Commit-ID: 63d77173266c1791f1553e9e8ccea65dc87c4485
Gitweb: http://git.kernel.org/tip/63d77173266c1791f1553e9e8ccea65dc87c4485
Author: H. Peter Anvin <hpa@xxxxxxxxx>
AuthorDate: Sun, 31 Jul 2011 13:54:50 -0700
Committer: H. Peter Anvin <hpa@xxxxxxxxx>
CommitDate: Sun, 31 Jul 2011 13:54:50 -0700
random: Add support for architectural random hooks
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@xxxxxxxxxxxxxxx>
Cc: Fenghua Yu <fenghua.yu@xxxxxxxxx>
Cc: Matt Mackall <mpm@xxxxxxxxxxx>
Cc: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Cc: "Theodore Ts'o" <tytso@xxxxxxx>
---
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 */
--
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