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, 341 insertions, 0 deletions

diff --git a/drivers/char/agp/backend.c b/drivers/char/agp/backend.c
new file mode 100644
index 000000000..8983addca
--- /dev/null
+++ b/drivers/char/agp/backend.c
@@ -0,0 +1,341 @@
+/*
+ * AGPGART driver backend routines.
+ * Copyright (C) 2004 Silicon Graphics, Inc.
+ * Copyright (C) 2002-2003 Dave Jones.
+ * Copyright (C) 1999 Jeff Hartmann.
+ * Copyright (C) 1999 Precision Insight, Inc.
+ * Copyright (C) 1999 Xi Graphics, Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * JEFF HARTMANN, DAVE JONES, OR ANY OTHER CONTRIBUTORS BE LIABLE FOR ANY CLAIM,
+ * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+ * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE
+ * OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * TODO:
+ * - Allocate more than order 0 pages to avoid too much linear map splitting.
+ */
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/pagemap.h>
+#include <linux/miscdevice.h>
+#include <linux/pm.h>
+#include <linux/agp_backend.h>
+#include <linux/agpgart.h>
+#include <linux/vmalloc.h>
+#include <asm/io.h>
+#include "agp.h"
+
+/* Due to XFree86 brain-damage, we can't go to 1.0 until they
+ * fix some real stupidity. It's only by chance we can bump
+ * past 0.99 at all due to some boolean logic error. */
+#define AGPGART_VERSION_MAJOR 0
+#define AGPGART_VERSION_MINOR 103
+static const struct agp_version agp_current_version =
+{
+	.major = AGPGART_VERSION_MAJOR,
+	.minor = AGPGART_VERSION_MINOR,
+};
+
+struct agp_bridge_data *(*agp_find_bridge)(struct pci_dev *) =
+	&agp_generic_find_bridge;
+
+struct agp_bridge_data *agp_bridge;
+LIST_HEAD(agp_bridges);
+EXPORT_SYMBOL(agp_bridge);
+EXPORT_SYMBOL(agp_bridges);
+EXPORT_SYMBOL(agp_find_bridge);
+
+/**
+ *	agp_backend_acquire  -  attempt to acquire an agp backend.
+ *	@pdev: the PCI device
+ *
+ */
+struct agp_bridge_data *agp_backend_acquire(struct pci_dev *pdev)
+{
+	struct agp_bridge_data *bridge;
+
+	bridge = agp_find_bridge(pdev);
+
+	if (!bridge)
+		return NULL;
+
+	if (atomic_read(&bridge->agp_in_use))
+		return NULL;
+	atomic_inc(&bridge->agp_in_use);
+	return bridge;
+}
+EXPORT_SYMBOL(agp_backend_acquire);
+
+
+/**
+ *	agp_backend_release  -  release the lock on the agp backend.
+ *	@bridge: the AGP backend to release
+ *
+ *	The caller must insure that the graphics aperture translation table
+ *	is read for use by another entity.
+ *
+ *	(Ensure that all memory it bound is unbound.)
+ */
+void agp_backend_release(struct agp_bridge_data *bridge)
+{
+
+	if (bridge)
+		atomic_dec(&bridge->agp_in_use);
+}
+EXPORT_SYMBOL(agp_backend_release);
+
+
+static const struct { int mem, agp; } maxes_table[] = {
+	{0, 0},
+	{32, 4},
+	{64, 28},
+	{128, 96},
+	{256, 204},
+	{512, 440},
+	{1024, 942},
+	{2048, 1920},
+	{4096, 3932}
+};
+
+static int agp_find_max(void)
+{
+	long memory, index, result;
+
+#if PAGE_SHIFT < 20
+	memory = totalram_pages() >> (20 - PAGE_SHIFT);
+#else
+	memory = totalram_pages() << (PAGE_SHIFT - 20);
+#endif
+	index = 1;
+
+	while ((memory > maxes_table[index].mem) && (index < 8))
+		index++;
+
+	result = maxes_table[index - 1].agp +
+	   ( (memory - maxes_table[index - 1].mem)  *
+	     (maxes_table[index].agp - maxes_table[index - 1].agp)) /
+	   (maxes_table[index].mem - maxes_table[index - 1].mem);
+
+	result = result << (20 - PAGE_SHIFT);
+	return result;
+}
+
+
+static int agp_backend_initialize(struct agp_bridge_data *bridge)
+{
+	int size_value, rc, got_gatt=0, got_keylist=0;
+
+	bridge->max_memory_agp = agp_find_max();
+	bridge->version = &agp_current_version;
+
+	if (bridge->driver->needs_scratch_page) {
+		struct page *page = bridge->driver->agp_alloc_page(bridge);
+
+		if (!page) {
+			dev_err(&bridge->dev->dev,
+				"can't get memory for scratch page\n");
+			return -ENOMEM;
+		}
+
+		bridge->scratch_page_page = page;
+		bridge->scratch_page_dma = page_to_phys(page);
+
+		bridge->scratch_page = bridge->driver->mask_memory(bridge,
+						   bridge->scratch_page_dma, 0);
+	}
+
+	size_value = bridge->driver->fetch_size();
+	if (size_value == 0) {
+		dev_err(&bridge->dev->dev, "can't determine aperture size\n");
+		rc = -EINVAL;
+		goto err_out;
+	}
+	if (bridge->driver->create_gatt_table(bridge)) {
+		dev_err(&bridge->dev->dev,
+			"can't get memory for graphics translation table\n");
+		rc = -ENOMEM;
+		goto err_out;
+	}
+	got_gatt = 1;
+
+	bridge->key_list = vzalloc(PAGE_SIZE * 4);
+	if (bridge->key_list == NULL) {
+		dev_err(&bridge->dev->dev,
+			"can't allocate memory for key lists\n");
+		rc = -ENOMEM;
+		goto err_out;
+	}
+	got_keylist = 1;
+
+	/* FIXME vmalloc'd memory not guaranteed contiguous */
+
+	if (bridge->driver->configure()) {
+		dev_err(&bridge->dev->dev, "error configuring host chipset\n");
+		rc = -EINVAL;
+		goto err_out;
+	}
+	INIT_LIST_HEAD(&bridge->mapped_list);
+	spin_lock_init(&bridge->mapped_lock);
+
+	return 0;
+
+err_out:
+	if (bridge->driver->needs_scratch_page) {
+		struct page *page = bridge->scratch_page_page;
+
+		bridge->driver->agp_destroy_page(page, AGP_PAGE_DESTROY_UNMAP);
+		bridge->driver->agp_destroy_page(page, AGP_PAGE_DESTROY_FREE);
+	}
+	if (got_gatt)
+		bridge->driver->free_gatt_table(bridge);
+	if (got_keylist) {
+		vfree(bridge->key_list);
+		bridge->key_list = NULL;
+	}
+	return rc;
+}
+
+/* cannot be __exit b/c as it could be called from __init code */
+static void agp_backend_cleanup(struct agp_bridge_data *bridge)
+{
+	if (bridge->driver->cleanup)
+		bridge->driver->cleanup();
+	if (bridge->driver->free_gatt_table)
+		bridge->driver->free_gatt_table(bridge);
+
+	vfree(bridge->key_list);
+	bridge->key_list = NULL;
+
+	if (bridge->driver->agp_destroy_page &&
+	    bridge->driver->needs_scratch_page) {
+		struct page *page = bridge->scratch_page_page;
+
+		bridge->driver->agp_destroy_page(page, AGP_PAGE_DESTROY_UNMAP);
+		bridge->driver->agp_destroy_page(page, AGP_PAGE_DESTROY_FREE);
+	}
+}
+
+/* When we remove the global variable agp_bridge from all drivers
+ * then agp_alloc_bridge and agp_generic_find_bridge need to be updated
+ */
+
+struct agp_bridge_data *agp_alloc_bridge(void)
+{
+	struct agp_bridge_data *bridge;
+
+	bridge = kzalloc_obj(*bridge);
+	if (!bridge)
+		return NULL;
+
+	atomic_set(&bridge->agp_in_use, 0);
+	atomic_set(&bridge->current_memory_agp, 0);
+
+	if (list_empty(&agp_bridges))
+		agp_bridge = bridge;
+
+	return bridge;
+}
+EXPORT_SYMBOL(agp_alloc_bridge);
+
+
+void agp_put_bridge(struct agp_bridge_data *bridge)
+{
+        kfree(bridge);
+
+        if (list_empty(&agp_bridges))
+                agp_bridge = NULL;
+}
+EXPORT_SYMBOL(agp_put_bridge);
+
+
+int agp_add_bridge(struct agp_bridge_data *bridge)
+{
+	int error;
+
+	if (agp_off) {
+		error = -ENODEV;
+		goto err_put_bridge;
+	}
+
+	if (!bridge->dev) {
+		printk (KERN_DEBUG PFX "Erk, registering with no pci_dev!\n");
+		error = -EINVAL;
+		goto err_put_bridge;
+	}
+
+	/* Grab reference on the chipset driver. */
+	if (!try_module_get(bridge->driver->owner)) {
+		dev_info(&bridge->dev->dev, "can't lock chipset driver\n");
+		error = -EINVAL;
+		goto err_put_bridge;
+	}
+
+	error = agp_backend_initialize(bridge);
+	if (error) {
+		dev_info(&bridge->dev->dev,
+			 "agp_backend_initialize() failed\n");
+		goto err_out;
+	}
+
+	if (list_empty(&agp_bridges)) {
+		dev_info(&bridge->dev->dev, "AGP aperture is %dM @ 0x%lx\n",
+			 bridge->driver->fetch_size(), bridge->gart_bus_addr);
+
+	}
+
+	list_add(&bridge->list, &agp_bridges);
+	return 0;
+
+err_out:
+	module_put(bridge->driver->owner);
+err_put_bridge:
+	agp_put_bridge(bridge);
+	return error;
+}
+EXPORT_SYMBOL_GPL(agp_add_bridge);
+
+
+void agp_remove_bridge(struct agp_bridge_data *bridge)
+{
+	agp_backend_cleanup(bridge);
+	list_del(&bridge->list);
+	module_put(bridge->driver->owner);
+}
+EXPORT_SYMBOL_GPL(agp_remove_bridge);
+
+int agp_off;
+int agp_try_unsupported_boot;
+EXPORT_SYMBOL(agp_off);
+EXPORT_SYMBOL(agp_try_unsupported_boot);
+
+#ifndef MODULE
+static __init int agp_setup(char *s)
+{
+	if (!strcmp(s,"off"))
+		agp_off = 1;
+	if (!strcmp(s,"try_unsupported"))
+		agp_try_unsupported_boot = 1;
+	return 1;
+}
+__setup("agp=", agp_setup);
+#endif
+
+MODULE_AUTHOR("Dave Jones, Jeff Hartmann");
+MODULE_DESCRIPTION("AGP GART driver");
+MODULE_LICENSE("GPL and additional rights");
+MODULE_ALIAS_MISCDEV(AGPGART_MINOR);