Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
Merge tag 'tty-4.11-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty
Pull tty/serial driver fixes from Greg KH:
"Here are some tty and serial driver fixes for 4.11-rc4.
One of these fix a long-standing issue in the ldisc code that was
found by Dmitry Vyukov with his great fuzzing work. The other fixes
resolve other reported issues, and there is one revert of a patch in
4.11-rc1 that wasn't correct.
All of these have been in linux-next for a while with no reported
issues"
* tag 'tty-4.11-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
tty: fix data race in tty_ldisc_ref_wait()
tty: don't panic on OOM in tty_set_ldisc()
Revert "tty: serial: pl011: add ttyAMA for matching pl011 console"
tty: acpi/spcr: QDF2400 E44 checks for wrong OEM revision
serial: 8250_dw: Fix breakage when HAVE_CLK=n
serial: 8250_dw: Honor clk_round_rate errors in dw8250_set_termios
+30
-75
+1
-1
drivers/acpi/spcr.c
+1
-1
drivers/acpi/spcr.c
+7
-2
drivers/tty/serial/8250/8250_dw.c
+7
-2
drivers/tty/serial/8250/8250_dw.c
···
257
257
{
258
258
unsigned int baud = tty_termios_baud_rate(termios);
259
259
struct dw8250_data *d = p->private_data;
260
-
unsigned int rate;
260
+
long rate;
261
261
int ret;
262
262
263
263
if (IS_ERR(d->clk) || !old)
···
265
265
266
266
clk_disable_unprepare(d->clk);
267
267
rate = clk_round_rate(d->clk, baud * 16);
268
-
ret = clk_set_rate(d->clk, rate);
268
+
if (rate < 0)
269
+
ret = rate;
270
+
else if (rate == 0)
271
+
ret = -ENOENT;
272
+
else
273
+
ret = clk_set_rate(d->clk, rate);
269
274
clk_prepare_enable(d->clk);
270
275
271
276
if (!ret)
+1
-1
drivers/tty/serial/amba-pl011.c
+1
-1
drivers/tty/serial/amba-pl011.c
···
2373
2373
if (strcmp(name, "qdf2400_e44") == 0) {
2374
2374
pr_info_once("UART: Working around QDF2400 SoC erratum 44");
2375
2375
qdf2400_e44_present = true;
2376
-
} else if (strcmp(name, "pl011") != 0 || strcmp(name, "ttyAMA") != 0) {
2376
+
} else if (strcmp(name, "pl011") != 0) {
2377
2377
return -ENODEV;
2378
2378
}
2379
2379
+21
-71
drivers/tty/tty_ldisc.c
+21
-71
drivers/tty/tty_ldisc.c
···
271
271
272
272
struct tty_ldisc *tty_ldisc_ref_wait(struct tty_struct *tty)
273
273
{
274
+
struct tty_ldisc *ld;
275
+
274
276
ldsem_down_read(&tty->ldisc_sem, MAX_SCHEDULE_TIMEOUT);
275
-
if (!tty->ldisc)
277
+
ld = tty->ldisc;
278
+
if (!ld)
276
279
ldsem_up_read(&tty->ldisc_sem);
277
-
return tty->ldisc;
280
+
return ld;
278
281
}
279
282
EXPORT_SYMBOL_GPL(tty_ldisc_ref_wait);
280
283
···
492
489
}
493
490
494
491
/**
495
-
* tty_ldisc_restore - helper for tty ldisc change
496
-
* @tty: tty to recover
497
-
* @old: previous ldisc
498
-
*
499
-
* Restore the previous line discipline or N_TTY when a line discipline
500
-
* change fails due to an open error
501
-
*/
502
-
503
-
static void tty_ldisc_restore(struct tty_struct *tty, struct tty_ldisc *old)
504
-
{
505
-
struct tty_ldisc *new_ldisc;
506
-
int r;
507
-
508
-
/* There is an outstanding reference here so this is safe */
509
-
old = tty_ldisc_get(tty, old->ops->num);
510
-
WARN_ON(IS_ERR(old));
511
-
tty->ldisc = old;
512
-
tty_set_termios_ldisc(tty, old->ops->num);
513
-
if (tty_ldisc_open(tty, old) < 0) {
514
-
tty_ldisc_put(old);
515
-
/* This driver is always present */
516
-
new_ldisc = tty_ldisc_get(tty, N_TTY);
517
-
if (IS_ERR(new_ldisc))
518
-
panic("n_tty: get");
519
-
tty->ldisc = new_ldisc;
520
-
tty_set_termios_ldisc(tty, N_TTY);
521
-
r = tty_ldisc_open(tty, new_ldisc);
522
-
if (r < 0)
523
-
panic("Couldn't open N_TTY ldisc for "
524
-
"%s --- error %d.",
525
-
tty_name(tty), r);
526
-
}
527
-
}
528
-
529
-
/**
530
492
* tty_set_ldisc - set line discipline
531
493
* @tty: the terminal to set
532
494
* @ldisc: the line discipline
···
504
536
505
537
int tty_set_ldisc(struct tty_struct *tty, int disc)
506
538
{
507
-
int retval;
508
-
struct tty_ldisc *old_ldisc, *new_ldisc;
509
-
510
-
new_ldisc = tty_ldisc_get(tty, disc);
511
-
if (IS_ERR(new_ldisc))
512
-
return PTR_ERR(new_ldisc);
539
+
int retval, old_disc;
513
540
514
541
tty_lock(tty);
515
542
retval = tty_ldisc_lock(tty, 5 * HZ);
···
517
554
}
518
555
519
556
/* Check the no-op case */
520
-
if (tty->ldisc->ops->num == disc)
557
+
old_disc = tty->ldisc->ops->num;
558
+
if (old_disc == disc)
521
559
goto out;
522
560
523
561
if (test_bit(TTY_HUPPED, &tty->flags)) {
···
527
563
goto out;
528
564
}
529
565
530
-
old_ldisc = tty->ldisc;
531
-
532
-
/* Shutdown the old discipline. */
533
-
tty_ldisc_close(tty, old_ldisc);
534
-
535
-
/* Now set up the new line discipline. */
536
-
tty->ldisc = new_ldisc;
537
-
tty_set_termios_ldisc(tty, disc);
538
-
539
-
retval = tty_ldisc_open(tty, new_ldisc);
566
+
retval = tty_ldisc_reinit(tty, disc);
540
567
if (retval < 0) {
541
568
/* Back to the old one or N_TTY if we can't */
542
-
tty_ldisc_put(new_ldisc);
543
-
tty_ldisc_restore(tty, old_ldisc);
569
+
if (tty_ldisc_reinit(tty, old_disc) < 0) {
570
+
pr_err("tty: TIOCSETD failed, reinitializing N_TTY\n");
571
+
if (tty_ldisc_reinit(tty, N_TTY) < 0) {
572
+
/* At this point we have tty->ldisc == NULL. */
573
+
pr_err("tty: reinitializing N_TTY failed\n");
574
+
}
575
+
}
544
576
}
545
577
546
-
if (tty->ldisc->ops->num != old_ldisc->ops->num && tty->ops->set_ldisc) {
578
+
if (tty->ldisc && tty->ldisc->ops->num != old_disc &&
579
+
tty->ops->set_ldisc) {
547
580
down_read(&tty->termios_rwsem);
548
581
tty->ops->set_ldisc(tty);
549
582
up_read(&tty->termios_rwsem);
550
583
}
551
584
552
-
/* At this point we hold a reference to the new ldisc and a
553
-
reference to the old ldisc, or we hold two references to
554
-
the old ldisc (if it was restored as part of error cleanup
555
-
above). In either case, releasing a single reference from
556
-
the old ldisc is correct. */
557
-
new_ldisc = old_ldisc;
558
585
out:
559
586
tty_ldisc_unlock(tty);
560
587
···
553
598
already running */
554
599
tty_buffer_restart_work(tty->port);
555
600
err:
556
-
tty_ldisc_put(new_ldisc); /* drop the extra reference */
557
601
tty_unlock(tty);
558
602
return retval;
559
603
}
···
613
659
int retval;
614
660
615
661
ld = tty_ldisc_get(tty, disc);
616
-
if (IS_ERR(ld)) {
617
-
BUG_ON(disc == N_TTY);
662
+
if (IS_ERR(ld))
618
663
return PTR_ERR(ld);
619
-
}
620
664
621
665
if (tty->ldisc) {
622
666
tty_ldisc_close(tty, tty->ldisc);
···
626
674
tty_set_termios_ldisc(tty, disc);
627
675
retval = tty_ldisc_open(tty, tty->ldisc);
628
676
if (retval) {
629
-
if (!WARN_ON(disc == N_TTY)) {
630
-
tty_ldisc_put(tty->ldisc);
631
-
tty->ldisc = NULL;
632
-
}
677
+
tty_ldisc_put(tty->ldisc);
678
+
tty->ldisc = NULL;
633
679
}
634
680
return retval;
635
681
}