Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Fix error output of boot instance creation failure

   Currently if a boot instance creation fails, instead of printing out
   the name of the instance that failed, it prints "(null)". That is
   because it prints "cur_str" that had already been processed by
   strsep(). Print the saved name instead.

   While at it, print the error code of the failure.

 - Fix use-after-free for same named historgrams

   Histograms can be named so that they can be used in multiple events.
   But if the named histogram has a variable attached, the second event
   that uses the named histogram which duplicates it and needs to free
   the original after duplication leaves the old variable in place and
   still visible. If another histogram uses than variable, it will use
   the stale one which will try to reference the freed duplicate
   histogram and crash the kernel.

   Free the duplicate variables along with the duplicated histogram
   data.

 - Check return value of kthread_run() in event self test

   The events self tests uses a kthread for testing but does not check
   if it succeeded in creating a kthread. If the kthread creation were
   to fail, the code will still try to call kthread_stop() on the error
   returned.

 - Fix race between reading trace_pipe and updating subbuffer size

   If a user is reading the trace_pipe file at the same time they update
   the ring buffer sub-buffer size, can cause the trace_pipe read to
   read stale data. Add trace_access_lock() around updating the ring
   buffer sub-buffer size.

 - Fix eventfs_inode on failure path in creation of the events directory

   In the creation of the "events" directory, if after allocating the
   eventfs_inode a failure is detected, it calls cleanup_ei() which
   calls free_ei(). The free_ei() will test if eventfs_inode being freed
   has no children. It is a bug if it does. But on the failure case of
   the creation of the "events" directory, the children lists have not
   yet been initialized and the free will trigger a warning because
   list_empty() on an uninitialized list returns false.

   Move the initialization into init_ei() where it makes more sense and
   makes sure that a created eventfs_inode has its lists initialized
   upon creation.

 - Check return value of kthread_run() in ftrace direct sample code

   The sample code that shows how to use the ftrace direct calls does
   not test the return of kthread_run() to see if it succeeds. Return a
   failure if the kthread_run() doesn't succeed.

 - Clear user events state on fork in case of alloc failure

   On fork, the child gets a pointer to the parent's user events state.
   It makes a copy of it then updates the child's pointer to it. But if
   the allocation fails, the duplication function leaves the child with
   a pointer to its parent's descriptor. When the child cleans up its
   data, it will free the parent's descriptor while the parent is still
   using it.

   In the duplication function, set the child's user_event_mm to NULL
   before testing if the allocation succeeded, and when it exits it will
   not free the parent's descriptor.

 - Fix retry exhaustion in simple ring buffer reader swap

   simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
   post-decrements it only after a failed link replacement. On the final
   attempt, a successful replacement leaves retry at zero, while a
   failed replacement leaves it at -1.

   But the check for success expects the retry value to be non-zero and
   exits with an error on zero. This is the opposite result. Fix it.

 - Fail nicely when the remote swap_reader_page() returns an error

   Currently, if the swap_reader_page() of a remote buffer fails, it
   triggers a WARN_ON_ONCE() and continues normally. Instead, have it
   exit with an error and a pr_warn() print instead of a full WARNING.

* tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Stop remote reader update when page swap fails
  tracing: Fix retry exhaustion in simple ring buffer reader swap
  tracing/user_events: Clear copied tracing state before fork duplication
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify
  eventfs: Initialize ei->children and ei->list in init_ei()
  tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
  tracing: Fix crash passing ERR_PTR to kthread_stop()
  tracing: Fix use-after-free with same-name named triggers
  tracing: Fix logged instance name on creation failure

1 files changed, 310 insertions, 0 deletions

diff --git a/drivers/usb/serial/ipw.c b/drivers/usb/serial/ipw.c
new file mode 100644
index 000000000..5be153f2c
--- /dev/null
+++ b/drivers/usb/serial/ipw.c
@@ -0,0 +1,310 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * IPWireless 3G UMTS TDD Modem driver (USB connected)
+ *
+ *   Copyright (C) 2004 Roelf Diedericks <roelfd@inet.co.za>
+ *   Copyright (C) 2004 Greg Kroah-Hartman <greg@kroah.com>
+ *
+ * All information about the device was acquired using SnoopyPro
+ * on MSFT's O/S, and examing the MSFT drivers' debug output
+ * (insanely left _on_ in the enduser version)
+ *
+ * It was written out of frustration with the IPWireless USB modem
+ * supplied by Axity3G/Sentech South Africa not supporting
+ * Linux whatsoever.
+ *
+ * Nobody provided any proprietary information that was not already
+ * available for this device.
+ *
+ * The modem adheres to the "3GPP TS  27.007 AT command set for 3G
+ * User Equipment (UE)" standard, available from
+ * http://www.3gpp.org/ftp/Specs/html-info/27007.htm
+ *
+ * The code was only tested the IPWireless handheld modem distributed
+ * in South Africa by Sentech.
+ *
+ * It may work for Woosh Inc in .nz too, as it appears they use the
+ * same kit.
+ *
+ * There is still some work to be done in terms of handling
+ * DCD, DTR, RTS, CTS which are currently faked.
+ * It's good enough for PPP at this point. It's based off all kinds of
+ * code found in usb/serial and usb/class
+ */
+
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/slab.h>
+#include <linux/tty.h>
+#include <linux/module.h>
+#include <linux/spinlock.h>
+#include <linux/usb.h>
+#include <linux/usb/serial.h>
+#include "usb-wwan.h"
+
+#define DRIVER_AUTHOR	"Roelf Diedericks"
+#define DRIVER_DESC	"IPWireless tty driver"
+
+#define IPW_TTY_MAJOR	240	/* real device node major id, experimental range */
+#define IPW_TTY_MINORS	256	/* we support 256 devices, dunno why, it'd be insane :) */
+
+#define USB_IPW_MAGIC	0x6d02	/* magic number for ipw struct */
+
+
+/* Message sizes */
+#define EVENT_BUFFER_SIZE	0xFF
+#define CHAR2INT16(c1, c0)	(((u32)((c1) & 0xff) << 8) + (u32)((c0) & 0xff))
+
+/* vendor/product pairs that are known work with this driver*/
+#define IPW_VID		0x0bc3
+#define IPW_PID		0x0001
+
+
+/* Vendor commands: */
+
+/* baud rates */
+enum {
+	ipw_sio_b256000 = 0x000e,
+	ipw_sio_b128000 = 0x001d,
+	ipw_sio_b115200 = 0x0020,
+	ipw_sio_b57600  = 0x0040,
+	ipw_sio_b56000  = 0x0042,
+	ipw_sio_b38400  = 0x0060,
+	ipw_sio_b19200  = 0x00c0,
+	ipw_sio_b14400  = 0x0100,
+	ipw_sio_b9600   = 0x0180,
+	ipw_sio_b4800   = 0x0300,
+	ipw_sio_b2400   = 0x0600,
+	ipw_sio_b1200   = 0x0c00,
+	ipw_sio_b600    = 0x1800
+};
+
+/* data bits */
+#define ipw_dtb_7		0x700
+#define ipw_dtb_8		0x810	/* ok so the define is misleading, I know, but forces 8,n,1 */
+					/* I mean, is there a point to any other setting these days? :) */
+
+/* usb control request types : */
+#define IPW_SIO_RXCTL		0x00	/* control bulk rx channel transmissions, value=1/0 (on/off) */
+#define IPW_SIO_SET_BAUD	0x01	/* set baud, value=requested ipw_sio_bxxxx */
+#define IPW_SIO_SET_LINE	0x03	/* set databits, parity. value=ipw_dtb_x */
+#define IPW_SIO_SET_PIN		0x03	/* set/clear dtr/rts value=ipw_pin_xxx */
+#define IPW_SIO_POLL		0x08	/* get serial port status byte, call with value=0 */
+#define IPW_SIO_INIT		0x11	/* initializes ? value=0 (appears as first thing todo on open) */
+#define IPW_SIO_PURGE		0x12	/* purge all transmissions?, call with value=numchar_to_purge */
+#define IPW_SIO_HANDFLOW	0x13	/* set xon/xoff limits value=0, and a buffer of 0x10 bytes */
+#define IPW_SIO_SETCHARS	0x13	/* set the flowcontrol special chars, value=0, buf=6 bytes, */
+					/* last 2 bytes contain flowcontrol chars e.g. 00 00 00 00 11 13 */
+
+/* values used for request IPW_SIO_SET_PIN */
+#define IPW_PIN_SETDTR		0x101
+#define IPW_PIN_SETRTS		0x202
+#define IPW_PIN_CLRDTR		0x100
+#define IPW_PIN_CLRRTS		0x200 /* unconfirmed */
+
+/* values used for request IPW_SIO_RXCTL */
+#define IPW_RXBULK_ON		1
+#define IPW_RXBULK_OFF		0
+
+/* various 16 byte hardcoded transferbuffers used by flow control */
+#define IPW_BYTES_FLOWINIT	{ 0x01, 0, 0, 0, 0x40, 0, 0, 0, \
+					0, 0, 0, 0, 0, 0, 0, 0 }
+
+/* Interpretation of modem status lines */
+/* These need sorting out by individually connecting pins and checking
+ * results. FIXME!
+ * When data is being sent we see 0x30 in the lower byte; this must
+ * contain DSR and CTS ...
+ */
+#define IPW_DSR			((1<<4) | (1<<5))
+#define IPW_CTS			((1<<5) | (1<<4))
+
+#define IPW_WANTS_TO_SEND	0x30
+
+static const struct usb_device_id id_table[] = {
+	{ USB_DEVICE(IPW_VID, IPW_PID) },
+	{ },
+};
+MODULE_DEVICE_TABLE(usb, id_table);
+
+static int ipw_open(struct tty_struct *tty, struct usb_serial_port *port)
+{
+	struct usb_device *udev = port->serial->dev;
+	struct device *dev = &port->dev;
+	u8 buf_flow_static[16] = IPW_BYTES_FLOWINIT;
+	u8 *buf_flow_init;
+	int result;
+
+	buf_flow_init = kmemdup(buf_flow_static, 16, GFP_KERNEL);
+	if (!buf_flow_init)
+		return -ENOMEM;
+
+	/* --1: Tell the modem to initialize (we think) From sniffs this is
+	 *	always the first thing that gets sent to the modem during
+	 *	opening of the device */
+	dev_dbg(dev, "%s: Sending SIO_INIT (we guess)\n", __func__);
+	result = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
+			 IPW_SIO_INIT,
+			 USB_TYPE_VENDOR | USB_RECIP_INTERFACE | USB_DIR_OUT,
+			 0,
+			 0, /* index */
+			 NULL,
+			 0,
+			 100000);
+	if (result < 0)
+		dev_err(dev, "Init of modem failed (error = %d)\n", result);
+
+	/* reset the bulk pipes */
+	usb_clear_halt(udev, usb_rcvbulkpipe(udev, port->bulk_in_endpointAddress));
+	usb_clear_halt(udev, usb_sndbulkpipe(udev, port->bulk_out_endpointAddress));
+
+	/*--2: Start reading from the device */
+	dev_dbg(dev, "%s: setting up bulk read callback\n", __func__);
+	usb_wwan_open(tty, port);
+
+	/*--3: Tell the modem to open the floodgates on the rx bulk channel */
+	dev_dbg(dev, "%s:asking modem for RxRead (RXBULK_ON)\n", __func__);
+	result = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
+			 IPW_SIO_RXCTL,
+			 USB_TYPE_VENDOR | USB_RECIP_INTERFACE | USB_DIR_OUT,
+			 IPW_RXBULK_ON,
+			 0, /* index */
+			 NULL,
+			 0,
+			 100000);
+	if (result < 0)
+		dev_err(dev, "Enabling bulk RxRead failed (error = %d)\n", result);
+
+	/*--4: setup the initial flowcontrol */
+	dev_dbg(dev, "%s:setting init flowcontrol (%s)\n", __func__, buf_flow_init);
+	result = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
+			 IPW_SIO_HANDFLOW,
+			 USB_TYPE_VENDOR | USB_RECIP_INTERFACE | USB_DIR_OUT,
+			 0,
+			 0,
+			 buf_flow_init,
+			 0x10,
+			 200000);
+	if (result < 0)
+		dev_err(dev, "initial flowcontrol failed (error = %d)\n", result);
+
+	kfree(buf_flow_init);
+	return 0;
+}
+
+static int ipw_attach(struct usb_serial *serial)
+{
+	struct usb_wwan_intf_private *data;
+
+	data = kzalloc_obj(struct usb_wwan_intf_private);
+	if (!data)
+		return -ENOMEM;
+
+	spin_lock_init(&data->susp_lock);
+	usb_set_serial_data(serial, data);
+	return 0;
+}
+
+static void ipw_release(struct usb_serial *serial)
+{
+	struct usb_wwan_intf_private *data = usb_get_serial_data(serial);
+
+	usb_set_serial_data(serial, NULL);
+	kfree(data);
+}
+
+static void ipw_dtr_rts(struct usb_serial_port *port, int on)
+{
+	struct usb_device *udev = port->serial->dev;
+	struct device *dev = &port->dev;
+	int result;
+
+	dev_dbg(dev, "%s: on = %d\n", __func__, on);
+
+	result = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
+			 IPW_SIO_SET_PIN,
+			 USB_TYPE_VENDOR | USB_RECIP_INTERFACE | USB_DIR_OUT,
+			 on ? IPW_PIN_SETDTR : IPW_PIN_CLRDTR,
+			 0,
+			 NULL,
+			 0,
+			 200000);
+	if (result < 0)
+		dev_err(dev, "setting dtr failed (error = %d)\n", result);
+
+	result = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
+			 IPW_SIO_SET_PIN, USB_TYPE_VENDOR |
+					USB_RECIP_INTERFACE | USB_DIR_OUT,
+			 on ? IPW_PIN_SETRTS : IPW_PIN_CLRRTS,
+			 0,
+			 NULL,
+			 0,
+			 200000);
+	if (result < 0)
+		dev_err(dev, "setting rts failed (error = %d)\n", result);
+}
+
+static void ipw_close(struct usb_serial_port *port)
+{
+	struct usb_device *udev = port->serial->dev;
+	struct device *dev = &port->dev;
+	int result;
+
+	/*--3: purge */
+	dev_dbg(dev, "%s:sending purge\n", __func__);
+	result = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
+			 IPW_SIO_PURGE, USB_TYPE_VENDOR |
+			 		USB_RECIP_INTERFACE | USB_DIR_OUT,
+			 0x03,
+			 0,
+			 NULL,
+			 0,
+			 200000);
+	if (result < 0)
+		dev_err(dev, "purge failed (error = %d)\n", result);
+
+
+	/* send RXBULK_off (tell modem to stop transmitting bulk data on
+	   rx chan) */
+	result = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
+			 IPW_SIO_RXCTL,
+			 USB_TYPE_VENDOR | USB_RECIP_INTERFACE | USB_DIR_OUT,
+			 IPW_RXBULK_OFF,
+			 0, /* index */
+			 NULL,
+			 0,
+			 100000);
+
+	if (result < 0)
+		dev_err(dev, "Disabling bulk RxRead failed (error = %d)\n", result);
+
+	usb_wwan_close(port);
+}
+
+static struct usb_serial_driver ipw_device = {
+	.driver = {
+		.name =		"ipw",
+	},
+	.description =		"IPWireless converter",
+	.id_table =		id_table,
+	.num_ports =		1,
+	.open =			ipw_open,
+	.close =		ipw_close,
+	.attach =		ipw_attach,
+	.release =		ipw_release,
+	.port_probe =		usb_wwan_port_probe,
+	.port_remove =		usb_wwan_port_remove,
+	.dtr_rts =		ipw_dtr_rts,
+	.write =		usb_wwan_write,
+};
+
+static struct usb_serial_driver * const serial_drivers[] = {
+	&ipw_device, NULL
+};
+
+module_usb_serial_driver(serial_drivers, id_table);
+
+/* Module information */
+MODULE_AUTHOR(DRIVER_AUTHOR);
+MODULE_DESCRIPTION(DRIVER_DESC);
+MODULE_LICENSE("GPL");