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, 324 insertions, 0 deletions

diff --git a/drivers/soc/mediatek/mtk-devapc.c b/drivers/soc/mediatek/mtk-devapc.c
new file mode 100644
index 000000000..f54c96613
--- /dev/null
+++ b/drivers/soc/mediatek/mtk-devapc.c
@@ -0,0 +1,324 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2020 MediaTek Inc.
+ */
+
+#include <linux/clk.h>
+#include <linux/interrupt.h>
+#include <linux/iopoll.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
+#include <linux/of_address.h>
+
+#define VIO_MOD_TO_REG_IND(m)	((m) / 32)
+#define VIO_MOD_TO_REG_OFF(m)	((m) % 32)
+
+struct mtk_devapc_vio_dbgs {
+	union {
+		u32 vio_dbg0;
+		struct {
+			u32 mstid:16;
+			u32 dmnid:6;
+			u32 vio_w:1;
+			u32 vio_r:1;
+			u32 addr_h:4;
+			u32 resv:4;
+		} dbg0_bits;
+	};
+
+	u32 vio_dbg1;
+};
+
+struct mtk_devapc_regs_ofs {
+	/* reg offset */
+	u32 vio_mask_offset;
+	u32 vio_sta_offset;
+	u32 vio_dbg0_offset;
+	u32 vio_dbg1_offset;
+	u32 apc_con_offset;
+	u32 vio_shift_sta_offset;
+	u32 vio_shift_sel_offset;
+	u32 vio_shift_con_offset;
+};
+
+struct mtk_devapc_data {
+	/* numbers of violation index */
+	u32 vio_idx_num;
+	const struct mtk_devapc_regs_ofs *regs_ofs;
+};
+
+struct mtk_devapc_context {
+	struct device *dev;
+	void __iomem *infra_base;
+	struct clk *infra_clk;
+	const struct mtk_devapc_data *data;
+};
+
+static void clear_vio_status(struct mtk_devapc_context *ctx)
+{
+	void __iomem *reg;
+	int i;
+
+	reg = ctx->infra_base + ctx->data->regs_ofs->vio_sta_offset;
+
+	for (i = 0; i < VIO_MOD_TO_REG_IND(ctx->data->vio_idx_num) - 1; i++)
+		writel(GENMASK(31, 0), reg + 4 * i);
+
+	writel(GENMASK(VIO_MOD_TO_REG_OFF(ctx->data->vio_idx_num) - 1, 0),
+	       reg + 4 * i);
+}
+
+static void mask_module_irq(struct mtk_devapc_context *ctx, bool mask)
+{
+	void __iomem *reg;
+	u32 val;
+	int i;
+
+	reg = ctx->infra_base + ctx->data->regs_ofs->vio_mask_offset;
+
+	if (mask)
+		val = GENMASK(31, 0);
+	else
+		val = 0;
+
+	for (i = 0; i < VIO_MOD_TO_REG_IND(ctx->data->vio_idx_num) - 1; i++)
+		writel(val, reg + 4 * i);
+
+	val = readl(reg + 4 * i);
+	if (mask)
+		val |= GENMASK(VIO_MOD_TO_REG_OFF(ctx->data->vio_idx_num) - 1,
+			       0);
+	else
+		val &= ~GENMASK(VIO_MOD_TO_REG_OFF(ctx->data->vio_idx_num) - 1,
+				0);
+
+	writel(val, reg + 4 * i);
+}
+
+#define PHY_DEVAPC_TIMEOUT	0x10000
+
+/*
+ * devapc_sync_vio_dbg - do "shift" mechansim" to get full violation information.
+ *                       shift mechanism is depends on devapc hardware design.
+ *                       Mediatek devapc set multiple slaves as a group.
+ *                       When violation is triggered, violation info is kept
+ *                       inside devapc hardware.
+ *                       Driver should do shift mechansim to sync full violation
+ *                       info to VIO_DBGs registers.
+ *
+ */
+static int devapc_sync_vio_dbg(struct mtk_devapc_context *ctx)
+{
+	void __iomem *pd_vio_shift_sta_reg;
+	void __iomem *pd_vio_shift_sel_reg;
+	void __iomem *pd_vio_shift_con_reg;
+	int min_shift_group;
+	int ret;
+	u32 val;
+
+	pd_vio_shift_sta_reg = ctx->infra_base +
+			       ctx->data->regs_ofs->vio_shift_sta_offset;
+	pd_vio_shift_sel_reg = ctx->infra_base +
+			       ctx->data->regs_ofs->vio_shift_sel_offset;
+	pd_vio_shift_con_reg = ctx->infra_base +
+			       ctx->data->regs_ofs->vio_shift_con_offset;
+
+	/* Find the minimum shift group which has violation */
+	val = readl(pd_vio_shift_sta_reg);
+	if (!val)
+		return false;
+
+	min_shift_group = __ffs(val);
+
+	/* Assign the group to sync */
+	writel(0x1 << min_shift_group, pd_vio_shift_sel_reg);
+
+	/* Start syncing */
+	writel(0x1, pd_vio_shift_con_reg);
+
+	ret = readl_poll_timeout(pd_vio_shift_con_reg, val, val == 0x3, 0,
+				 PHY_DEVAPC_TIMEOUT);
+	if (ret) {
+		dev_err(ctx->dev, "%s: Shift violation info failed\n", __func__);
+		return false;
+	}
+
+	/* Stop syncing */
+	writel(0x0, pd_vio_shift_con_reg);
+
+	/* Write clear */
+	writel(0x1 << min_shift_group, pd_vio_shift_sta_reg);
+
+	return true;
+}
+
+/*
+ * devapc_extract_vio_dbg - extract full violation information after doing
+ *                          shift mechanism.
+ */
+static void devapc_extract_vio_dbg(struct mtk_devapc_context *ctx)
+{
+	struct mtk_devapc_vio_dbgs vio_dbgs;
+	void __iomem *vio_dbg0_reg;
+	void __iomem *vio_dbg1_reg;
+
+	vio_dbg0_reg = ctx->infra_base + ctx->data->regs_ofs->vio_dbg0_offset;
+	vio_dbg1_reg = ctx->infra_base + ctx->data->regs_ofs->vio_dbg1_offset;
+
+	vio_dbgs.vio_dbg0 = readl(vio_dbg0_reg);
+	vio_dbgs.vio_dbg1 = readl(vio_dbg1_reg);
+
+	/* Print violation information */
+	if (vio_dbgs.dbg0_bits.vio_w)
+		dev_info(ctx->dev, "Write Violation\n");
+	else if (vio_dbgs.dbg0_bits.vio_r)
+		dev_info(ctx->dev, "Read Violation\n");
+
+	dev_info(ctx->dev, "Bus ID:0x%x, Dom ID:0x%x, Vio Addr:0x%x\n",
+		 vio_dbgs.dbg0_bits.mstid, vio_dbgs.dbg0_bits.dmnid,
+		 vio_dbgs.vio_dbg1);
+}
+
+/*
+ * devapc_violation_irq - the devapc Interrupt Service Routine (ISR) will dump
+ *                        violation information including which master violates
+ *                        access slave.
+ */
+static irqreturn_t devapc_violation_irq(int irq_number, void *data)
+{
+	struct mtk_devapc_context *ctx = data;
+
+	while (devapc_sync_vio_dbg(ctx))
+		devapc_extract_vio_dbg(ctx);
+
+	clear_vio_status(ctx);
+
+	return IRQ_HANDLED;
+}
+
+/*
+ * start_devapc - unmask slave's irq to start receiving devapc violation.
+ */
+static void start_devapc(struct mtk_devapc_context *ctx)
+{
+	writel(BIT(31), ctx->infra_base + ctx->data->regs_ofs->apc_con_offset);
+
+	mask_module_irq(ctx, false);
+}
+
+/*
+ * stop_devapc - mask slave's irq to stop service.
+ */
+static void stop_devapc(struct mtk_devapc_context *ctx)
+{
+	mask_module_irq(ctx, true);
+
+	writel(BIT(2), ctx->infra_base + ctx->data->regs_ofs->apc_con_offset);
+}
+
+static const struct mtk_devapc_regs_ofs devapc_regs_ofs_mt6779 = {
+	.vio_mask_offset = 0x0,
+	.vio_sta_offset = 0x400,
+	.vio_dbg0_offset = 0x900,
+	.vio_dbg1_offset = 0x904,
+	.apc_con_offset = 0xF00,
+	.vio_shift_sta_offset = 0xF10,
+	.vio_shift_sel_offset = 0xF14,
+	.vio_shift_con_offset = 0xF20,
+};
+
+static const struct mtk_devapc_data devapc_mt6779 = {
+	.vio_idx_num = 511,
+	.regs_ofs = &devapc_regs_ofs_mt6779,
+};
+
+static const struct mtk_devapc_data devapc_mt8186 = {
+	.vio_idx_num = 519,
+	.regs_ofs = &devapc_regs_ofs_mt6779,
+};
+
+static const struct of_device_id mtk_devapc_dt_match[] = {
+	{
+		.compatible = "mediatek,mt6779-devapc",
+		.data = &devapc_mt6779,
+	}, {
+		.compatible = "mediatek,mt8186-devapc",
+		.data = &devapc_mt8186,
+	}, {
+	},
+};
+MODULE_DEVICE_TABLE(of, mtk_devapc_dt_match);
+
+static int mtk_devapc_probe(struct platform_device *pdev)
+{
+	struct device_node *node = pdev->dev.of_node;
+	struct mtk_devapc_context *ctx;
+	u32 devapc_irq;
+	int ret;
+
+	if (IS_ERR(node))
+		return -ENODEV;
+
+	ctx = devm_kzalloc(&pdev->dev, sizeof(*ctx), GFP_KERNEL);
+	if (!ctx)
+		return -ENOMEM;
+
+	ctx->data = of_device_get_match_data(&pdev->dev);
+	ctx->dev = &pdev->dev;
+
+	ctx->infra_base = of_iomap(node, 0);
+	if (!ctx->infra_base)
+		return -EINVAL;
+
+	devapc_irq = irq_of_parse_and_map(node, 0);
+	if (!devapc_irq) {
+		ret = -EINVAL;
+		goto err;
+	}
+
+	ctx->infra_clk = devm_clk_get_enabled(&pdev->dev, "devapc-infra-clock");
+	if (IS_ERR(ctx->infra_clk)) {
+		ret = -EINVAL;
+		goto err;
+	}
+
+	ret = devm_request_irq(&pdev->dev, devapc_irq, devapc_violation_irq,
+			       IRQF_TRIGGER_NONE, "devapc", ctx);
+	if (ret)
+		goto err;
+
+	platform_set_drvdata(pdev, ctx);
+
+	start_devapc(ctx);
+
+	return 0;
+
+err:
+	iounmap(ctx->infra_base);
+	return ret;
+}
+
+static void mtk_devapc_remove(struct platform_device *pdev)
+{
+	struct mtk_devapc_context *ctx = platform_get_drvdata(pdev);
+
+	stop_devapc(ctx);
+	iounmap(ctx->infra_base);
+}
+
+static struct platform_driver mtk_devapc_driver = {
+	.probe = mtk_devapc_probe,
+	.remove = mtk_devapc_remove,
+	.driver = {
+		.name = "mtk-devapc",
+		.of_match_table = mtk_devapc_dt_match,
+	},
+};
+
+module_platform_driver(mtk_devapc_driver);
+
+MODULE_DESCRIPTION("Mediatek Device APC Driver");
+MODULE_AUTHOR("Neal Liu <neal.liu@mediatek.com>");
+MODULE_LICENSE("GPL");