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, 627 insertions, 0 deletions

diff --git a/drivers/char/nwflash.c b/drivers/char/nwflash.c
new file mode 100644
index 000000000..9f52f0306
--- /dev/null
+++ b/drivers/char/nwflash.c
@@ -0,0 +1,627 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Flash memory interface rev.5 driver for the Intel
+ * Flash chips used on the NetWinder.
+ *
+ * 20/08/2000	RMK	use __ioremap to map flash into virtual memory
+ *			make a few more places use "volatile"
+ * 22/05/2001	RMK	- Lock read against write
+ *			- merge printk level changes (with mods) from Alan Cox.
+ *			- use *ppos as the file position, not file->f_pos.
+ *			- fix check for out of range pos and r/w size
+ *
+ * Please note that we are tampering with the only flash chip in the
+ * machine, which contains the bootup code.  We therefore have the
+ * power to convert these machines into doorstops...
+ */
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/fs.h>
+#include <linux/errno.h>
+#include <linux/mm.h>
+#include <linux/delay.h>
+#include <linux/proc_fs.h>
+#include <linux/miscdevice.h>
+#include <linux/spinlock.h>
+#include <linux/rwsem.h>
+#include <linux/init.h>
+#include <linux/mutex.h>
+#include <linux/jiffies.h>
+
+#include <asm/hardware/dec21285.h>
+#include <asm/io.h>
+#include <asm/mach-types.h>
+#include <linux/uaccess.h>
+
+/*****************************************************************************/
+#include <asm/nwflash.h>
+
+#define	NWFLASH_VERSION "6.4"
+
+static DEFINE_MUTEX(flash_mutex);
+static void kick_open(void);
+static int get_flash_id(void);
+static int erase_block(int nBlock);
+static int write_block(unsigned long p, const char __user *buf, int count);
+
+#define KFLASH_SIZE	1024*1024	//1 Meg
+#define KFLASH_SIZE4	4*1024*1024	//4 Meg
+#define KFLASH_ID	0x89A6		//Intel flash
+#define KFLASH_ID4	0xB0D4		//Intel flash 4Meg
+
+static bool flashdebug;		//if set - we will display progress msgs
+
+static int gbWriteEnable;
+static int gbWriteBase64Enable;
+static volatile unsigned char *FLASH_BASE;
+static int gbFlashSize = KFLASH_SIZE;
+static DEFINE_MUTEX(nwflash_mutex);
+
+static int get_flash_id(void)
+{
+	volatile unsigned int c1, c2;
+
+	/*
+	 * try to get flash chip ID
+	 */
+	kick_open();
+	c2 = inb(0x80);
+	*(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0x90;
+	udelay(15);
+	c1 = *(volatile unsigned char *) FLASH_BASE;
+	c2 = inb(0x80);
+
+	/*
+	 * on 4 Meg flash the second byte is actually at offset 2...
+	 */
+	if (c1 == 0xB0)
+		c2 = *(volatile unsigned char *) (FLASH_BASE + 2);
+	else
+		c2 = *(volatile unsigned char *) (FLASH_BASE + 1);
+
+	c2 += (c1 << 8);
+
+	/*
+	 * set it back to read mode
+	 */
+	*(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0xFF;
+
+	if (c2 == KFLASH_ID4)
+		gbFlashSize = KFLASH_SIZE4;
+
+	return c2;
+}
+
+static long flash_ioctl(struct file *filep, unsigned int cmd, unsigned long arg)
+{
+	mutex_lock(&flash_mutex);
+	switch (cmd) {
+	case CMD_WRITE_DISABLE:
+		gbWriteBase64Enable = 0;
+		gbWriteEnable = 0;
+		break;
+
+	case CMD_WRITE_ENABLE:
+		gbWriteEnable = 1;
+		break;
+
+	case CMD_WRITE_BASE64K_ENABLE:
+		gbWriteBase64Enable = 1;
+		break;
+
+	default:
+		gbWriteBase64Enable = 0;
+		gbWriteEnable = 0;
+		mutex_unlock(&flash_mutex);
+		return -EINVAL;
+	}
+	mutex_unlock(&flash_mutex);
+	return 0;
+}
+
+static ssize_t flash_read(struct file *file, char __user *buf, size_t size,
+			  loff_t *ppos)
+{
+	ssize_t ret;
+
+	if (flashdebug)
+		printk(KERN_DEBUG "flash_read: flash_read: offset=0x%llx, "
+		       "buffer=%p, count=0x%zx.\n", *ppos, buf, size);
+	/*
+	 * We now lock against reads and writes. --rmk
+	 */
+	if (mutex_lock_interruptible(&nwflash_mutex))
+		return -ERESTARTSYS;
+
+	ret = simple_read_from_buffer(buf, size, ppos, (void *)FLASH_BASE, gbFlashSize);
+	mutex_unlock(&nwflash_mutex);
+
+	return ret;
+}
+
+static ssize_t flash_write(struct file *file, const char __user *buf,
+			   size_t size, loff_t * ppos)
+{
+	unsigned long p = *ppos;
+	unsigned int count = size;
+	int written;
+	int nBlock, temp, rc;
+	int i, j;
+
+	if (flashdebug)
+		printk("flash_write: offset=0x%lX, buffer=0x%p, count=0x%X.\n",
+		       p, buf, count);
+
+	if (!gbWriteEnable)
+		return -EINVAL;
+
+	if (p < 64 * 1024 && (!gbWriteBase64Enable))
+		return -EINVAL;
+
+	/*
+	 * check for out of range pos or count
+	 */
+	if (p >= gbFlashSize)
+		return count ? -ENXIO : 0;
+
+	if (count > gbFlashSize - p)
+		count = gbFlashSize - p;
+			
+	if (!access_ok(buf, count))
+		return -EFAULT;
+
+	/*
+	 * We now lock against reads and writes. --rmk
+	 */
+	if (mutex_lock_interruptible(&nwflash_mutex))
+		return -ERESTARTSYS;
+
+	written = 0;
+
+	nBlock = (int) p >> 16;	//block # of 64K bytes
+
+	/*
+	 * # of 64K blocks to erase and write
+	 */
+	temp = ((int) (p + count) >> 16) - nBlock + 1;
+
+	/*
+	 * write ends at exactly 64k boundary?
+	 */
+	if (((int) (p + count) & 0xFFFF) == 0)
+		temp -= 1;
+
+	if (flashdebug)
+		printk(KERN_DEBUG "flash_write: writing %d block(s) "
+			"starting at %d.\n", temp, nBlock);
+
+	for (; temp; temp--, nBlock++) {
+		if (flashdebug)
+			printk(KERN_DEBUG "flash_write: erasing block %d.\n", nBlock);
+
+		/*
+		 * first we have to erase the block(s), where we will write...
+		 */
+		i = 0;
+		j = 0;
+	  RetryBlock:
+		do {
+			rc = erase_block(nBlock);
+			i++;
+		} while (rc && i < 10);
+
+		if (rc) {
+			printk(KERN_ERR "flash_write: erase error %x\n", rc);
+			break;
+		}
+		if (flashdebug)
+			printk(KERN_DEBUG "flash_write: writing offset %lX, "
+			       "from buf %p, bytes left %X.\n", p, buf,
+			       count - written);
+
+		/*
+		 * write_block will limit write to space left in this block
+		 */
+		rc = write_block(p, buf, count - written);
+		j++;
+
+		/*
+		 * if somehow write verify failed? Can't happen??
+		 */
+		if (!rc) {
+			/*
+			 * retry up to 10 times
+			 */
+			if (j < 10)
+				goto RetryBlock;
+			else
+				/*
+				 * else quit with error...
+				 */
+				rc = -1;
+
+		}
+		if (rc < 0) {
+			printk(KERN_ERR "flash_write: write error %X\n", rc);
+			break;
+		}
+		p += rc;
+		buf += rc;
+		written += rc;
+		*ppos += rc;
+
+		if (flashdebug)
+			printk(KERN_DEBUG "flash_write: written 0x%X bytes OK.\n", written);
+	}
+
+	mutex_unlock(&nwflash_mutex);
+
+	return written;
+}
+
+
+/*
+ * The memory devices use the full 32/64 bits of the offset, and so we cannot
+ * check against negative addresses: they are ok. The return value is weird,
+ * though, in that case (0).
+ *
+ * also note that seeking relative to the "end of file" isn't supported:
+ * it has no meaning, so it returns -EINVAL.
+ */
+static loff_t flash_llseek(struct file *file, loff_t offset, int orig)
+{
+	loff_t ret;
+
+	mutex_lock(&flash_mutex);
+	if (flashdebug)
+		printk(KERN_DEBUG "flash_llseek: offset=0x%X, orig=0x%X.\n",
+		       (unsigned int) offset, orig);
+
+	ret = no_seek_end_llseek_size(file, offset, orig, gbFlashSize);
+	mutex_unlock(&flash_mutex);
+	return ret;
+}
+
+
+/*
+ * assume that main Write routine did the parameter checking...
+ * so just go ahead and erase, what requested!
+ */
+
+static int erase_block(int nBlock)
+{
+	volatile unsigned int c1;
+	volatile unsigned char *pWritePtr;
+	unsigned long timeout;
+	int temp, temp1;
+
+	/*
+	 * reset footbridge to the correct offset 0 (...0..3)
+	 */
+	*CSR_ROMWRITEREG = 0;
+
+	/*
+	 * dummy ROM read
+	 */
+	c1 = *(volatile unsigned char *) (FLASH_BASE + 0x8000);
+
+	kick_open();
+	/*
+	 * reset status if old errors
+	 */
+	*(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0x50;
+
+	/*
+	 * erase a block...
+	 * aim at the middle of a current block...
+	 */
+	pWritePtr = (unsigned char *) ((unsigned int) (FLASH_BASE + 0x8000 + (nBlock << 16)));
+	/*
+	 * dummy read
+	 */
+	c1 = *pWritePtr;
+
+	kick_open();
+	/*
+	 * erase
+	 */
+	*(volatile unsigned char *) pWritePtr = 0x20;
+
+	/*
+	 * confirm
+	 */
+	*(volatile unsigned char *) pWritePtr = 0xD0;
+
+	/*
+	 * wait 10 ms
+	 */
+	msleep(10);
+
+	/*
+	 * wait while erasing in process (up to 10 sec)
+	 */
+	timeout = jiffies + 10 * HZ;
+	c1 = 0;
+	while (!(c1 & 0x80) && time_before(jiffies, timeout)) {
+		msleep(10);
+		/*
+		 * read any address
+		 */
+		c1 = *(volatile unsigned char *) (pWritePtr);
+		//              printk("Flash_erase: status=%X.\n",c1);
+	}
+
+	/*
+	 * set flash for normal read access
+	 */
+	kick_open();
+//      *(volatile unsigned char*)(FLASH_BASE+0x8000) = 0xFF;
+	*(volatile unsigned char *) pWritePtr = 0xFF;	//back to normal operation
+
+	/*
+	 * check if erase errors were reported
+	 */
+	if (c1 & 0x20) {
+		printk(KERN_ERR "flash_erase: err at %p\n", pWritePtr);
+
+		/*
+		 * reset error
+		 */
+		*(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0x50;
+		return -2;
+	}
+
+	/*
+	 * just to make sure - verify if erased OK...
+	 */
+	msleep(10);
+
+	pWritePtr = (unsigned char *) ((unsigned int) (FLASH_BASE + (nBlock << 16)));
+
+	for (temp = 0; temp < 16 * 1024; temp++, pWritePtr += 4) {
+		if ((temp1 = *(volatile unsigned int *) pWritePtr) != 0xFFFFFFFF) {
+			printk(KERN_ERR "flash_erase: verify err at %p = %X\n",
+			       pWritePtr, temp1);
+			return -1;
+		}
+	}
+
+	return 0;
+
+}
+
+/*
+ * write_block will limit number of bytes written to the space in this block
+ */
+static int write_block(unsigned long p, const char __user *buf, int count)
+{
+	volatile unsigned int c1;
+	volatile unsigned int c2;
+	unsigned char *pWritePtr;
+	unsigned int uAddress;
+	unsigned int offset;
+	unsigned long timeout;
+	unsigned long timeout1;
+
+	pWritePtr = (unsigned char *) ((unsigned int) (FLASH_BASE + p));
+
+	/*
+	 * check if write will end in this block....
+	 */
+	offset = p & 0xFFFF;
+
+	if (offset + count > 0x10000)
+		count = 0x10000 - offset;
+
+	/*
+	 * wait up to 30 sec for this block
+	 */
+	timeout = jiffies + 30 * HZ;
+
+	for (offset = 0; offset < count; offset++, pWritePtr++) {
+		uAddress = (unsigned int) pWritePtr;
+		uAddress &= 0xFFFFFFFC;
+		if (__get_user(c2, buf + offset))
+			return -EFAULT;
+
+	  WriteRetry:
+	  	/*
+	  	 * dummy read
+	  	 */
+		c1 = *(volatile unsigned char *) (FLASH_BASE + 0x8000);
+
+		/*
+		 * kick open the write gate
+		 */
+		kick_open();
+
+		/*
+		 * program footbridge to the correct offset...0..3
+		 */
+		*CSR_ROMWRITEREG = (unsigned int) pWritePtr & 3;
+
+		/*
+		 * write cmd
+		 */
+		*(volatile unsigned char *) (uAddress) = 0x40;
+
+		/*
+		 * data to write
+		 */
+		*(volatile unsigned char *) (uAddress) = c2;
+
+		/*
+		 * get status
+		 */
+		*(volatile unsigned char *) (FLASH_BASE + 0x10000) = 0x70;
+
+		c1 = 0;
+
+		/*
+		 * wait up to 1 sec for this byte
+		 */
+		timeout1 = jiffies + 1 * HZ;
+
+		/*
+		 * while not ready...
+		 */
+		while (!(c1 & 0x80) && time_before(jiffies, timeout1))
+			c1 = *(volatile unsigned char *) (FLASH_BASE + 0x8000);
+
+		/*
+		 * if timeout getting status
+		 */
+		if (time_after_eq(jiffies, timeout1)) {
+			kick_open();
+			/*
+			 * reset err
+			 */
+			*(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0x50;
+
+			goto WriteRetry;
+		}
+		/*
+		 * switch on read access, as a default flash operation mode
+		 */
+		kick_open();
+		/*
+		 * read access
+		 */
+		*(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0xFF;
+
+		/*
+		 * if hardware reports an error writing, and not timeout - 
+		 * reset the chip and retry
+		 */
+		if (c1 & 0x10) {
+			kick_open();
+			/*
+			 * reset err
+			 */
+			*(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0x50;
+
+			/*
+			 * before timeout?
+			 */
+			if (time_before(jiffies, timeout)) {
+				if (flashdebug)
+					printk(KERN_DEBUG "write_block: Retrying write at 0x%X)n",
+					       pWritePtr - FLASH_BASE);
+
+				/*
+				 * wait couple ms
+				 */
+				msleep(10);
+
+				goto WriteRetry;
+			} else {
+				printk(KERN_ERR "write_block: timeout at 0x%X\n",
+				       pWritePtr - FLASH_BASE);
+				/*
+				 * return error -2
+				 */
+				return -2;
+
+			}
+		}
+	}
+
+	msleep(10);
+
+	pWritePtr = (unsigned char *) ((unsigned int) (FLASH_BASE + p));
+
+	for (offset = 0; offset < count; offset++) {
+		char c, c1;
+		if (__get_user(c, buf))
+			return -EFAULT;
+		buf++;
+		if ((c1 = *pWritePtr++) != c) {
+			printk(KERN_ERR "write_block: verify error at 0x%X (%02X!=%02X)\n",
+			       pWritePtr - FLASH_BASE, c1, c);
+			return 0;
+		}
+	}
+
+	return count;
+}
+
+
+static void kick_open(void)
+{
+	unsigned long flags;
+
+	/*
+	 * we want to write a bit pattern XXX1 to Xilinx to enable
+	 * the write gate, which will be open for about the next 2ms.
+	 */
+	raw_spin_lock_irqsave(&nw_gpio_lock, flags);
+	nw_cpld_modify(CPLD_FLASH_WR_ENABLE, CPLD_FLASH_WR_ENABLE);
+	raw_spin_unlock_irqrestore(&nw_gpio_lock, flags);
+
+	/*
+	 * let the ISA bus to catch on...
+	 */
+	udelay(25);
+}
+
+static const struct file_operations flash_fops =
+{
+	.owner		= THIS_MODULE,
+	.llseek		= flash_llseek,
+	.read		= flash_read,
+	.write		= flash_write,
+	.unlocked_ioctl	= flash_ioctl,
+};
+
+static struct miscdevice flash_miscdev =
+{
+	NWFLASH_MINOR,
+	"nwflash",
+	&flash_fops
+};
+
+static int __init nwflash_init(void)
+{
+	int ret = -ENODEV;
+
+	if (machine_is_netwinder()) {
+		int id;
+
+		FLASH_BASE = ioremap(DC21285_FLASH, KFLASH_SIZE4);
+		if (!FLASH_BASE)
+			goto out;
+
+		id = get_flash_id();
+		if ((id != KFLASH_ID) && (id != KFLASH_ID4)) {
+			ret = -ENXIO;
+			iounmap((void *)FLASH_BASE);
+			printk("Flash: incorrect ID 0x%04X.\n", id);
+			goto out;
+		}
+
+		printk("Flash ROM driver v.%s, flash device ID 0x%04X, size %d Mb.\n",
+		       NWFLASH_VERSION, id, gbFlashSize / (1024 * 1024));
+
+		ret = misc_register(&flash_miscdev);
+		if (ret < 0) {
+			iounmap((void *)FLASH_BASE);
+		}
+	}
+out:
+	return ret;
+}
+
+static void __exit nwflash_exit(void)
+{
+	misc_deregister(&flash_miscdev);
+	iounmap((void *)FLASH_BASE);
+}
+
+MODULE_DESCRIPTION("NetWinder flash memory driver");
+MODULE_LICENSE("GPL");
+
+module_param(flashdebug, bool, 0644);
+
+module_init(nwflash_init);
+module_exit(nwflash_exit);