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author | H. Peter Anvin <hpa@zytor.com> | 2011-07-31 20:54:50 (GMT) |
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committer | H. Peter Anvin <hpa@zytor.com> | 2011-07-31 20:54:50 (GMT) |
commit | 63d77173266c1791f1553e9e8ccea65dc87c4485 (patch) | |
tree | 81c69a2f30a9bd8302d690000215b474886d0152 | |
parent | 02f8c6aee8df3cdc935e9bdd4f2d020306035dbe (diff) | |
download | linux-fsl-qoriq-63d77173266c1791f1553e9e8ccea65dc87c4485.tar.xz |
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@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>
-rw-r--r-- | drivers/char/random.c | 25 | ||||
-rw-r--r-- | 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 */ |