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/scsi/mac_scsi.c b/drivers/scsi/mac_scsi.c
new file mode 100644
index 000000000..a86bd839d
--- /dev/null
+++ b/drivers/scsi/mac_scsi.c
@@ -0,0 +1,560 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Generic Macintosh NCR5380 driver
+ *
+ * Copyright 1998, Michael Schmitz <mschmitz@lbl.gov>
+ *
+ * Copyright 2019 Finn Thain
+ *
+ * derived in part from:
+ */
+/*
+ * Generic Generic NCR5380 driver
+ *
+ * Copyright 1995, Russell King
+ */
+
+#include <linux/delay.h>
+#include <linux/types.h>
+#include <linux/module.h>
+#include <linux/ioport.h>
+#include <linux/init.h>
+#include <linux/blkdev.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+
+#include <asm/hwtest.h>
+#include <asm/io.h>
+#include <asm/macintosh.h>
+#include <asm/macints.h>
+#include <asm/setup.h>
+
+#include <scsi/scsi_host.h>
+
+/* Definitions for the core NCR5380 driver. */
+
+#define NCR5380_implementation_fields   int pdma_residual
+
+#define NCR5380_read(reg)           in_8(hostdata->io + ((reg) << 4))
+#define NCR5380_write(reg, value)   out_8(hostdata->io + ((reg) << 4), value)
+
+#define NCR5380_dma_xfer_len            macscsi_dma_xfer_len
+#define NCR5380_dma_recv_setup          macscsi_pread
+#define NCR5380_dma_send_setup          macscsi_pwrite
+#define NCR5380_dma_residual            macscsi_dma_residual
+
+#define NCR5380_intr                    macscsi_intr
+#define NCR5380_queue_command           macscsi_queue_command
+#define NCR5380_abort                   macscsi_abort
+#define NCR5380_host_reset              macscsi_host_reset
+#define NCR5380_info                    macscsi_info
+
+#include "NCR5380.h"
+
+static int setup_can_queue = -1;
+module_param(setup_can_queue, int, 0);
+static int setup_cmd_per_lun = -1;
+module_param(setup_cmd_per_lun, int, 0);
+static int setup_sg_tablesize = -1;
+module_param(setup_sg_tablesize, int, 0);
+static int setup_use_pdma = 512;
+module_param(setup_use_pdma, int, 0);
+static int setup_hostid = -1;
+module_param(setup_hostid, int, 0);
+static int setup_toshiba_delay = -1;
+module_param(setup_toshiba_delay, int, 0);
+
+#ifndef MODULE
+static int __init mac_scsi_setup(char *str)
+{
+	int ints[8];
+
+	(void)get_options(str, ARRAY_SIZE(ints), ints);
+
+	if (ints[0] < 1) {
+		pr_err("Usage: mac5380=<can_queue>[,<cmd_per_lun>[,<sg_tablesize>[,<hostid>[,<use_tags>[,<use_pdma>[,<toshiba_delay>]]]]]]\n");
+		return 0;
+	}
+	if (ints[0] >= 1)
+		setup_can_queue = ints[1];
+	if (ints[0] >= 2)
+		setup_cmd_per_lun = ints[2];
+	if (ints[0] >= 3)
+		setup_sg_tablesize = ints[3];
+	if (ints[0] >= 4)
+		setup_hostid = ints[4];
+	/* ints[5] (use_tagged_queuing) is ignored */
+	if (ints[0] >= 6)
+		setup_use_pdma = ints[6];
+	if (ints[0] >= 7)
+		setup_toshiba_delay = ints[7];
+	return 1;
+}
+
+__setup("mac5380=", mac_scsi_setup);
+#endif /* !MODULE */
+
+/*
+ * According to "Inside Macintosh: Devices", Mac OS requires disk drivers to
+ * specify the number of bytes between the delays expected from a SCSI target.
+ * This allows the operating system to "prevent bus errors when a target fails
+ * to deliver the next byte within the processor bus error timeout period."
+ * Linux SCSI drivers lack knowledge of the timing behaviour of SCSI targets
+ * so bus errors are unavoidable.
+ *
+ * If a MOVE.B instruction faults during a receive operation, we assume the
+ * target sent nothing and try again. That assumption probably depends on
+ * target firmware but it seems to hold up okay. If a fault happens during a
+ * send operation, the target may or may not have seen /ACK and got the byte.
+ * It's uncertain so the whole SCSI command gets retried.
+ *
+ * The NOP is needed for synchronization because the fault address in the
+ * exception stack frame may or may not be the instruction that actually
+ * caused the bus error. Post-increment addressing can't be used.
+ */
+
+#define MOVE_BYTE(operands) \
+	asm volatile ( \
+		"1:     moveb " operands "     \n" \
+		"11:    nop                    \n" \
+		"       addq #1,%0             \n" \
+		"       subq #1,%1             \n" \
+		"40:                           \n" \
+		"                              \n" \
+		".section .fixup,\"ax\"        \n" \
+		".even                         \n" \
+		"90:    movel #1, %2           \n" \
+		"       jra 40b                \n" \
+		".previous                     \n" \
+		"                              \n" \
+		".section __ex_table,\"a\"     \n" \
+		".align  4                     \n" \
+		".long   1b,90b                \n" \
+		".long  11b,90b                \n" \
+		".previous                     \n" \
+		: "+a" (addr), "+r" (n), "+r" (result) : "a" (io))
+
+/*
+ * If a MOVE.W (or MOVE.L) instruction faults, it cannot be retried because
+ * the residual byte count would be uncertain. In that situation the MOVE_WORD
+ * macro clears n in the fixup section to abort the transfer.
+ */
+
+#define MOVE_WORD(operands) \
+	asm volatile ( \
+		"1:     movew " operands "     \n" \
+		"11:    nop                    \n" \
+		"       subq #2,%1             \n" \
+		"40:                           \n" \
+		"                              \n" \
+		".section .fixup,\"ax\"        \n" \
+		".even                         \n" \
+		"90:    movel #0, %1           \n" \
+		"       movel #2, %2           \n" \
+		"       jra 40b                \n" \
+		".previous                     \n" \
+		"                              \n" \
+		".section __ex_table,\"a\"     \n" \
+		".align  4                     \n" \
+		".long   1b,90b                \n" \
+		".long  11b,90b                \n" \
+		".previous                     \n" \
+		: "+a" (addr), "+r" (n), "+r" (result) : "a" (io))
+
+#define MOVE_16_WORDS(operands) \
+	asm volatile ( \
+		"1:     movew " operands "     \n" \
+		"2:     movew " operands "     \n" \
+		"3:     movew " operands "     \n" \
+		"4:     movew " operands "     \n" \
+		"5:     movew " operands "     \n" \
+		"6:     movew " operands "     \n" \
+		"7:     movew " operands "     \n" \
+		"8:     movew " operands "     \n" \
+		"9:     movew " operands "     \n" \
+		"10:    movew " operands "     \n" \
+		"11:    movew " operands "     \n" \
+		"12:    movew " operands "     \n" \
+		"13:    movew " operands "     \n" \
+		"14:    movew " operands "     \n" \
+		"15:    movew " operands "     \n" \
+		"16:    movew " operands "     \n" \
+		"17:    nop                    \n" \
+		"       subl  #32,%1           \n" \
+		"40:                           \n" \
+		"                              \n" \
+		".section .fixup,\"ax\"        \n" \
+		".even                         \n" \
+		"90:    movel #0, %1           \n" \
+		"       movel #2, %2           \n" \
+		"       jra 40b                \n" \
+		".previous                     \n" \
+		"                              \n" \
+		".section __ex_table,\"a\"     \n" \
+		".align  4                     \n" \
+		".long   1b,90b                \n" \
+		".long   2b,90b                \n" \
+		".long   3b,90b                \n" \
+		".long   4b,90b                \n" \
+		".long   5b,90b                \n" \
+		".long   6b,90b                \n" \
+		".long   7b,90b                \n" \
+		".long   8b,90b                \n" \
+		".long   9b,90b                \n" \
+		".long  10b,90b                \n" \
+		".long  11b,90b                \n" \
+		".long  12b,90b                \n" \
+		".long  13b,90b                \n" \
+		".long  14b,90b                \n" \
+		".long  15b,90b                \n" \
+		".long  16b,90b                \n" \
+		".long  17b,90b                \n" \
+		".previous                     \n" \
+		: "+a" (addr), "+r" (n), "+r" (result) : "a" (io))
+
+static inline int mac_pdma_recv(void __iomem *io, unsigned char *start, int n)
+{
+	unsigned char *addr = start;
+	int result = 0;
+
+	if (n >= 1) {
+		MOVE_BYTE("%3@,%0@");
+		if (result)
+			goto out;
+	}
+	if (n >= 1 && ((unsigned long)addr & 1)) {
+		MOVE_BYTE("%3@,%0@");
+		if (result)
+			goto out;
+	}
+	while (n >= 32)
+		MOVE_16_WORDS("%3@,%0@+");
+	while (n >= 2)
+		MOVE_WORD("%3@,%0@+");
+	if (result)
+		return start - addr; /* Negated to indicate uncertain length */
+	if (n == 1)
+		MOVE_BYTE("%3@,%0@");
+out:
+	return addr - start;
+}
+
+static inline int mac_pdma_send(unsigned char *start, void __iomem *io, int n)
+{
+	unsigned char *addr = start;
+	int result = 0;
+
+	if (n >= 1) {
+		MOVE_BYTE("%0@,%3@");
+		if (result)
+			return -1;
+	}
+	if (n >= 1 && ((unsigned long)addr & 1)) {
+		MOVE_BYTE("%0@,%3@");
+		if (result)
+			return -2;
+	}
+	while (n >= 32)
+		MOVE_16_WORDS("%0@+,%3@");
+	while (n >= 2)
+		MOVE_WORD("%0@+,%3@");
+	if (result)
+		return start - addr - 1; /* Negated to indicate uncertain length */
+	if (n == 1)
+		MOVE_BYTE("%0@,%3@");
+	return addr - start;
+}
+
+/* The "SCSI DMA" chip on the IIfx implements this register. */
+#define CTRL_REG                0x8
+#define CTRL_INTERRUPTS_ENABLE  BIT(1)
+#define CTRL_HANDSHAKE_MODE     BIT(3)
+
+static inline void write_ctrl_reg(struct NCR5380_hostdata *hostdata, u32 value)
+{
+	out_be32(hostdata->io + (CTRL_REG << 4), value);
+}
+
+static inline int macscsi_wait_for_drq(struct NCR5380_hostdata *hostdata)
+{
+	unsigned int n = 1; /* effectively multiplies NCR5380_REG_POLL_TIME */
+	unsigned char basr;
+
+again:
+	basr = NCR5380_read(BUS_AND_STATUS_REG);
+
+	if (!(basr & BASR_PHASE_MATCH))
+		return 1;
+
+	if (basr & BASR_IRQ)
+		return -1;
+
+	if (basr & BASR_DRQ)
+		return 0;
+
+	if (n-- == 0) {
+		NCR5380_dprint(NDEBUG_PSEUDO_DMA, hostdata->host);
+		dsprintk(NDEBUG_PSEUDO_DMA, hostdata->host,
+			 "%s: DRQ timeout\n", __func__);
+		return -1;
+	}
+
+	NCR5380_poll_politely2(hostdata,
+			       BUS_AND_STATUS_REG, BASR_DRQ, BASR_DRQ,
+			       BUS_AND_STATUS_REG, BASR_PHASE_MATCH, 0, 0);
+	goto again;
+}
+
+static inline int macscsi_pread(struct NCR5380_hostdata *hostdata,
+                                unsigned char *dst, int len)
+{
+	u8 __iomem *s = hostdata->pdma_io + (INPUT_DATA_REG << 4);
+	unsigned char *d = dst;
+
+	hostdata->pdma_residual = len;
+
+	while (macscsi_wait_for_drq(hostdata) == 0) {
+		int bytes, chunk_bytes;
+
+		if (macintosh_config->ident == MAC_MODEL_IIFX)
+			write_ctrl_reg(hostdata, CTRL_HANDSHAKE_MODE |
+			                         CTRL_INTERRUPTS_ENABLE);
+
+		chunk_bytes = min(hostdata->pdma_residual, 512);
+		bytes = mac_pdma_recv(s, d, chunk_bytes);
+
+		if (macintosh_config->ident == MAC_MODEL_IIFX)
+			write_ctrl_reg(hostdata, CTRL_INTERRUPTS_ENABLE);
+
+		if (bytes > 0) {
+			d += bytes;
+			hostdata->pdma_residual -= bytes;
+		}
+
+		if (hostdata->pdma_residual == 0)
+			break;
+
+		if (bytes > 0)
+			continue;
+
+		NCR5380_dprint(NDEBUG_PSEUDO_DMA, hostdata->host);
+		dsprintk(NDEBUG_PSEUDO_DMA, hostdata->host,
+			 "%s: bus error [%d/%d] (%d/%d)\n",
+			 __func__, d - dst, len, bytes, chunk_bytes);
+
+		if (bytes == 0)
+			continue;
+
+		if (macscsi_wait_for_drq(hostdata) <= 0)
+			set_host_byte(hostdata->connected, DID_ERROR);
+		break;
+	}
+
+	return 0;
+}
+
+static inline int macscsi_pwrite(struct NCR5380_hostdata *hostdata,
+                                 unsigned char *src, int len)
+{
+	unsigned char *s = src;
+	u8 __iomem *d = hostdata->pdma_io + (OUTPUT_DATA_REG << 4);
+
+	hostdata->pdma_residual = len;
+
+	while (macscsi_wait_for_drq(hostdata) == 0) {
+		int bytes, chunk_bytes;
+
+		if (macintosh_config->ident == MAC_MODEL_IIFX)
+			write_ctrl_reg(hostdata, CTRL_HANDSHAKE_MODE |
+			                         CTRL_INTERRUPTS_ENABLE);
+
+		chunk_bytes = min(hostdata->pdma_residual, 512);
+		bytes = mac_pdma_send(s, d, chunk_bytes);
+
+		if (macintosh_config->ident == MAC_MODEL_IIFX)
+			write_ctrl_reg(hostdata, CTRL_INTERRUPTS_ENABLE);
+
+		if (bytes > 0) {
+			s += bytes;
+			hostdata->pdma_residual -= bytes;
+		}
+
+		if (hostdata->pdma_residual == 0)
+			break;
+
+		if (bytes > 0)
+			continue;
+
+		NCR5380_dprint(NDEBUG_PSEUDO_DMA, hostdata->host);
+		dsprintk(NDEBUG_PSEUDO_DMA, hostdata->host,
+			 "%s: bus error [%d/%d] (%d/%d)\n",
+			 __func__, s - src, len, bytes, chunk_bytes);
+
+		if (bytes == 0)
+			continue;
+
+		if (macscsi_wait_for_drq(hostdata) <= 0)
+			set_host_byte(hostdata->connected, DID_ERROR);
+		break;
+	}
+
+	return 0;
+}
+
+static int macscsi_dma_xfer_len(struct NCR5380_hostdata *hostdata,
+                                struct scsi_cmnd *cmd)
+{
+	int resid = NCR5380_to_ncmd(cmd)->this_residual;
+
+	if (hostdata->flags & FLAG_NO_PSEUDO_DMA || resid < setup_use_pdma)
+		return 0;
+
+	return resid;
+}
+
+static int macscsi_dma_residual(struct NCR5380_hostdata *hostdata)
+{
+	return hostdata->pdma_residual;
+}
+
+#include "NCR5380.c"
+
+#define DRV_MODULE_NAME         "mac_scsi"
+#define PFX                     DRV_MODULE_NAME ": "
+
+static struct scsi_host_template mac_scsi_template = {
+	.module			= THIS_MODULE,
+	.proc_name		= DRV_MODULE_NAME,
+	.name			= "Macintosh NCR5380 SCSI",
+	.info			= macscsi_info,
+	.queuecommand		= macscsi_queue_command,
+	.eh_abort_handler	= macscsi_abort,
+	.eh_host_reset_handler	= macscsi_host_reset,
+	.can_queue		= 16,
+	.this_id		= 7,
+	.sg_tablesize		= SG_ALL,
+	.cmd_per_lun		= 2,
+	.dma_boundary		= PAGE_SIZE - 1,
+	.cmd_size		= sizeof(struct NCR5380_cmd),
+	.max_sectors		= 128,
+};
+
+static int __init mac_scsi_probe(struct platform_device *pdev)
+{
+	struct Scsi_Host *instance;
+	struct NCR5380_hostdata *hostdata;
+	int error;
+	int host_flags = 0;
+	struct resource *irq, *pio_mem, *pdma_mem = NULL;
+
+	pio_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!pio_mem)
+		return -ENODEV;
+
+	pdma_mem = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+
+	irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
+
+	if (!hwreg_present((unsigned char *)pio_mem->start +
+	                   (STATUS_REG << 4))) {
+		pr_info(PFX "no device detected at %pap\n", &pio_mem->start);
+		return -ENODEV;
+	}
+
+	if (setup_can_queue > 0)
+		mac_scsi_template.can_queue = setup_can_queue;
+	if (setup_cmd_per_lun > 0)
+		mac_scsi_template.cmd_per_lun = setup_cmd_per_lun;
+	if (setup_sg_tablesize > 0)
+		mac_scsi_template.sg_tablesize = setup_sg_tablesize;
+	if (setup_hostid >= 0)
+		mac_scsi_template.this_id = setup_hostid & 7;
+
+	if (macintosh_config->ident == MAC_MODEL_IIFX)
+		mac_scsi_template.sg_tablesize = 1;
+
+	instance = scsi_host_alloc(&mac_scsi_template,
+	                           sizeof(struct NCR5380_hostdata));
+	if (!instance)
+		return -ENOMEM;
+
+	if (irq)
+		instance->irq = irq->start;
+	else
+		instance->irq = NO_IRQ;
+
+	hostdata = shost_priv(instance);
+	hostdata->base = pio_mem->start;
+	hostdata->io = (u8 __iomem *)pio_mem->start;
+
+	if (pdma_mem && setup_use_pdma)
+		hostdata->pdma_io = (u8 __iomem *)pdma_mem->start;
+	else
+		host_flags |= FLAG_NO_PSEUDO_DMA;
+
+	host_flags |= setup_toshiba_delay > 0 ? FLAG_TOSHIBA_DELAY : 0;
+
+	if (instance->sg_tablesize > 1)
+		host_flags |= FLAG_DMA_FIXUP;
+
+	error = NCR5380_init(instance, host_flags | FLAG_LATE_DMA_SETUP);
+	if (error)
+		goto fail_init;
+
+	if (instance->irq != NO_IRQ) {
+		error = request_irq(instance->irq, macscsi_intr, IRQF_SHARED,
+		                    "NCR5380", instance);
+		if (error)
+			goto fail_irq;
+	}
+
+	NCR5380_maybe_reset_bus(instance);
+
+	error = scsi_add_host(instance, NULL);
+	if (error)
+		goto fail_host;
+
+	platform_set_drvdata(pdev, instance);
+
+	scsi_scan_host(instance);
+	return 0;
+
+fail_host:
+	if (instance->irq != NO_IRQ)
+		free_irq(instance->irq, instance);
+fail_irq:
+	NCR5380_exit(instance);
+fail_init:
+	scsi_host_put(instance);
+	return error;
+}
+
+static void __exit mac_scsi_remove(struct platform_device *pdev)
+{
+	struct Scsi_Host *instance = platform_get_drvdata(pdev);
+
+	scsi_remove_host(instance);
+	if (instance->irq != NO_IRQ)
+		free_irq(instance->irq, instance);
+	NCR5380_exit(instance);
+	scsi_host_put(instance);
+}
+
+/*
+ * mac_scsi_remove() lives in .exit.text. For drivers registered via
+ * module_platform_driver_probe() this is ok because they cannot get unbound at
+ * runtime. So mark the driver struct with __refdata to prevent modpost
+ * triggering a section mismatch warning.
+ */
+static struct platform_driver mac_scsi_driver __refdata = {
+	.remove = __exit_p(mac_scsi_remove),
+	.driver = {
+		.name	= DRV_MODULE_NAME,
+	},
+};
+
+module_platform_driver_probe(mac_scsi_driver, mac_scsi_probe);
+
+MODULE_ALIAS("platform:" DRV_MODULE_NAME);
+MODULE_DESCRIPTION("Macintosh NCR5380 SCSI driver");
+MODULE_LICENSE("GPL");