diff options
Diffstat (limited to 'drivers/char')
| -rw-r--r-- | drivers/char/mem.c | 2 | ||||
| -rw-r--r-- | drivers/char/pcmcia/cm4040_cs.c | 6 | ||||
| -rw-r--r-- | drivers/char/random.c | 47 |
3 files changed, 48 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/pcmcia/cm4040_cs.c b/drivers/char/pcmcia/cm4040_cs.c index d4dbd8d8e524..382c864814d9 100644 --- a/drivers/char/pcmcia/cm4040_cs.c +++ b/drivers/char/pcmcia/cm4040_cs.c @@ -374,7 +374,7 @@ static ssize_t cm4040_write(struct file *filp, const char __user *buf, rc = write_sync_reg(SCR_HOST_TO_READER_START, dev); if (rc <= 0) { - DEBUGP(5, dev, "write_sync_reg c=%.2Zx\n", rc); + DEBUGP(5, dev, "write_sync_reg c=%.2zx\n", rc); DEBUGP(2, dev, "<- cm4040_write (failed)\n"); if (rc == -ERESTARTSYS) return rc; @@ -387,7 +387,7 @@ static ssize_t cm4040_write(struct file *filp, const char __user *buf, for (i = 0; i < bytes_to_write; i++) { rc = wait_for_bulk_out_ready(dev); if (rc <= 0) { - DEBUGP(5, dev, "wait_for_bulk_out_ready rc=%.2Zx\n", + DEBUGP(5, dev, "wait_for_bulk_out_ready rc=%.2zx\n", rc); DEBUGP(2, dev, "<- cm4040_write (failed)\n"); if (rc == -ERESTARTSYS) @@ -403,7 +403,7 @@ static ssize_t cm4040_write(struct file *filp, const char __user *buf, rc = write_sync_reg(SCR_HOST_TO_READER_DONE, dev); if (rc <= 0) { - DEBUGP(5, dev, "write_sync_reg c=%.2Zx\n", rc); + DEBUGP(5, dev, "write_sync_reg c=%.2zx\n", rc); DEBUGP(2, dev, "<- cm4040_write (failed)\n"); if (rc == -ERESTARTSYS) return rc; diff --git a/drivers/char/random.c b/drivers/char/random.c index 0ab024918907..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); @@ -1097,12 +1104,16 @@ 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 int idx; if (regs == NULL) return 0; - if (f->reg_idx >= sizeof(struct pt_regs) / sizeof(__u32)) - f->reg_idx = 0; - return *(ptr + f->reg_idx++); + 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; } void add_interrupt_randomness(int irq, int irq_flags) @@ -2019,6 +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 @@ -2029,6 +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 @@ -2041,11 +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; } @@ -2055,22 +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. |