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, 388 insertions, 0 deletions

diff --git a/drivers/mailbox/stm32-ipcc.c b/drivers/mailbox/stm32-ipcc.c
new file mode 100644
index 000000000..c6134de1a
--- /dev/null
+++ b/drivers/mailbox/stm32-ipcc.c
@@ -0,0 +1,388 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) STMicroelectronics 2018 - All Rights Reserved
+ * Authors: Ludovic Barre <ludovic.barre@st.com> for STMicroelectronics.
+ *          Fabien Dessenne <fabien.dessenne@st.com> for STMicroelectronics.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/mailbox_controller.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/pm_wakeirq.h>
+
+#define IPCC_XCR		0x000
+#define XCR_RXOIE		BIT(0)
+#define XCR_TXOIE		BIT(16)
+
+#define IPCC_XMR		0x004
+#define IPCC_XSCR		0x008
+#define IPCC_XTOYSR		0x00c
+
+#define IPCC_PROC_OFFST		0x010
+
+#define IPCC_HWCFGR		0x3f0
+#define IPCFGR_CHAN_MASK	GENMASK(7, 0)
+
+#define IPCC_VER		0x3f4
+#define VER_MINREV_MASK		GENMASK(3, 0)
+#define VER_MAJREV_MASK		GENMASK(7, 4)
+
+#define RX_BIT_MASK		GENMASK(15, 0)
+#define RX_BIT_CHAN(chan)	BIT(chan)
+#define TX_BIT_SHIFT		16
+#define TX_BIT_MASK		GENMASK(31, 16)
+#define TX_BIT_CHAN(chan)	BIT(TX_BIT_SHIFT + (chan))
+
+#define STM32_MAX_PROCS		2
+
+enum {
+	IPCC_IRQ_RX,
+	IPCC_IRQ_TX,
+	IPCC_IRQ_NUM,
+};
+
+struct stm32_ipcc {
+	struct mbox_controller controller;
+	void __iomem *reg_base;
+	void __iomem *reg_proc;
+	struct clk *clk;
+	spinlock_t lock; /* protect access to IPCC registers */
+	int irqs[IPCC_IRQ_NUM];
+	u32 proc_id;
+	u32 n_chans;
+	u32 xcr;
+	u32 xmr;
+};
+
+static inline void stm32_ipcc_set_bits(spinlock_t *lock, void __iomem *reg,
+				       u32 mask)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(lock, flags);
+	writel_relaxed(readl_relaxed(reg) | mask, reg);
+	spin_unlock_irqrestore(lock, flags);
+}
+
+static inline void stm32_ipcc_clr_bits(spinlock_t *lock, void __iomem *reg,
+				       u32 mask)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(lock, flags);
+	writel_relaxed(readl_relaxed(reg) & ~mask, reg);
+	spin_unlock_irqrestore(lock, flags);
+}
+
+static irqreturn_t stm32_ipcc_rx_irq(int irq, void *data)
+{
+	struct stm32_ipcc *ipcc = data;
+	struct device *dev = ipcc->controller.dev;
+	u32 status, mr, tosr, chan;
+	irqreturn_t ret = IRQ_NONE;
+	int proc_offset;
+
+	/* read 'channel occupied' status from other proc */
+	proc_offset = ipcc->proc_id ? -IPCC_PROC_OFFST : IPCC_PROC_OFFST;
+	tosr = readl_relaxed(ipcc->reg_proc + proc_offset + IPCC_XTOYSR);
+	mr = readl_relaxed(ipcc->reg_proc + IPCC_XMR);
+
+	/* search for unmasked 'channel occupied' */
+	status = tosr & FIELD_GET(RX_BIT_MASK, ~mr);
+
+	for (chan = 0; chan < ipcc->n_chans; chan++) {
+		if (!(status & (1 << chan)))
+			continue;
+
+		dev_dbg(dev, "%s: chan:%d rx\n", __func__, chan);
+
+		mbox_chan_received_data(&ipcc->controller.chans[chan], NULL);
+
+		stm32_ipcc_set_bits(&ipcc->lock, ipcc->reg_proc + IPCC_XSCR,
+				    RX_BIT_CHAN(chan));
+
+		ret = IRQ_HANDLED;
+	}
+
+	return ret;
+}
+
+static irqreturn_t stm32_ipcc_tx_irq(int irq, void *data)
+{
+	struct stm32_ipcc *ipcc = data;
+	struct device *dev = ipcc->controller.dev;
+	u32 status, mr, tosr, chan;
+	irqreturn_t ret = IRQ_NONE;
+
+	tosr = readl_relaxed(ipcc->reg_proc + IPCC_XTOYSR);
+	mr = readl_relaxed(ipcc->reg_proc + IPCC_XMR);
+
+	/* search for unmasked 'channel free' */
+	status = ~tosr & FIELD_GET(TX_BIT_MASK, ~mr);
+
+	for (chan = 0; chan < ipcc->n_chans ; chan++) {
+		if (!(status & (1 << chan)))
+			continue;
+
+		dev_dbg(dev, "%s: chan:%d tx\n", __func__, chan);
+
+		/* mask 'tx channel free' interrupt */
+		stm32_ipcc_set_bits(&ipcc->lock, ipcc->reg_proc + IPCC_XMR,
+				    TX_BIT_CHAN(chan));
+
+		mbox_chan_txdone(&ipcc->controller.chans[chan], 0);
+
+		ret = IRQ_HANDLED;
+	}
+
+	return ret;
+}
+
+static int stm32_ipcc_send_data(struct mbox_chan *link, void *data)
+{
+	unsigned long chan = (unsigned long)link->con_priv;
+	struct stm32_ipcc *ipcc = container_of(link->mbox, struct stm32_ipcc,
+					       controller);
+
+	dev_dbg(ipcc->controller.dev, "%s: chan:%lu\n", __func__, chan);
+
+	/* set channel n occupied */
+	stm32_ipcc_set_bits(&ipcc->lock, ipcc->reg_proc + IPCC_XSCR,
+			    TX_BIT_CHAN(chan));
+
+	/* unmask 'tx channel free' interrupt */
+	stm32_ipcc_clr_bits(&ipcc->lock, ipcc->reg_proc + IPCC_XMR,
+			    TX_BIT_CHAN(chan));
+
+	return 0;
+}
+
+static int stm32_ipcc_startup(struct mbox_chan *link)
+{
+	unsigned long chan = (unsigned long)link->con_priv;
+	struct stm32_ipcc *ipcc = container_of(link->mbox, struct stm32_ipcc,
+					       controller);
+	int ret;
+
+	ret = clk_prepare_enable(ipcc->clk);
+	if (ret) {
+		dev_err(ipcc->controller.dev, "can not enable the clock\n");
+		return ret;
+	}
+
+	/* unmask 'rx channel occupied' interrupt */
+	stm32_ipcc_clr_bits(&ipcc->lock, ipcc->reg_proc + IPCC_XMR,
+			    RX_BIT_CHAN(chan));
+
+	return 0;
+}
+
+static void stm32_ipcc_shutdown(struct mbox_chan *link)
+{
+	unsigned long chan = (unsigned long)link->con_priv;
+	struct stm32_ipcc *ipcc = container_of(link->mbox, struct stm32_ipcc,
+					       controller);
+
+	/* mask rx/tx interrupt */
+	stm32_ipcc_set_bits(&ipcc->lock, ipcc->reg_proc + IPCC_XMR,
+			    RX_BIT_CHAN(chan) | TX_BIT_CHAN(chan));
+
+	clk_disable_unprepare(ipcc->clk);
+}
+
+static const struct mbox_chan_ops stm32_ipcc_ops = {
+	.send_data	= stm32_ipcc_send_data,
+	.startup	= stm32_ipcc_startup,
+	.shutdown	= stm32_ipcc_shutdown,
+};
+
+static int stm32_ipcc_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node;
+	struct stm32_ipcc *ipcc;
+	unsigned long i;
+	int ret;
+	u32 ip_ver;
+	static const char * const irq_name[] = {"rx", "tx"};
+	irq_handler_t irq_thread[] = {stm32_ipcc_rx_irq, stm32_ipcc_tx_irq};
+
+	if (!np) {
+		dev_err(dev, "No DT found\n");
+		return -ENODEV;
+	}
+
+	ipcc = devm_kzalloc(dev, sizeof(*ipcc), GFP_KERNEL);
+	if (!ipcc)
+		return -ENOMEM;
+
+	spin_lock_init(&ipcc->lock);
+
+	/* proc_id */
+	if (of_property_read_u32(np, "st,proc-id", &ipcc->proc_id)) {
+		dev_err(dev, "Missing st,proc-id\n");
+		return -ENODEV;
+	}
+
+	if (ipcc->proc_id >= STM32_MAX_PROCS) {
+		dev_err(dev, "Invalid proc_id (%d)\n", ipcc->proc_id);
+		return -EINVAL;
+	}
+
+	/* regs */
+	ipcc->reg_base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(ipcc->reg_base))
+		return PTR_ERR(ipcc->reg_base);
+
+	ipcc->reg_proc = ipcc->reg_base + ipcc->proc_id * IPCC_PROC_OFFST;
+
+	/* clock */
+	ipcc->clk = devm_clk_get(dev, NULL);
+	if (IS_ERR(ipcc->clk))
+		return PTR_ERR(ipcc->clk);
+
+	ret = clk_prepare_enable(ipcc->clk);
+	if (ret) {
+		dev_err(dev, "can not enable the clock\n");
+		return ret;
+	}
+
+	/* irq */
+	for (i = 0; i < IPCC_IRQ_NUM; i++) {
+		ipcc->irqs[i] = platform_get_irq_byname(pdev, irq_name[i]);
+		if (ipcc->irqs[i] < 0) {
+			ret = ipcc->irqs[i];
+			goto err_clk;
+		}
+
+		ret = devm_request_threaded_irq(dev, ipcc->irqs[i], NULL,
+						irq_thread[i], IRQF_ONESHOT,
+						dev_name(dev), ipcc);
+		if (ret)
+			goto err_clk;
+	}
+
+	/* mask and enable rx/tx irq */
+	stm32_ipcc_set_bits(&ipcc->lock, ipcc->reg_proc + IPCC_XMR,
+			    RX_BIT_MASK | TX_BIT_MASK);
+	stm32_ipcc_set_bits(&ipcc->lock, ipcc->reg_proc + IPCC_XCR,
+			    XCR_RXOIE | XCR_TXOIE);
+
+	/* wakeup */
+	if (of_property_read_bool(np, "wakeup-source")) {
+		device_set_wakeup_capable(dev, true);
+
+		ret = dev_pm_set_wake_irq(dev, ipcc->irqs[IPCC_IRQ_RX]);
+		if (ret) {
+			dev_err(dev, "Failed to set wake up irq\n");
+			goto err_init_wkp;
+		}
+	}
+
+	/* mailbox controller */
+	ipcc->n_chans = readl_relaxed(ipcc->reg_base + IPCC_HWCFGR);
+	ipcc->n_chans &= IPCFGR_CHAN_MASK;
+
+	ipcc->controller.dev = dev;
+	ipcc->controller.txdone_irq = true;
+	ipcc->controller.ops = &stm32_ipcc_ops;
+	ipcc->controller.num_chans = ipcc->n_chans;
+	ipcc->controller.chans = devm_kcalloc(dev, ipcc->controller.num_chans,
+					      sizeof(*ipcc->controller.chans),
+					      GFP_KERNEL);
+	if (!ipcc->controller.chans) {
+		ret = -ENOMEM;
+		goto err_irq_wkp;
+	}
+
+	for (i = 0; i < ipcc->controller.num_chans; i++)
+		ipcc->controller.chans[i].con_priv = (void *)i;
+
+	ret = devm_mbox_controller_register(dev, &ipcc->controller);
+	if (ret)
+		goto err_irq_wkp;
+
+	platform_set_drvdata(pdev, ipcc);
+
+	ip_ver = readl_relaxed(ipcc->reg_base + IPCC_VER);
+
+	dev_info(dev, "ipcc rev:%ld.%ld enabled, %d chans, proc %d\n",
+		 FIELD_GET(VER_MAJREV_MASK, ip_ver),
+		 FIELD_GET(VER_MINREV_MASK, ip_ver),
+		 ipcc->controller.num_chans, ipcc->proc_id);
+
+	clk_disable_unprepare(ipcc->clk);
+	return 0;
+
+err_irq_wkp:
+	if (of_property_read_bool(np, "wakeup-source"))
+		dev_pm_clear_wake_irq(dev);
+err_init_wkp:
+	device_set_wakeup_capable(dev, false);
+err_clk:
+	clk_disable_unprepare(ipcc->clk);
+	return ret;
+}
+
+static void stm32_ipcc_remove(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+
+	if (of_property_read_bool(dev->of_node, "wakeup-source"))
+		dev_pm_clear_wake_irq(&pdev->dev);
+
+	device_set_wakeup_capable(dev, false);
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int stm32_ipcc_suspend(struct device *dev)
+{
+	struct stm32_ipcc *ipcc = dev_get_drvdata(dev);
+
+	ipcc->xmr = readl_relaxed(ipcc->reg_proc + IPCC_XMR);
+	ipcc->xcr = readl_relaxed(ipcc->reg_proc + IPCC_XCR);
+
+	return 0;
+}
+
+static int stm32_ipcc_resume(struct device *dev)
+{
+	struct stm32_ipcc *ipcc = dev_get_drvdata(dev);
+
+	writel_relaxed(ipcc->xmr, ipcc->reg_proc + IPCC_XMR);
+	writel_relaxed(ipcc->xcr, ipcc->reg_proc + IPCC_XCR);
+
+	return 0;
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(stm32_ipcc_pm_ops,
+			 stm32_ipcc_suspend, stm32_ipcc_resume);
+
+static const struct of_device_id stm32_ipcc_of_match[] = {
+	{ .compatible = "st,stm32mp1-ipcc" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, stm32_ipcc_of_match);
+
+static struct platform_driver stm32_ipcc_driver = {
+	.driver = {
+		.name = "stm32-ipcc",
+		.pm = &stm32_ipcc_pm_ops,
+		.of_match_table = stm32_ipcc_of_match,
+	},
+	.probe		= stm32_ipcc_probe,
+	.remove		= stm32_ipcc_remove,
+};
+
+module_platform_driver(stm32_ipcc_driver);
+
+MODULE_AUTHOR("Ludovic Barre <ludovic.barre@st.com>");
+MODULE_AUTHOR("Fabien Dessenne <fabien.dessenne@st.com>");
+MODULE_DESCRIPTION("STM32 IPCC driver");
+MODULE_LICENSE("GPL v2");