		if (ENTROPY_BITS(&input_pool) < random_write_wakeup_thresh)
		if (ENTROPY_BITS(&input_pool) < random_write_wakeup_bits)
		mask \|= POLLOUT \| POLLWRNORM;
		return mask;
		}
		@@ -1507,18 +1535,18 @@ EXPORT_SYMBOL(generate_random_uuid);
		#include <linux/sysctl.h>

		static int min_read_thresh = 8, min_write_thresh;
		static int max_read_thresh = INPUT_POOL_WORDS * 32;
		static int max_read_thresh = OUTPUT_POOL_WORDS * 32;
		static int max_write_thresh = INPUT_POOL_WORDS * 32;
		static char sysctl_bootid[16];

		/*
		* These functions is used to return both the bootid UUID, and random
		* This function is used to return both the bootid UUID, and random
		* UUID. The difference is in whether table->data is NULL; if it is,
		* then a new UUID is generated and returned to the user.
		*
		* If the user accesses this via the proc interface, it will be returned
		* as an ASCII string in the standard UUID format. If accesses via the
		* sysctl system call, it is returned as 16 bytes of binary data.
		* If the user accesses this via the proc interface, the UUID will be
		* returned as an ASCII string in the standard UUID format; if via the
		* sysctl system call, as 16 bytes of binary data.
		*/
		static int proc_do_uuid(struct ctl_table *table, int write,
		void __user buffer, size_t lenp, loff_t *ppos)
		@@ -1583,7 +1611,7 @@ struct ctl_table random_table[] = {
		},
		{
		.procname = "read_wakeup_threshold",
		.data = &random_read_wakeup_thresh,
		.data = &random_read_wakeup_bits,
		.maxlen = sizeof(int),
		.mode = 0644,
		.proc_handler = proc_dointvec_minmax,
		@@ -1592,7 +1620,7 @@ struct ctl_table random_table[] = {
		},
		{
		.procname = "write_wakeup_threshold",
		.data = &random_write_wakeup_thresh,
		.data = &random_write_wakeup_bits,
		.maxlen = sizeof(int),
		.mode = 0644,
		.proc_handler = proc_dointvec_minmax,

include/linux/random.h

+16 −0

Original line number	Diff line number	Diff line
		@@ -88,6 +88,22 @@ static inline int arch_get_random_int(unsigned int *v)
		{
		return 0;
		}
		static inline int arch_has_random(void)
		{
		return 0;
		}
		static inline int arch_get_random_seed_long(unsigned long *v)
		{
		return 0;
		}
		static inline int arch_get_random_seed_int(unsigned int *v)
		{
		return 0;
		}
		static inline int arch_has_random_seed(void)
		{
		return 0;
		}
		#endif

		/* Pseudo random number generator from numerical recipes. */