Commit 2a7f87ed authored by John Ogness's avatar John Ogness Committed by Petr Mladek
Browse files

printk: ringbuffer: relocate get_data() 



Move the internal get_data() function as-is above prb_reserve() so
that a later change can make use of the static function.

Signed-off-by: default avatarJohn Ogness <john.ogness@linutronix.de>
Reviewed-by: default avatarPetr Mladek <pmladek@suse.com>
Signed-off-by: default avatarPetr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20200914123354.832-2-john.ogness@linutronix.de
parent e7c1fe21

kernel/printk/printk_ringbuffer.c

+58 −58
Original line number Diff line number Diff line
@@ -1055,6 +1055,64 @@ static unsigned int space_used(struct prb_data_ring *data_ring, 
		DATA_SIZE(data_ring) - DATA_INDEX(data_ring, blk_lpos->begin));

}



/*

 * Given @blk_lpos, return a pointer to the writer data from the data block

 * and calculate the size of the data part. A NULL pointer is returned if

 * @blk_lpos specifies values that could never be legal.

 *

 * This function (used by readers) performs strict validation on the lpos

 * values to possibly detect bugs in the writer code. A WARN_ON_ONCE() is

 * triggered if an internal error is detected.

 */

static const char *get_data(struct prb_data_ring *data_ring,

			    struct prb_data_blk_lpos *blk_lpos,

			    unsigned int *data_size)

{

	struct prb_data_block *db;



	/* Data-less data block description. */

	if (LPOS_DATALESS(blk_lpos->begin) && LPOS_DATALESS(blk_lpos->next)) {

		if (blk_lpos->begin == NO_LPOS && blk_lpos->next == NO_LPOS) {

			*data_size = 0;

			return "";

		}

		return NULL;

	}



	/* Regular data block: @begin less than @next and in same wrap. */

	if (DATA_WRAPS(data_ring, blk_lpos->begin) == DATA_WRAPS(data_ring, blk_lpos->next) &&

	    blk_lpos->begin < blk_lpos->next) {

		db = to_block(data_ring, blk_lpos->begin);

		*data_size = blk_lpos->next - blk_lpos->begin;



	/* Wrapping data block: @begin is one wrap behind @next. */

	} else if (DATA_WRAPS(data_ring, blk_lpos->begin + DATA_SIZE(data_ring)) ==

		   DATA_WRAPS(data_ring, blk_lpos->next)) {

		db = to_block(data_ring, 0);

		*data_size = DATA_INDEX(data_ring, blk_lpos->next);



	/* Illegal block description. */

	} else {

		WARN_ON_ONCE(1);

		return NULL;

	}



	/* A valid data block will always be aligned to the ID size. */

	if (WARN_ON_ONCE(blk_lpos->begin != ALIGN(blk_lpos->begin, sizeof(db->id))) ||

	    WARN_ON_ONCE(blk_lpos->next != ALIGN(blk_lpos->next, sizeof(db->id)))) {

		return NULL;

	}



	/* A valid data block will always have at least an ID. */

	if (WARN_ON_ONCE(*data_size < sizeof(db->id)))

		return NULL;



	/* Subtract block ID space from size to reflect data size. */

	*data_size -= sizeof(db->id);



	return &db->data[0];

}



/**

 * prb_reserve() - Reserve space in the ringbuffer.

 *
@@ -1209,64 +1267,6 @@ void prb_commit(struct prb_reserved_entry *e) 
	local_irq_restore(e->irqflags);

}



/*

 * Given @blk_lpos, return a pointer to the writer data from the data block

 * and calculate the size of the data part. A NULL pointer is returned if

 * @blk_lpos specifies values that could never be legal.

 *

 * This function (used by readers) performs strict validation on the lpos

 * values to possibly detect bugs in the writer code. A WARN_ON_ONCE() is

 * triggered if an internal error is detected.

 */

static const char *get_data(struct prb_data_ring *data_ring,

			    struct prb_data_blk_lpos *blk_lpos,

			    unsigned int *data_size)

{

	struct prb_data_block *db;



	/* Data-less data block description. */

	if (LPOS_DATALESS(blk_lpos->begin) && LPOS_DATALESS(blk_lpos->next)) {

		if (blk_lpos->begin == NO_LPOS && blk_lpos->next == NO_LPOS) {

			*data_size = 0;

			return "";

		}

		return NULL;

	}



	/* Regular data block: @begin less than @next and in same wrap. */

	if (DATA_WRAPS(data_ring, blk_lpos->begin) == DATA_WRAPS(data_ring, blk_lpos->next) &&

	    blk_lpos->begin < blk_lpos->next) {

		db = to_block(data_ring, blk_lpos->begin);

		*data_size = blk_lpos->next - blk_lpos->begin;



	/* Wrapping data block: @begin is one wrap behind @next. */

	} else if (DATA_WRAPS(data_ring, blk_lpos->begin + DATA_SIZE(data_ring)) ==

		   DATA_WRAPS(data_ring, blk_lpos->next)) {

		db = to_block(data_ring, 0);

		*data_size = DATA_INDEX(data_ring, blk_lpos->next);



	/* Illegal block description. */

	} else {

		WARN_ON_ONCE(1);

		return NULL;

	}



	/* A valid data block will always be aligned to the ID size. */

	if (WARN_ON_ONCE(blk_lpos->begin != ALIGN(blk_lpos->begin, sizeof(db->id))) ||

	    WARN_ON_ONCE(blk_lpos->next != ALIGN(blk_lpos->next, sizeof(db->id)))) {

		return NULL;

	}



	/* A valid data block will always have at least an ID. */

	if (WARN_ON_ONCE(*data_size < sizeof(db->id)))

		return NULL;



	/* Subtract block ID space from size to reflect data size. */

	*data_size -= sizeof(db->id);



	return &db->data[0];

}



/*

 * Count the number of lines in provided text. All text has at least 1 line

 * (even if @text_size is 0). Each '\n' processed is counted as an additional

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