From 6133313b3bcbd0473feac85c8a8d7ef704ff2279 Mon Sep 17 00:00:00 2001 From: "H. Peter Anvin" Date: Sun, 31 Jul 2011 13:54:50 -0700 Subject: [PATCH] random: Add support for architectural random hooks commit 63d77173266c1791f1553e9e8ccea65dc87c4485 upstream. 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 Cc: Fenghua Yu Cc: Matt Mackall Cc: Herbert Xu Cc: "Theodore Ts'o" Signed-off-by: Greg Kroah-Hartman --- drivers/char/random.c | 23 +++++++++++++++++++++-- include/linux/random.h | 13 +++++++++++++ 2 files changed, 34 insertions(+), 2 deletions(-) diff --git a/drivers/char/random.c b/drivers/char/random.c index c35a785005b0..154eeda26db5 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); @@ -1318,9 +1332,14 @@ late_initcall(random_int_secret_init); DEFINE_PER_CPU(__u32 [MD5_DIGEST_WORDS], get_random_int_hash); unsigned int get_random_int(void) { - __u32 *hash = get_cpu_var(get_random_int_hash); + __u32 *hash; unsigned int ret; + if (arch_get_random_int(&ret)) + return ret; + + hash = get_cpu_var(get_random_int_hash); + hash[0] += current->pid + jiffies + get_cycles(); md5_transform(hash, random_int_secret); ret = hash[0]; diff --git a/include/linux/random.h b/include/linux/random.h index d13059f3ea32..8f74538c96db 100644 --- a/include/linux/random.h +++ b/include/linux/random.h @@ -91,6 +91,19 @@ static inline void prandom32_seed(struct rnd_state *state, u64 seed) state->s3 = __seed(i, 15); } +#ifdef CONFIG_ARCH_RANDOM +# include +#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 */ -- 2.34.1