From 2a7f87ed05b9035ef818d0f46fe6aef5640224e3 Mon Sep 17 00:00:00 2001 From: John Ogness Date: Mon, 14 Sep 2020 14:39:49 +0206 Subject: 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: John Ogness Reviewed-by: Petr Mladek Signed-off-by: Petr Mladek Link: https://lore.kernel.org/r/20200914123354.832-2-john.ogness@linutronix.de --- kernel/printk/printk_ringbuffer.c | 116 +++++++++++++++++++------------------- 1 file changed, 58 insertions(+), 58 deletions(-) (limited to 'kernel/printk') diff --git a/kernel/printk/printk_ringbuffer.c b/kernel/printk/printk_ringbuffer.c index 11b860ad5264..664552cb931c 100644 --- a/kernel/printk/printk_ringbuffer.c +++ b/kernel/printk/printk_ringbuffer.c @@ -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 -- cgit v1.2.3