diff options
author | David S. Miller <davem@davemloft.net> | 2017-06-15 11:31:37 -0400 |
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committer | David S. Miller <davem@davemloft.net> | 2017-06-15 11:59:32 -0400 |
commit | 0ddead90b223faae475f3296a50bf574b7f7c69a (patch) | |
tree | e729c7fcdc7e3697f7fae2f3028ed0d11931c425 /drivers/char | |
parent | f7aec129a356ad049edddcb7e77b04a474fcf41f (diff) | |
parent | a090bd4ff8387c409732a8e059fbf264ea0bdd56 (diff) | |
download | linux-0ddead90b223faae475f3296a50bf574b7f7c69a.tar.bz2 |
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
The conflicts were two cases of overlapping changes in
batman-adv and the qed driver.
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/char')
-rw-r--r-- | drivers/char/mem.c | 2 | ||||
-rw-r--r-- | drivers/char/random.c | 49 |
2 files changed, 44 insertions, 7 deletions
diff --git a/drivers/char/mem.c b/drivers/char/mem.c index 6e0cbe092220..593a8818aca9 100644 --- a/drivers/char/mem.c +++ b/drivers/char/mem.c @@ -343,7 +343,7 @@ static int mmap_mem(struct file *file, struct vm_area_struct *vma) phys_addr_t offset = (phys_addr_t)vma->vm_pgoff << PAGE_SHIFT; /* It's illegal to wrap around the end of the physical address space. */ - if (offset + (phys_addr_t)size < offset) + if (offset + (phys_addr_t)size - 1 < offset) return -EINVAL; if (!valid_mmap_phys_addr_range(vma->vm_pgoff, size)) diff --git a/drivers/char/random.c b/drivers/char/random.c index a561f0c2f428..e870f329db88 100644 --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -1,6 +1,9 @@ /* * random.c -- A strong random number generator * + * Copyright (C) 2017 Jason A. Donenfeld <Jason@zx2c4.com>. All + * Rights Reserved. + * * Copyright Matt Mackall <mpm@selenic.com>, 2003, 2004, 2005 * * Copyright Theodore Ts'o, 1994, 1995, 1996, 1997, 1998, 1999. All @@ -762,6 +765,8 @@ static DECLARE_WAIT_QUEUE_HEAD(crng_init_wait); static struct crng_state **crng_node_pool __read_mostly; #endif +static void invalidate_batched_entropy(void); + static void crng_initialize(struct crng_state *crng) { int i; @@ -799,6 +804,7 @@ static int crng_fast_load(const char *cp, size_t len) cp++; crng_init_cnt++; len--; } if (crng_init_cnt >= CRNG_INIT_CNT_THRESH) { + invalidate_batched_entropy(); crng_init = 1; wake_up_interruptible(&crng_init_wait); pr_notice("random: fast init done\n"); @@ -836,6 +842,7 @@ static void crng_reseed(struct crng_state *crng, struct entropy_store *r) memzero_explicit(&buf, sizeof(buf)); crng->init_time = jiffies; if (crng == &primary_crng && crng_init < 2) { + invalidate_batched_entropy(); crng_init = 2; process_random_ready_list(); wake_up_interruptible(&crng_init_wait); @@ -1097,15 +1104,15 @@ static void add_interrupt_bench(cycles_t start) static __u32 get_reg(struct fast_pool *f, struct pt_regs *regs) { __u32 *ptr = (__u32 *) regs; - unsigned long flags; + unsigned int idx; if (regs == NULL) return 0; - local_irq_save(flags); - if (f->reg_idx >= sizeof(struct pt_regs) / sizeof(__u32)) - f->reg_idx = 0; - ptr += f->reg_idx++; - local_irq_restore(flags); + idx = READ_ONCE(f->reg_idx); + if (idx >= sizeof(struct pt_regs) / sizeof(__u32)) + idx = 0; + ptr += idx++; + WRITE_ONCE(f->reg_idx, idx); return *ptr; } @@ -2023,6 +2030,7 @@ struct batched_entropy { }; unsigned int position; }; +static rwlock_t batched_entropy_reset_lock = __RW_LOCK_UNLOCKED(batched_entropy_reset_lock); /* * Get a random word for internal kernel use only. The quality of the random @@ -2033,6 +2041,8 @@ static DEFINE_PER_CPU(struct batched_entropy, batched_entropy_u64); u64 get_random_u64(void) { u64 ret; + bool use_lock = crng_init < 2; + unsigned long flags; struct batched_entropy *batch; #if BITS_PER_LONG == 64 @@ -2045,11 +2055,15 @@ u64 get_random_u64(void) #endif batch = &get_cpu_var(batched_entropy_u64); + if (use_lock) + read_lock_irqsave(&batched_entropy_reset_lock, flags); if (batch->position % ARRAY_SIZE(batch->entropy_u64) == 0) { extract_crng((u8 *)batch->entropy_u64); batch->position = 0; } ret = batch->entropy_u64[batch->position++]; + if (use_lock) + read_unlock_irqrestore(&batched_entropy_reset_lock, flags); put_cpu_var(batched_entropy_u64); return ret; } @@ -2059,22 +2073,45 @@ static DEFINE_PER_CPU(struct batched_entropy, batched_entropy_u32); u32 get_random_u32(void) { u32 ret; + bool use_lock = crng_init < 2; + unsigned long flags; struct batched_entropy *batch; if (arch_get_random_int(&ret)) return ret; batch = &get_cpu_var(batched_entropy_u32); + if (use_lock) + read_lock_irqsave(&batched_entropy_reset_lock, flags); if (batch->position % ARRAY_SIZE(batch->entropy_u32) == 0) { extract_crng((u8 *)batch->entropy_u32); batch->position = 0; } ret = batch->entropy_u32[batch->position++]; + if (use_lock) + read_unlock_irqrestore(&batched_entropy_reset_lock, flags); put_cpu_var(batched_entropy_u32); return ret; } EXPORT_SYMBOL(get_random_u32); +/* It's important to invalidate all potential batched entropy that might + * be stored before the crng is initialized, which we can do lazily by + * simply resetting the counter to zero so that it's re-extracted on the + * next usage. */ +static void invalidate_batched_entropy(void) +{ + int cpu; + unsigned long flags; + + write_lock_irqsave(&batched_entropy_reset_lock, flags); + for_each_possible_cpu (cpu) { + per_cpu_ptr(&batched_entropy_u32, cpu)->position = 0; + per_cpu_ptr(&batched_entropy_u64, cpu)->position = 0; + } + write_unlock_irqrestore(&batched_entropy_reset_lock, flags); +} + /** * randomize_page - Generate a random, page aligned address * @start: The smallest acceptable address the caller will take. |