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authorLinus Torvalds <torvalds@linux-foundation.org>2017-03-26 11:03:42 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2017-03-26 11:03:42 -0700
commitf1638fc65ee23875cf4021e342e8a564debe33e4 (patch)
treeaf091401ed9d05c93a9b9545f963fcc566e6d4d9
parent53b4d5911d6adef3f543e1ad23643068c5c343ac (diff)
parenta4a3e061149f09c075f108b6f1cf04d9739a6bc2 (diff)
downloadlinux-stericsson-f1638fc65ee23875cf4021e342e8a564debe33e4.tar.gz
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
-rw-r--r--drivers/acpi/spcr.c2
-rw-r--r--drivers/tty/serial/8250/8250_dw.c9
-rw-r--r--drivers/tty/serial/amba-pl011.c2
-rw-r--r--drivers/tty/tty_ldisc.c92
4 files changed, 30 insertions, 75 deletions
diff --git a/drivers/acpi/spcr.c b/drivers/acpi/spcr.c
index 01c94669a2b0..3afa8c1fa127 100644
--- a/drivers/acpi/spcr.c
+++ b/drivers/acpi/spcr.c
@@ -30,7 +30,7 @@ static bool qdf2400_erratum_44_present(struct acpi_table_header *h)
return true;
if (!memcmp(h->oem_table_id, "QDF2400 ", ACPI_OEM_TABLE_ID_SIZE) &&
- h->oem_revision == 0)
+ h->oem_revision == 1)
return true;
return false;
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;
}