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authorLinus Torvalds <torvalds@linux-foundation.org>2016-02-14 12:29:59 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2016-02-14 12:29:59 -0800
commit779ee19da757d6bbf5504840f8b624f525de9797 (patch)
treec538becc24cb3a49b59d6ed782160a84dee8c1bb
parent9db8cc1ae5b0805230f710ddf4f2de0591db820a (diff)
parentc8053b58762745d93930826b60a4073854a15ce5 (diff)
Merge tag 'tty-4.5-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty
Pull tty/serial fixes from Greg KH: "Here are a number of small tty and serial driver fixes for 4.5-rc4 that resolve some reported issues. One of them got reverted as it wasn't correct based on testing, and all have been in linux-next for a while" * tag 'tty-4.5-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: Revert "8250: uniphier: allow modular build with 8250 console" pty: make sure super_block is still valid in final /dev/tty close pty: fix possible use after free of tty->driver_data tty: Add support for PCIe WCH382 2S multi-IO card serial/omap: mark wait_for_xmitr as __maybe_unused serial: omap: Prevent DoS using unprivileged ioctl(TIOCSRS485) 8250: uniphier: allow modular build with 8250 console tty: Drop krefs for interrupted tty lock
-rw-r--r--drivers/tty/pty.c21
-rw-r--r--drivers/tty/serial/8250/8250_pci.c21
-rw-r--r--drivers/tty/serial/omap-serial.c10
-rw-r--r--drivers/tty/tty_io.c3
-rw-r--r--drivers/tty/tty_mutex.c7
-rw-r--r--fs/devpts/inode.c20
-rw-r--r--include/linux/devpts_fs.h4
7 files changed, 79 insertions, 7 deletions
diff --git a/drivers/tty/pty.c b/drivers/tty/pty.c
index b3110040164a..2348fa613707 100644
--- a/drivers/tty/pty.c
+++ b/drivers/tty/pty.c
@@ -681,7 +681,14 @@ static void pty_unix98_remove(struct tty_driver *driver, struct tty_struct *tty)
/* this is called once with whichever end is closed last */
static void pty_unix98_shutdown(struct tty_struct *tty)
{
- devpts_kill_index(tty->driver_data, tty->index);
+ struct inode *ptmx_inode;
+
+ if (tty->driver->subtype == PTY_TYPE_MASTER)
+ ptmx_inode = tty->driver_data;
+ else
+ ptmx_inode = tty->link->driver_data;
+ devpts_kill_index(ptmx_inode, tty->index);
+ devpts_del_ref(ptmx_inode);
}
static const struct tty_operations ptm_unix98_ops = {
@@ -773,6 +780,18 @@ static int ptmx_open(struct inode *inode, struct file *filp)
set_bit(TTY_PTY_LOCK, &tty->flags); /* LOCK THE SLAVE */
tty->driver_data = inode;
+ /*
+ * In the case where all references to ptmx inode are dropped and we
+ * still have /dev/tty opened pointing to the master/slave pair (ptmx
+ * is closed/released before /dev/tty), we must make sure that the inode
+ * is still valid when we call the final pty_unix98_shutdown, thus we
+ * hold an additional reference to the ptmx inode. For the same /dev/tty
+ * last close case, we also need to make sure the super_block isn't
+ * destroyed (devpts instance unmounted), before /dev/tty is closed and
+ * on its release devpts_kill_index is called.
+ */
+ devpts_add_ref(inode);
+
tty_add_file(tty, filp);
slave_inode = devpts_pty_new(inode,
diff --git a/drivers/tty/serial/8250/8250_pci.c b/drivers/tty/serial/8250/8250_pci.c
index e71ec78fc11e..7cd6f9a90542 100644
--- a/drivers/tty/serial/8250/8250_pci.c
+++ b/drivers/tty/serial/8250/8250_pci.c
@@ -1941,6 +1941,7 @@ pci_wch_ch38x_setup(struct serial_private *priv,
#define PCIE_VENDOR_ID_WCH 0x1c00
#define PCIE_DEVICE_ID_WCH_CH382_2S1P 0x3250
#define PCIE_DEVICE_ID_WCH_CH384_4S 0x3470
+#define PCIE_DEVICE_ID_WCH_CH382_2S 0x3253
#define PCI_VENDOR_ID_PERICOM 0x12D8
#define PCI_DEVICE_ID_PERICOM_PI7C9X7951 0x7951
@@ -2637,6 +2638,14 @@ static struct pci_serial_quirk pci_serial_quirks[] __refdata = {
.subdevice = PCI_ANY_ID,
.setup = pci_wch_ch353_setup,
},
+ /* WCH CH382 2S card (16850 clone) */
+ {
+ .vendor = PCIE_VENDOR_ID_WCH,
+ .device = PCIE_DEVICE_ID_WCH_CH382_2S,
+ .subvendor = PCI_ANY_ID,
+ .subdevice = PCI_ANY_ID,
+ .setup = pci_wch_ch38x_setup,
+ },
/* WCH CH382 2S1P card (16850 clone) */
{
.vendor = PCIE_VENDOR_ID_WCH,
@@ -2955,6 +2964,7 @@ enum pci_board_num_t {
pbn_fintek_4,
pbn_fintek_8,
pbn_fintek_12,
+ pbn_wch382_2,
pbn_wch384_4,
pbn_pericom_PI7C9X7951,
pbn_pericom_PI7C9X7952,
@@ -3775,6 +3785,13 @@ static struct pciserial_board pci_boards[] = {
.base_baud = 115200,
.first_offset = 0x40,
},
+ [pbn_wch382_2] = {
+ .flags = FL_BASE0,
+ .num_ports = 2,
+ .base_baud = 115200,
+ .uart_offset = 8,
+ .first_offset = 0xC0,
+ },
[pbn_wch384_4] = {
.flags = FL_BASE0,
.num_ports = 4,
@@ -5574,6 +5591,10 @@ static struct pci_device_id serial_pci_tbl[] = {
PCI_ANY_ID, PCI_ANY_ID,
0, 0, pbn_b0_bt_2_115200 },
+ { PCIE_VENDOR_ID_WCH, PCIE_DEVICE_ID_WCH_CH382_2S,
+ PCI_ANY_ID, PCI_ANY_ID,
+ 0, 0, pbn_wch382_2 },
+
{ PCIE_VENDOR_ID_WCH, PCIE_DEVICE_ID_WCH_CH384_4S,
PCI_ANY_ID, PCI_ANY_ID,
0, 0, pbn_wch384_4 },
diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c
index b645f9228ed7..fa49eb1e2fa2 100644
--- a/drivers/tty/serial/omap-serial.c
+++ b/drivers/tty/serial/omap-serial.c
@@ -1165,7 +1165,7 @@ serial_omap_type(struct uart_port *port)
#define BOTH_EMPTY (UART_LSR_TEMT | UART_LSR_THRE)
-static void wait_for_xmitr(struct uart_omap_port *up)
+static void __maybe_unused wait_for_xmitr(struct uart_omap_port *up)
{
unsigned int status, tmout = 10000;
@@ -1343,7 +1343,7 @@ static inline void serial_omap_add_console_port(struct uart_omap_port *up)
/* Enable or disable the rs485 support */
static int
-serial_omap_config_rs485(struct uart_port *port, struct serial_rs485 *rs485conf)
+serial_omap_config_rs485(struct uart_port *port, struct serial_rs485 *rs485)
{
struct uart_omap_port *up = to_uart_omap_port(port);
unsigned int mode;
@@ -1356,8 +1356,12 @@ serial_omap_config_rs485(struct uart_port *port, struct serial_rs485 *rs485conf)
up->ier = 0;
serial_out(up, UART_IER, 0);
+ /* Clamp the delays to [0, 100ms] */
+ rs485->delay_rts_before_send = min(rs485->delay_rts_before_send, 100U);
+ rs485->delay_rts_after_send = min(rs485->delay_rts_after_send, 100U);
+
/* store new config */
- port->rs485 = *rs485conf;
+ port->rs485 = *rs485;
/*
* Just as a precaution, only allow rs485
diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
index 5cec01c75691..a7eacef1bd22 100644
--- a/drivers/tty/tty_io.c
+++ b/drivers/tty/tty_io.c
@@ -2066,13 +2066,12 @@ retry_open:
if (tty) {
mutex_unlock(&tty_mutex);
retval = tty_lock_interruptible(tty);
+ tty_kref_put(tty); /* drop kref from tty_driver_lookup_tty() */
if (retval) {
if (retval == -EINTR)
retval = -ERESTARTSYS;
goto err_unref;
}
- /* safe to drop the kref from tty_driver_lookup_tty() */
- tty_kref_put(tty);
retval = tty_reopen(tty);
if (retval < 0) {
tty_unlock(tty);
diff --git a/drivers/tty/tty_mutex.c b/drivers/tty/tty_mutex.c
index d2f3c4cd697f..dfa9ec03fa8e 100644
--- a/drivers/tty/tty_mutex.c
+++ b/drivers/tty/tty_mutex.c
@@ -21,10 +21,15 @@ EXPORT_SYMBOL(tty_lock);
int tty_lock_interruptible(struct tty_struct *tty)
{
+ int ret;
+
if (WARN(tty->magic != TTY_MAGIC, "L Bad %p\n", tty))
return -EIO;
tty_kref_get(tty);
- return mutex_lock_interruptible(&tty->legacy_mutex);
+ ret = mutex_lock_interruptible(&tty->legacy_mutex);
+ if (ret)
+ tty_kref_put(tty);
+ return ret;
}
void __lockfunc tty_unlock(struct tty_struct *tty)
diff --git a/fs/devpts/inode.c b/fs/devpts/inode.c
index 1f107fd51328..655f21f99160 100644
--- a/fs/devpts/inode.c
+++ b/fs/devpts/inode.c
@@ -575,6 +575,26 @@ void devpts_kill_index(struct inode *ptmx_inode, int idx)
mutex_unlock(&allocated_ptys_lock);
}
+/*
+ * pty code needs to hold extra references in case of last /dev/tty close
+ */
+
+void devpts_add_ref(struct inode *ptmx_inode)
+{
+ struct super_block *sb = pts_sb_from_inode(ptmx_inode);
+
+ atomic_inc(&sb->s_active);
+ ihold(ptmx_inode);
+}
+
+void devpts_del_ref(struct inode *ptmx_inode)
+{
+ struct super_block *sb = pts_sb_from_inode(ptmx_inode);
+
+ iput(ptmx_inode);
+ deactivate_super(sb);
+}
+
/**
* devpts_pty_new -- create a new inode in /dev/pts/
* @ptmx_inode: inode of the master
diff --git a/include/linux/devpts_fs.h b/include/linux/devpts_fs.h
index 251a2090a554..e0ee0b3000b2 100644
--- a/include/linux/devpts_fs.h
+++ b/include/linux/devpts_fs.h
@@ -19,6 +19,8 @@
int devpts_new_index(struct inode *ptmx_inode);
void devpts_kill_index(struct inode *ptmx_inode, int idx);
+void devpts_add_ref(struct inode *ptmx_inode);
+void devpts_del_ref(struct inode *ptmx_inode);
/* mknod in devpts */
struct inode *devpts_pty_new(struct inode *ptmx_inode, dev_t device, int index,
void *priv);
@@ -32,6 +34,8 @@ void devpts_pty_kill(struct inode *inode);
/* Dummy stubs in the no-pty case */
static inline int devpts_new_index(struct inode *ptmx_inode) { return -EINVAL; }
static inline void devpts_kill_index(struct inode *ptmx_inode, int idx) { }
+static inline void devpts_add_ref(struct inode *ptmx_inode) { }
+static inline void devpts_del_ref(struct inode *ptmx_inode) { }
static inline struct inode *devpts_pty_new(struct inode *ptmx_inode,
dev_t device, int index, void *priv)
{