lkml.org 
[lkml]   [2011]   [Jul]   [31]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v3 1/3] random: Add support for architectural random hooks
Date
From: "H. Peter Anvin" <hpa@zytor.com>

Add support for architecture-specific hooks into the kernel-directed
random number generator interfaces. This patchset does not use the
architecture random number generator interfaces for the
userspace-directed interfaces (/dev/random and /dev/urandom), thus
eliminating the need to distinguish between them based on a pool
pointer.

Changes in version 3:
- Moved the hooks from extract_entropy() to get_random_bytes().
- Changes the hooks to inlines.

Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: "Theodore Ts'o" <tytso@mit.edu>
---
drivers/char/random.c | 25 ++++++++++++++++++++++---
include/linux/random.h | 13 +++++++++++++
2 files changed, 35 insertions(+), 3 deletions(-)

diff --git a/drivers/char/random.c b/drivers/char/random.c
index d4ddeba..bb58712 100644
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -932,7 +932,21 @@ static ssize_t extract_entropy_user(struct entropy_store *r, void __user *buf,
*/
void get_random_bytes(void *buf, int nbytes)
{
- extract_entropy(&nonblocking_pool, buf, nbytes, 0, 0);
+ char *p = buf;
+
+ while (nbytes) {
+ unsigned long v;
+ int chunk = min(nbytes, (int)sizeof(unsigned long));
+
+ if (!arch_get_random_long(&v))
+ break;
+
+ memcpy(buf, &v, chunk);
+ p += chunk;
+ nbytes -= chunk;
+ }
+
+ extract_entropy(&nonblocking_pool, p, nbytes, 0, 0);
}
EXPORT_SYMBOL(get_random_bytes);

@@ -1635,8 +1649,13 @@ DEFINE_PER_CPU(__u32 [4], get_random_int_hash);
unsigned int get_random_int(void)
{
struct keydata *keyptr;
- __u32 *hash = get_cpu_var(get_random_int_hash);
- int ret;
+ __u32 *hash;
+ unsigned int ret;
+
+ if (arch_get_random_int(&ret))
+ return ret;
+
+ hash = get_cpu_var(get_random_int_hash);

keyptr = get_keyptr();
hash[0] += current->pid + jiffies + get_cycles();
diff --git a/include/linux/random.h b/include/linux/random.h
index fb7ab9d..079cbba 100644
--- a/include/linux/random.h
+++ b/include/linux/random.h
@@ -102,6 +102,19 @@ static inline void prandom32_seed(struct rnd_state *state, u64 seed)
state->s3 = __seed(i, 15);
}

+#ifdef CONFIG_ARCH_RANDOM
+# include <asm/archrandom.h>
+#else
+static inline int arch_get_random_long(unsigned long *v)
+{
+ return 0;
+}
+static inline int arch_get_random_int(unsigned int *v)
+{
+ return 0;
+}
+#endif
+
#endif /* __KERNEL___ */

#endif /* _LINUX_RANDOM_H */
--
1.7.6


\
 
 \ /
  Last update: 2011-07-31 23:31    [W:0.144 / U:2.672 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site