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, 540 insertions, 0 deletions

diff --git a/drivers/gpu/host1x/syncpt.c b/drivers/gpu/host1x/syncpt.c
new file mode 100644
index 000000000..2c111710f
--- /dev/null
+++ b/drivers/gpu/host1x/syncpt.c
@@ -0,0 +1,540 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Tegra host1x Syncpoints
+ *
+ * Copyright (c) 2010-2015, NVIDIA Corporation.
+ */
+
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/dma-fence.h>
+#include <linux/overflow.h>
+#include <linux/slab.h>
+
+#include <trace/events/host1x.h>
+
+#include "syncpt.h"
+#include "dev.h"
+#include "intr.h"
+#include "debug.h"
+
+#define SYNCPT_CHECK_PERIOD (2 * HZ)
+#define MAX_STUCK_CHECK_COUNT 15
+
+static struct host1x_syncpt_base *
+host1x_syncpt_base_request(struct host1x *host)
+{
+	struct host1x_syncpt_base *bases = host->bases;
+	unsigned int i;
+
+	for (i = 0; i < host->info->nb_bases; i++)
+		if (!bases[i].requested)
+			break;
+
+	if (i >= host->info->nb_bases)
+		return NULL;
+
+	bases[i].requested = true;
+	return &bases[i];
+}
+
+static void host1x_syncpt_base_free(struct host1x_syncpt_base *base)
+{
+	if (base)
+		base->requested = false;
+}
+
+/**
+ * host1x_syncpt_alloc() - allocate a syncpoint
+ * @host: host1x device data
+ * @flags: bitfield of HOST1X_SYNCPT_* flags
+ * @name: name for the syncpoint for use in debug prints
+ *
+ * Allocates a hardware syncpoint for the caller's use. The caller then has
+ * the sole authority to mutate the syncpoint's value until it is freed again.
+ *
+ * If no free syncpoints are available, or a NULL name was specified, returns
+ * NULL.
+ */
+struct host1x_syncpt *host1x_syncpt_alloc(struct host1x *host,
+					  unsigned long flags,
+					  const char *name)
+{
+	struct host1x_syncpt *sp = host->syncpt;
+	char *full_name;
+	unsigned int i;
+
+	if (!name)
+		return NULL;
+
+	mutex_lock(&host->syncpt_mutex);
+
+	for (i = 0; i < host->info->nb_pts && kref_read(&sp->ref); i++, sp++)
+		;
+
+	if (i >= host->info->nb_pts)
+		goto unlock;
+
+	if (flags & HOST1X_SYNCPT_HAS_BASE) {
+		sp->base = host1x_syncpt_base_request(host);
+		if (!sp->base)
+			goto unlock;
+	}
+
+	full_name = kasprintf(GFP_KERNEL, "%u-%s", sp->id, name);
+	if (!full_name)
+		goto free_base;
+
+	sp->name = full_name;
+
+	if (flags & HOST1X_SYNCPT_CLIENT_MANAGED)
+		sp->client_managed = true;
+	else
+		sp->client_managed = false;
+
+	kref_init(&sp->ref);
+
+	mutex_unlock(&host->syncpt_mutex);
+	return sp;
+
+free_base:
+	host1x_syncpt_base_free(sp->base);
+	sp->base = NULL;
+unlock:
+	mutex_unlock(&host->syncpt_mutex);
+	return NULL;
+}
+EXPORT_SYMBOL(host1x_syncpt_alloc);
+
+/**
+ * host1x_syncpt_id() - retrieve syncpoint ID
+ * @sp: host1x syncpoint
+ *
+ * Given a pointer to a struct host1x_syncpt, retrieves its ID. This ID is
+ * often used as a value to program into registers that control how hardware
+ * blocks interact with syncpoints.
+ */
+u32 host1x_syncpt_id(struct host1x_syncpt *sp)
+{
+	return sp->id;
+}
+EXPORT_SYMBOL(host1x_syncpt_id);
+
+/**
+ * host1x_syncpt_incr_max() - update the value sent to hardware
+ * @sp: host1x syncpoint
+ * @incrs: number of increments
+ */
+u32 host1x_syncpt_incr_max(struct host1x_syncpt *sp, u32 incrs)
+{
+	/*
+	 * Syncpoint values are intended to be modulo 2^32, so overflow
+	 * here is intended.
+	 */
+	return (u32)atomic_add_return(incrs, &sp->max_val);
+}
+EXPORT_SYMBOL(host1x_syncpt_incr_max);
+
+ /*
+ * Write cached syncpoint and waitbase values to hardware.
+ */
+void host1x_syncpt_restore(struct host1x *host)
+{
+	struct host1x_syncpt *sp_base = host->syncpt;
+	unsigned int i;
+
+	for (i = 0; i < host1x_syncpt_nb_pts(host); i++) {
+		/*
+		 * Unassign syncpt from channels for purposes of Tegra186
+		 * syncpoint protection. This prevents any channel from
+		 * accessing it until it is reassigned.
+		 */
+		host1x_hw_syncpt_assign_to_channel(host, sp_base + i, NULL);
+		host1x_hw_syncpt_restore(host, sp_base + i);
+	}
+
+	for (i = 0; i < host1x_syncpt_nb_bases(host); i++)
+		host1x_hw_syncpt_restore_wait_base(host, sp_base + i);
+
+	host1x_hw_syncpt_enable_protection(host);
+
+	wmb();
+}
+
+/*
+ * Update the cached syncpoint and waitbase values by reading them
+ * from the registers.
+  */
+void host1x_syncpt_save(struct host1x *host)
+{
+	struct host1x_syncpt *sp_base = host->syncpt;
+	unsigned int i;
+
+	for (i = 0; i < host1x_syncpt_nb_pts(host); i++) {
+		if (host1x_syncpt_client_managed(sp_base + i))
+			host1x_hw_syncpt_load(host, sp_base + i);
+		else
+			WARN_ON(!host1x_syncpt_idle(sp_base + i));
+	}
+
+	for (i = 0; i < host1x_syncpt_nb_bases(host); i++)
+		host1x_hw_syncpt_load_wait_base(host, sp_base + i);
+}
+
+/*
+ * Updates the cached syncpoint value by reading a new value from the hardware
+ * register
+ */
+u32 host1x_syncpt_load(struct host1x_syncpt *sp)
+{
+	u32 val;
+
+	val = host1x_hw_syncpt_load(sp->host, sp);
+	trace_host1x_syncpt_load_min(sp->id, val);
+
+	return val;
+}
+
+/*
+ * Get the current syncpoint base
+ */
+u32 host1x_syncpt_load_wait_base(struct host1x_syncpt *sp)
+{
+	host1x_hw_syncpt_load_wait_base(sp->host, sp);
+
+	return sp->base_val;
+}
+
+/**
+ * host1x_syncpt_incr() - increment syncpoint value from CPU, updating cache
+ * @sp: host1x syncpoint
+ */
+int host1x_syncpt_incr(struct host1x_syncpt *sp)
+{
+	return host1x_hw_syncpt_cpu_incr(sp->host, sp);
+}
+EXPORT_SYMBOL(host1x_syncpt_incr);
+
+/**
+ * host1x_syncpt_wait() - wait for a syncpoint to reach a given value
+ * @sp: host1x syncpoint
+ * @thresh: threshold
+ * @timeout: maximum time to wait for the syncpoint to reach the given value
+ * @value: return location for the syncpoint value
+ */
+int host1x_syncpt_wait(struct host1x_syncpt *sp, u32 thresh, long timeout,
+		       u32 *value)
+{
+	struct dma_fence *fence;
+	long wait_err;
+	u32 curr;
+
+	curr = host1x_syncpt_load(sp);
+
+	if (value)
+		*value = curr;
+
+	if (host1x_syncpt_is_expired(sp, thresh))
+		return 0;
+
+	if (timeout < 0)
+		timeout = LONG_MAX;
+	else if (timeout == 0)
+		return -EAGAIN;
+
+	fence = host1x_fence_create(sp, thresh, false);
+	if (IS_ERR(fence))
+		return PTR_ERR(fence);
+
+	wait_err = dma_fence_wait_timeout(fence, true, timeout);
+	if (wait_err == 0)
+		host1x_fence_cancel(fence);
+	dma_fence_put(fence);
+
+	/*
+	 * Don't rely on dma_fence_wait_timeout return value,
+	 * since it returns zero both on timeout and if the
+	 * wait completed with 0 jiffies left.
+	 */
+	if (wait_err == 0 && !host1x_syncpt_is_expired(sp, thresh)) {
+		if (value)
+			*value = host1x_syncpt_load(sp);
+
+		return -EAGAIN;
+	} else if (wait_err < 0) {
+		return wait_err;
+	} else {
+		/* Success, read the value cached by ISR */
+		if (value)
+			*value = host1x_syncpt_read_min(sp);
+
+		return 0;
+	}
+}
+EXPORT_SYMBOL(host1x_syncpt_wait);
+
+/*
+ * Returns true if syncpoint is expired, false if we may need to wait
+ */
+bool host1x_syncpt_is_expired(struct host1x_syncpt *sp, u32 thresh)
+{
+	u32 current_val;
+
+	smp_rmb();
+
+	current_val = (u32)atomic_read(&sp->min_val);
+
+	return (wrapping_sub(u32, current_val, thresh) & 0x80000000U) == 0U;
+}
+
+int host1x_syncpt_init(struct host1x *host)
+{
+	struct host1x_syncpt_base *bases;
+	struct host1x_syncpt *syncpt;
+	unsigned int i;
+
+	syncpt = devm_kcalloc(host->dev, host->info->nb_pts, sizeof(*syncpt),
+			      GFP_KERNEL);
+	if (!syncpt)
+		return -ENOMEM;
+
+	bases = devm_kcalloc(host->dev, host->info->nb_bases, sizeof(*bases),
+			     GFP_KERNEL);
+	if (!bases)
+		return -ENOMEM;
+
+	for (i = 0; i < host->info->nb_pts; i++) {
+		syncpt[i].id = i;
+		syncpt[i].host = host;
+	}
+
+	for (i = 0; i < host->info->nb_bases; i++)
+		bases[i].id = i;
+
+	mutex_init(&host->syncpt_mutex);
+	host->syncpt = syncpt;
+	host->bases = bases;
+
+	/* Allocate sync point to use for clearing waits for expired fences */
+	host->nop_sp = host1x_syncpt_alloc(host, 0, "reserved-nop");
+	if (!host->nop_sp)
+		return -ENOMEM;
+
+	if (host->info->reserve_vblank_syncpts) {
+		kref_init(&host->syncpt[26].ref);
+		kref_init(&host->syncpt[27].ref);
+	}
+
+	return 0;
+}
+
+/**
+ * host1x_syncpt_request() - request a syncpoint
+ * @client: client requesting the syncpoint
+ * @flags: flags
+ *
+ * host1x client drivers can use this function to allocate a syncpoint for
+ * subsequent use. A syncpoint returned by this function will be reserved for
+ * use by the client exclusively. When no longer using a syncpoint, a host1x
+ * client driver needs to release it using host1x_syncpt_put().
+ */
+struct host1x_syncpt *host1x_syncpt_request(struct host1x_client *client,
+					    unsigned long flags)
+{
+	struct host1x *host = dev_get_drvdata(client->host->parent);
+
+	return host1x_syncpt_alloc(host, flags, dev_name(client->dev));
+}
+EXPORT_SYMBOL(host1x_syncpt_request);
+
+static void syncpt_release(struct kref *ref)
+{
+	struct host1x_syncpt *sp = container_of(ref, struct host1x_syncpt, ref);
+
+	atomic_set(&sp->max_val, host1x_syncpt_read(sp));
+
+	sp->locked = false;
+
+	host1x_syncpt_base_free(sp->base);
+	kfree(sp->name);
+	sp->base = NULL;
+	sp->name = NULL;
+	sp->client_managed = false;
+
+	mutex_unlock(&sp->host->syncpt_mutex);
+}
+
+/**
+ * host1x_syncpt_put() - free a requested syncpoint
+ * @sp: host1x syncpoint
+ *
+ * Release a syncpoint previously allocated using host1x_syncpt_request(). A
+ * host1x client driver should call this when the syncpoint is no longer in
+ * use.
+ */
+void host1x_syncpt_put(struct host1x_syncpt *sp)
+{
+	if (!sp)
+		return;
+
+	kref_put_mutex(&sp->ref, syncpt_release, &sp->host->syncpt_mutex);
+}
+EXPORT_SYMBOL(host1x_syncpt_put);
+
+void host1x_syncpt_deinit(struct host1x *host)
+{
+	struct host1x_syncpt *sp = host->syncpt;
+	unsigned int i;
+
+	for (i = 0; i < host->info->nb_pts; i++, sp++)
+		kfree(sp->name);
+}
+
+/**
+ * host1x_syncpt_read_max() - read maximum syncpoint value
+ * @sp: host1x syncpoint
+ *
+ * The maximum syncpoint value indicates how many operations there are in
+ * queue, either in channel or in a software thread.
+ */
+u32 host1x_syncpt_read_max(struct host1x_syncpt *sp)
+{
+	smp_rmb();
+
+	return (u32)atomic_read(&sp->max_val);
+}
+EXPORT_SYMBOL(host1x_syncpt_read_max);
+
+/**
+ * host1x_syncpt_read_min() - read minimum syncpoint value
+ * @sp: host1x syncpoint
+ *
+ * The minimum syncpoint value is a shadow of the current sync point value in
+ * hardware.
+ */
+u32 host1x_syncpt_read_min(struct host1x_syncpt *sp)
+{
+	smp_rmb();
+
+	return (u32)atomic_read(&sp->min_val);
+}
+EXPORT_SYMBOL(host1x_syncpt_read_min);
+
+/**
+ * host1x_syncpt_read() - read the current syncpoint value
+ * @sp: host1x syncpoint
+ */
+u32 host1x_syncpt_read(struct host1x_syncpt *sp)
+{
+	return host1x_syncpt_load(sp);
+}
+EXPORT_SYMBOL(host1x_syncpt_read);
+
+unsigned int host1x_syncpt_nb_pts(struct host1x *host)
+{
+	return host->info->nb_pts;
+}
+
+unsigned int host1x_syncpt_nb_bases(struct host1x *host)
+{
+	return host->info->nb_bases;
+}
+
+unsigned int host1x_syncpt_nb_mlocks(struct host1x *host)
+{
+	return host->info->nb_mlocks;
+}
+
+/**
+ * host1x_syncpt_get_by_id() - obtain a syncpoint by ID
+ * @host: host1x controller
+ * @id: syncpoint ID
+ */
+struct host1x_syncpt *host1x_syncpt_get_by_id(struct host1x *host,
+					      unsigned int id)
+{
+	if (id >= host->info->nb_pts)
+		return NULL;
+
+	if (kref_get_unless_zero(&host->syncpt[id].ref))
+		return &host->syncpt[id];
+	else
+		return NULL;
+}
+EXPORT_SYMBOL(host1x_syncpt_get_by_id);
+
+/**
+ * host1x_syncpt_get_by_id_noref() - obtain a syncpoint by ID but don't
+ * 	increase the refcount.
+ * @host: host1x controller
+ * @id: syncpoint ID
+ */
+struct host1x_syncpt *host1x_syncpt_get_by_id_noref(struct host1x *host,
+						    unsigned int id)
+{
+	if (id >= host->info->nb_pts)
+		return NULL;
+
+	return &host->syncpt[id];
+}
+EXPORT_SYMBOL(host1x_syncpt_get_by_id_noref);
+
+/**
+ * host1x_syncpt_get() - increment syncpoint refcount
+ * @sp: syncpoint
+ */
+struct host1x_syncpt *host1x_syncpt_get(struct host1x_syncpt *sp)
+{
+	kref_get(&sp->ref);
+
+	return sp;
+}
+EXPORT_SYMBOL(host1x_syncpt_get);
+
+/**
+ * host1x_syncpt_get_base() - obtain the wait base associated with a syncpoint
+ * @sp: host1x syncpoint
+ */
+struct host1x_syncpt_base *host1x_syncpt_get_base(struct host1x_syncpt *sp)
+{
+	return sp ? sp->base : NULL;
+}
+EXPORT_SYMBOL(host1x_syncpt_get_base);
+
+/**
+ * host1x_syncpt_base_id() - retrieve the ID of a syncpoint wait base
+ * @base: host1x syncpoint wait base
+ */
+u32 host1x_syncpt_base_id(struct host1x_syncpt_base *base)
+{
+	return base->id;
+}
+EXPORT_SYMBOL(host1x_syncpt_base_id);
+
+static void do_nothing(struct kref *ref)
+{
+}
+
+/**
+ * host1x_syncpt_release_vblank_reservation() - Make VBLANK syncpoint
+ *   available for allocation
+ *
+ * @client: host1x bus client
+ * @syncpt_id: syncpoint ID to make available
+ *
+ * Makes VBLANK<i> syncpoint available for allocatation if it was
+ * reserved at initialization time. This should be called by the display
+ * driver after it has ensured that any VBLANK increment programming configured
+ * by the boot chain has been disabled.
+ */
+void host1x_syncpt_release_vblank_reservation(struct host1x_client *client,
+					      u32 syncpt_id)
+{
+	struct host1x *host = dev_get_drvdata(client->host->parent);
+
+	if (!host->info->reserve_vblank_syncpts)
+		return;
+
+	kref_put(&host->syncpt[syncpt_id].ref, do_nothing);
+}
+EXPORT_SYMBOL(host1x_syncpt_release_vblank_reservation);