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TTY: hvsi, sanitize uses of tty
- use tty, not hp->tty wherever possible - pass tty down to some functions and go to step one - do not defer tty_hangup calls -- it is as simple as schedule_work, so might be called with hp->lock held - do not defer tty buffer flips -- since the driver does not use low_latency (it cannot actually), the flip is a simple tail move plus schedule_work. It will make our life easier in the next patch. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: linuxppc-dev@lists.ozlabs.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Jiri Slaby
Greg Kroah-Hartman
parent
d73a4e790d
commit
28c0447d74
@ -237,7 +237,7 @@ static int hvsi_read(struct hvsi_struct *hp, char *buf, int count)
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}
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static void hvsi_recv_control(struct hvsi_struct *hp, uint8_t *packet,
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struct tty_struct **to_hangup, struct hvsi_struct **to_handshake)
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struct tty_struct *tty, struct hvsi_struct **to_handshake)
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{
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struct hvsi_control *header = (struct hvsi_control *)packet;
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@ -247,9 +247,8 @@ static void hvsi_recv_control(struct hvsi_struct *hp, uint8_t *packet,
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/* CD went away; no more connection */
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pr_debug("hvsi%i: CD dropped\n", hp->index);
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hp->mctrl &= TIOCM_CD;
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/* If userland hasn't done an open(2) yet, hp->tty is NULL. */
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if (hp->tty && !C_CLOCAL(hp->tty))
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*to_hangup = hp->tty;
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if (tty && !C_CLOCAL(tty))
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tty_hangup(tty);
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}
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break;
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case VSV_CLOSE_PROTOCOL:
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@ -331,7 +330,8 @@ static void hvsi_recv_query(struct hvsi_struct *hp, uint8_t *packet)
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}
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}
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static void hvsi_insert_chars(struct hvsi_struct *hp, const char *buf, int len)
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static void hvsi_insert_chars(struct hvsi_struct *hp, struct tty_struct *tty,
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const char *buf, int len)
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{
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int i;
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@ -347,7 +347,7 @@ static void hvsi_insert_chars(struct hvsi_struct *hp, const char *buf, int len)
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continue;
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}
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#endif /* CONFIG_MAGIC_SYSRQ */
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tty_insert_flip_char(hp->tty, c, 0);
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tty_insert_flip_char(tty, c, 0);
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}
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}
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@ -360,7 +360,7 @@ static void hvsi_insert_chars(struct hvsi_struct *hp, const char *buf, int len)
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* revisited.
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*/
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#define TTY_THRESHOLD_THROTTLE 128
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static struct tty_struct *hvsi_recv_data(struct hvsi_struct *hp,
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static bool hvsi_recv_data(struct hvsi_struct *hp, struct tty_struct *tty,
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const uint8_t *packet)
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{
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const struct hvsi_header *header = (const struct hvsi_header *)packet;
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@ -371,14 +371,14 @@ static struct tty_struct *hvsi_recv_data(struct hvsi_struct *hp,
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pr_debug("queueing %i chars '%.*s'\n", datalen, datalen, data);
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if (datalen == 0)
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return NULL;
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return false;
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if (overflow > 0) {
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pr_debug("%s: got >TTY_THRESHOLD_THROTTLE bytes\n", __func__);
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datalen = TTY_THRESHOLD_THROTTLE;
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}
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hvsi_insert_chars(hp, data, datalen);
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hvsi_insert_chars(hp, tty, data, datalen);
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if (overflow > 0) {
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/*
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@ -390,7 +390,7 @@ static struct tty_struct *hvsi_recv_data(struct hvsi_struct *hp,
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hp->n_throttle = overflow;
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}
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return hp->tty;
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return true;
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}
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/*
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@ -399,14 +399,13 @@ static struct tty_struct *hvsi_recv_data(struct hvsi_struct *hp,
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* machine during console handshaking (in which case tty = NULL and we ignore
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* incoming data).
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*/
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static int hvsi_load_chunk(struct hvsi_struct *hp, struct tty_struct **flip,
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struct tty_struct **hangup, struct hvsi_struct **handshake)
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static int hvsi_load_chunk(struct hvsi_struct *hp, struct tty_struct *tty,
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struct hvsi_struct **handshake)
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{
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uint8_t *packet = hp->inbuf;
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int chunklen;
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bool flip = false;
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*flip = NULL;
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*hangup = NULL;
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*handshake = NULL;
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chunklen = hvsi_read(hp, hp->inbuf_end, HVSI_MAX_READ);
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@ -440,12 +439,12 @@ static int hvsi_load_chunk(struct hvsi_struct *hp, struct tty_struct **flip,
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case VS_DATA_PACKET_HEADER:
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if (!is_open(hp))
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break;
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if (hp->tty == NULL)
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if (tty == NULL)
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break; /* no tty buffer to put data in */
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*flip = hvsi_recv_data(hp, packet);
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flip = hvsi_recv_data(hp, tty, packet);
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break;
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case VS_CONTROL_PACKET_HEADER:
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hvsi_recv_control(hp, packet, hangup, handshake);
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hvsi_recv_control(hp, packet, tty, handshake);
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break;
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case VS_QUERY_RESPONSE_PACKET_HEADER:
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hvsi_recv_response(hp, packet);
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@ -462,28 +461,26 @@ static int hvsi_load_chunk(struct hvsi_struct *hp, struct tty_struct **flip,
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packet += len_packet(packet);
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if (*hangup || *handshake) {
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pr_debug("%s: hangup or handshake\n", __func__);
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/*
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* we need to send the hangup now before receiving any more data.
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* If we get "data, hangup, data", we can't deliver the second
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* data before the hangup.
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*/
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if (*handshake) {
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pr_debug("%s: handshake\n", __func__);
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break;
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}
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}
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compact_inbuf(hp, packet);
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if (flip)
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tty_flip_buffer_push(tty);
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return 1;
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}
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static void hvsi_send_overflow(struct hvsi_struct *hp)
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static void hvsi_send_overflow(struct hvsi_struct *hp, struct tty_struct *tty)
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{
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pr_debug("%s: delivering %i bytes overflow\n", __func__,
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hp->n_throttle);
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hvsi_insert_chars(hp, hp->throttle_buf, hp->n_throttle);
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hvsi_insert_chars(hp, tty, hp->throttle_buf, hp->n_throttle);
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hp->n_throttle = 0;
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}
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@ -494,8 +491,6 @@ static void hvsi_send_overflow(struct hvsi_struct *hp)
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static irqreturn_t hvsi_interrupt(int irq, void *arg)
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{
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struct hvsi_struct *hp = (struct hvsi_struct *)arg;
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struct tty_struct *flip;
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struct tty_struct *hangup;
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struct hvsi_struct *handshake;
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unsigned long flags;
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int again = 1;
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@ -504,25 +499,9 @@ static irqreturn_t hvsi_interrupt(int irq, void *arg)
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while (again) {
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spin_lock_irqsave(&hp->lock, flags);
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again = hvsi_load_chunk(hp, &flip, &hangup, &handshake);
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again = hvsi_load_chunk(hp, hp->tty, &handshake);
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spin_unlock_irqrestore(&hp->lock, flags);
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/*
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* we have to call tty_flip_buffer_push() and tty_hangup() outside our
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* spinlock. But we also have to keep going until we've read all the
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* available data.
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*/
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if (flip) {
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/* there was data put in the tty flip buffer */
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tty_flip_buffer_push(flip);
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flip = NULL;
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}
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if (hangup) {
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tty_hangup(hangup);
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}
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if (handshake) {
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pr_debug("hvsi%i: attempting re-handshake\n", handshake->index);
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schedule_work(&handshake->handshaker);
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@ -534,15 +513,11 @@ static irqreturn_t hvsi_interrupt(int irq, void *arg)
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&& (!test_bit(TTY_THROTTLED, &hp->tty->flags))) {
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/* we weren't hung up and we weren't throttled, so we can deliver the
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* rest now */
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flip = hp->tty;
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hvsi_send_overflow(hp);
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hvsi_send_overflow(hp, hp->tty);
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tty_flip_buffer_push(hp->tty);
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}
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spin_unlock_irqrestore(&hp->lock, flags);
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if (flip) {
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tty_flip_buffer_push(flip);
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}
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return IRQ_HANDLED;
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}
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@ -966,8 +941,8 @@ static int hvsi_write(struct tty_struct *tty,
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* and hvsi_write_worker will be scheduled. subsequent hvsi_write() calls
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* will see there is no room in outbuf and return.
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*/
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while ((count > 0) && (hvsi_write_room(hp->tty) > 0)) {
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int chunksize = min(count, hvsi_write_room(hp->tty));
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while ((count > 0) && (hvsi_write_room(tty) > 0)) {
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int chunksize = min(count, hvsi_write_room(tty));
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BUG_ON(hp->n_outbuf < 0);
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memcpy(hp->outbuf + hp->n_outbuf, source, chunksize);
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@ -1014,19 +989,16 @@ static void hvsi_unthrottle(struct tty_struct *tty)
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{
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struct hvsi_struct *hp = tty->driver_data;
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unsigned long flags;
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int shouldflip = 0;
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pr_debug("%s\n", __func__);
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spin_lock_irqsave(&hp->lock, flags);
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if (hp->n_throttle) {
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hvsi_send_overflow(hp);
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shouldflip = 1;
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hvsi_send_overflow(hp, tty);
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tty_flip_buffer_push(tty);
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}
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spin_unlock_irqrestore(&hp->lock, flags);
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if (shouldflip)
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tty_flip_buffer_push(hp->tty);
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h_vio_signal(hp->vtermno, VIO_IRQ_ENABLE);
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}
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