Commit 19fa5be1 authored by Greg Price's avatar Greg Price Committed by Theodore Ts'o
Browse files

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: default avatarGreg Price <price@mit.edu>
Signed-off-by: default avatar"Theodore Ts'o" <tytso@mit.edu>
parent 12ff3a51

drivers/char/random.c

+21 −10
Original line number Diff line number Diff line
@@ -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 @@ static size_t account(struct entropy_store *r, size_t nbytes, int min, 
	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)

{