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, 268 insertions, 0 deletions

diff --git a/arch/m68k/mac/macints.c b/arch/m68k/mac/macints.c
new file mode 100644
index 000000000..5cbaf6e94
--- /dev/null
+++ b/arch/m68k/mac/macints.c
@@ -0,0 +1,268 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *	Macintosh interrupts
+ *
+ * General design:
+ * In contrary to the Amiga and Atari platforms, the Mac hardware seems to
+ * exclusively use the autovector interrupts (the 'generic level0-level7'
+ * interrupts with exception vectors 0x19-0x1f). The following interrupt levels
+ * are used:
+ *	1	- VIA1
+ *		  - slot 0: one second interrupt (CA2)
+ *		  - slot 1: VBlank (CA1)
+ *		  - slot 2: ADB data ready (SR full)
+ *		  - slot 3: ADB data  (CB2)
+ *		  - slot 4: ADB clock (CB1)
+ *		  - slot 5: timer 2
+ *		  - slot 6: timer 1
+ *		  - slot 7: status of IRQ; signals 'any enabled int.'
+ *
+ *	2	- VIA2 or RBV
+ *		  - slot 0: SCSI DRQ (CA2)
+ *		  - slot 1: NUBUS IRQ (CA1) need to read port A to find which
+ *		  - slot 2: /EXP IRQ (only on IIci)
+ *		  - slot 3: SCSI IRQ (CB2)
+ *		  - slot 4: ASC IRQ (CB1)
+ *		  - slot 5: timer 2 (not on IIci)
+ *		  - slot 6: timer 1 (not on IIci)
+ *		  - slot 7: status of IRQ; signals 'any enabled int.'
+ *
+ * Levels 3-6 vary by machine type. For VIA or RBV Macintoshes:
+ *
+ *	3	- unused (?)
+ *
+ *	4	- SCC
+ *
+ *	5	- unused (?)
+ *		  [serial errors or special conditions seem to raise level 6
+ *		  interrupts on some models (LC4xx?)]
+ *
+ *	6	- off switch (?)
+ *
+ * Machines with Quadra-like VIA hardware, except PSC and PMU machines, support
+ * an alternate interrupt mapping, as used by A/UX. It spreads ethernet and
+ * sound out to their own autovector IRQs and gives VIA1 a higher priority:
+ *
+ *	1	- unused (?)
+ *
+ *	3	- on-board SONIC
+ *
+ *	5	- Apple Sound Chip (ASC)
+ *
+ *	6	- VIA1
+ *
+ * For OSS Macintoshes (IIfx only), we apply an interrupt mapping similar to
+ * the Quadra (A/UX) mapping:
+ *
+ *	1	- ISM IOP (ADB)
+ *
+ *	2	- SCSI
+ *
+ *	3	- NuBus
+ *
+ *	4	- SCC IOP
+ *
+ *	6	- VIA1
+ *
+ * For PSC Macintoshes (660AV, 840AV):
+ *
+ *	3	- PSC level 3
+ *		  - slot 0: MACE
+ *
+ *	4	- PSC level 4
+ *		  - slot 1: SCC channel A interrupt
+ *		  - slot 2: SCC channel B interrupt
+ *		  - slot 3: MACE DMA
+ *
+ *	5	- PSC level 5
+ *
+ *	6	- PSC level 6
+ *
+ * Finally we have good 'ole level 7, the non-maskable interrupt:
+ *
+ *	7	- NMI (programmer's switch on the back of some Macs)
+ *		  Also RAM parity error on models which support it (IIc, IIfx?)
+ *
+ * The current interrupt logic looks something like this:
+ *
+ * - We install dispatchers for the autovector interrupts (1-7). These
+ *   dispatchers are responsible for querying the hardware (the
+ *   VIA/RBV/OSS/PSC chips) to determine the actual interrupt source. Using
+ *   this information a machspec interrupt number is generated by placing the
+ *   index of the interrupt hardware into the low three bits and the original
+ *   autovector interrupt number in the upper 5 bits. The handlers for the
+ *   resulting machspec interrupt are then called.
+ *
+ * - Nubus is a special case because its interrupts are hidden behind two
+ *   layers of hardware. Nubus interrupts come in as index 1 on VIA #2,
+ *   which translates to IRQ number 17. In this spot we install _another_
+ *   dispatcher. This dispatcher finds the interrupting slot number (9-F) and
+ *   then forms a new machspec interrupt number as above with the slot number
+ *   minus 9 in the low three bits and the pseudo-level 7 in the upper five
+ *   bits.  The handlers for this new machspec interrupt number are then
+ *   called. This puts Nubus interrupts into the range 56-62.
+ *
+ * - The Baboon interrupts (used on some PowerBooks) are an even more special
+ *   case. They're hidden behind the Nubus slot $C interrupt thus adding a
+ *   third layer of indirection. Why oh why did the Apple engineers do that?
+ *
+ */
+
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/sched/debug.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/delay.h>
+
+#include <asm/irq.h>
+#include <asm/macintosh.h>
+#include <asm/macints.h>
+#include <asm/mac_via.h>
+#include <asm/mac_psc.h>
+#include <asm/mac_oss.h>
+#include <asm/mac_iop.h>
+#include <asm/mac_baboon.h>
+#include <asm/hwtest.h>
+#include <asm/irq_regs.h>
+#include <asm/processor.h>
+
+static unsigned int mac_irq_startup(struct irq_data *);
+static void mac_irq_shutdown(struct irq_data *);
+
+static struct irq_chip mac_irq_chip = {
+	.name		= "mac",
+	.irq_enable	= mac_irq_enable,
+	.irq_disable	= mac_irq_disable,
+	.irq_startup	= mac_irq_startup,
+	.irq_shutdown	= mac_irq_shutdown,
+};
+
+static irqreturn_t mac_nmi_handler(int irq, void *dev_id)
+{
+	static volatile int in_nmi;
+
+	if (in_nmi)
+		return IRQ_HANDLED;
+	in_nmi = 1;
+
+	pr_info("Non-Maskable Interrupt\n");
+	show_registers(get_irq_regs());
+
+	in_nmi = 0;
+	return IRQ_HANDLED;
+}
+
+void __init mac_init_IRQ(void)
+{
+	m68k_setup_irq_controller(&mac_irq_chip, handle_simple_irq, IRQ_USER,
+				  NUM_MAC_SOURCES - IRQ_USER);
+
+	/*
+	 * Now register the handlers for the master IRQ handlers
+	 * at levels 1-7. Most of the work is done elsewhere.
+	 */
+
+	if (oss_present)
+		oss_register_interrupts();
+	else
+		via_register_interrupts();
+	if (psc)
+		psc_register_interrupts();
+	if (baboon_present)
+		baboon_register_interrupts();
+	iop_register_interrupts();
+	if (request_irq(IRQ_AUTO_7, mac_nmi_handler, 0, "NMI",
+			mac_nmi_handler))
+		pr_err("Couldn't register NMI\n");
+}
+
+/*
+ *  mac_irq_enable - enable an interrupt source
+ * mac_irq_disable - disable an interrupt source
+ *
+ * These routines are just dispatchers to the VIA/OSS/PSC routines.
+ */
+
+void mac_irq_enable(struct irq_data *data)
+{
+	int irq = data->irq;
+	int irq_src = IRQ_SRC(irq);
+
+	switch(irq_src) {
+	case 1:
+	case 2:
+	case 7:
+		if (oss_present)
+			oss_irq_enable(irq);
+		else
+			via_irq_enable(irq);
+		break;
+	case 3:
+	case 4:
+	case 5:
+	case 6:
+		if (psc)
+			psc_irq_enable(irq);
+		else if (oss_present)
+			oss_irq_enable(irq);
+		break;
+	case 8:
+		if (baboon_present)
+			baboon_irq_enable(irq);
+		break;
+	}
+}
+
+void mac_irq_disable(struct irq_data *data)
+{
+	int irq = data->irq;
+	int irq_src = IRQ_SRC(irq);
+
+	switch(irq_src) {
+	case 1:
+	case 2:
+	case 7:
+		if (oss_present)
+			oss_irq_disable(irq);
+		else
+			via_irq_disable(irq);
+		break;
+	case 3:
+	case 4:
+	case 5:
+	case 6:
+		if (psc)
+			psc_irq_disable(irq);
+		else if (oss_present)
+			oss_irq_disable(irq);
+		break;
+	case 8:
+		if (baboon_present)
+			baboon_irq_disable(irq);
+		break;
+	}
+}
+
+static unsigned int mac_irq_startup(struct irq_data *data)
+{
+	int irq = data->irq;
+
+	if (IRQ_SRC(irq) == 7 && !oss_present)
+		via_nubus_irq_startup(irq);
+	else
+		mac_irq_enable(data);
+
+	return 0;
+}
+
+static void mac_irq_shutdown(struct irq_data *data)
+{
+	int irq = data->irq;
+
+	if (IRQ_SRC(irq) == 7 && !oss_present)
+		via_nubus_irq_shutdown(irq);
+	else
+		mac_irq_disable(data);
+}