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s390/qeth: tolerate pre-filled RX buffer

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When preparing a buffer for RX refill, tolerate that it already has a
pool_entry attached. Otherwise we could easily leak such a pool_entry
when re-driving the RX refill after an error (from eg. do_qdio()).

This needs some minor adjustment in the code that drains RX buffer(s)
prior to RX refill and during teardown, so that ->pool_entry is NULLed
accordingly.

Fixes: 4a71df5004 ("qeth: new qeth device driver")
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Julian Wiedmann 2020-07-30 17:01:18 +02:00 committed by David S. Miller
parent 9fc95f50ee
commit eff73e16ee
1 changed files with 14 additions and 6 deletions
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14
drivers/s390/net/qeth_core_main.c
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@ -204,12 +204,17 @@ EXPORT_SYMBOL_GPL(qeth_threads_running);
void qeth_clear_working_pool_list(struct qeth_card *card)
{
struct qeth_buffer_pool_entry *pool_entry, *tmp;
struct qeth_qdio_q *queue = card->qdio.in_q;
unsigned int i;
QETH_CARD_TEXT(card, 5, "clwrklst");
list_for_each_entry_safe(pool_entry, tmp,
&card->qdio.in_buf_pool.entry_list, list){
list_del(&pool_entry->list);
}
for (i = 0; i < ARRAY_SIZE(queue->bufs); i++)
queue->bufs[i].pool_entry = NULL;
}
EXPORT_SYMBOL_GPL(qeth_clear_working_pool_list);
@ -2965,7 +2970,7 @@ static struct qeth_buffer_pool_entry *qeth_find_free_buffer_pool_entry(
static int qeth_init_input_buffer(struct qeth_card *card,
struct qeth_qdio_buffer *buf)
{
struct qeth_buffer_pool_entry *pool_entry;
struct qeth_buffer_pool_entry *pool_entry = buf->pool_entry;
int i;
if ((card->options.cq == QETH_CQ_ENABLED) && (!buf->rx_skb)) {
@ -2976,18 +2981,20 @@ static int qeth_init_input_buffer(struct qeth_card *card,
return -ENOMEM;
}
if (!pool_entry) {
pool_entry = qeth_find_free_buffer_pool_entry(card);
if (!pool_entry)
return -ENOBUFS;
buf->pool_entry = pool_entry;
}
/*
* since the buffer is accessed only from the input_tasklet
* there shouldn't be a need to synchronize; also, since we use
* the QETH_IN_BUF_REQUEUE_THRESHOLD we should never run out off
* buffers
*/
buf->pool_entry = pool_entry;
for (i = 0; i < QETH_MAX_BUFFER_ELEMENTS(card); ++i) {
buf->buffer->element[i].length = PAGE_SIZE;
buf->buffer->element[i].addr =
@ -5771,6 +5778,7 @@ static unsigned int qeth_rx_poll(struct qeth_card *card, int budget)
if (done) {
QETH_CARD_STAT_INC(card, rx_bufs);
qeth_put_buffer_pool_entry(card, buffer->pool_entry);
buffer->pool_entry = NULL;
qeth_queue_input_buffer(card, card->rx.b_index);
card->rx.b_count--;