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author | Greg Price <price@MIT.EDU> | 2013-11-29 21:50:06 +0100 |
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committer | Theodore Ts'o <tytso@mit.edu> | 2014-03-20 03:18:50 +0100 |
commit | 19fa5be1d92be3112521145bf99f77007abf6b16 (patch) | |
tree | 62683ecd9f194b7da5dcaa4147f2c3542b2e37db | |
parent | random: simplify loop in random_read (diff) | |
download | linux-19fa5be1d92be3112521145bf99f77007abf6b16.tar.xz linux-19fa5be1d92be3112521145bf99f77007abf6b16.zip |
random: fix comment on "account"
This comment didn't quite keep up as extract_entropy() was split into
four functions. Put each bit by the function it describes.
Signed-off-by: Greg Price <price@mit.edu>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
-rw-r--r-- | drivers/char/random.c | 31 |
1 files changed, 21 insertions, 10 deletions
diff --git a/drivers/char/random.c b/drivers/char/random.c index fcc2bff8f887..2c532a6b0a21 100644 --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -958,17 +958,9 @@ static void push_to_pool(struct work_struct *work) } /* - * These functions extracts randomness from the "entropy pool", and - * returns it in a buffer. - * - * The min parameter specifies the minimum amount we can pull before - * failing to avoid races that defeat catastrophic reseeding while the - * reserved parameter indicates how much entropy we must leave in the - * pool after each pull to avoid starving other readers. - * - * Note: extract_entropy() assumes that .poolwords is a multiple of 16 words. + * This function decides how many bytes to actually take from the + * given pool, and also debits the entropy count accordingly. */ - static size_t account(struct entropy_store *r, size_t nbytes, int min, int reserved) { @@ -1018,6 +1010,12 @@ retry: return ibytes; } +/* + * This function does the actual extraction for extract_entropy and + * extract_entropy_user. + * + * Note: we assume that .poolwords is a multiple of 16 words. + */ static void extract_buf(struct entropy_store *r, __u8 *out) { int i; @@ -1079,6 +1077,15 @@ static void extract_buf(struct entropy_store *r, __u8 *out) memset(&hash, 0, sizeof(hash)); } +/* + * This function extracts randomness from the "entropy pool", and + * returns it in a buffer. + * + * The min parameter specifies the minimum amount we can pull before + * failing to avoid races that defeat catastrophic reseeding while the + * reserved parameter indicates how much entropy we must leave in the + * pool after each pull to avoid starving other readers. + */ static ssize_t extract_entropy(struct entropy_store *r, void *buf, size_t nbytes, int min, int reserved) { @@ -1129,6 +1136,10 @@ static ssize_t extract_entropy(struct entropy_store *r, void *buf, return ret; } +/* + * This function extracts randomness from the "entropy pool", and + * returns it in a userspace buffer. + */ static ssize_t extract_entropy_user(struct entropy_store *r, void __user *buf, size_t nbytes) { |