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, 440 insertions, 0 deletions

diff --git a/drivers/net/wan/c101.c b/drivers/net/wan/c101.c
new file mode 100644
index 000000000..f35a15cf5
--- /dev/null
+++ b/drivers/net/wan/c101.c
@@ -0,0 +1,440 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Moxa C101 synchronous serial card driver for Linux
+ *
+ * Copyright (C) 2000-2003 Krzysztof Halasa <khc@pm.waw.pl>
+ *
+ * For information see <https://www.kernel.org/pub/linux/utils/net/hdlc/>
+ *
+ * Sources of information:
+ *    Hitachi HD64570 SCA User's Manual
+ *    Moxa C101 User's Manual
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/capability.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/string.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/netdevice.h>
+#include <linux/hdlc.h>
+#include <linux/delay.h>
+#include <asm/io.h>
+
+#include "hd64570.h"
+
+static const char *version = "Moxa C101 driver version: 1.15";
+static const char *devname = "C101";
+
+#undef DEBUG_PKT
+#define DEBUG_RINGS
+
+#define C101_PAGE 0x1D00
+#define C101_DTR 0x1E00
+#define C101_SCA 0x1F00
+#define C101_WINDOW_SIZE 0x2000
+#define C101_MAPPED_RAM_SIZE 0x4000
+
+#define RAM_SIZE (256 * 1024)
+#define TX_RING_BUFFERS 10
+#define RX_RING_BUFFERS ((RAM_SIZE - C101_WINDOW_SIZE) /		\
+			 (sizeof(pkt_desc) + HDLC_MAX_MRU) - TX_RING_BUFFERS)
+
+#define CLOCK_BASE 9830400	/* 9.8304 MHz */
+#define PAGE0_ALWAYS_MAPPED
+
+static char *hw;		/* pointer to hw=xxx command line string */
+
+typedef struct card_s {
+	struct net_device *dev;
+	spinlock_t lock;	/* TX lock */
+	u8 __iomem *win0base;	/* ISA window base address */
+	u32 phy_winbase;	/* ISA physical base address */
+	sync_serial_settings settings;
+	int rxpart;		/* partial frame received, next frame invalid*/
+	unsigned short encoding;
+	unsigned short parity;
+	u16 rx_ring_buffers;	/* number of buffers in a ring */
+	u16 tx_ring_buffers;
+	u16 buff_offset;	/* offset of first buffer of first channel */
+	u16 rxin;		/* rx ring buffer 'in' pointer */
+	u16 txin;		/* tx ring buffer 'in' and 'last' pointers */
+	u16 txlast;
+	u8 rxs, txs, tmc;	/* SCA registers */
+	u8 irq;			/* IRQ (3-15) */
+	u8 page;
+
+	struct card_s *next_card;
+} card_t;
+
+typedef card_t port_t;
+
+static card_t *first_card;
+static card_t **new_card = &first_card;
+
+#define sca_in(reg, card)	   readb((card)->win0base + C101_SCA + (reg))
+#define sca_out(value, reg, card)  writeb(value, (card)->win0base + C101_SCA + (reg))
+#define sca_inw(reg, card)	   readw((card)->win0base + C101_SCA + (reg))
+
+/* EDA address register must be set in EDAL, EDAH order - 8 bit ISA bus */
+#define sca_outw(value, reg, card) do { \
+	writeb(value & 0xFF, (card)->win0base + C101_SCA + (reg)); \
+	writeb((value >> 8) & 0xFF, (card)->win0base + C101_SCA + (reg + 1));\
+} while (0)
+
+#define port_to_card(port)	   (port)
+#define log_node(port)		   (0)
+#define phy_node(port)		   (0)
+#define winsize(card)		   (C101_WINDOW_SIZE)
+#define win0base(card)		   ((card)->win0base)
+#define winbase(card)		   ((card)->win0base + 0x2000)
+#define get_port(card, port)	   (card)
+static void sca_msci_intr(port_t *port);
+
+static inline u8 sca_get_page(card_t *card)
+{
+	return card->page;
+}
+
+static inline void openwin(card_t *card, u8 page)
+{
+	card->page = page;
+	writeb(page, card->win0base + C101_PAGE);
+}
+
+#include "hd64570.c"
+
+static inline void set_carrier(port_t *port)
+{
+	if (!(sca_in(MSCI1_OFFSET + ST3, port) & ST3_DCD))
+		netif_carrier_on(port_to_dev(port));
+	else
+		netif_carrier_off(port_to_dev(port));
+}
+
+static void sca_msci_intr(port_t *port)
+{
+	u8 stat = sca_in(MSCI0_OFFSET + ST1, port); /* read MSCI ST1 status */
+
+	/* Reset MSCI TX underrun and CDCD (ignored) status bit */
+	sca_out(stat & (ST1_UDRN | ST1_CDCD), MSCI0_OFFSET + ST1, port);
+
+	if (stat & ST1_UDRN) {
+		/* TX Underrun error detected */
+		port_to_dev(port)->stats.tx_errors++;
+		port_to_dev(port)->stats.tx_fifo_errors++;
+	}
+
+	stat = sca_in(MSCI1_OFFSET + ST1, port); /* read MSCI1 ST1 status */
+	/* Reset MSCI CDCD status bit - uses ch#2 DCD input */
+	sca_out(stat & ST1_CDCD, MSCI1_OFFSET + ST1, port);
+
+	if (stat & ST1_CDCD)
+		set_carrier(port);
+}
+
+static void c101_set_iface(port_t *port)
+{
+	u8 rxs = port->rxs & CLK_BRG_MASK;
+	u8 txs = port->txs & CLK_BRG_MASK;
+
+	switch (port->settings.clock_type) {
+	case CLOCK_INT:
+		rxs |= CLK_BRG_RX; /* TX clock */
+		txs |= CLK_RXCLK_TX; /* BRG output */
+		break;
+
+	case CLOCK_TXINT:
+		rxs |= CLK_LINE_RX; /* RXC input */
+		txs |= CLK_BRG_TX; /* BRG output */
+		break;
+
+	case CLOCK_TXFROMRX:
+		rxs |= CLK_LINE_RX; /* RXC input */
+		txs |= CLK_RXCLK_TX; /* RX clock */
+		break;
+
+	default:	/* EXTernal clock */
+		rxs |= CLK_LINE_RX; /* RXC input */
+		txs |= CLK_LINE_TX; /* TXC input */
+	}
+
+	port->rxs = rxs;
+	port->txs = txs;
+	sca_out(rxs, MSCI1_OFFSET + RXS, port);
+	sca_out(txs, MSCI1_OFFSET + TXS, port);
+	sca_set_port(port);
+}
+
+static int c101_open(struct net_device *dev)
+{
+	port_t *port = dev_to_port(dev);
+	int result;
+
+	result = hdlc_open(dev);
+	if (result)
+		return result;
+
+	writeb(1, port->win0base + C101_DTR);
+	sca_out(0, MSCI1_OFFSET + CTL, port); /* RTS uses ch#2 output */
+	sca_open(dev);
+	/* DCD is connected to port 2 !@#$%^& - disable MSCI0 CDCD interrupt */
+	sca_out(IE1_UDRN, MSCI0_OFFSET + IE1, port);
+	sca_out(IE0_TXINT, MSCI0_OFFSET + IE0, port);
+
+	set_carrier(port);
+
+	/* enable MSCI1 CDCD interrupt */
+	sca_out(IE1_CDCD, MSCI1_OFFSET + IE1, port);
+	sca_out(IE0_RXINTA, MSCI1_OFFSET + IE0, port);
+	sca_out(0x48, IER0, port); /* TXINT #0 and RXINT #1 */
+	c101_set_iface(port);
+	return 0;
+}
+
+static int c101_close(struct net_device *dev)
+{
+	port_t *port = dev_to_port(dev);
+
+	sca_close(dev);
+	writeb(0, port->win0base + C101_DTR);
+	sca_out(CTL_NORTS, MSCI1_OFFSET + CTL, port);
+	hdlc_close(dev);
+	return 0;
+}
+
+static int c101_siocdevprivate(struct net_device *dev, struct ifreq *ifr,
+			       void __user *data, int cmd)
+{
+#ifdef DEBUG_RINGS
+	port_t *port = dev_to_port(dev);
+
+	if (cmd == SIOCDEVPRIVATE) {
+		sca_dump_rings(dev);
+		printk(KERN_DEBUG "MSCI1: ST: %02x %02x %02x %02x\n",
+		       sca_in(MSCI1_OFFSET + ST0, port),
+		       sca_in(MSCI1_OFFSET + ST1, port),
+		       sca_in(MSCI1_OFFSET + ST2, port),
+		       sca_in(MSCI1_OFFSET + ST3, port));
+		return 0;
+	}
+#endif
+
+	return -EOPNOTSUPP;
+}
+
+static int c101_ioctl(struct net_device *dev, struct if_settings *ifs)
+{
+	const size_t size = sizeof(sync_serial_settings);
+	sync_serial_settings new_line;
+	sync_serial_settings __user *line = ifs->ifs_ifsu.sync;
+	port_t *port = dev_to_port(dev);
+
+	switch (ifs->type) {
+	case IF_GET_IFACE:
+		ifs->type = IF_IFACE_SYNC_SERIAL;
+		if (ifs->size < size) {
+			ifs->size = size; /* data size wanted */
+			return -ENOBUFS;
+		}
+		if (copy_to_user(line, &port->settings, size))
+			return -EFAULT;
+		return 0;
+
+	case IF_IFACE_SYNC_SERIAL:
+		if (!capable(CAP_NET_ADMIN))
+			return -EPERM;
+
+		if (copy_from_user(&new_line, line, size))
+			return -EFAULT;
+
+		if (new_line.clock_type != CLOCK_EXT &&
+		    new_line.clock_type != CLOCK_TXFROMRX &&
+		    new_line.clock_type != CLOCK_INT &&
+		    new_line.clock_type != CLOCK_TXINT)
+			return -EINVAL;	/* No such clock setting */
+
+		if (new_line.loopback != 0 && new_line.loopback != 1)
+			return -EINVAL;
+
+		memcpy(&port->settings, &new_line, size); /* Update settings */
+		c101_set_iface(port);
+		return 0;
+
+	default:
+		return hdlc_ioctl(dev, ifs);
+	}
+}
+
+static void c101_destroy_card(card_t *card)
+{
+	readb(card->win0base + C101_PAGE); /* Resets SCA? */
+
+	if (card->irq)
+		free_irq(card->irq, card);
+
+	if (card->win0base) {
+		iounmap(card->win0base);
+		release_mem_region(card->phy_winbase, C101_MAPPED_RAM_SIZE);
+	}
+
+	free_netdev(card->dev);
+
+	kfree(card);
+}
+
+static const struct net_device_ops c101_ops = {
+	.ndo_open       = c101_open,
+	.ndo_stop       = c101_close,
+	.ndo_start_xmit = hdlc_start_xmit,
+	.ndo_siocwandev = c101_ioctl,
+	.ndo_siocdevprivate = c101_siocdevprivate,
+};
+
+static int __init c101_run(unsigned long irq, unsigned long winbase)
+{
+	struct net_device *dev;
+	hdlc_device *hdlc;
+	card_t *card;
+	int result;
+
+	if (irq < 3 || irq > 15 || irq == 6) /* FIXME */ {
+		pr_err("invalid IRQ value\n");
+		return -ENODEV;
+	}
+
+	if (winbase < 0xC0000 || winbase > 0xDFFFF || (winbase & 0x3FFF) != 0) {
+		pr_err("invalid RAM value\n");
+		return -ENODEV;
+	}
+
+	card = kzalloc_obj(card_t);
+	if (!card)
+		return -ENOBUFS;
+
+	card->dev = alloc_hdlcdev(card);
+	if (!card->dev) {
+		pr_err("unable to allocate memory\n");
+		kfree(card);
+		return -ENOBUFS;
+	}
+
+	if (request_irq(irq, sca_intr, 0, devname, card)) {
+		pr_err("could not allocate IRQ\n");
+		c101_destroy_card(card);
+		return -EBUSY;
+	}
+	card->irq = irq;
+
+	if (!request_mem_region(winbase, C101_MAPPED_RAM_SIZE, devname)) {
+		pr_err("could not request RAM window\n");
+		c101_destroy_card(card);
+		return -EBUSY;
+	}
+	card->phy_winbase = winbase;
+	card->win0base = ioremap(winbase, C101_MAPPED_RAM_SIZE);
+	if (!card->win0base) {
+		pr_err("could not map I/O address\n");
+		c101_destroy_card(card);
+		return -EFAULT;
+	}
+
+	card->tx_ring_buffers = TX_RING_BUFFERS;
+	card->rx_ring_buffers = RX_RING_BUFFERS;
+	card->buff_offset = C101_WINDOW_SIZE; /* Bytes 1D00-1FFF reserved */
+
+	readb(card->win0base + C101_PAGE); /* Resets SCA? */
+	udelay(100);
+	writeb(0, card->win0base + C101_PAGE);
+	writeb(0, card->win0base + C101_DTR); /* Power-up for RAM? */
+
+	sca_init(card, 0);
+
+	dev = port_to_dev(card);
+	hdlc = dev_to_hdlc(dev);
+
+	spin_lock_init(&card->lock);
+	dev->irq = irq;
+	dev->mem_start = winbase;
+	dev->mem_end = winbase + C101_MAPPED_RAM_SIZE - 1;
+	dev->tx_queue_len = 50;
+	dev->netdev_ops = &c101_ops;
+	hdlc->attach = sca_attach;
+	hdlc->xmit = sca_xmit;
+	card->settings.clock_type = CLOCK_EXT;
+
+	result = register_hdlc_device(dev);
+	if (result) {
+		pr_warn("unable to register hdlc device\n");
+		c101_destroy_card(card);
+		return result;
+	}
+
+	sca_init_port(card); /* Set up C101 memory */
+	set_carrier(card);
+
+	netdev_info(dev, "Moxa C101 on IRQ%u, using %u TX + %u RX packets rings\n",
+		    card->irq, card->tx_ring_buffers, card->rx_ring_buffers);
+
+	*new_card = card;
+	new_card = &card->next_card;
+	return 0;
+}
+
+static int __init c101_init(void)
+{
+	if (!hw) {
+#ifdef MODULE
+		pr_info("no card initialized\n");
+#endif
+		return -EINVAL;	/* no parameters specified, abort */
+	}
+
+	pr_info("%s\n", version);
+
+	do {
+		unsigned long irq, ram;
+
+		irq = simple_strtoul(hw, &hw, 0);
+
+		if (*hw++ != ',')
+			break;
+		ram = simple_strtoul(hw, &hw, 0);
+
+		if (*hw == ':' || *hw == '\x0')
+			c101_run(irq, ram);
+
+		if (*hw == '\x0')
+			return first_card ? 0 : -EINVAL;
+	} while (*hw++ == ':');
+
+	pr_err("invalid hardware parameters\n");
+	return first_card ? 0 : -EINVAL;
+}
+
+static void __exit c101_cleanup(void)
+{
+	card_t *card = first_card;
+
+	while (card) {
+		card_t *ptr = card;
+
+		card = card->next_card;
+		unregister_hdlc_device(port_to_dev(ptr));
+		c101_destroy_card(ptr);
+	}
+}
+
+module_init(c101_init);
+module_exit(c101_cleanup);
+
+MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>");
+MODULE_DESCRIPTION("Moxa C101 serial port driver");
+MODULE_LICENSE("GPL v2");
+module_param(hw, charp, 0444);
+MODULE_PARM_DESC(hw, "irq,ram:irq,...");