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, 560 insertions, 0 deletions

diff --git a/drivers/clk/ti/divider.c b/drivers/clk/ti/divider.c
new file mode 100644
index 000000000..3b438c2d6
--- /dev/null
+++ b/drivers/clk/ti/divider.c
@@ -0,0 +1,560 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * TI Divider Clock
+ *
+ * Copyright (C) 2013 Texas Instruments, Inc.
+ *
+ * Tero Kristo <t-kristo@ti.com>
+ */
+
+#include <linux/clk-provider.h>
+#include <linux/slab.h>
+#include <linux/err.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/clk/ti.h>
+#include "clock.h"
+
+#undef pr_fmt
+#define pr_fmt(fmt) "%s: " fmt, __func__
+
+static unsigned int _get_table_div(const struct clk_div_table *table,
+				   unsigned int val)
+{
+	const struct clk_div_table *clkt;
+
+	for (clkt = table; clkt->div; clkt++)
+		if (clkt->val == val)
+			return clkt->div;
+	return 0;
+}
+
+static void _setup_mask(struct clk_omap_divider *divider)
+{
+	u16 mask;
+	u32 max_val;
+	const struct clk_div_table *clkt;
+
+	if (divider->table) {
+		max_val = 0;
+
+		for (clkt = divider->table; clkt->div; clkt++)
+			if (clkt->val > max_val)
+				max_val = clkt->val;
+	} else {
+		max_val = divider->max;
+
+		if (!(divider->flags & CLK_DIVIDER_ONE_BASED) &&
+		    !(divider->flags & CLK_DIVIDER_POWER_OF_TWO))
+			max_val--;
+	}
+
+	if (divider->flags & CLK_DIVIDER_POWER_OF_TWO)
+		mask = fls(max_val) - 1;
+	else
+		mask = max_val;
+
+	divider->mask = (1 << fls(mask)) - 1;
+}
+
+static unsigned int _get_div(struct clk_omap_divider *divider, unsigned int val)
+{
+	if (divider->flags & CLK_DIVIDER_ONE_BASED)
+		return val;
+	if (divider->flags & CLK_DIVIDER_POWER_OF_TWO)
+		return 1 << val;
+	if (divider->table)
+		return _get_table_div(divider->table, val);
+	return val + 1;
+}
+
+static unsigned int _get_table_val(const struct clk_div_table *table,
+				   unsigned int div)
+{
+	const struct clk_div_table *clkt;
+
+	for (clkt = table; clkt->div; clkt++)
+		if (clkt->div == div)
+			return clkt->val;
+	return 0;
+}
+
+static unsigned int _get_val(struct clk_omap_divider *divider, u8 div)
+{
+	if (divider->flags & CLK_DIVIDER_ONE_BASED)
+		return div;
+	if (divider->flags & CLK_DIVIDER_POWER_OF_TWO)
+		return __ffs(div);
+	if (divider->table)
+		return  _get_table_val(divider->table, div);
+	return div - 1;
+}
+
+static unsigned long ti_clk_divider_recalc_rate(struct clk_hw *hw,
+						unsigned long parent_rate)
+{
+	struct clk_omap_divider *divider = to_clk_omap_divider(hw);
+	unsigned int div, val;
+
+	val = ti_clk_ll_ops->clk_readl(&divider->reg) >> divider->shift;
+	val &= divider->mask;
+
+	div = _get_div(divider, val);
+	if (!div) {
+		WARN(!(divider->flags & CLK_DIVIDER_ALLOW_ZERO),
+		     "%s: Zero divisor and CLK_DIVIDER_ALLOW_ZERO not set\n",
+		     clk_hw_get_name(hw));
+		return parent_rate;
+	}
+
+	return DIV_ROUND_UP(parent_rate, div);
+}
+
+/*
+ * The reverse of DIV_ROUND_UP: The maximum number which
+ * divided by m is r
+ */
+#define MULT_ROUND_UP(r, m) ((r) * (m) + (m) - 1)
+
+static bool _is_valid_table_div(const struct clk_div_table *table,
+				unsigned int div)
+{
+	const struct clk_div_table *clkt;
+
+	for (clkt = table; clkt->div; clkt++)
+		if (clkt->div == div)
+			return true;
+	return false;
+}
+
+static bool _is_valid_div(struct clk_omap_divider *divider, unsigned int div)
+{
+	if (divider->flags & CLK_DIVIDER_POWER_OF_TWO)
+		return is_power_of_2(div);
+	if (divider->table)
+		return _is_valid_table_div(divider->table, div);
+	return true;
+}
+
+static int _div_round_up(const struct clk_div_table *table,
+			 unsigned long parent_rate, unsigned long rate)
+{
+	const struct clk_div_table *clkt;
+	int up = INT_MAX;
+	int div = DIV_ROUND_UP_ULL((u64)parent_rate, rate);
+
+	for (clkt = table; clkt->div; clkt++) {
+		if (clkt->div == div)
+			return clkt->div;
+		else if (clkt->div < div)
+			continue;
+
+		if ((clkt->div - div) < (up - div))
+			up = clkt->div;
+	}
+
+	return up;
+}
+
+static int _div_round(const struct clk_div_table *table,
+		      unsigned long parent_rate, unsigned long rate)
+{
+	if (!table)
+		return DIV_ROUND_UP(parent_rate, rate);
+
+	return _div_round_up(table, parent_rate, rate);
+}
+
+static int ti_clk_divider_bestdiv(struct clk_hw *hw, unsigned long rate,
+				  unsigned long *best_parent_rate)
+{
+	struct clk_omap_divider *divider = to_clk_omap_divider(hw);
+	int i, bestdiv = 0;
+	unsigned long parent_rate, best = 0, now, maxdiv;
+	unsigned long parent_rate_saved = *best_parent_rate;
+
+	if (!rate)
+		rate = 1;
+
+	maxdiv = divider->max;
+
+	if (!(clk_hw_get_flags(hw) & CLK_SET_RATE_PARENT)) {
+		parent_rate = *best_parent_rate;
+		bestdiv = _div_round(divider->table, parent_rate, rate);
+		bestdiv = bestdiv == 0 ? 1 : bestdiv;
+		bestdiv = bestdiv > maxdiv ? maxdiv : bestdiv;
+		return bestdiv;
+	}
+
+	/*
+	 * The maximum divider we can use without overflowing
+	 * unsigned long in rate * i below
+	 */
+	maxdiv = min(ULONG_MAX / rate, maxdiv);
+
+	for (i = 1; i <= maxdiv; i++) {
+		if (!_is_valid_div(divider, i))
+			continue;
+		if (rate * i == parent_rate_saved) {
+			/*
+			 * It's the most ideal case if the requested rate can be
+			 * divided from parent clock without needing to change
+			 * parent rate, so return the divider immediately.
+			 */
+			*best_parent_rate = parent_rate_saved;
+			return i;
+		}
+		parent_rate = clk_hw_round_rate(clk_hw_get_parent(hw),
+				MULT_ROUND_UP(rate, i));
+		now = DIV_ROUND_UP(parent_rate, i);
+		if (now <= rate && now > best) {
+			bestdiv = i;
+			best = now;
+			*best_parent_rate = parent_rate;
+		}
+	}
+
+	if (!bestdiv) {
+		bestdiv = divider->max;
+		*best_parent_rate =
+			clk_hw_round_rate(clk_hw_get_parent(hw), 1);
+	}
+
+	return bestdiv;
+}
+
+static int ti_clk_divider_determine_rate(struct clk_hw *hw,
+					 struct clk_rate_request *req)
+{
+	int div;
+	div = ti_clk_divider_bestdiv(hw, req->rate, &req->best_parent_rate);
+
+	req->rate = DIV_ROUND_UP(req->best_parent_rate, div);
+
+	return 0;
+}
+
+static int ti_clk_divider_set_rate(struct clk_hw *hw, unsigned long rate,
+				   unsigned long parent_rate)
+{
+	struct clk_omap_divider *divider;
+	unsigned int div, value;
+	u32 val;
+
+	if (!hw || !rate)
+		return -EINVAL;
+
+	divider = to_clk_omap_divider(hw);
+
+	div = DIV_ROUND_UP(parent_rate, rate);
+
+	if (div > divider->max)
+		div = divider->max;
+	if (div < divider->min)
+		div = divider->min;
+
+	value = _get_val(divider, div);
+
+	val = ti_clk_ll_ops->clk_readl(&divider->reg);
+	val &= ~(divider->mask << divider->shift);
+	val |= value << divider->shift;
+	ti_clk_ll_ops->clk_writel(val, &divider->reg);
+
+	ti_clk_latch(&divider->reg, divider->latch);
+
+	return 0;
+}
+
+/**
+ * clk_divider_save_context - Save the divider value
+ * @hw: pointer  struct clk_hw
+ *
+ * Save the divider value
+ */
+static int clk_divider_save_context(struct clk_hw *hw)
+{
+	struct clk_omap_divider *divider = to_clk_omap_divider(hw);
+	u32 val;
+
+	val = ti_clk_ll_ops->clk_readl(&divider->reg) >> divider->shift;
+	divider->context = val & divider->mask;
+
+	return 0;
+}
+
+/**
+ * clk_divider_restore_context - restore the saved the divider value
+ * @hw: pointer  struct clk_hw
+ *
+ * Restore the saved the divider value
+ */
+static void clk_divider_restore_context(struct clk_hw *hw)
+{
+	struct clk_omap_divider *divider = to_clk_omap_divider(hw);
+	u32 val;
+
+	val = ti_clk_ll_ops->clk_readl(&divider->reg);
+	val &= ~(divider->mask << divider->shift);
+	val |= divider->context << divider->shift;
+	ti_clk_ll_ops->clk_writel(val, &divider->reg);
+}
+
+const struct clk_ops ti_clk_divider_ops = {
+	.recalc_rate = ti_clk_divider_recalc_rate,
+	.determine_rate = ti_clk_divider_determine_rate,
+	.set_rate = ti_clk_divider_set_rate,
+	.save_context = clk_divider_save_context,
+	.restore_context = clk_divider_restore_context,
+};
+
+static struct clk *_register_divider(struct device_node *node,
+				     u32 flags,
+				     struct clk_omap_divider *div)
+{
+	struct clk_init_data init = {};
+	const char *parent_name;
+	const char *name;
+
+	parent_name = of_clk_get_parent_name(node, 0);
+
+	name = ti_dt_clk_name(node);
+	init.name = name;
+	init.ops = &ti_clk_divider_ops;
+	init.flags = flags;
+	init.parent_names = (parent_name ? &parent_name : NULL);
+	init.num_parents = (parent_name ? 1 : 0);
+
+	div->hw.init = &init;
+
+	/* register the clock */
+	return of_ti_clk_register(node, &div->hw, name);
+}
+
+int ti_clk_parse_divider_data(int *div_table, int num_dividers, int max_div,
+			      u8 flags, struct clk_omap_divider *divider)
+{
+	int valid_div = 0;
+	int i;
+	struct clk_div_table *tmp;
+	u16 min_div = 0;
+
+	if (!div_table) {
+		divider->min = 1;
+		divider->max = max_div;
+		_setup_mask(divider);
+		return 0;
+	}
+
+	i = 0;
+
+	while (!num_dividers || i < num_dividers) {
+		if (div_table[i] == -1)
+			break;
+		if (div_table[i])
+			valid_div++;
+		i++;
+	}
+
+	num_dividers = i;
+
+	tmp = kzalloc_objs(*tmp, valid_div + 1);
+	if (!tmp)
+		return -ENOMEM;
+
+	valid_div = 0;
+
+	for (i = 0; i < num_dividers; i++)
+		if (div_table[i] > 0) {
+			tmp[valid_div].div = div_table[i];
+			tmp[valid_div].val = i;
+			valid_div++;
+			if (div_table[i] > max_div)
+				max_div = div_table[i];
+			if (!min_div || div_table[i] < min_div)
+				min_div = div_table[i];
+		}
+
+	divider->min = min_div;
+	divider->max = max_div;
+	divider->table = tmp;
+	_setup_mask(divider);
+
+	return 0;
+}
+
+static int __init ti_clk_get_div_table(struct device_node *node,
+				       struct clk_omap_divider *div)
+{
+	struct clk_div_table *table;
+	const __be32 *divspec;
+	u32 val;
+	u32 num_div;
+	u32 valid_div;
+	int i;
+
+	divspec = of_get_property(node, "ti,dividers", &num_div);
+
+	if (!divspec)
+		return 0;
+
+	num_div /= 4;
+
+	valid_div = 0;
+
+	/* Determine required size for divider table */
+	for (i = 0; i < num_div; i++) {
+		of_property_read_u32_index(node, "ti,dividers", i, &val);
+		if (val)
+			valid_div++;
+	}
+
+	if (!valid_div) {
+		pr_err("no valid dividers for %pOFn table\n", node);
+		return -EINVAL;
+	}
+
+	table = kzalloc_objs(*table, valid_div + 1);
+	if (!table)
+		return -ENOMEM;
+
+	valid_div = 0;
+
+	for (i = 0; i < num_div; i++) {
+		of_property_read_u32_index(node, "ti,dividers", i, &val);
+		if (val) {
+			table[valid_div].div = val;
+			table[valid_div].val = i;
+			valid_div++;
+		}
+	}
+
+	div->table = table;
+
+	return 0;
+}
+
+static int _populate_divider_min_max(struct device_node *node,
+				     struct clk_omap_divider *divider)
+{
+	u32 min_div = 0;
+	u32 max_div = 0;
+	u32 val;
+	const struct clk_div_table *clkt;
+
+	if (!divider->table) {
+		/* Clk divider table not provided, determine min/max divs */
+		if (of_property_read_u32(node, "ti,min-div", &min_div))
+			min_div = 1;
+
+		if (of_property_read_u32(node, "ti,max-div", &max_div)) {
+			pr_err("no max-div for %pOFn!\n", node);
+			return -EINVAL;
+		}
+	} else {
+
+		for (clkt = divider->table; clkt->div; clkt++) {
+			val = clkt->div;
+			if (val > max_div)
+				max_div = val;
+			if (!min_div || val < min_div)
+				min_div = val;
+		}
+	}
+
+	divider->min = min_div;
+	divider->max = max_div;
+	_setup_mask(divider);
+
+	return 0;
+}
+
+static int __init ti_clk_divider_populate(struct device_node *node,
+					  struct clk_omap_divider *div,
+					  u32 *flags)
+{
+	u32 val;
+	int ret;
+
+	ret = ti_clk_get_reg_addr(node, 0, &div->reg);
+	if (ret)
+		return ret;
+
+	div->shift = div->reg.bit;
+
+	if (!of_property_read_u32(node, "ti,latch-bit", &val))
+		div->latch = val;
+	else
+		div->latch = -EINVAL;
+
+	*flags = 0;
+	div->flags = 0;
+
+	if (of_property_read_bool(node, "ti,index-starts-at-one"))
+		div->flags |= CLK_DIVIDER_ONE_BASED;
+
+	if (of_property_read_bool(node, "ti,index-power-of-two"))
+		div->flags |= CLK_DIVIDER_POWER_OF_TWO;
+
+	if (of_property_read_bool(node, "ti,set-rate-parent"))
+		*flags |= CLK_SET_RATE_PARENT;
+
+	ret = ti_clk_get_div_table(node, div);
+	if (ret)
+		return ret;
+
+	return _populate_divider_min_max(node, div);
+}
+
+/**
+ * of_ti_divider_clk_setup - Setup function for simple div rate clock
+ * @node: device node for this clock
+ *
+ * Sets up a basic divider clock.
+ */
+static void __init of_ti_divider_clk_setup(struct device_node *node)
+{
+	struct clk *clk;
+	u32 flags = 0;
+	struct clk_omap_divider *div;
+
+	div = kzalloc_obj(*div);
+	if (!div)
+		return;
+
+	if (ti_clk_divider_populate(node, div, &flags))
+		goto cleanup;
+
+	clk = _register_divider(node, flags, div);
+	if (!IS_ERR(clk)) {
+		of_clk_add_provider(node, of_clk_src_simple_get, clk);
+		of_ti_clk_autoidle_setup(node);
+		return;
+	}
+
+cleanup:
+	kfree(div->table);
+	kfree(div);
+}
+CLK_OF_DECLARE(divider_clk, "ti,divider-clock", of_ti_divider_clk_setup);
+
+static void __init of_ti_composite_divider_clk_setup(struct device_node *node)
+{
+	struct clk_omap_divider *div;
+	u32 tmp;
+
+	div = kzalloc_obj(*div);
+	if (!div)
+		return;
+
+	if (ti_clk_divider_populate(node, div, &tmp))
+		goto cleanup;
+
+	if (!ti_clk_add_component(node, &div->hw, CLK_COMPONENT_TYPE_DIVIDER))
+		return;
+
+cleanup:
+	kfree(div->table);
+	kfree(div);
+}
+CLK_OF_DECLARE(ti_composite_divider_clk, "ti,composite-divider-clock",
+	       of_ti_composite_divider_clk_setup);