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author | Linus Torvalds <torvalds@linux-foundation.org> | 2017-03-26 11:03:42 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-03-26 11:03:42 -0700 |
commit | f1638fc65ee23875cf4021e342e8a564debe33e4 (patch) | |
tree | af091401ed9d05c93a9b9545f963fcc566e6d4d9 /drivers/tty | |
parent | 53b4d5911d6adef3f543e1ad23643068c5c343ac (diff) | |
parent | a4a3e061149f09c075f108b6f1cf04d9739a6bc2 (diff) | |
download | blackbird-op-linux-f1638fc65ee23875cf4021e342e8a564debe33e4.tar.gz blackbird-op-linux-f1638fc65ee23875cf4021e342e8a564debe33e4.zip |
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
Diffstat (limited to 'drivers/tty')
-rw-r--r-- | drivers/tty/serial/8250/8250_dw.c | 9 | ||||
-rw-r--r-- | drivers/tty/serial/amba-pl011.c | 2 | ||||
-rw-r--r-- | drivers/tty/tty_ldisc.c | 92 |
3 files changed, 29 insertions, 74 deletions
diff --git a/drivers/tty/serial/8250/8250_dw.c b/drivers/tty/serial/8250/8250_dw.c index 6ee55a2d47bb..e65808c482f1 100644 --- a/drivers/tty/serial/8250/8250_dw.c +++ b/drivers/tty/serial/8250/8250_dw.c @@ -257,7 +257,7 @@ static void dw8250_set_termios(struct uart_port *p, struct ktermios *termios, { unsigned int baud = tty_termios_baud_rate(termios); struct dw8250_data *d = p->private_data; - unsigned int rate; + long rate; int ret; if (IS_ERR(d->clk) || !old) @@ -265,7 +265,12 @@ static void dw8250_set_termios(struct uart_port *p, struct ktermios *termios, clk_disable_unprepare(d->clk); rate = clk_round_rate(d->clk, baud * 16); - ret = clk_set_rate(d->clk, rate); + if (rate < 0) + ret = rate; + else if (rate == 0) + ret = -ENOENT; + else + ret = clk_set_rate(d->clk, rate); clk_prepare_enable(d->clk); if (!ret) diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c index 8789ea423ccf..56f92d7348bf 100644 --- a/drivers/tty/serial/amba-pl011.c +++ b/drivers/tty/serial/amba-pl011.c @@ -2373,7 +2373,7 @@ static int __init pl011_console_match(struct console *co, char *name, int idx, if (strcmp(name, "qdf2400_e44") == 0) { pr_info_once("UART: Working around QDF2400 SoC erratum 44"); qdf2400_e44_present = true; - } else if (strcmp(name, "pl011") != 0 || strcmp(name, "ttyAMA") != 0) { + } else if (strcmp(name, "pl011") != 0) { return -ENODEV; } diff --git a/drivers/tty/tty_ldisc.c b/drivers/tty/tty_ldisc.c index 68947f6de5ad..b0500a0a87b8 100644 --- a/drivers/tty/tty_ldisc.c +++ b/drivers/tty/tty_ldisc.c @@ -271,10 +271,13 @@ const struct file_operations tty_ldiscs_proc_fops = { struct tty_ldisc *tty_ldisc_ref_wait(struct tty_struct *tty) { + struct tty_ldisc *ld; + ldsem_down_read(&tty->ldisc_sem, MAX_SCHEDULE_TIMEOUT); - if (!tty->ldisc) + ld = tty->ldisc; + if (!ld) ldsem_up_read(&tty->ldisc_sem); - return tty->ldisc; + return ld; } EXPORT_SYMBOL_GPL(tty_ldisc_ref_wait); @@ -489,41 +492,6 @@ static void tty_ldisc_close(struct tty_struct *tty, struct tty_ldisc *ld) } /** - * tty_ldisc_restore - helper for tty ldisc change - * @tty: tty to recover - * @old: previous ldisc - * - * Restore the previous line discipline or N_TTY when a line discipline - * change fails due to an open error - */ - -static void tty_ldisc_restore(struct tty_struct *tty, struct tty_ldisc *old) -{ - struct tty_ldisc *new_ldisc; - int r; - - /* There is an outstanding reference here so this is safe */ - old = tty_ldisc_get(tty, old->ops->num); - WARN_ON(IS_ERR(old)); - tty->ldisc = old; - tty_set_termios_ldisc(tty, old->ops->num); - if (tty_ldisc_open(tty, old) < 0) { - tty_ldisc_put(old); - /* This driver is always present */ - new_ldisc = tty_ldisc_get(tty, N_TTY); - if (IS_ERR(new_ldisc)) - panic("n_tty: get"); - tty->ldisc = new_ldisc; - tty_set_termios_ldisc(tty, N_TTY); - r = tty_ldisc_open(tty, new_ldisc); - if (r < 0) - panic("Couldn't open N_TTY ldisc for " - "%s --- error %d.", - tty_name(tty), r); - } -} - -/** * tty_set_ldisc - set line discipline * @tty: the terminal to set * @ldisc: the line discipline @@ -536,12 +504,7 @@ static void tty_ldisc_restore(struct tty_struct *tty, struct tty_ldisc *old) int tty_set_ldisc(struct tty_struct *tty, int disc) { - int retval; - struct tty_ldisc *old_ldisc, *new_ldisc; - - new_ldisc = tty_ldisc_get(tty, disc); - if (IS_ERR(new_ldisc)) - return PTR_ERR(new_ldisc); + int retval, old_disc; tty_lock(tty); retval = tty_ldisc_lock(tty, 5 * HZ); @@ -554,7 +517,8 @@ int tty_set_ldisc(struct tty_struct *tty, int disc) } /* Check the no-op case */ - if (tty->ldisc->ops->num == disc) + old_disc = tty->ldisc->ops->num; + if (old_disc == disc) goto out; if (test_bit(TTY_HUPPED, &tty->flags)) { @@ -563,34 +527,25 @@ int tty_set_ldisc(struct tty_struct *tty, int disc) goto out; } - old_ldisc = tty->ldisc; - - /* Shutdown the old discipline. */ - tty_ldisc_close(tty, old_ldisc); - - /* Now set up the new line discipline. */ - tty->ldisc = new_ldisc; - tty_set_termios_ldisc(tty, disc); - - retval = tty_ldisc_open(tty, new_ldisc); + retval = tty_ldisc_reinit(tty, disc); if (retval < 0) { /* Back to the old one or N_TTY if we can't */ - tty_ldisc_put(new_ldisc); - tty_ldisc_restore(tty, old_ldisc); + if (tty_ldisc_reinit(tty, old_disc) < 0) { + pr_err("tty: TIOCSETD failed, reinitializing N_TTY\n"); + if (tty_ldisc_reinit(tty, N_TTY) < 0) { + /* At this point we have tty->ldisc == NULL. */ + pr_err("tty: reinitializing N_TTY failed\n"); + } + } } - if (tty->ldisc->ops->num != old_ldisc->ops->num && tty->ops->set_ldisc) { + if (tty->ldisc && tty->ldisc->ops->num != old_disc && + tty->ops->set_ldisc) { down_read(&tty->termios_rwsem); tty->ops->set_ldisc(tty); up_read(&tty->termios_rwsem); } - /* At this point we hold a reference to the new ldisc and a - reference to the old ldisc, or we hold two references to - the old ldisc (if it was restored as part of error cleanup - above). In either case, releasing a single reference from - the old ldisc is correct. */ - new_ldisc = old_ldisc; out: tty_ldisc_unlock(tty); @@ -598,7 +553,6 @@ out: already running */ tty_buffer_restart_work(tty->port); err: - tty_ldisc_put(new_ldisc); /* drop the extra reference */ tty_unlock(tty); return retval; } @@ -659,10 +613,8 @@ int tty_ldisc_reinit(struct tty_struct *tty, int disc) int retval; ld = tty_ldisc_get(tty, disc); - if (IS_ERR(ld)) { - BUG_ON(disc == N_TTY); + if (IS_ERR(ld)) return PTR_ERR(ld); - } if (tty->ldisc) { tty_ldisc_close(tty, tty->ldisc); @@ -674,10 +626,8 @@ int tty_ldisc_reinit(struct tty_struct *tty, int disc) tty_set_termios_ldisc(tty, disc); retval = tty_ldisc_open(tty, tty->ldisc); if (retval) { - if (!WARN_ON(disc == N_TTY)) { - tty_ldisc_put(tty->ldisc); - tty->ldisc = NULL; - } + tty_ldisc_put(tty->ldisc); + tty->ldisc = NULL; } return retval; } |