diff options
Diffstat (limited to 'drivers/char/random.c')
| -rw-r--r-- | drivers/char/random.c | 869 |
1 files changed, 398 insertions, 471 deletions
diff --git a/drivers/char/random.c b/drivers/char/random.c index 605969ed0f96..68613f0b6887 100644 --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -1,8 +1,7 @@ /* * random.c -- A strong random number generator * - * Copyright (C) 2017 Jason A. Donenfeld <Jason@zx2c4.com>. All - * Rights Reserved. + * Copyright (C) 2017-2022 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved. * * Copyright Matt Mackall <mpm@selenic.com>, 2003, 2004, 2005 * @@ -78,12 +77,12 @@ * an *estimate* of how many bits of randomness have been stored into * the random number generator's internal state. * - * When random bytes are desired, they are obtained by taking the SHA - * hash of the contents of the "entropy pool". The SHA hash avoids + * When random bytes are desired, they are obtained by taking the BLAKE2s + * hash of the contents of the "entropy pool". The BLAKE2s hash avoids * exposing the internal state of the entropy pool. It is believed to * be computationally infeasible to derive any useful information - * about the input of SHA from its output. Even if it is possible to - * analyze SHA in some clever way, as long as the amount of data + * about the input of BLAKE2s from its output. Even if it is possible to + * analyze BLAKE2s in some clever way, as long as the amount of data * returned from the generator is less than the inherent entropy in * the pool, the output data is totally unpredictable. For this * reason, the routine decreases its internal estimate of how many @@ -93,7 +92,7 @@ * If this estimate goes to zero, the routine can still generate * random numbers; however, an attacker may (at least in theory) be * able to infer the future output of the generator from prior - * outputs. This requires successful cryptanalysis of SHA, which is + * outputs. This requires successful cryptanalysis of BLAKE2s, which is * not believed to be feasible, but there is a remote possibility. * Nonetheless, these numbers should be useful for the vast majority * of purposes. @@ -102,7 +101,7 @@ * =============================== * * There are four exported interfaces; two for use within the kernel, - * and two or use from userspace. + * and two for use from userspace. * * Exported interfaces ---- userspace output * ----------------------------------------- @@ -125,7 +124,7 @@ * * The primary kernel interface is * - * void get_random_bytes(void *buf, int nbytes); + * void get_random_bytes(void *buf, int nbytes); * * This interface will return the requested number of random bytes, * and place it in the requested buffer. This is equivalent to a @@ -133,10 +132,10 @@ * * For less critical applications, there are the functions: * - * u32 get_random_u32() - * u64 get_random_u64() - * unsigned int get_random_int() - * unsigned long get_random_long() + * u32 get_random_u32() + * u64 get_random_u64() + * unsigned int get_random_int() + * unsigned long get_random_long() * * These are produced by a cryptographic RNG seeded from get_random_bytes, * and so do not deplete the entropy pool as much. These are recommended @@ -198,10 +197,13 @@ * from the devices are: * * void add_device_randomness(const void *buf, unsigned int size); - * void add_input_randomness(unsigned int type, unsigned int code, + * void add_input_randomness(unsigned int type, unsigned int code, * unsigned int value); - * void add_interrupt_randomness(int irq, int irq_flags); - * void add_disk_randomness(struct gendisk *disk); + * void add_interrupt_randomness(int irq); + * void add_disk_randomness(struct gendisk *disk); + * void add_hwgenerator_randomness(const char *buffer, size_t count, + * size_t entropy); + * void add_bootloader_randomness(const void *buf, unsigned int size); * * add_device_randomness() is for adding data to the random pool that * is likely to differ between two devices (or possibly even per boot). @@ -228,6 +230,14 @@ * particular randomness source. They do this by keeping track of the * first and second order deltas of the event timings. * + * add_hwgenerator_randomness() is for true hardware RNGs, and will credit + * entropy as specified by the caller. If the entropy pool is full it will + * block until more entropy is needed. + * + * add_bootloader_randomness() is the same as add_hwgenerator_randomness() or + * add_device_randomness(), depending on whether or not the configuration + * option CONFIG_RANDOM_TRUST_BOOTLOADER is set. + * * Ensuring unpredictability at system startup * ============================================ * @@ -286,8 +296,8 @@ * /dev/random and /dev/urandom created already, they can be created * by using the commands: * - * mknod /dev/random c 1 8 - * mknod /dev/urandom c 1 9 + * mknod /dev/random c 1 8 + * mknod /dev/urandom c 1 9 * * Acknowledgements: * ================= @@ -327,7 +337,6 @@ #include <linux/spinlock.h> #include <linux/kthread.h> #include <linux/percpu.h> -#include <linux/fips.h> #include <linux/ptrace.h> #include <linux/workqueue.h> #include <linux/irq.h> @@ -336,7 +345,7 @@ #include <linux/completion.h> #include <linux/uuid.h> #include <crypto/chacha.h> -#include <crypto/sha1.h> +#include <crypto/blake2s.h> #include <asm/processor.h> #include <linux/uaccess.h> @@ -350,33 +359,11 @@ /* #define ADD_INTERRUPT_BENCH */ /* - * Configuration information - */ -#define INPUT_POOL_SHIFT 12 -#define INPUT_POOL_WORDS (1 << (INPUT_POOL_SHIFT-5)) -#define OUTPUT_POOL_SHIFT 10 -#define OUTPUT_POOL_WORDS (1 << (OUTPUT_POOL_SHIFT-5)) -#define EXTRACT_SIZE 10 - - -#define LONGS(x) (((x) + sizeof(unsigned long) - 1)/sizeof(unsigned long)) - -/* - * To allow fractional bits to be tracked, the entropy_count field is - * denominated in units of 1/8th bits. - * - * 2*(ENTROPY_SHIFT + poolbitshift) must <= 31, or the multiply in - * credit_entropy_bits() needs to be 64 bits wide. - */ -#define ENTROPY_SHIFT 3 -#define ENTROPY_BITS(r) ((r)->entropy_count >> ENTROPY_SHIFT) - -/* * 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_bits = 28 * OUTPUT_POOL_WORDS; +static int random_write_wakeup_bits = 28 * (1 << 5); /* * Originally, we used a primitive polynomial of degree .poolwords @@ -395,7 +382,7 @@ static int random_write_wakeup_bits = 28 * OUTPUT_POOL_WORDS; * Thanks to Colin Plumb for suggesting this. * * The mixing operation is much less sensitive than the output hash, - * where we use SHA-1. All that we want of mixing operation is that + * where we use BLAKE2s. All that we want of mixing operation is that * it be a good non-cryptographic hash; i.e. it not produce collisions * when fed "random" data of the sort we expect to see. As long as * the pool state differs for different inputs, we have preserved the @@ -423,14 +410,27 @@ static int random_write_wakeup_bits = 28 * OUTPUT_POOL_WORDS; * polynomial which improves the resulting TGFSR polynomial to be * irreducible, which we have made here. */ -static const struct poolinfo { - int poolbitshift, poolwords, poolbytes, poolfracbits; -#define S(x) ilog2(x)+5, (x), (x)*4, (x) << (ENTROPY_SHIFT+5) - int tap1, tap2, tap3, tap4, tap5; -} poolinfo_table[] = { - /* was: x^128 + x^103 + x^76 + x^51 +x^25 + x + 1 */ +enum poolinfo { + POOL_WORDS = 128, + POOL_WORDMASK = POOL_WORDS - 1, + POOL_BYTES = POOL_WORDS * sizeof(u32), + POOL_BITS = POOL_BYTES * 8, + POOL_BITSHIFT = ilog2(POOL_BITS), + + /* To allow fractional bits to be tracked, the entropy_count field is + * denominated in units of 1/8th bits. */ + POOL_ENTROPY_SHIFT = 3, +#define POOL_ENTROPY_BITS() (input_pool.entropy_count >> POOL_ENTROPY_SHIFT) + POOL_FRACBITS = POOL_BITS << POOL_ENTROPY_SHIFT, + /* x^128 + x^104 + x^76 + x^51 +x^25 + x + 1 */ - { S(128), 104, 76, 51, 25, 1 }, + POOL_TAP1 = 104, + POOL_TAP2 = 76, + POOL_TAP3 = 51, + POOL_TAP4 = 25, + POOL_TAP5 = 1, + + EXTRACT_SIZE = BLAKE2S_HASH_SIZE / 2 }; /* @@ -443,13 +443,17 @@ static DEFINE_SPINLOCK(random_ready_list_lock); static LIST_HEAD(random_ready_list); struct crng_state { - __u32 state[16]; - unsigned long init_time; - spinlock_t lock; + u32 state[16]; + unsigned long init_time; + spinlock_t lock; }; static struct crng_state primary_crng = { .lock = __SPIN_LOCK_UNLOCKED(primary_crng.lock), + .state[0] = CHACHA_CONSTANT_EXPA, + .state[1] = CHACHA_CONSTANT_ND_3, + .state[2] = CHACHA_CONSTANT_2_BY, + .state[3] = CHACHA_CONSTANT_TE_K, }; /* @@ -461,13 +465,14 @@ static struct crng_state primary_crng = { * its value (from 0->1->2). */ static int crng_init = 0; +static bool crng_need_final_init = false; #define crng_ready() (likely(crng_init > 1)) static int crng_init_cnt = 0; static unsigned long crng_global_init_time = 0; -#define CRNG_INIT_CNT_THRESH (2*CHACHA_KEY_SIZE) -static void _extract_crng(struct crng_state *crng, __u8 out[CHACHA_BLOCK_SIZE]); +#define CRNG_INIT_CNT_THRESH (2 * CHACHA_KEY_SIZE) +static void _extract_crng(struct crng_state *crng, u8 out[CHACHA_BLOCK_SIZE]); static void _crng_backtrack_protect(struct crng_state *crng, - __u8 tmp[CHACHA_BLOCK_SIZE], int used); + u8 tmp[CHACHA_BLOCK_SIZE], int used); static void process_random_ready_list(void); static void _get_random_bytes(void *buf, int nbytes); @@ -488,38 +493,23 @@ MODULE_PARM_DESC(ratelimit_disable, "Disable random ratelimit suppression"); * **********************************************************************/ -struct entropy_store; -struct entropy_store { - /* read-only data: */ - const struct poolinfo *poolinfo; - __u32 *pool; - const char *name; +static u32 input_pool_data[POOL_WORDS] __latent_entropy; - /* read-write data: */ +static struct { spinlock_t lock; - unsigned short add_ptr; - unsigned short input_rotate; + u16 add_ptr; + u16 input_rotate; int entropy_count; - unsigned int last_data_init:1; - __u8 last_data[EXTRACT_SIZE]; +} input_pool = { + .lock = __SPIN_LOCK_UNLOCKED(input_pool.lock), }; -static ssize_t extract_entropy(struct entropy_store *r, void *buf, - size_t nbytes, int min, int rsvd); -static ssize_t _extract_entropy(struct entropy_store *r, void *buf, - size_t nbytes, int fips); - -static void crng_reseed(struct crng_state *crng, struct entropy_store *r); -static __u32 input_pool_data[INPUT_POOL_WORDS] __latent_entropy; +static ssize_t extract_entropy(void *buf, size_t nbytes, int min); +static ssize_t _extract_entropy(void *buf, size_t nbytes); -static struct entropy_store input_pool = { - .poolinfo = &poolinfo_table[0], - .name = "input", - .lock = __SPIN_LOCK_UNLOCKED(input_pool.lock), - .pool = input_pool_data -}; +static void crng_reseed(struct crng_state *crng, bool use_input_pool); -static __u32 const twist_table[8] = { +static const u32 twist_table[8] = { 0x00000000, 0x3b6e20c8, 0x76dc4190, 0x4db26158, 0xedb88320, 0xd6d6a3e8, 0x9b64c2b0, 0xa00ae278 }; @@ -533,39 +523,31 @@ static __u32 const twist_table[8] = { * it's cheap to do so and helps slightly in the expected case where * the entropy is concentrated in the low-order bits. */ -static void _mix_pool_bytes(struct entropy_store *r, const void *in, - int nbytes) +static void _mix_pool_bytes(const void *in, int nbytes) { - unsigned long i, tap1, tap2, tap3, tap4, tap5; + unsigned long i; int input_rotate; - int wordmask = r->poolinfo->poolwords - 1; - const char *bytes = in; - __u32 w; + const u8 *bytes = in; + u32 w; - tap1 = r->poolinfo->tap1; - tap2 = r->poolinfo->tap2; - tap3 = r->poolinfo->tap3; - tap4 = r->poolinfo->tap4; - tap5 = r->poolinfo->tap5; - - input_rotate = r->input_rotate; - i = r->add_ptr; + input_rotate = input_pool.input_rotate; + i = input_pool.add_ptr; /* mix one byte at a time to simplify size handling and churn faster */ while (nbytes--) { w = rol32(*bytes++, input_rotate); - i = (i - 1) & wordmask; + i = (i - 1) & POOL_WORDMASK; /* XOR in the various taps */ - w ^= r->pool[i]; - w ^= r->pool[(i + tap1) & wordmask]; - w ^= r->pool[(i + tap2) & wordmask]; - w ^= r->pool[(i + tap3) & wordmask]; - w ^= r->pool[(i + tap4) & wordmask]; - w ^= r->pool[(i + tap5) & wordmask]; + w ^= input_pool_data[i]; + w ^= input_pool_data[(i + POOL_TAP1) & POOL_WORDMASK]; + w ^= input_pool_data[(i + POOL_TAP2) & POOL_WORDMASK]; + w ^= input_pool_data[(i + POOL_TAP3) & POOL_WORDMASK]; + w ^= input_pool_data[(i + POOL_TAP4) & POOL_WORDMASK]; + w ^= input_pool_data[(i + POOL_TAP5) & POOL_WORDMASK]; /* Mix the result back in with a twist */ - r->pool[i] = (w >> 3) ^ twist_table[w & 7]; + input_pool_data[i] = (w >> 3) ^ twist_table[w & 7]; /* * Normally, we add 7 bits of rotation to the pool. @@ -576,33 +558,31 @@ static void _mix_pool_bytes(struct entropy_store *r, const void *in, input_rotate = (input_rotate + (i ? 7 : 14)) & 31; } - r->input_rotate = input_rotate; - r->add_ptr = i; + input_pool.input_rotate = input_rotate; + input_pool.add_ptr = i; } -static void __mix_pool_bytes(struct entropy_store *r, const void *in, - int nbytes) +static void __mix_pool_bytes(const void *in, int nbytes) { - trace_mix_pool_bytes_nolock(r->name, nbytes, _RET_IP_); - _mix_pool_bytes(r, in, nbytes); + trace_mix_pool_bytes_nolock(nbytes, _RET_IP_); + _mix_pool_bytes(in, nbytes); } -static void mix_pool_bytes(struct entropy_store *r, const void *in, - int nbytes) +static void mix_pool_bytes(const void *in, int nbytes) { unsigned long flags; - trace_mix_pool_bytes(r->name, nbytes, _RET_IP_); - spin_lock_irqsave(&r->lock, flags); - _mix_pool_bytes(r, in, nbytes); - spin_unlock_irqrestore(&r->lock, flags); + trace_mix_pool_bytes(nbytes, _RET_IP_); + spin_lock_irqsave(&input_pool.lock, flags); + _mix_pool_bytes(in, nbytes); + spin_unlock_irqrestore(&input_pool.lock, flags); } struct fast_pool { - __u32 pool[4]; - unsigned long last; - unsigned short reg_idx; - unsigned char count; + u32 pool[4]; + unsigned long last; + u16 reg_idx; + u8 count; }; /* @@ -612,8 +592,8 @@ struct fast_pool { */ static void fast_mix(struct fast_pool *f) { - __u32 a = f->pool[0], b = f->pool[1]; - __u32 c = f->pool[2], d = f->pool[3]; + u32 a = f->pool[0], b = f->pool[1]; + u32 c = f->pool[2], d = f->pool[3]; a += b; c += d; b = rol32(b, 6); d = rol32(d, 27); @@ -657,17 +637,19 @@ static void process_random_ready_list(void) * Use credit_entropy_bits_safe() if the value comes from userspace * or otherwise should be checked for extreme values. */ -static void credit_entropy_bits(struct entropy_store *r, int nbits) +static void credit_entropy_bits(int nbits) { - int entropy_count, orig; - const int pool_size = r->poolinfo->poolfracbits; - int nfrac = nbits << ENTROPY_SHIFT; + int entropy_count, entropy_bits, orig; + int nfrac = nbits << POOL_ENTROPY_SHIFT; + + /* Ensure that the multiplication can avoid being 64 bits wide. */ + BUILD_BUG_ON(2 * (POOL_ENTROPY_SHIFT + POOL_BITSHIFT) > 31); if (!nbits) return; retry: - entropy_count = orig = READ_ONCE(r->entropy_count); + entropy_count = orig = READ_ONCE(input_pool.entropy_count); if (nfrac < 0) { /* Debit */ entropy_count += nfrac; @@ -694,50 +676,43 @@ retry: * turns no matter how large nbits is. */ int pnfrac = nfrac; - const int s = r->poolinfo->poolbitshift + ENTROPY_SHIFT + 2; + const int s = POOL_BITSHIFT + POOL_ENTROPY_SHIFT + 2; /* The +2 corresponds to the /4 in the denominator */ do { - unsigned int anfrac = min(pnfrac, pool_size/2); + unsigned int anfrac = min(pnfrac, POOL_FRACBITS / 2); unsigned int add = - ((pool_size - entropy_count)*anfrac*3) >> s; + ((POOL_FRACBITS - entropy_count) * anfrac * 3) >> s; entropy_count += add; pnfrac -= anfrac; - } while (unlikely(entropy_count < pool_size-2 && pnfrac)); + } while (unlikely(entropy_count < POOL_FRACBITS - 2 && pnfrac)); } if (WARN_ON(entropy_count < 0)) { - pr_warn("negative entropy/overflow: pool %s count %d\n", - r->name, entropy_count); + pr_warn("negative entropy/overflow: count %d\n", entropy_count); entropy_count = 0; - } else if (entropy_count > pool_size) - entropy_count = pool_size; - if (cmpxchg(&r->entropy_count, orig, entropy_count) != orig) + } else if (entropy_count > POOL_FRACBITS) + entropy_count = POOL_FRACBITS; + if (cmpxchg(&input_pool.entropy_count, orig, entropy_count) != orig) goto retry; - trace_credit_entropy_bits(r->name, nbits, - entropy_count >> ENTROPY_SHIFT, _RET_IP_); - - if (r == &input_pool) { - int entropy_bits = entropy_count >> ENTROPY_SHIFT; + trace_credit_entropy_bits(nbits, entropy_count >> POOL_ENTROPY_SHIFT, _RET_IP_); - if (crng_init < 2 && entropy_bits >= 128) - crng_reseed(&primary_crng, r); - } + entropy_bits = entropy_count >> POOL_ENTROPY_SHIFT; + if (crng_init < 2 && entropy_bits >= 128) + crng_reseed(&primary_crng, true); } -static int credit_entropy_bits_safe(struct entropy_store *r, int nbits) +static int credit_entropy_bits_safe(int nbits) { - const int nbits_max = r->poolinfo->poolwords * 32; - if (nbits < 0) return -EINVAL; /* Cap the value to avoid overflows */ - nbits = min(nbits, nbits_max); + nbits = min(nbits, POOL_BITS); - credit_entropy_bits(r, nbits); + credit_entropy_bits(nbits); return 0; } @@ -747,11 +722,10 @@ static int credit_entropy_bits_safe(struct entropy_store *r, int nbits) * *********************************************************************/ -#define CRNG_RESEED_INTERVAL (300*HZ) +#define CRNG_RESEED_INTERVAL (300 * HZ) static DECLARE_WAIT_QUEUE_HEAD(crng_init_wait); -#ifdef CONFIG_NUMA /* * Hack to deal with crazy userspace progams when they are all trying * to access /dev/urandom in parallel. The programs are almost @@ -759,7 +733,6 @@ static DECLARE_WAIT_QUEUE_HEAD(crng_init_wait); * their brain damage. */ static struct crng_state **crng_node_pool __read_mostly; -#endif static void invalidate_batched_entropy(void); static void numa_crng_init(void); @@ -773,9 +746,9 @@ early_param("random.trust_cpu", parse_trust_cpu); static bool crng_init_try_arch(struct crng_state *crng) { - int i; - bool arch_init = true; - unsigned long rv; + int i; + bool arch_init = true; + unsigned long rv; for (i = 4; i < 16; i++) { if (!arch_get_random_seed_long(&rv) && @@ -791,9 +764,9 @@ static bool crng_init_try_arch(struct crng_state *crng) static bool __init crng_init_try_arch_early(struct crng_state *crng) { - int i; - bool arch_init = true; - unsigned long rv; + int i; + bool arch_init = true; + unsigned long rv; for (i = 4; i < 16; i++) { if (!arch_get_random_seed_long_early(&rv) && @@ -807,35 +780,63 @@ static bool __init crng_init_try_arch_early(struct crng_state *crng) return arch_init; } -static void __maybe_unused crng_initialize_secondary(struct crng_state *crng) +static void crng_initialize_secondary(struct crng_state *crng) { chacha_init_consts(crng->state); - _get_random_bytes(&crng->state[4], sizeof(__u32) * 12); + _get_random_bytes(&crng->state[4], sizeof(u32) * 12); crng_init_try_arch(crng); crng->init_time = jiffies - CRNG_RESEED_INTERVAL - 1; } static void __init crng_initialize_primary(struct crng_state *crng) { - chacha_init_consts(crng->state); - _extract_entropy(&input_pool, &crng->state[4], sizeof(__u32) * 12, 0); - if (crng_init_try_arch_early(crng) && trust_cpu) { + _extract_entropy(&crng->state[4], sizeof(u32) * 12); + if (crng_init_try_arch_early(crng) && trust_cpu && crng_init < 2) { invalidate_batched_entropy(); numa_crng_init(); crng_init = 2; - pr_notice("crng done (trusting CPU's manufacturer)\n"); + pr_notice("crng init done (trusting CPU's manufacturer)\n"); } crng->init_time = jiffies - CRNG_RESEED_INTERVAL - 1; } -#ifdef CONFIG_NUMA +static void crng_finalize_init(struct crng_state *crng) +{ + if (crng != &primary_crng || crng_init >= 2) + return; + if (!system_wq) { + /* We can't call numa_crng_init until we have workqueues, + * so mark this for processing later. */ + crng_need_final_init = true; + return; + } + + invalidate_batched_entropy(); + numa_crng_init(); + crng_init = 2; + process_random_ready_list(); + wake_up_interruptible(&crng_init_wait); + kill_fasync(&fasync, SIGIO, POLL_IN); + pr_notice("crng init done\n"); + if (unseeded_warning.missed) { + pr_notice("%d get_random_xx warning(s) missed due to ratelimiting\n", + unseeded_warning.missed); + unseeded_warning.missed = 0; + } + if (urandom_warning.missed) { + pr_notice("%d urandom warning(s) missed due to ratelimiting\n", + urandom_warning.missed); + urandom_warning.missed = 0; + } +} + static void do_numa_crng_init(struct work_struct *work) { int i; struct crng_state *crng; struct crng_state **pool; - pool = kcalloc(nr_node_ids, sizeof(*pool), GFP_KERNEL|__GFP_NOFAIL); + pool = kcalloc(nr_node_ids, sizeof(*pool), GFP_KERNEL | __GFP_NOFAIL); for_each_online_node(i) { crng = kmalloc_node(sizeof(struct crng_state), GFP_KERNEL | __GFP_NOFAIL, i); @@ -843,8 +844,8 @@ static void do_numa_crng_init(struct work_struct *work) crng_initialize_secondary(crng); pool[i] = crng; } - mb(); - if (cmpxchg(&crng_node_pool, NULL, pool)) { + /* pairs with READ_ONCE() in select_crng() */ + if (cmpxchg_release(&crng_node_pool, NULL, pool) != NULL) { for_each_node(i) kfree(pool[i]); kfree(pool); @@ -855,20 +856,35 @@ static DECLARE_WORK(numa_crng_init_work, do_numa_crng_init); static void numa_crng_init(void) { - schedule_work(&numa_crng_init_work); + if (IS_ENABLED(CONFIG_NUMA)) + schedule_work(&numa_crng_init_work); +} + +static struct crng_state *select_crng(void) +{ + if (IS_ENABLED(CONFIG_NUMA)) { + struct crng_state **pool; + int nid = numa_node_id(); + + /* pairs with cmpxchg_release() in do_numa_crng_init() */ + pool = READ_ONCE(crng_node_pool); + if (pool && pool[nid]) + return pool[nid]; + } + + return &primary_crng; } -#else -static void numa_crng_init(void) {} -#endif /* * crng_fast_load() can be called by code in the interrupt service - * path. So we can't afford to dilly-dally. + * path. So we can't afford to dilly-dally. Returns the number of + * bytes processed from cp. */ -static int crng_fast_load(const char *cp, size_t len) +static size_t crng_fast_load(const u8 *cp, size_t len) { unsigned long flags; - char *p; + u8 *p; + size_t ret = 0; if (!spin_trylock_irqsave(&primary_crng.lock, flags)) return 0; @@ -876,10 +892,10 @@ static int crng_fast_load(const char *cp, size_t len) spin_unlock_irqrestore(&primary_crng.lock, flags); return 0; } - p = (unsigned char *) &primary_crng.state[4]; + p = (u8 *)&primary_crng.state[4]; while (len > 0 && crng_init_cnt < CRNG_INIT_CNT_THRESH) { p[crng_init_cnt % CHACHA_KEY_SIZE] ^= *cp; - cp++; crng_init_cnt++; len--; + cp++; crng_init_cnt++; len--; ret++; } spin_unlock_irqrestore(&primary_crng.lock, flags); if (crng_init_cnt >= CRNG_INIT_CNT_THRESH) { @@ -887,7 +903,7 @@ static int crng_fast_load(const char *cp, size_t len) crng_init = 1; pr_notice("fast init done\n"); } - return 1; + return ret; } /* @@ -904,14 +920,14 @@ static int crng_fast_load(const char *cp, size_t len) * like a fixed DMI table (for example), which might very well be * unique to the machine, but is otherwise unvarying. */ -static int crng_slow_load(const char *cp, size_t len) +static int crng_slow_load(const u8 *cp, size_t len) { - unsigned long flags; - static unsigned char lfsr = 1; - unsigned char tmp; - unsigned i, max = CHACHA_KEY_SIZE; - const char * src_buf = cp; - char * dest_buf = (char *) &primary_crng.state[4]; + unsigned long flags; + static u8 lfsr = 1; + u8 tmp; + unsigned int i, max = CHACHA_KEY_SIZE; + const u8 *src_buf = cp; + u8 *dest_buf = (u8 *)&primary_crng.state[4]; if (!spin_trylock_irqsave(&primary_crng.lock, flags)) return 0; @@ -922,7 +938,7 @@ static int crng_slow_load(const char *cp, size_t len) if (len > max) max = len; - for (i = 0; i < max ; i++) { + for (i = 0; i < max; i++) { tmp = lfsr; lfsr >>= 1; if (tmp & 1) @@ -935,17 +951,17 @@ static int crng_slow_load(const char *cp, size_t len) return 1; } -static void crng_reseed(struct crng_state *crng, struct entropy_store *r) +static void crng_reseed(struct crng_state *crng, bool use_input_pool) { - unsigned long flags; - int i, num; + unsigned long flags; + int i, num; union { - __u8 block[CHACHA_BLOCK_SIZE]; - __u32 key[8]; + u8 block[CHACHA_BLOCK_SIZE]; + u32 key[8]; } buf; - if (r) { - num = extract_entropy(r, &buf, 32, 16, 0); + if (use_input_pool) { + num = extract_entropy(&buf, 32, 16); if (num == 0) return; } else { @@ -955,65 +971,38 @@ static void crng_reseed(struct crng_state *crng, struct entropy_store *r) } spin_lock_irqsave(&crng->lock, flags); for (i = 0; i < 8; i++) { - unsigned long rv; + unsigned long rv; if (!arch_get_random_seed_long(&rv) && !arch_get_random_long(&rv)) rv = random_get_entropy(); - crng->state[i+4] ^= buf.key[i] ^ rv; + crng->state[i + 4] ^= buf.key[i] ^ rv; } memzero_explicit(&buf, sizeof(buf)); - crng->init_time = jiffies; + WRITE_ONCE(crng->init_time, jiffies); spin_unlock_irqrestore(&crng->lock, flags); - if (crng == &primary_crng && crng_init < 2) { - invalidate_batched_entropy(); - numa_crng_init(); - crng_init = 2; - process_random_ready_list(); - wake_up_interruptible(&crng_init_wait); - kill_fasync(&fasync, SIGIO, POLL_IN); - pr_notice("crng init done\n"); - if (unseeded_warning.missed) { - pr_notice("%d get_random_xx warning(s) missed due to ratelimiting\n", - unseeded_warning.missed); - unseeded_warning.missed = 0; - } - if (urandom_warning.missed) { - pr_notice("%d urandom warning(s) missed due to ratelimiting\n", - urandom_warning.missed); - urandom_warning.missed = 0; - } - } + crng_finalize_init(crng); } -static void _extract_crng(struct crng_state *crng, - __u8 out[CHACHA_BLOCK_SIZE]) +static void _extract_crng(struct crng_state *crng, u8 out[CHACHA_BLOCK_SIZE]) { - unsigned long v, flags; + unsigned long flags, init_time; - if (crng_ready() && - (time_after(crng_global_init_time, crng->init_time) || - time_after(jiffies, crng->init_time + CRNG_RESEED_INTERVAL))) - crng_reseed(crng, crng == &primary_crng ? &input_pool : NULL); + if (crng_ready()) { + init_time = READ_ONCE(crng->init_time); + if (time_after(READ_ONCE(crng_global_init_time), init_time) || + time_after(jiffies, init_time + CRNG_RESEED_INTERVAL)) + crng_reseed(crng, crng == &primary_crng); + } spin_lock_irqsave(&crng->lock, flags); - if (arch_get_random_long(&v)) - crng->state[14] ^= v; chacha20_block(&crng->state[0], out); if (crng->state[12] == 0) crng->state[13]++; spin_unlock_irqrestore(&crng->lock, flags); } -static void extract_crng(__u8 out[CHACHA_BLOCK_SIZE]) +static void extract_crng(u8 out[CHACHA_BLOCK_SIZE]) { - struct crng_state *crng = NULL; - -#ifdef CONFIG_NUMA - if (crng_node_pool) - crng = crng_node_pool[numa_node_id()]; - if (crng == NULL) -#endif - crng = &primary_crng; - _extract_crng(crng, out); + _extract_crng(select_crng(), out); } /* @@ -1021,42 +1010,34 @@ static void extract_crng(__u8 out[CHACHA_BLOCK_SIZE]) * enough) to mutate the CRNG key to provide backtracking protection. */ static void _crng_backtrack_protect(struct crng_state *crng, - __u8 tmp[CHACHA_BLOCK_SIZE], int used) + u8 tmp[CHACHA_BLOCK_SIZE], int used) { - unsigned long flags; - __u32 *s, *d; - int i; + unsigned long flags; + u32 *s, *d; + int i; - used = round_up(used, sizeof(__u32)); + used = round_up(used, sizeof(u32)); if (used + CHACHA_KEY_SIZE > CHACHA_BLOCK_SIZE) { extract_crng(tmp); used = 0; } spin_lock_irqsave(&crng->lock, flags); - s = (__u32 *) &tmp[used]; + s = (u32 *)&tmp[used]; d = &crng->state[4]; - for (i=0; i < 8; i++) + for (i = 0; i < 8; i++) *d++ ^= *s++; spin_unlock_irqrestore(&crng->lock, flags); } -static void crng_backtrack_protect(__u8 tmp[CHACHA_BLOCK_SIZE], int used) +static void crng_backtrack_protect(u8 tmp[CHACHA_BLOCK_SIZE], int used) { - struct crng_state *crng = NULL; - -#ifdef CONFIG_NUMA - if (crng_node_pool) - crng = crng_node_pool[numa_node_id()]; - if (crng == NULL) -#endif - crng = &primary_crng; - _crng_backtrack_protect(crng, tmp, used); + _crng_backtrack_protect(select_crng(), tmp, used); } static ssize_t extract_crng_user(void __user *buf, size_t nbytes) { ssize_t ret = 0, i = CHACHA_BLOCK_SIZE; - __u8 tmp[CHACHA_BLOCK_SIZE] __aligned(4); + u8 tmp[CHACHA_BLOCK_SIZE] __aligned(4); int large_request = (nbytes > 256); while (nbytes) { @@ -1088,7 +1069,6 @@ static ssize_t extract_crng_user(void __user *buf, size_t nbytes) return ret; } - /********************************************************************* * * Entropy input management @@ -1121,8 +1101,8 @@ void add_device_randomness(const void *buf, unsigned int size) trace_add_device_randomness(size, _RET_IP_); spin_lock_irqsave(&input_pool.lock, flags); - _mix_pool_bytes(&input_pool, buf, size); - _mix_pool_bytes(&input_pool, &time, sizeof(time)); + _mix_pool_bytes(buf, size); + _mix_pool_bytes(&time, sizeof(time)); spin_unlock_irqrestore(&input_pool.lock, flags); } EXPORT_SYMBOL(add_device_randomness); @@ -1141,19 +1121,17 @@ static struct timer_rand_state input_timer_state = INIT_TIMER_RAND_STATE; */ static void add_timer_randomness(struct timer_rand_state *state, unsigned num) { - struct entropy_store *r; struct { long jiffies; - unsigned cycles; - unsigned num; + unsigned int cycles; + unsigned int num; } sample; long delta, delta2, delta3; sample.jiffies = jiffies; sample.cycles = random_get_entropy(); sample.num = num; - r = &input_pool; - mix_pool_bytes(r, &sample, sizeof(sample)); + mix_pool_bytes(&sample, sizeof(sample)); /* * Calculate number of bits of randomness we probably added. @@ -1185,11 +1163,11 @@ static void add_timer_randomness(struct timer_rand_state *state, unsigned num) * Round down by 1 bit on general principles, * and limit entropy estimate to 12 bits. */ - credit_entropy_bits(r, min_t(int, fls(delta>>1), 11)); + credit_entropy_bits(min_t(int, fls(delta >> 1), 11)); } void add_input_randomness(unsigned int type, unsigned int code, - unsigned int value) + unsigned int value) { static unsigned char last_value; @@ -1200,7 +1178,7 @@ void add_input_randomness(unsigned int type, unsigned int code, last_value = value; add_timer_randomness(&input_timer_state, (type << 4) ^ code ^ (code >> 4) ^ value); - trace_add_input_randomness(ENTROPY_BITS(&input_pool)); + trace_add_input_randomness(POOL_ENTROPY_BITS()); } EXPORT_SYMBOL_GPL(add_input_randomness); @@ -1209,48 +1187,47 @@ static DEFINE_PER_CPU(struct fast_pool, irq_randomness); #ifdef ADD_INTERRUPT_BENCH static unsigned long avg_cycles, avg_deviation; -#define AVG_SHIFT 8 /* Exponential average factor k=1/256 */ -#define FIXED_1_2 (1 << (AVG_SHIFT-1)) +#define AVG_SHIFT 8 /* Exponential average factor k=1/256 */ +#define FIXED_1_2 (1 << (AVG_SHIFT - 1)) static void add_interrupt_bench(cycles_t start) { - long delta = random_get_entropy() - start; - - /* Use a weighted moving average */ - delta = delta - ((avg_cycles + FIXED_1_2) >> AVG_SHIFT); - avg_cycles += delta; - /* And average deviation */ - delta = abs(delta) - ((avg_deviation + FIXED_1_2) >> AVG_SHIFT); - avg_deviation += delta; + long delta = random_get_entropy() - start; + + /* Use a weighted moving average */ + delta = delta - ((avg_cycles + FIXED_1_2) >> AVG_SHIFT); + avg_cycles += delta; + /* And average deviation */ + delta = abs(delta) - ((avg_deviation + FIXED_1_2) >> AVG_SHIFT); + avg_deviation += delta; } #else #define add_interrupt_bench(x) #endif -static __u32 get_reg(struct fast_pool *f, struct pt_regs *regs) +static u32 get_reg(struct fast_pool *f, struct pt_regs *regs) { - __u32 *ptr = (__u32 *) regs; + u32 *ptr = (u32 *)regs; unsigned int idx; if (regs == NULL) return 0; idx = READ_ONCE(f->reg_idx); - if (idx >= sizeof(struct pt_regs) / sizeof(__u32)) + if (idx >= sizeof(struct pt_regs) / sizeof(u32)) idx = 0; ptr += idx++; WRITE_ONCE(f->reg_idx, idx); return *ptr; } -void add_interrupt_randomness(int irq, int irq_flags) +void add_interrupt_randomness(int irq) { - struct entropy_store *r; - struct fast_pool *fast_pool = this_cpu_ptr(&irq_randomness); - struct pt_regs *regs = get_irq_regs(); - unsigned long now = jiffies; - cycles_t cycles = random_get_entropy(); - __u32 c_high, j_high; - __u64 ip; + struct fast_pool *fast_pool = this_cpu_ptr(&irq_randomness); + struct pt_regs *regs = get_irq_regs(); + unsigned long now = jiffies; + cycles_t cycles = random_get_entropy(); + u32 c_high, j_high; + u64 ip; if (cycles == 0) cycles = get_reg(fast_pool, regs); @@ -1260,38 +1237,35 @@ void add_interrupt_randomness(int irq, int irq_flags) fast_pool->pool[1] ^= now ^ c_high; ip = regs ? instruction_pointer(regs) : _RET_IP_; fast_pool->pool[2] ^= ip; - fast_pool->pool[3] ^= (sizeof(ip) > 4) ? ip >> 32 : - get_reg(fast_pool, regs); + fast_pool->pool[3] ^= + (sizeof(ip) > 4) ? ip >> 32 : get_reg(fast_pool, regs); fast_mix(fast_pool); add_interrupt_bench(cycles); if (unlikely(crng_init == 0)) { if ((fast_pool->count >= 64) && - crng_fast_load((char *) fast_pool->pool, - sizeof(fast_pool->pool))) { + crng_fast_load((u8 *)fast_pool->pool, sizeof(fast_pool->pool)) > 0) { fast_pool->count = 0; fast_pool->last = now; } return; } - if ((fast_pool->count < 64) && - !time_after(now, fast_pool->last + HZ)) + if ((fast_pool->count < 64) && !time_after(now, fast_pool->last + HZ)) return; - r = &input_pool; - if (!spin_trylock(&r->lock)) + if (!spin_trylock(&input_pool.lock)) return; fast_pool->last = now; - __mix_pool_bytes(r, &fast_pool->pool, sizeof(fast_pool->pool)); - spin_unlock(&r->lock); + __mix_pool_bytes(&fast_pool->pool, sizeof(fast_pool->pool)); + spin_unlock(&input_pool.lock); fast_pool->count = 0; /* award one bit for the contents of the fast pool */ - credit_entropy_bits(r, 1); + credit_entropy_bits(1); } EXPORT_SYMBOL_GPL(add_interrupt_randomness); @@ -1302,7 +1276,7 @@ void add_disk_randomness(struct gendisk *disk) return; /* first major is 1, so we get >= 0x200 here */ add_timer_randomness(disk->random, 0x100 + disk_devt(disk)); - trace_add_disk_randomness(disk_devt(disk), ENTROPY_BITS(&input_pool)); + trace_add_disk_randomness(disk_devt(disk), POOL_ENTROPY_BITS()); } EXPORT_SYMBOL_GPL(add_disk_randomness); #endif @@ -1317,43 +1291,36 @@ EXPORT_SYMBOL_GPL(add_disk_randomness); * 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) +static size_t account(size_t nbytes, int min) { - int entropy_count, orig, have_bytes; + int entropy_count, orig; size_t ibytes, nfrac; - BUG_ON(r->entropy_count > r->poolinfo->poolfracbits); + BUG_ON(input_pool.entropy_count > POOL_FRACBITS); /* Can we pull enough? */ retry: - entropy_count = orig = READ_ONCE(r->entropy_count); - ibytes = nbytes; - /* never pull more than available */ - have_bytes = entropy_count >> (ENTROPY_SHIFT + 3); - - if ((have_bytes -= reserved) < 0) - have_bytes = 0; - ibytes = min_t(size_t, ibytes, have_bytes); - if (ibytes < min) - ibytes = 0; - + entropy_count = orig = READ_ONCE(input_pool.entropy_count); if (WARN_ON(entropy_count < 0)) { - pr_warn("negative entropy count: pool %s count %d\n", - r->name, entropy_count); + pr_warn("negative entropy count: count %d\n", entropy_count); entropy_count = 0; } - nfrac = ibytes << (ENTROPY_SHIFT + 3); - if ((size_t) entropy_count > nfrac) + + /* never pull more than available */ + ibytes = min_t(size_t, nbytes, entropy_count >> (POOL_ENTROPY_SHIFT + 3)); + if (ibytes < min) + ibytes = 0; + nfrac = ibytes << (POOL_ENTROPY_SHIFT + 3); + if ((size_t)entropy_count > nfrac) entropy_count -= nfrac; else entropy_count = 0; - if (cmpxchg(&r->entropy_count, orig, entropy_count) != orig) + if (cmpxchg(&input_pool.entropy_count, orig, entropy_count) != orig) goto retry; - trace_debit_entropy(r->name, 8 * ibytes); - if (ibytes && ENTROPY_BITS(r) < random_write_wakeup_bits) { + trace_debit_entropy(8 * ibytes); + if (ibytes && POOL_ENTROPY_BITS() < random_write_wakeup_bits) { wake_up_interruptible(&random_write_wait); kill_fasync(&fasync, SIGIO, POLL_OUT); } @@ -1366,77 +1333,59 @@ retry: * * Note: we assume that .poolwords is a multiple of 16 words. */ -static void extract_buf(struct entropy_store *r, __u8 *out) +static void extract_buf(u8 *out) { - int i; - union { - __u32 w[5]; - unsigned long l[LONGS(20)]; - } hash; - __u32 workspace[SHA1_WORKSPACE_WORDS]; + struct blake2s_state state __aligned(__alignof__(unsigned long)); + u8 hash[BLAKE2S_HASH_SIZE]; + unsigned long *salt; unsigned long flags; + blake2s_init(&state, sizeof(hash)); + /* * If we have an architectural hardware random number - * generator, use it for SHA's initial vector + * generator, use it for BLAKE2's salt & personal fields. */ - sha1_init(hash.w); - for (i = 0; i < LONGS(20); i++) { + for (salt = (unsigned long *)&state.h[4]; + salt < (unsigned long *)&state.h[8]; ++salt) { unsigned long v; if (!arch_get_random_long(&v)) break; - hash.l[i] = v; + *salt ^= 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) - sha1_transform(hash.w, (__u8 *)(r->pool + i), workspace); + /* Generate a hash across the pool */ + spin_lock_irqsave(&input_pool.lock, flags); + blake2s_update(&state, (const u8 *)input_pool_data, POOL_BYTES); + blake2s_final(&state, hash); /* final zeros out state */ /* * We mix the hash back into the pool to prevent backtracking * attacks (where the attacker knows the state of the pool * plus the current outputs, and attempts to find previous - * ouputs), unless the hash function can be inverted. By - * mixing at least a SHA1 worth of hash data back, we make + * outputs), unless the hash function can be inverted. By + * mixing at least a hash worth of hash data back, we make * brute-forcing the feedback as hard as brute-forcing the * hash. */ - __mix_pool_bytes(r, hash.w, sizeof(hash.w)); - spin_unlock_irqrestore(&r->lock, flags); - - memzero_explicit(workspace, sizeof(workspace)); + __mix_pool_bytes(hash, sizeof(hash)); + spin_unlock_irqrestore(&input_pool.lock, flags); - /* - * In case the hash function has some recognizable output - * pattern, we fold it in half. Thus, we always feed back - * twice as much data as we output. + /* Note that EXTRACT_SIZE is half of hash size here, because above + * we've dumped the full length back into mixer. By reducing the + * amount that we emit, we retain a level of forward secrecy. */ - hash.w[0] ^= hash.w[3]; - hash.w[1] ^= hash.w[4]; - hash.w[2] ^= rol32(hash.w[2], 16); - - memcpy(out, &hash, EXTRACT_SIZE); - memzero_explicit(&hash, sizeof(hash)); + memcpy(out, hash, EXTRACT_SIZE); + memzero_explicit(hash, sizeof(hash)); } -static ssize_t _extract_entropy(struct entropy_store *r, void *buf, - size_t nbytes, int fips) +static ssize_t _extract_entropy(void *buf, size_t nbytes) { ssize_t ret = 0, i; - __u8 tmp[EXTRACT_SIZE]; - unsigned long flags; + u8 tmp[EXTRACT_SIZE]; while (nbytes) { - extract_buf(r, tmp); - - if (fips) { - spin_lock_irqsave(&r->lock, flags); - if (!memcmp(tmp, r->last_data, EXTRACT_SIZE)) - panic("Hardware RNG duplicated output!\n"); - memcpy(r->last_data, tmp, EXTRACT_SIZE); - spin_unlock_irqrestore(&r->lock, flags); - } + extract_buf(tmp); i = min_t(int, nbytes, EXTRACT_SIZE); memcpy(buf, tmp, i); nbytes -= i; @@ -1455,42 +1404,19 @@ static ssize_t _extract_entropy(struct entropy_store *r, void *buf, * 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. + * failing to avoid races that defeat catastrophic reseeding. */ -static ssize_t extract_entropy(struct entropy_store *r, void *buf, - size_t nbytes, int min, int reserved) +static ssize_t extract_entropy(void *buf, size_t nbytes, int min) { - __u8 tmp[EXTRACT_SIZE]; - unsigned long flags; - - /* if last_data isn't primed, we need EXTRACT_SIZE extra bytes */ - if (fips_enabled) { - spin_lock_irqsave(&r->lock, flags); - if (!r->last_data_init) { - r->last_data_init = 1; - spin_unlock_irqrestore(&r->lock, flags); - trace_extract_entropy(r->name, EXTRACT_SIZE, - ENTROPY_BITS(r), _RET_IP_); - extract_buf(r, tmp); - spin_lock_irqsave(&r->lock, flags); - memcpy(r->last_data, tmp, EXTRACT_SIZE); - } - spin_unlock_irqrestore(&r->lock, flags); - } - - trace_extract_entropy(r->name, nbytes, ENTROPY_BITS(r), _RET_IP_); - nbytes = account(r, nbytes, min, reserved); - - return _extract_entropy(r, buf, nbytes, fips_enabled); + trace_extract_entropy(nbytes, POOL_ENTROPY_BITS(), _RET_IP_); + nbytes = account(nbytes, min); + return _extract_entropy(buf, nbytes); } #define warn_unseeded_randomness(previous) \ - _warn_unseeded_randomness(__func__, (void *) _RET_IP_, (previous)) + _warn_unseeded_randomness(__func__, (void *)_RET_IP_, (previous)) -static void _warn_unseeded_randomness(const char *func_name, void *caller, - void **previous) +static void _warn_unseeded_randomness(const char *func_name, void *caller, void **previous) { #ifdef CONFIG_WARN_ALL_UNSEEDED_RANDOM const bool print_once = false; @@ -1498,8 +1424,7 @@ static void _warn_unseeded_randomness(const char *func_name, void *caller, static bool print_once __read_mostly; #endif - if (print_once || - crng_ready() || + if (print_once || crng_ready() || (previous && (caller == READ_ONCE(*previous)))) return; WRITE_ONCE(*previous, caller); @@ -1507,9 +1432,8 @@ static void _warn_unseeded_randomness(const char *func_name, void *caller, print_once = true; #endif if (__ratelimit(&unseeded_warning)) - printk_deferred(KERN_NOTICE "random: %s called from %pS " - "with crng_init=%d\n", func_name, caller, - crng_init); + printk_deferred(KERN_NOTICE "random: %s called from %pS with crng_init=%d\n", + func_name, caller, crng_init); } /* @@ -1524,7 +1448,7 @@ static void _warn_unseeded_randomness(const char *func_name, void *caller, */ static void _get_random_bytes(void *buf, int nbytes) { - __u8 tmp[CHACHA_BLOCK_SIZE] __aligned(4); + u8 tmp[CHACHA_BLOCK_SIZE] __aligned(4); trace_get_random_bytes(nbytes, _RET_IP_); @@ -1552,7 +1476,6 @@ void get_random_bytes(void *buf, int nbytes) } EXPORT_SYMBOL(get_random_bytes); - /* * Each time the timer fires, we expect that we got an unpredictable * jump in the cycle counter. Even if the timer is running on another @@ -1568,7 +1491,7 @@ EXPORT_SYMBOL(get_random_bytes); */ static void entropy_timer(struct timer_list *t) { - credit_entropy_bits(&input_pool, 1); + credit_entropy_bits(1); } /* @@ -1591,15 +1514,15 @@ static void try_to_generate_entropy(void) timer_setup_on_stack(&stack.timer, entropy_timer, 0); while (!crng_ready()) { if (!timer_pending(&stack.timer)) - mod_timer(&stack.timer, jiffies+1); - mix_pool_bytes(&input_pool, &stack.now, sizeof(stack.now)); + mod_timer(&stack.timer, jiffies + 1); + mix_pool_bytes(&stack.now, sizeof(stack.now)); schedule(); stack.now = random_get_entropy(); } del_timer_sync(&stack.timer); destroy_timer_on_stack(&stack.timer); - mix_pool_bytes(&input_pool, &stack.now, sizeof(stack.now)); + mix_pool_bytes(&stack.now, sizeof(stack.now)); } /* @@ -1718,7 +1641,7 @@ EXPORT_SYMBOL(del_random_ready_callback); int __must_check get_random_bytes_arch(void *buf, int nbytes) { int left = nbytes; - char *p = buf; + u8 *p = buf; trace_get_random_bytes_arch(left, _RET_IP_); while (left) { @@ -1740,26 +1663,24 @@ EXPORT_SYMBOL(get_random_bytes_arch); /* * init_std_data - initialize pool with system data * - * @r: pool to initialize - * * This function clears the pool's entropy count and mixes some system * data into the pool to prepare it for use. The pool is not cleared * as that can only decrease the entropy in the pool. */ -static void __init init_std_data(struct entropy_store *r) +static void __init init_std_data(void) { int i; ktime_t now = ktime_get_real(); unsigned long rv; - mix_pool_bytes(r, &now, sizeof(now)); - for (i = r->poolinfo->poolbytes; i > 0; i -= sizeof(rv)) { + mix_pool_bytes(&now, sizeof(now)); + for (i = POOL_BYTES; i > 0; i -= sizeof(rv)) { if (!arch_get_random_seed_long(&rv) && !arch_get_random_long(&rv)) rv = random_get_entropy(); - mix_pool_bytes(r, &rv, sizeof(rv)); + mix_pool_bytes(&rv, sizeof(rv)); } - mix_pool_bytes(r, utsname(), sizeof(*(utsname()))); + mix_pool_bytes(utsname(), sizeof(*(utsname()))); } /* @@ -1774,7 +1695,9 @@ static void __init init_std_data(struct entropy_store *r) */ int __init rand_initialize(void) { - init_std_data(&input_pool); + init_std_data(); + if (crng_need_final_init) + crng_finalize_init(&primary_crng); crng_initialize_primary(&primary_crng); crng_global_init_time = jiffies; if (ratelimit_disable) { @@ -1801,22 +1724,20 @@ void rand_initialize_disk(struct gendisk *disk) } #endif -static ssize_t -urandom_read_nowarn(struct file *file, char __user *buf, size_t nbytes, - loff_t *ppos) +static ssize_t urandom_read_nowarn(struct file *file, char __user *buf, + size_t nbytes, loff_t *ppos) { int ret; - nbytes = min_t(size_t, nbytes, INT_MAX >> (ENTROPY_SHIFT + 3)); + nbytes = min_t(size_t, nbytes, INT_MAX >> (POOL_ENTROPY_SHIFT + 3)); ret = extract_crng_user(buf, nbytes); - trace_urandom_read(8 * nbytes, 0, ENTROPY_BITS(&input_pool)); + trace_urandom_read(8 * nbytes, 0, POOL_ENTROPY_BITS()); return ret; } -static ssize_t -urandom_read(struct file *file, char __user *buf, size_t nbytes, loff_t *ppos) +static ssize_t urandom_read(struct file *file, char __user *buf, size_t nbytes, + loff_t *ppos) { - unsigned long flags; static int maxwarn = 10; if (!crng_ready() && maxwarn > 0) { @@ -1824,16 +1745,13 @@ urandom_read(struct file *file, char __user *buf, size_t nbytes, loff_t *ppos) if (__ratelimit(&urandom_warning)) pr_notice("%s: uninitialized urandom read (%zd bytes read)\n", current->comm, nbytes); - spin_lock_irqsave(&primary_crng.lock, flags); - crng_init_cnt = 0; - spin_unlock_irqrestore(&primary_crng.lock, flags); } return urandom_read_nowarn(file, buf, nbytes, ppos); } -static ssize_t -random_read(struct file *file, char __user *buf, size_t nbytes, loff_t *ppos) +static ssize_t random_read(struct file *file, char __user *buf, size_t nbytes, + loff_t *ppos) { int ret; @@ -1843,8 +1761,7 @@ random_read(struct file *file, char __user *buf, size_t nbytes, loff_t *ppos) return urandom_read_nowarn(file, buf, nbytes, ppos); } -static __poll_t -random_poll(struct file *file, poll_table * wait) +static __poll_t random_poll(struct file *file, poll_table *wait) { __poll_t mask; @@ -1853,16 +1770,15 @@ random_poll(struct file *file, poll_table * wait) mask = 0; if (crng_ready()) mask |= EPOLLIN | EPOLLRDNORM; - if (ENTROPY_BITS(&input_pool) < random_write_wakeup_bits) + if (POOL_ENTROPY_BITS() < random_write_wakeup_bits) mask |= EPOLLOUT | EPOLLWRNORM; return mask; } -static int -write_pool(struct entropy_store *r, const char __user *buffer, size_t count) +static int write_pool(const char __user *buffer, size_t count) { size_t bytes; - __u32 t, buf[16]; + u32 t, buf[16]; const char __user *p = buffer; while (count > 0) { @@ -1872,7 +1788,7 @@ write_pool(struct entropy_store *r, const char __user *buffer, size_t count) if (copy_from_user(&buf, p, bytes)) return -EFAULT; - for (b = bytes ; b > 0 ; b -= sizeof(__u32), i++) { + for (b = bytes; b > 0; b -= sizeof(u32), i++) { if (!arch_get_random_int(&t)) break; buf[i] ^= t; @@ -1881,7 +1797,7 @@ write_pool(struct entropy_store *r, const char __user *buffer, size_t count) count -= bytes; p += bytes; - mix_pool_bytes(r, buf, bytes); + mix_pool_bytes(buf, bytes); cond_resched(); } @@ -1893,7 +1809,7 @@ static ssize_t random_write(struct file *file, const char __user *buffer, { size_t ret; - ret = write_pool(&input_pool, buffer, count); + ret = write_pool(buffer, count); if (ret) return ret; @@ -1909,7 +1825,7 @@ static long random_ioctl(struct file *f, unsigned int cmd, unsigned long arg) switch (cmd) { case RNDGETENTCNT: /* inherently racy, no point locking */ - ent_count = ENTROPY_BITS(&input_pool); + ent_count = POOL_ENTROPY_BITS(); if (put_user(ent_count, p)) return -EFAULT; return 0; @@ -1918,7 +1834,7 @@ static long random_ioctl(struct file *f, unsigned int cmd, unsigned long arg) return -EPERM; if (get_user(ent_count, p)) return -EFAULT; - return credit_entropy_bits_safe(&input_pool, ent_count); + return credit_entropy_bits_safe(ent_count); case RNDADDENTROPY: if (!capable(CAP_SYS_ADMIN)) return -EPERM; @@ -1928,11 +1844,10 @@ static long random_ioctl(struct file *f, unsigned int cmd, unsigned long arg) return -EINVAL; if (get_user(size, p++)) return -EFAULT; - retval = write_pool(&input_pool, (const char __user *)p, - size); + retval = write_pool((const char __user *)p, size); if (retval < 0) return retval; - return credit_entropy_bits_safe(&input_pool, ent_count); + return credit_entropy_bits_safe(ent_count); case RNDZAPENTCNT: case RNDCLEARPOOL: /* @@ -1948,8 +1863,8 @@ static long random_ioctl(struct file *f, unsigned int cmd, unsigned long arg) return -EPERM; if (crng_init < 2) return -ENODATA; - crng_reseed(&primary_crng, &input_pool); - crng_global_init_time = jiffies - 1; + crng_reseed(&primary_crng, true); + WRITE_ONCE(crng_global_init_time, jiffies - 1); return 0; default: return -EINVAL; @@ -1962,9 +1877,9 @@ static int random_fasync(int fd, struct file *filp, int on) } const struct file_operations random_fops = { - .read = random_read, + .read = random_read, .write = random_write, - .poll = random_poll, + .poll = random_poll, .unlocked_ioctl = random_ioctl, .compat_ioctl = compat_ptr_ioctl, .fasync = random_fasync, @@ -1972,7 +1887,7 @@ const struct file_operations random_fops = { }; const struct file_operations urandom_fops = { - .read = urandom_read, + .read = urandom_read, .write = random_write, .unlocked_ioctl = random_ioctl, .compat_ioctl = compat_ptr_ioctl, @@ -1980,19 +1895,19 @@ const struct file_operations urandom_fops = { .llseek = noop_llseek, }; -SYSCALL_DEFINE3(getrandom, char __user *, buf, size_t, count, - unsigned int, flags) +SYSCALL_DEFINE3(getrandom, char __user *, buf, size_t, count, unsigned int, + flags) { int ret; - if (flags & ~(GRND_NONBLOCK|GRND_RANDOM|GRND_INSECURE)) + if (flags & ~(GRND_NONBLOCK | GRND_RANDOM | GRND_INSECURE)) return -EINVAL; /* * Requesting insecure and blocking randomness at the same time makes * no sense. */ - if ((flags & (GRND_INSECURE|GRND_RANDOM)) == (GRND_INSECURE|GRND_RANDOM)) + if ((flags & (GRND_INSECURE | GRND_RANDOM)) == (GRND_INSECURE | GRND_RANDOM)) return -EINVAL; if (count > INT_MAX) @@ -2019,7 +1934,7 @@ SYSCALL_DEFINE3(getrandom, char __user *, buf, size_t, count, #include <linux/sysctl.h> static int min_write_thresh; -static int max_write_thresh = INPUT_POOL_WORDS * 32; +static int max_write_thresh = POOL_BITS; static int random_min_urandom_seed = 60; static char sysctl_bootid[16]; @@ -2032,8 +1947,8 @@ static char sysctl_bootid[16]; * 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 *buffer, size_t *lenp, loff_t *ppos) +static int proc_do_uuid(struct ctl_table *table, int write, void *buffer, + size_t *lenp, loff_t *ppos) { struct ctl_table fake_table; unsigned char buf[64], tmp_uuid[16], *uuid; @@ -2062,13 +1977,13 @@ static int proc_do_uuid(struct ctl_table *table, int write, /* * Return entropy available scaled to integral bits */ -static int proc_do_entropy(struct ctl_table *table, int write, - void *buffer, size_t *lenp, loff_t *ppos) +static int proc_do_entropy(struct ctl_table *table, int write, void *buffer, + size_t *lenp, loff_t *ppos) { struct ctl_table fake_table; int entropy_count; - entropy_count = *(int *)table->data >> ENTROPY_SHIFT; + entropy_count = *(int *)table->data >> POOL_ENTROPY_SHIFT; fake_table.data = &entropy_count; fake_table.maxlen = sizeof(entropy_count); @@ -2076,9 +1991,8 @@ static int proc_do_entropy(struct ctl_table *table, int write, return proc_dointvec(&fake_table, write, buffer, lenp, ppos); } -static int sysctl_poolsize = INPUT_POOL_WORDS * 32; -extern struct ctl_table random_table[]; -struct ctl_table random_table[] = { +static int sysctl_poolsize = POOL_BITS; +static struct ctl_table random_table[] = { { .procname = "poolsize", .data = &sysctl_poolsize, @@ -2140,7 +2054,18 @@ struct ctl_table random_table[] = { #endif { } }; -#endif /* CONFIG_SYSCTL */ + +/* + * rand_initialize() is called before sysctl_init(), + * so we cannot call register_sysctl_init() in rand_initialize() + */ +static int __init random_sysctls_init(void) +{ + register_sysctl_init("kernel/random", random_table); + return 0; +} +device_initcall(random_sysctls_init); +#endif /* CONFIG_SYSCTL */ struct batched_entropy { union { @@ -2160,7 +2085,7 @@ struct batched_entropy { * point prior. */ static DEFINE_PER_CPU(struct batched_entropy, batched_entropy_u64) = { - .batch_lock = __SPIN_LOCK_UNLOCKED(batched_entropy_u64.lock), + .batch_lock = __SPIN_LOCK_UNLOCKED(batched_entropy_u64.lock), }; u64 get_random_u64(void) @@ -2185,7 +2110,7 @@ u64 get_random_u64(void) EXPORT_SYMBOL(get_random_u64); static DEFINE_PER_CPU(struct batched_entropy, batched_entropy_u32) = { - .batch_lock = __SPIN_LOCK_UNLOCKED(batched_entropy_u32.lock), + .batch_lock = __SPIN_LOCK_UNLOCKED(batched_entropy_u32.lock), }; u32 get_random_u32(void) { @@ -2217,7 +2142,7 @@ static void invalidate_batched_entropy(void) int cpu; unsigned long flags; - for_each_possible_cpu (cpu) { + for_each_possible_cpu(cpu) { struct batched_entropy *batched_entropy; batched_entropy = per_cpu_ptr(&batched_entropy_u32, cpu); @@ -2246,8 +2171,7 @@ static void invalidate_batched_entropy(void) * Return: A page aligned address within [start, start + range). On error, * @start is returned. */ -unsigned long -randomize_page(unsigned long start, unsigned long range) +unsigned long randomize_page(unsigned long start, unsigned long range) { if (!PAGE_ALIGNED(start)) { range -= PAGE_ALIGN(start) - start; @@ -2272,21 +2196,24 @@ randomize_page(unsigned long start, unsigned long range) void add_hwgenerator_randomness(const char *buffer, size_t count, size_t entropy) { - struct entropy_store *poolp = &input_pool; - if (unlikely(crng_init == 0)) { - crng_fast_load(buffer, count); - return; + size_t ret = crng_fast_load(buffer, count); + mix_pool_bytes(buffer, ret); + count -= ret; + buffer += ret; + if (!count || crng_init == 0) + return; } /* Suspend writing if we're above the trickle threshold. * We'll be woken up again once below random_write_wakeup_thresh, * or when the calling thread is about to terminate. */ - wait_event_interruptible(random_write_wait, kthread_should_stop() || - ENTROPY_BITS(&input_pool) <= random_write_wakeup_bits); - mix_pool_bytes(poolp, buffer, count); - credit_entropy_bits(poolp, entropy); + wait_event_interruptible(random_write_wait, + !system_wq || kthread_should_stop() || + POOL_ENTROPY_BITS() <= random_write_wakeup_bits); + mix_pool_bytes(buffer, count); + credit_entropy_bits(entropy); } EXPORT_SYMBOL_GPL(add_hwgenerator_randomness); |