diff options
author | H. Peter Anvin <hpa@zytor.com> | 2011-07-31 13:54:50 -0700 |
---|---|---|
committer | Willy Tarreau <w@1wt.eu> | 2012-10-07 23:41:11 +0200 |
commit | 3ddb94a16e0a9ae80a138f0cc4977f8093357e6e (patch) | |
tree | 6a4ecf006d88d7a6356e3284314da77d68806bc3 /drivers | |
parent | 165359736411775606024738396bb2797872360b (diff) |
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 <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>
[PG: .34 already had "unsigned int ret" in get_random_int, so the
diffstat here is slightly smaller than that of 63d7717. ]
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/char/random.c | 23 |
1 files changed, 21 insertions, 2 deletions
diff --git a/drivers/char/random.c b/drivers/char/random.c index 0adb8c87a30d..93b3c29d15b5 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); @@ -1360,9 +1374,14 @@ 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]; |