diff options
| -rw-r--r-- | include/linux/prandom.h | 19 | ||||
| -rw-r--r-- | kernel/time/timer.c | 2 | ||||
| -rw-r--r-- | lib/random32.c | 5 | ||||
| -rw-r--r-- | net/core/dev.c | 4 |
4 files changed, 30 insertions, 0 deletions
diff --git a/include/linux/prandom.h b/include/linux/prandom.h index cc1e71334e53..bbf4b4ad61df 100644 --- a/include/linux/prandom.h +++ b/include/linux/prandom.h @@ -16,6 +16,12 @@ void prandom_bytes(void *buf, size_t nbytes); void prandom_seed(u32 seed); void prandom_reseed_late(void); +DECLARE_PER_CPU(unsigned long, net_rand_noise); + +#define PRANDOM_ADD_NOISE(a, b, c, d) \ + prandom_u32_add_noise((unsigned long)(a), (unsigned long)(b), \ + (unsigned long)(c), (unsigned long)(d)) + #if BITS_PER_LONG == 64 /* * The core SipHash round function. Each line can be executed in @@ -50,6 +56,18 @@ void prandom_reseed_late(void); #error Unsupported BITS_PER_LONG #endif +static inline void prandom_u32_add_noise(unsigned long a, unsigned long b, + unsigned long c, unsigned long d) +{ + /* + * This is not used cryptographically; it's just + * a convenient 4-word hash function. (3 xor, 2 add, 2 rol) + */ + a ^= raw_cpu_read(net_rand_noise); + PRND_SIPROUND(a, b, c, d); + raw_cpu_write(net_rand_noise, d); +} + struct rnd_state { __u32 s1, s2, s3, s4; }; @@ -99,6 +117,7 @@ static inline void prandom_seed_state(struct rnd_state *state, u64 seed) state->s2 = __seed(i, 8U); state->s3 = __seed(i, 16U); state->s4 = __seed(i, 128U); + PRANDOM_ADD_NOISE(state, i, 0, 0); } /* Pseudo random number generator from numerical recipes. */ diff --git a/kernel/time/timer.c b/kernel/time/timer.c index 3e341af741b9..de37e33a868d 100644 --- a/kernel/time/timer.c +++ b/kernel/time/timer.c @@ -1706,6 +1706,8 @@ void update_process_times(int user_tick) { struct task_struct *p = current; + PRANDOM_ADD_NOISE(jiffies, user_tick, p, 0); + /* Note: this timer irq context must be accounted for as well. */ account_process_tick(p, user_tick); run_local_timers(); diff --git a/lib/random32.c b/lib/random32.c index be9f242a4207..7f047844e494 100644 --- a/lib/random32.c +++ b/lib/random32.c @@ -337,6 +337,8 @@ struct siprand_state { }; static DEFINE_PER_CPU(struct siprand_state, net_rand_state) __latent_entropy; +DEFINE_PER_CPU(unsigned long, net_rand_noise); +EXPORT_PER_CPU_SYMBOL(net_rand_noise); /* * This is the core CPRNG function. As "pseudorandom", this is not used @@ -360,9 +362,12 @@ static DEFINE_PER_CPU(struct siprand_state, net_rand_state) __latent_entropy; static inline u32 siprand_u32(struct siprand_state *s) { unsigned long v0 = s->v0, v1 = s->v1, v2 = s->v2, v3 = s->v3; + unsigned long n = raw_cpu_read(net_rand_noise); + v3 ^= n; PRND_SIPROUND(v0, v1, v2, v3); PRND_SIPROUND(v0, v1, v2, v3); + v0 ^= n; s->v0 = v0; s->v1 = v1; s->v2 = v2; s->v3 = v3; return v1 + v3; } diff --git a/net/core/dev.c b/net/core/dev.c index 9499a414d67e..82dc6b48e45f 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -145,6 +145,7 @@ #include <linux/indirect_call_wrapper.h> #include <net/devlink.h> #include <linux/pm_runtime.h> +#include <linux/prandom.h> #include "net-sysfs.h" @@ -3558,6 +3559,7 @@ static int xmit_one(struct sk_buff *skb, struct net_device *dev, dev_queue_xmit_nit(skb, dev); len = skb->len; + PRANDOM_ADD_NOISE(skb, dev, txq, len + jiffies); trace_net_dev_start_xmit(skb, dev); rc = netdev_start_xmit(skb, dev, txq, more); trace_net_dev_xmit(skb, rc, dev, len); @@ -4130,6 +4132,7 @@ static int __dev_queue_xmit(struct sk_buff *skb, struct net_device *sb_dev) if (!skb) goto out; + PRANDOM_ADD_NOISE(skb, dev, txq, jiffies); HARD_TX_LOCK(dev, txq, cpu); if (!netif_xmit_stopped(txq)) { @@ -4195,6 +4198,7 @@ int dev_direct_xmit(struct sk_buff *skb, u16 queue_id) skb_set_queue_mapping(skb, queue_id); txq = skb_get_tx_queue(dev, skb); + PRANDOM_ADD_NOISE(skb, dev, txq, jiffies); local_bh_disable(); |