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, 394 insertions, 0 deletions

diff --git a/drivers/net/arcnet/com20020.c b/drivers/net/arcnet/com20020.c
new file mode 100644
index 000000000..21f962357
--- /dev/null
+++ b/drivers/net/arcnet/com20020.c
@@ -0,0 +1,394 @@
+/*
+ * Linux ARCnet driver - COM20020 chipset support
+ *
+ * Written 1997 by David Woodhouse.
+ * Written 1994-1999 by Avery Pennarun.
+ * Written 1999 by Martin Mares <mj@ucw.cz>.
+ * Derived from skeleton.c by Donald Becker.
+ *
+ * Special thanks to Contemporary Controls, Inc. (www.ccontrols.com)
+ *  for sponsoring the further development of this driver.
+ *
+ * **********************
+ *
+ * The original copyright of skeleton.c was as follows:
+ *
+ * skeleton.c Written 1993 by Donald Becker.
+ * Copyright 1993 United States Government as represented by the
+ * Director, National Security Agency.  This software may only be used
+ * and distributed according to the terms of the GNU General Public License as
+ * modified by SRC, incorporated herein by reference.
+ *
+ * **********************
+ *
+ * For more details, see drivers/net/arcnet.c
+ *
+ * **********************
+ */
+
+#define pr_fmt(fmt) "arcnet:" KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/ioport.h>
+#include <linux/errno.h>
+#include <linux/delay.h>
+#include <linux/netdevice.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+
+#include "arcdevice.h"
+#include "com20020.h"
+
+static const char * const clockrates[] = {
+	"XXXXXXX", "XXXXXXXX", "XXXXXX", "2.5 Mb/s",
+	"1.25Mb/s", "625 Kb/s", "312.5 Kb/s", "156.25 Kb/s",
+	"Reserved", "Reserved", "Reserved"
+};
+
+static void com20020_command(struct net_device *dev, int command);
+static int com20020_status(struct net_device *dev);
+static void com20020_setmask(struct net_device *dev, int mask);
+static int com20020_reset(struct net_device *dev, int really_reset);
+static void com20020_copy_to_card(struct net_device *dev, int bufnum,
+				  int offset, void *buf, int count);
+static void com20020_copy_from_card(struct net_device *dev, int bufnum,
+				    int offset, void *buf, int count);
+static void com20020_set_rx_mode(struct net_device *dev);
+static void com20020_close(struct net_device *);
+
+static void com20020_copy_from_card(struct net_device *dev, int bufnum,
+				    int offset, void *buf, int count)
+{
+	int ioaddr = dev->base_addr, ofs = 512 * bufnum + offset;
+
+	/* set up the address register */
+	outb((ofs >> 8) | RDDATAflag | AUTOINCflag,
+	     ioaddr + COM20020_REG_W_ADDR_HI);
+	outb(ofs & 0xff, ioaddr + COM20020_REG_W_ADDR_LO);
+
+	/* copy the data */
+	TIME(dev, "insb", count,
+	     insb(ioaddr + COM20020_REG_RW_MEMDATA, buf, count));
+}
+
+static void com20020_copy_to_card(struct net_device *dev, int bufnum,
+				  int offset, void *buf, int count)
+{
+	int ioaddr = dev->base_addr, ofs = 512 * bufnum + offset;
+
+	/* set up the address register */
+	outb((ofs >> 8) | AUTOINCflag, ioaddr + COM20020_REG_W_ADDR_HI);
+	outb(ofs & 0xff, ioaddr + COM20020_REG_W_ADDR_LO);
+
+	/* copy the data */
+	TIME(dev, "outsb", count,
+	     outsb(ioaddr + COM20020_REG_RW_MEMDATA, buf, count));
+}
+
+/* Reset the card and check some basic stuff during the detection stage. */
+int com20020_check(struct net_device *dev)
+{
+	int ioaddr = dev->base_addr, status;
+	struct arcnet_local *lp = netdev_priv(dev);
+
+	outb(XTOcfg(3) | RESETcfg, ioaddr + COM20020_REG_W_CONFIG);
+	udelay(5);
+	outb(XTOcfg(3), ioaddr + COM20020_REG_W_CONFIG);
+	mdelay(RESETtime);
+
+	lp->setup = lp->clockm ? 0 : (lp->clockp << 1);
+	lp->setup2 = (lp->clockm << 4) | 8;
+
+	/* CHECK: should we do this for SOHARD cards ? */
+	/* Enable P1Mode for backplane mode */
+	lp->setup = lp->setup | P1MODE;
+
+	com20020_set_subaddress(lp, ioaddr, SUB_SETUP1);
+	outb(lp->setup, ioaddr + COM20020_REG_W_XREG);
+
+	if (lp->clockm != 0) {
+		com20020_set_subaddress(lp, ioaddr, SUB_SETUP2);
+		outb(lp->setup2, ioaddr + COM20020_REG_W_XREG);
+
+		/* must now write the magic "restart operation" command */
+		mdelay(1);
+		outb(STARTIOcmd, ioaddr + COM20020_REG_W_COMMAND);
+	}
+
+	lp->config = (lp->timeout << 3) | (lp->backplane << 2) | SUB_NODE;
+	/* set node ID to 0x42 (but transmitter is disabled, so it's okay) */
+	outb(lp->config, ioaddr + COM20020_REG_W_CONFIG);
+	outb(0x42, ioaddr + COM20020_REG_W_XREG);
+
+	status = inb(ioaddr + COM20020_REG_R_STATUS);
+
+	if ((status & 0x99) != (NORXflag | TXFREEflag | RESETflag)) {
+		arc_printk(D_NORMAL, dev, "status invalid (%Xh).\n", status);
+		return -ENODEV;
+	}
+	arc_printk(D_INIT_REASONS, dev, "status after reset: %X\n", status);
+
+	outb(CFLAGScmd | RESETclear | CONFIGclear,
+	     ioaddr + COM20020_REG_W_COMMAND);
+	status = inb(ioaddr + COM20020_REG_R_STATUS);
+	arc_printk(D_INIT_REASONS, dev, "status after reset acknowledged: %X\n",
+		   status);
+
+	/* Read first location of memory */
+	outb(0 | RDDATAflag | AUTOINCflag, ioaddr + COM20020_REG_W_ADDR_HI);
+	outb(0, ioaddr + COM20020_REG_W_ADDR_LO);
+
+	status = inb(ioaddr + COM20020_REG_RW_MEMDATA);
+	if (status != TESTvalue) {
+		arc_printk(D_NORMAL, dev, "Signature byte not found (%02Xh != D1h).\n",
+			   status);
+		return -ENODEV;
+	}
+	return 0;
+}
+
+static int com20020_set_hwaddr(struct net_device *dev, void *addr)
+{
+	int ioaddr = dev->base_addr;
+	struct arcnet_local *lp = netdev_priv(dev);
+	struct sockaddr *hwaddr = addr;
+
+	dev_addr_set(dev, hwaddr->sa_data);
+	com20020_set_subaddress(lp, ioaddr, SUB_NODE);
+	outb(dev->dev_addr[0], ioaddr + COM20020_REG_W_XREG);
+
+	return 0;
+}
+
+static int com20020_netdev_open(struct net_device *dev)
+{
+	int ioaddr = dev->base_addr;
+	struct arcnet_local *lp = netdev_priv(dev);
+
+	lp->config |= TXENcfg;
+	outb(lp->config, ioaddr + COM20020_REG_W_CONFIG);
+
+	return arcnet_open(dev);
+}
+
+static int com20020_netdev_close(struct net_device *dev)
+{
+	int ioaddr = dev->base_addr;
+	struct arcnet_local *lp = netdev_priv(dev);
+
+	arcnet_close(dev);
+
+	/* disable transmitter */
+	lp->config &= ~TXENcfg;
+	outb(lp->config, ioaddr + COM20020_REG_W_CONFIG);
+	return 0;
+}
+
+const struct net_device_ops com20020_netdev_ops = {
+	.ndo_open	= com20020_netdev_open,
+	.ndo_stop	= com20020_netdev_close,
+	.ndo_start_xmit = arcnet_send_packet,
+	.ndo_tx_timeout = arcnet_timeout,
+	.ndo_set_mac_address = com20020_set_hwaddr,
+	.ndo_set_rx_mode = com20020_set_rx_mode,
+};
+
+/* Set up the struct net_device associated with this card.  Called after
+ * probing succeeds.
+ */
+int com20020_found(struct net_device *dev, int shared)
+{
+	struct arcnet_local *lp;
+	int ioaddr = dev->base_addr;
+
+	/* Initialize the rest of the device structure. */
+
+	lp = netdev_priv(dev);
+
+	lp->hw.owner = THIS_MODULE;
+	lp->hw.command = com20020_command;
+	lp->hw.status = com20020_status;
+	lp->hw.intmask = com20020_setmask;
+	lp->hw.reset = com20020_reset;
+	lp->hw.copy_to_card = com20020_copy_to_card;
+	lp->hw.copy_from_card = com20020_copy_from_card;
+	lp->hw.close = com20020_close;
+
+	/* FIXME: do this some other way! */
+	if (!dev->dev_addr[0])
+		arcnet_set_addr(dev, inb(ioaddr + 8));
+
+	com20020_set_subaddress(lp, ioaddr, SUB_SETUP1);
+	outb(lp->setup, ioaddr + COM20020_REG_W_XREG);
+
+	if (lp->card_flags & ARC_CAN_10MBIT) {
+		com20020_set_subaddress(lp, ioaddr, SUB_SETUP2);
+		outb(lp->setup2, ioaddr + COM20020_REG_W_XREG);
+
+		/* must now write the magic "restart operation" command */
+		mdelay(1);
+		outb(STARTIOcmd, ioaddr + COM20020_REG_W_COMMAND);
+	}
+
+	lp->config = (lp->timeout << 3) | (lp->backplane << 2) | SUB_NODE;
+	/* Default 0x38 + register: Node ID */
+	outb(lp->config, ioaddr + COM20020_REG_W_CONFIG);
+	outb(dev->dev_addr[0], ioaddr + COM20020_REG_W_XREG);
+
+	/* reserve the irq */
+	if (request_irq(dev->irq, arcnet_interrupt, shared,
+			"arcnet (COM20020)", dev)) {
+		arc_printk(D_NORMAL, dev, "Can't get IRQ %d!\n", dev->irq);
+		return -ENODEV;
+	}
+
+	arc_printk(D_NORMAL, dev, "%s: station %02Xh found at %03lXh, IRQ %d.\n",
+		   lp->card_name, dev->dev_addr[0], dev->base_addr, dev->irq);
+
+	if (lp->backplane)
+		arc_printk(D_NORMAL, dev, "Using backplane mode.\n");
+
+	if (lp->timeout != 3)
+		arc_printk(D_NORMAL, dev, "Using extended timeout value of %d\n",
+			   lp->timeout);
+
+	arc_printk(D_NORMAL, dev, "Using CKP %d - data rate %s\n",
+		   lp->setup >> 1,
+		   clockrates[3 -
+			      ((lp->setup2 & 0xF0) >> 4) +
+			      ((lp->setup & 0x0F) >> 1)]);
+			/* The clockrates array index looks very fragile.
+			 * It seems like it could have negative indexing.
+			 */
+
+	if (register_netdev(dev)) {
+		free_irq(dev->irq, dev);
+		return -EIO;
+	}
+	return 0;
+}
+
+/* Do a hardware reset on the card, and set up necessary registers.
+ *
+ * This should be called as little as possible, because it disrupts the
+ * token on the network (causes a RECON) and requires a significant delay.
+ *
+ * However, it does make sure the card is in a defined state.
+ */
+static int com20020_reset(struct net_device *dev, int really_reset)
+{
+	struct arcnet_local *lp = netdev_priv(dev);
+	u_int ioaddr = dev->base_addr;
+	u_char inbyte;
+
+	arc_printk(D_DEBUG, dev, "%s: %d: %s: dev: %p, lp: %p, dev->name: %s\n",
+		   __FILE__, __LINE__, __func__, dev, lp, dev->name);
+	arc_printk(D_INIT, dev, "Resetting %s (status=%02Xh)\n",
+		   dev->name, inb(ioaddr + COM20020_REG_R_STATUS));
+
+	arc_printk(D_DEBUG, dev, "%s: %d: %s\n", __FILE__, __LINE__, __func__);
+	lp->config |= (lp->timeout << 3) | (lp->backplane << 2);
+	/* power-up defaults */
+	outb(lp->config, ioaddr + COM20020_REG_W_CONFIG);
+	arc_printk(D_DEBUG, dev, "%s: %d: %s\n", __FILE__, __LINE__, __func__);
+
+	if (really_reset) {
+		/* reset the card */
+		outb(lp->config | RESETcfg, ioaddr + COM20020_REG_W_CONFIG);
+		udelay(5);
+		outb(lp->config, ioaddr + COM20020_REG_W_CONFIG);
+		mdelay(RESETtime * 2);
+				/* COM20020 seems to be slower sometimes */
+	}
+	/* clear flags & end reset */
+	arc_printk(D_DEBUG, dev, "%s: %d: %s\n", __FILE__, __LINE__, __func__);
+	outb(CFLAGScmd | RESETclear | CONFIGclear,
+	     ioaddr + COM20020_REG_W_COMMAND);
+
+	/* verify that the ARCnet signature byte is present */
+	arc_printk(D_DEBUG, dev, "%s: %d: %s\n", __FILE__, __LINE__, __func__);
+
+	com20020_copy_from_card(dev, 0, 0, &inbyte, 1);
+	arc_printk(D_DEBUG, dev, "%s: %d: %s\n", __FILE__, __LINE__, __func__);
+	if (inbyte != TESTvalue) {
+		arc_printk(D_DEBUG, dev, "%s: %d: %s\n",
+			   __FILE__, __LINE__, __func__);
+		arc_printk(D_NORMAL, dev, "reset failed: TESTvalue not present.\n");
+		return 1;
+	}
+	/* enable extended (512-byte) packets */
+	outb(CONFIGcmd | EXTconf, ioaddr + COM20020_REG_W_COMMAND);
+
+	arc_printk(D_DEBUG, dev, "%s: %d: %s\n", __FILE__, __LINE__, __func__);
+
+	/* done!  return success. */
+	return 0;
+}
+
+static void com20020_setmask(struct net_device *dev, int mask)
+{
+	u_int ioaddr = dev->base_addr;
+
+	arc_printk(D_DURING, dev, "Setting mask to %x at %x\n", mask, ioaddr);
+	outb(mask, ioaddr + COM20020_REG_W_INTMASK);
+}
+
+static void com20020_command(struct net_device *dev, int cmd)
+{
+	u_int ioaddr = dev->base_addr;
+
+	outb(cmd, ioaddr + COM20020_REG_W_COMMAND);
+}
+
+static int com20020_status(struct net_device *dev)
+{
+	u_int ioaddr = dev->base_addr;
+
+	return inb(ioaddr + COM20020_REG_R_STATUS) +
+		(inb(ioaddr + COM20020_REG_R_DIAGSTAT) << 8);
+}
+
+static void com20020_close(struct net_device *dev)
+{
+	struct arcnet_local *lp = netdev_priv(dev);
+	int ioaddr = dev->base_addr;
+
+	/* disable transmitter */
+	lp->config &= ~TXENcfg;
+	outb(lp->config, ioaddr + COM20020_REG_W_CONFIG);
+}
+
+/* ARCnet does not support multicast, only unicast and broadcast */
+static void com20020_set_rx_mode(struct net_device *dev)
+{
+	struct arcnet_local *lp = netdev_priv(dev);
+	int ioaddr = dev->base_addr;
+
+	if ((dev->flags & IFF_PROMISC) && (dev->flags & IFF_UP)) {
+		/* Enable promiscuous mode */
+		if (!(lp->setup & PROMISCset))
+			arc_printk(D_NORMAL, dev, "Setting promiscuous flag...\n");
+		com20020_set_subaddress(lp, ioaddr, SUB_SETUP1);
+		lp->setup |= PROMISCset;
+		outb(lp->setup, ioaddr + COM20020_REG_W_XREG);
+	} else {
+		/* Disable promiscuous mode, use normal mode */
+		if ((lp->setup & PROMISCset))
+			arc_printk(D_NORMAL, dev, "Resetting promiscuous flag...\n");
+		com20020_set_subaddress(lp, ioaddr, SUB_SETUP1);
+		lp->setup &= ~PROMISCset;
+		outb(lp->setup, ioaddr + COM20020_REG_W_XREG);
+	}
+}
+
+#ifdef CONFIG_ARCNET_COM20020_PCI_MODULE
+EXPORT_SYMBOL(com20020_check);
+EXPORT_SYMBOL(com20020_found);
+EXPORT_SYMBOL(com20020_netdev_ops);
+#endif
+
+MODULE_DESCRIPTION("ARCnet COM20020 chipset core driver");
+MODULE_LICENSE("GPL");