Merge tag 'trace-v5.7' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing updates from Steven Rostedt:
 "New tracing features:

   - The ring buffer is no longer disabled when reading the trace file.

     The trace_pipe file was made to be used for live tracing and
     reading as it acted like the normal producer/consumer. As the trace
     file would not consume the data, the easy way of handling it was to
     just disable writes to the ring buffer.

     This came to a surprise to the BPF folks who complained about lost
     events due to reading. This is no longer an issue. If someone wants
     to keep the old disabling there's a new option "pause-on-trace"
     that can be set.

   - New set_ftrace_notrace_pid file. PIDs in this file will not be
     traced by the function tracer.

     Similar to set_ftrace_pid, which makes the function tracer only
     trace those tasks with PIDs in the file, the set_ftrace_notrace_pid
     does the reverse.

   - New set_event_notrace_pid file. PIDs in this file will cause events
     not to be traced if triggered by a task with a matching PID.

     Similar to the set_event_pid file but will not be traced. Note,
     sched_waking and sched_switch events may still be traced if one of
     the tasks referenced by those events contains a PID that is allowed
     to be traced.

  Tracing related features:

   - New bootconfig option, that is attached to the initrd file.

     If bootconfig is on the command line, then the initrd file is
     searched looking for a bootconfig appended at the end.

   - New GPU tracepoint infrastructure to help the gfx drivers to get
     off debugfs (acked by Greg Kroah-Hartman)

  And other minor updates and fixes"

* tag 'trace-v5.7' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (27 commits)
  tracing: Do not allocate buffer in trace_find_next_entry() in atomic
  tracing: Add documentation on set_ftrace_notrace_pid and set_event_notrace_pid
  selftests/ftrace: Add test to test new set_event_notrace_pid file
  selftests/ftrace: Add test to test new set_ftrace_notrace_pid file
  tracing: Create set_event_notrace_pid to not trace tasks
  ftrace: Create set_ftrace_notrace_pid to not trace tasks
  ftrace: Make function trace pid filtering a bit more exact
  ftrace/kprobe: Show the maxactive number on kprobe_events
  tracing: Have the document reflect that the trace file keeps tracing enabled
  ring-buffer/tracing: Have iterator acknowledge dropped events
  tracing: Do not disable tracing when reading the trace file
  ring-buffer: Do not disable recording when there is an iterator
  ring-buffer: Make resize disable per cpu buffer instead of total buffer
  ring-buffer: Optimize rb_iter_head_event()
  ring-buffer: Do not die if rb_iter_peek() fails more than thrice
  ring-buffer: Have rb_iter_head_event() handle concurrent writer
  ring-buffer: Add page_stamp to iterator for synchronization
  ring-buffer: Rename ring_buffer_read() to read_buffer_iter_advance()
  ring-buffer: Have ring_buffer_empty() not depend on tracing stopped
  tracing: Save off entry when peeking at next entry
  ...

Documentation/trace/ftrace.rst

@@ -125,10 +125,13 @@ of ftrace. Here is a list of some of the key files:
   trace:
 
 	This file holds the output of the trace in a human
-	readable format (described below). Note, tracing is temporarily
-	disabled when the file is open for reading. Once all readers
-	are closed, tracing is re-enabled. Opening this file for
+	readable format (described below). Opening this file for
 	writing with the O_TRUNC flag clears the ring buffer content.
+        Note, this file is not a consumer. If tracing is off
+        (no tracer running, or tracing_on is zero), it will produce
+        the same output each time it is read. When tracing is on,
+        it may produce inconsistent results as it tries to read
+        the entire buffer without consuming it.
 
   trace_pipe:
 
@@ -142,9 +145,7 @@ of ftrace. Here is a list of some of the key files:
 	will not be read again with a sequential read. The
 	"trace" file is static, and if the tracer is not
 	adding more data, it will display the same
-	information every time it is read. Unlike the
-	"trace" file, opening this file for reading will not
-	temporarily disable tracing.
+	information every time it is read.
 
   trace_options:
 
@@ -262,6 +263,20 @@ of ftrace. Here is a list of some of the key files:
 	traced by the function tracer as well. This option will also
 	cause PIDs of tasks that exit to be removed from the file.
 
+  set_ftrace_notrace_pid:
+
+        Have the function tracer ignore threads whose PID are listed in
+        this file.
+
+        If the "function-fork" option is set, then when a task whose
+	PID is listed in this file forks, the child's PID will
+	automatically be added to this file, and the child will not be
+	traced by the function tracer as well. This option will also
+	cause PIDs of tasks that exit to be removed from the file.
+
+        If a PID is in both this file and "set_ftrace_pid", then this
+        file takes precedence, and the thread will not be traced.
+
   set_event_pid:
 
 	Have the events only trace a task with a PID listed in this file.
@@ -273,6 +288,19 @@ of ftrace. Here is a list of some of the key files:
 	cause the PIDs of tasks to be removed from this file when the task
 	exits.
 
+  set_event_notrace_pid:
+
+	Have the events not trace a task with a PID listed in this file.
+	Note, sched_switch and sched_wakeup will trace threads not listed
+	in this file, even if a thread's PID is in the file if the
+        sched_switch or sched_wakeup events also trace a thread that should
+        be traced.
+
+	To have the PIDs of children of tasks with their PID in this file
+	added on fork, enable the "event-fork" option. That option will also
+	cause the PIDs of tasks to be removed from this file when the task
+	exits.
+
   set_graph_function:
 
 	Functions listed in this file will cause the function graph
@@ -1125,6 +1153,12 @@ Here are the available options:
 	the trace displays additional information about the
 	latency, as described in "Latency trace format".
 
+  pause-on-trace
+	When set, opening the trace file for read, will pause
+	writing to the ring buffer (as if tracing_on was set to zero).
+	This simulates the original behavior of the trace file.
+	When the file is closed, tracing will be enabled again.
+
   record-cmd
 	When any event or tracer is enabled, a hook is enabled
 	in the sched_switch trace point to fill comm cache
@@ -1176,6 +1210,8 @@ Here are the available options:
 	tasks fork. Also, when tasks with PIDs in set_event_pid exit,
 	their PIDs will be removed from the file.
 
+        This affects PIDs listed in set_event_notrace_pid as well.
+
   function-trace
 	The latency tracers will enable function tracing
 	if this option is enabled (default it is). When
@@ -1190,6 +1226,8 @@ Here are the available options:
 	set_ftrace_pid exit, their PIDs will be removed from the
 	file.
 
+        This affects PIDs in set_ftrace_notrace_pid as well.
+
   display-graph
 	When set, the latency tracers (irqsoff, wakeup, etc) will
 	use function graph tracing instead of function tracing.
@@ -2126,6 +2164,8 @@ periodically make a CPU constantly busy with interrupts disabled.
   # cat trace
   # tracer: hwlat
   #
+  # entries-in-buffer/entries-written: 13/13   #P:8
+  #
   #                              _-----=> irqs-off
   #                             / _----=> need-resched
   #                            | / _---=> hardirq/softirq
@@ -2133,12 +2173,18 @@ periodically make a CPU constantly busy with interrupts disabled.
   #                            ||| /     delay
   #           TASK-PID   CPU#  ||||    TIMESTAMP  FUNCTION
   #              | |       |   ||||       |         |
-             <...>-3638  [001] d... 19452.055471: #1     inner/outer(us):   12/14    ts:1499801089.066141940
-             <...>-3638  [003] d... 19454.071354: #2     inner/outer(us):   11/9     ts:1499801091.082164365
-             <...>-3638  [002] dn.. 19461.126852: #3     inner/outer(us):   12/9     ts:1499801098.138150062
-             <...>-3638  [001] d... 19488.340960: #4     inner/outer(us):    8/12    ts:1499801125.354139633
-             <...>-3638  [003] d... 19494.388553: #5     inner/outer(us):    8/12    ts:1499801131.402150961
-             <...>-3638  [003] d... 19501.283419: #6     inner/outer(us):    0/12    ts:1499801138.297435289 nmi-total:4 nmi-count:1
+             <...>-1729  [001] d...   678.473449: #1     inner/outer(us):   11/12    ts:1581527483.343962693 count:6
+             <...>-1729  [004] d...   689.556542: #2     inner/outer(us):   16/9     ts:1581527494.889008092 count:1
+             <...>-1729  [005] d...   714.756290: #3     inner/outer(us):   16/16    ts:1581527519.678961629 count:5
+             <...>-1729  [001] d...   718.788247: #4     inner/outer(us):    9/17    ts:1581527523.889012713 count:1
+             <...>-1729  [002] d...   719.796341: #5     inner/outer(us):   13/9     ts:1581527524.912872606 count:1
+             <...>-1729  [006] d...   844.787091: #6     inner/outer(us):    9/12    ts:1581527649.889048502 count:2
+             <...>-1729  [003] d...   849.827033: #7     inner/outer(us):   18/9     ts:1581527654.889013793 count:1
+             <...>-1729  [007] d...   853.859002: #8     inner/outer(us):    9/12    ts:1581527658.889065736 count:1
+             <...>-1729  [001] d...   855.874978: #9     inner/outer(us):    9/11    ts:1581527660.861991877 count:1
+             <...>-1729  [001] d...   863.938932: #10    inner/outer(us):    9/11    ts:1581527668.970010500 count:1 nmi-total:7 nmi-count:1
+             <...>-1729  [007] d...   878.050780: #11    inner/outer(us):    9/12    ts:1581527683.385002600 count:1 nmi-total:5 nmi-count:1
+             <...>-1729  [007] d...   886.114702: #12    inner/outer(us):    9/12    ts:1581527691.385001600 count:1
 
 
 The above output is somewhat the same in the header. All events will have
@@ -2148,7 +2194,7 @@ interrupts disabled 'd'. Under the FUNCTION title there is:
 	This is the count of events recorded that were greater than the
 	tracing_threshold (See below).
 
- inner/outer(us):   12/14
+ inner/outer(us):   11/11
 
       This shows two numbers as "inner latency" and "outer latency". The test
       runs in a loop checking a timestamp twice. The latency detected within
@@ -2156,11 +2202,15 @@ interrupts disabled 'd'. Under the FUNCTION title there is:
       after the previous timestamp and the next timestamp in the loop is
       the "outer latency".
 
- ts:1499801089.066141940
+ ts:1581527483.343962693
+
+      The absolute timestamp that the first latency was recorded in the window.
+
+ count:6
 
-      The absolute timestamp that the event happened.
+      The number of times a latency was detected during the window.
 
- nmi-total:4 nmi-count:1
+ nmi-total:7 nmi-count:1
 
       On architectures that support it, if an NMI comes in during the
       test, the time spent in NMI is reported in "nmi-total" (in

drivers/Kconfig

@@ -200,6 +200,8 @@ source "drivers/thunderbolt/Kconfig"
 
 source "drivers/android/Kconfig"
 
+source "drivers/gpu/trace/Kconfig"
+
 source "drivers/nvdimm/Kconfig"
 
 source "drivers/dax/Kconfig"

drivers/gpu/Makefile

@@ -5,3 +5,4 @@
 obj-$(CONFIG_TEGRA_HOST1X)	+= host1x/
 obj-y			+= drm/ vga/
 obj-$(CONFIG_IMX_IPUV3_CORE)	+= ipu-v3/
+obj-$(CONFIG_TRACE_GPU_MEM)		+= trace/

drivers/gpu/trace/Kconfig

+# SPDX-License-Identifier: GPL-2.0-only
+
+config TRACE_GPU_MEM
+	bool

drivers/gpu/trace/Makefile

+# SPDX-License-Identifier: GPL-2.0
+
+obj-$(CONFIG_TRACE_GPU_MEM) += trace_gpu_mem.o

drivers/gpu/trace/trace_gpu_mem.c

+// SPDX-License-Identifier: GPL-2.0
+/*
+ * GPU memory trace points
+ *
+ * Copyright (C) 2020 Google, Inc.
+ */
+
+#include <linux/module.h>
+
+#define CREATE_TRACE_POINTS
+#include <trace/events/gpu_mem.h>
+
+EXPORT_TRACEPOINT_SYMBOL(gpu_mem_total);

include/linux/bootconfig.h

@@ -216,7 +216,8 @@ static inline int __init xbc_node_compose_key(struct xbc_node *node,
 }
 
 /* XBC node initializer */
-int __init xbc_init(char *buf);
+int __init xbc_init(char *buf, const char **emsg, int *epos);
+
 
 /* XBC cleanup data structures */
 void __init xbc_destroy_all(void);

include/linux/ring_buffer.h

@@ -135,10 +135,10 @@ void ring_buffer_read_finish(struct ring_buffer_iter *iter);
 
 struct ring_buffer_event *
 ring_buffer_iter_peek(struct ring_buffer_iter *iter, u64 *ts);
-struct ring_buffer_event *
-ring_buffer_read(struct ring_buffer_iter *iter, u64 *ts);
+void ring_buffer_iter_advance(struct ring_buffer_iter *iter);
 void ring_buffer_iter_reset(struct ring_buffer_iter *iter);
 int ring_buffer_iter_empty(struct ring_buffer_iter *iter);
+bool ring_buffer_iter_dropped(struct ring_buffer_iter *iter);
 
 unsigned long ring_buffer_size(struct trace_buffer *buffer, int cpu);
 

include/linux/trace_events.h

@@ -85,6 +85,8 @@ struct trace_iterator {
 	struct mutex		mutex;
 	struct ring_buffer_iter	**buffer_iter;
 	unsigned long		iter_flags;
+	void			*temp;	/* temp holder */
+	unsigned int		temp_size;
 
 	/* trace_seq for __print_flags() and __print_symbolic() etc. */
 	struct trace_seq	tmp_seq;

include/trace/events/gpu_mem.h

+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * GPU memory trace points
+ *
+ * Copyright (C) 2020 Google, Inc.
+ */
+
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM gpu_mem
+
+#if !defined(_TRACE_GPU_MEM_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_GPU_MEM_H
+
+#include <linux/tracepoint.h>
+
+/*
+ * The gpu_memory_total event indicates that there's an update to either the
+ * global or process total gpu memory counters.
+ *
+ * This event should be emitted whenever the kernel device driver allocates,
+ * frees, imports, unimports memory in the GPU addressable space.
+ *
+ * @gpu_id: This is the gpu id.
+ *
+ * @pid: Put 0 for global total, while positive pid for process total.
+ *
+ * @size: Virtual size of the allocation in bytes.
+ *
+ */
+TRACE_EVENT(gpu_mem_total,
+
+	TP_PROTO(uint32_t gpu_id, uint32_t pid, uint64_t size),
+
+	TP_ARGS(gpu_id, pid, size),
+
+	TP_STRUCT__entry(
+		__field(uint32_t, gpu_id)
+		__field(uint32_t, pid)
+		__field(uint64_t, size)
+	),
+
+	TP_fast_assign(
+		__entry->gpu_id = gpu_id;
+		__entry->pid = pid;
+		__entry->size = size;
+	),
+
+	TP_printk("gpu_id=%u pid=%u size=%llu",
+		__entry->gpu_id,
+		__entry->pid,
+		__entry->size)
+);
+
+#endif /* _TRACE_GPU_MEM_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>

init/main.c

@@ -353,6 +353,8 @@ static int __init bootconfig_params(char *param, char *val,
 static void __init setup_boot_config(const char *cmdline)
 {
 	static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata;
+	const char *msg;
+	int pos;
 	u32 size, csum;
 	char *data, *copy;
 	u32 *hdr;
@@ -400,10 +402,14 @@ static void __init setup_boot_config(const char *cmdline)
 	memcpy(copy, data, size);
 	copy[size] = '\0';
 
-	ret = xbc_init(copy);
-	if (ret < 0)
-		pr_err("Failed to parse bootconfig\n");
-	else {
+	ret = xbc_init(copy, &msg, &pos);
+	if (ret < 0) {
+		if (pos < 0)
+			pr_err("Failed to init bootconfig: %s.\n", msg);
+		else
+			pr_err("Failed to parse bootconfig: %s at %d.\n",
+				msg, pos);
+	} else {
 		pr_info("Load bootconfig: %d bytes %d nodes\n", size, ret);
 		/* keys starting with "kernel." are passed via cmdline */
 		extra_command_line = xbc_make_cmdline("kernel");

kernel/trace/trace.c

@@ -386,16 +386,22 @@ trace_find_filtered_pid(struct trace_pid_list *filtered_pids, pid_t search_pid)
  * Returns false if @task should be traced.
  */
 bool
-trace_ignore_this_task(struct trace_pid_list *filtered_pids, struct task_struct *task)
+trace_ignore_this_task(struct trace_pid_list *filtered_pids,
+		       struct trace_pid_list *filtered_no_pids,
+		       struct task_struct *task)
 {
 	/*
-	 * Return false, because if filtered_pids does not exist,
-	 * all pids are good to trace.
+	 * If filterd_no_pids is not empty, and the task's pid is listed
+	 * in filtered_no_pids, then return true.
+	 * Otherwise, if filtered_pids is empty, that means we can
+	 * trace all tasks. If it has content, then only trace pids
+	 * within filtered_pids.
 	 */
-	if (!filtered_pids)
-		return false;
 
-	return !trace_find_filtered_pid(filtered_pids, task->pid);
+	return (filtered_pids &&
+		!trace_find_filtered_pid(filtered_pids, task->pid)) ||
+		(filtered_no_pids &&
+		 trace_find_filtered_pid(filtered_no_pids, task->pid));
 }
 
 /**
@@ -3378,7 +3384,7 @@ static void trace_iterator_increment(struct trace_iterator *iter)
 
 	iter->idx++;
 	if (buf_iter)
-		ring_buffer_read(buf_iter, NULL);
+		ring_buffer_iter_advance(buf_iter);
 }
 
 static struct trace_entry *
@@ -3388,11 +3394,15 @@ peek_next_entry(struct trace_iterator *iter, int cpu, u64 *ts,
 	struct ring_buffer_event *event;
 	struct ring_buffer_iter *buf_iter = trace_buffer_iter(iter, cpu);
 
-	if (buf_iter)
+	if (buf_iter) {
 		event = ring_buffer_iter_peek(buf_iter, ts);
-	else
+		if (lost_events)
+			*lost_events = ring_buffer_iter_dropped(buf_iter) ?
+				(unsigned long)-1 : 0;
+	} else {
 		event = ring_buffer_peek(iter->array_buffer->buffer, cpu, ts,
 					 lost_events);
+	}
 
 	if (event) {
 		iter->ent_size = ring_buffer_event_length(event);
@@ -3462,11 +3472,51 @@ __find_next_entry(struct trace_iterator *iter, int *ent_cpu,
 	return next;
 }
 
+#define STATIC_TEMP_BUF_SIZE	128
+static char static_temp_buf[STATIC_TEMP_BUF_SIZE];
+
 /* Find the next real entry, without updating the iterator itself */
 struct trace_entry *trace_find_next_entry(struct trace_iterator *iter,
 					  int *ent_cpu, u64 *ent_ts)
 {
-	return __find_next_entry(iter, ent_cpu, NULL, ent_ts);
+	/* __find_next_entry will reset ent_size */
+	int ent_size = iter->ent_size;
+	struct trace_entry *entry;
+
+	/*
+	 * If called from ftrace_dump(), then the iter->temp buffer
+	 * will be the static_temp_buf and not created from kmalloc.
+	 * If the entry size is greater than the buffer, we can
+	 * not save it. Just return NULL in that case. This is only
+	 * used to add markers when two consecutive events' time
+	 * stamps have a large delta. See trace_print_lat_context()
+	 */
+	if (iter->temp == static_temp_buf &&
+	    STATIC_TEMP_BUF_SIZE < ent_size)
+		return NULL;
+
+	/*
+	 * The __find_next_entry() may call peek_next_entry(), which may
+	 * call ring_buffer_peek() that may make the contents of iter->ent
+	 * undefined. Need to copy iter->ent now.
+	 */
+	if (iter->ent && iter->ent != iter->temp) {
+		if ((!iter->temp || iter->temp_size < iter->ent_size) &&
+		    !WARN_ON_ONCE(iter->temp == static_temp_buf)) {
+			kfree(iter->temp);
+			iter->temp = kmalloc(iter->ent_size, GFP_KERNEL);
+			if (!iter->temp)
+				return NULL;
+		}
+		memcpy(iter->temp, iter->ent, iter->ent_size);
+		iter->temp_size = iter->ent_size;
+		iter->ent = iter->temp;
+	}
+	entry = __find_next_entry(iter, ent_cpu, NULL, ent_ts);
+	/* Put back the original ent_size */
+	iter->ent_size = ent_size;
+
+	return entry;
 }
 
 /* Find the next real entry, and increment the iterator to the next entry */
@@ -3538,7 +3588,7 @@ void tracing_iter_reset(struct trace_iterator *iter, int cpu)
 		if (ts >= iter->array_buffer->time_start)
 			break;
 		entries++;
-		ring_buffer_read(buf_iter, NULL);
+		ring_buffer_iter_advance(buf_iter);
 	}
 
 	per_cpu_ptr(iter->array_buffer->data, cpu)->skipped_entries = entries;
@@ -3981,8 +4031,12 @@ enum print_line_t print_trace_line(struct trace_iterator *iter)
 	enum print_line_t ret;
 
 	if (iter->lost_events) {
-		trace_seq_printf(&iter->seq, "CPU:%d [LOST %lu EVENTS]\n",
-				 iter->cpu, iter->lost_events);
+		if (iter->lost_events == (unsigned long)-1)
+			trace_seq_printf(&iter->seq, "CPU:%d [LOST EVENTS]\n",
+					 iter->cpu);
+		else
+			trace_seq_printf(&iter->seq, "CPU:%d [LOST %lu EVENTS]\n",
+					 iter->cpu, iter->lost_events);
 		if (trace_seq_has_overflowed(&iter->seq))
 			return TRACE_TYPE_PARTIAL_LINE;
 	}
@@ -4197,6 +4251,18 @@ __tracing_open(struct inode *inode, struct file *file, bool snapshot)
 	if (!iter->buffer_iter)
 		goto release;
 
+	/*
+	 * trace_find_next_entry() may need to save off iter->ent.
+	 * It will place it into the iter->temp buffer. As most
+	 * events are less than 128, allocate a buffer of that size.
+	 * If one is greater, then trace_find_next_entry() will
+	 * allocate a new buffer to adjust for the bigger iter->ent.
+	 * It's not critical if it fails to get allocated here.
+	 */
+	iter->temp = kmalloc(128, GFP_KERNEL);
+	if (iter->temp)
+		iter->temp_size = 128;
+
 	/*
 	 * We make a copy of the current tracer to avoid concurrent
 	 * changes on it while we are reading.
@@ -4237,8 +4303,11 @@ __tracing_open(struct inode *inode, struct file *file, bool snapshot)
 	if (trace_clocks[tr->clock_id].in_ns)
 		iter->iter_flags |= TRACE_FILE_TIME_IN_NS;
 
-	/* stop the trace while dumping if we are not opening "snapshot" */
-	if (!iter->snapshot)
+	/*
+	 * If pause-on-trace is enabled, then stop the trace while
+	 * dumping, unless this is the "snapshot" file
+	 */
+	if (!iter->snapshot && (tr->trace_flags & TRACE_ITER_PAUSE_ON_TRACE))
 		tracing_stop_tr(tr);
 
 	if (iter->cpu_file == RING_BUFFER_ALL_CPUS) {
@@ -4269,6 +4338,7 @@ __tracing_open(struct inode *inode, struct file *file, bool snapshot)
  fail:
 	mutex_unlock(&trace_types_lock);
 	kfree(iter->trace);
+	kfree(iter->temp);
 	kfree(iter->buffer_iter);
 release:
 	seq_release_private(inode, file);
@@ -4334,7 +4404,7 @@ static int tracing_release(struct inode *inode, struct file *file)
 	if (iter->trace && iter->trace->close)
 		iter->trace->close(iter);
 
-	if (!iter->snapshot)
+	if (!iter->snapshot && tr->stop_count)
 		/* reenable tracing if it was previously enabled */
 		tracing_start_tr(tr);
 
@@ -4344,6 +4414,7 @@ static int tracing_release(struct inode *inode, struct file *file)
 
 	mutex_destroy(&iter->mutex);
 	free_cpumask_var(iter->started);
+	kfree(iter->temp);
 	kfree(iter->trace);
 	kfree(iter->buffer_iter);
 	seq_release_private(inode, file);
@@ -4964,6 +5035,8 @@ static const char readme_msg[] =
 #ifdef CONFIG_FUNCTION_TRACER
 	"  set_ftrace_pid\t- Write pid(s) to only function trace those pids\n"
 	"\t\t    (function)\n"
+	"  set_ftrace_notrace_pid\t- Write pid(s) to not function trace those pids\n"
+	"\t\t    (function)\n"
 #endif
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 	"  set_graph_function\t- Trace the nested calls of a function (function_graph)\n"
@@ -9146,6 +9219,9 @@ void ftrace_dump(enum ftrace_dump_mode oops_dump_mode)
 
 	/* Simulate the iterator */
 	trace_init_global_iter(&iter);
+	/* Can not use kmalloc for iter.temp */
+	iter.temp = static_temp_buf;
+	iter.temp_size = STATIC_TEMP_BUF_SIZE;
 
 	for_each_tracing_cpu(cpu) {
 		atomic_inc(&per_cpu_ptr(iter.array_buffer->data, cpu)->disabled);
@@ -9334,7 +9410,7 @@ __init static int tracer_alloc_buffers(void)
 		goto out_free_buffer_mask;
 
 	/* Only allocate trace_printk buffers if a trace_printk exists */
-	if (__stop___trace_bprintk_fmt != __start___trace_bprintk_fmt)
+	if (&__stop___trace_bprintk_fmt != &__start___trace_bprintk_fmt)
 		/* Must be called before global_trace.buffer is allocated */
 		trace_printk_init_buffers();
 

kernel/trace/trace.h

@@ -178,10 +178,10 @@ struct trace_array_cpu {
 	kuid_t			uid;
 	char			comm[TASK_COMM_LEN];
 
-	bool			ignore_pid;
 #ifdef CONFIG_FUNCTION_TRACER
-	bool			ftrace_ignore_pid;
+	int			ftrace_ignore_pid;
 #endif
+	bool			ignore_pid;
 };
 
 struct tracer;
@@ -207,6 +207,30 @@ struct trace_pid_list {
 	unsigned long			*pids;
 };
 
+enum {
+	TRACE_PIDS		= BIT(0),
+	TRACE_NO_PIDS		= BIT(1),
+};
+
+static inline bool pid_type_enabled(int type, struct trace_pid_list *pid_list,
+				    struct trace_pid_list *no_pid_list)
+{
+	/* Return true if the pid list in type has pids */
+	return ((type & TRACE_PIDS) && pid_list) ||
+		((type & TRACE_NO_PIDS) && no_pid_list);
+}
+
+static inline bool still_need_pid_events(int type, struct trace_pid_list *pid_list,
+					 struct trace_pid_list *no_pid_list)
+{
+	/*
+	 * Turning off what is in @type, return true if the "other"
+	 * pid list, still has pids in it.
+	 */
+	return (!(type & TRACE_PIDS) && pid_list) ||
+		(!(type & TRACE_NO_PIDS) && no_pid_list);
+}
+
 typedef bool (*cond_update_fn_t)(struct trace_array *tr, void *cond_data);
 
 /**
@@ -285,6 +309,7 @@ struct trace_array {
 #endif
 #endif
 	struct trace_pid_list	__rcu *filtered_pids;
+	struct trace_pid_list	__rcu *filtered_no_pids;
 	/*
 	 * max_lock is used to protect the swapping of buffers
 	 * when taking a max snapshot. The buffers themselves are
@@ -331,6 +356,7 @@ struct trace_array {
 #ifdef CONFIG_FUNCTION_TRACER
 	struct ftrace_ops	*ops;
 	struct trace_pid_list	__rcu *function_pids;
+	struct trace_pid_list	__rcu *function_no_pids;
 #ifdef CONFIG_DYNAMIC_FTRACE
 	/* All of these are protected by the ftrace_lock */
 	struct list_head	func_probes;
@@ -557,12 +583,7 @@ struct tracer {
  * caller, and we can skip the current check.
  */
 enum {
-	TRACE_BUFFER_BIT,
-	TRACE_BUFFER_NMI_BIT,
-	TRACE_BUFFER_IRQ_BIT,
-	TRACE_BUFFER_SIRQ_BIT,
-
-	/* Start of function recursion bits */
+	/* Function recursion bits */
 	TRACE_FTRACE_BIT,
 	TRACE_FTRACE_NMI_BIT,
 	TRACE_FTRACE_IRQ_BIT,
@@ -787,6 +808,7 @@ extern int pid_max;
 bool trace_find_filtered_pid(struct trace_pid_list *filtered_pids,
 			     pid_t search_pid);
 bool trace_ignore_this_task(struct trace_pid_list *filtered_pids,
+			    struct trace_pid_list *filtered_no_pids,
 			    struct task_struct *task);
 void trace_filter_add_remove_task(struct trace_pid_list *pid_list,
 				  struct task_struct *self,
@@ -1307,6 +1329,7 @@ extern int trace_get_user(struct trace_parser *parser, const char __user *ubuf,
 		C(IRQ_INFO,		"irq-info"),		\
 		C(MARKERS,		"markers"),		\
 		C(EVENT_FORK,		"event-fork"),		\
+		C(PAUSE_ON_TRACE,	"pause-on-trace"),	\
 		FUNCTION_FLAGS					\
 		FGRAPH_FLAGS					\
 		STACK_FLAGS					\

kernel/trace/trace_entries.h

@@ -325,14 +325,16 @@ FTRACE_ENTRY(hwlat, hwlat_entry,
 		__field_desc(	long,	timestamp,	tv_nsec		)
 		__field(	unsigned int,		nmi_count	)
 		__field(	unsigned int,		seqnum		)
+		__field(	unsigned int,		count		)
 	),
 
-	F_printk("cnt:%u\tts:%010llu.%010lu\tinner:%llu\touter:%llu\tnmi-ts:%llu\tnmi-count:%u\n",
+	F_printk("cnt:%u\tts:%010llu.%010lu\tinner:%llu\touter:%llu\tcount:%d\tnmi-ts:%llu\tnmi-count:%u\n",
 		 __entry->seqnum,
 		 __entry->tv_sec,
 		 __entry->tv_nsec,
 		 __entry->duration,
 		 __entry->outer_duration,
+		 __entry->count,
 		 __entry->nmi_total_ts,
 		 __entry->nmi_count)
 );

kernel/trace/trace_functions_graph.c

@@ -482,7 +482,7 @@ get_return_for_leaf(struct trace_iterator *iter,
 
 	/* this is a leaf, now advance the iterator */
 	if (ring_iter)
-		ring_buffer_read(ring_iter, NULL);
+		ring_buffer_iter_advance(ring_iter);
 
 	return next;
 }

kernel/trace/trace_hwlat.c

@@ -83,6 +83,7 @@ struct hwlat_sample {
 	u64			nmi_total_ts;	/* Total time spent in NMIs */
 	struct timespec64	timestamp;	/* wall time */
 	int			nmi_count;	/* # NMIs during this sample */
+	int			count;		/* # of iteratons over threash */
 };
 
 /* keep the global state somewhere. */
@@ -124,6 +125,7 @@ static void trace_hwlat_sample(struct hwlat_sample *sample)
 	entry->timestamp		= sample->timestamp;
 	entry->nmi_total_ts		= sample->nmi_total_ts;
 	entry->nmi_count		= sample->nmi_count;
+	entry->count			= sample->count;
 
 	if (!call_filter_check_discard(call, entry, buffer, event))
 		trace_buffer_unlock_commit_nostack(buffer, event);
@@ -167,12 +169,14 @@ void trace_hwlat_callback(bool enter)
 static int get_sample(void)
 {
 	struct trace_array *tr = hwlat_trace;
+	struct hwlat_sample s;
 	time_type start, t1, t2, last_t2;
-	s64 diff, total, last_total = 0;
+	s64 diff, outer_diff, total, last_total = 0;
 	u64 sample = 0;
 	u64 thresh = tracing_thresh;
 	u64 outer_sample = 0;
 	int ret = -1;
+	unsigned int count = 0;
 
 	do_div(thresh, NSEC_PER_USEC); /* modifies interval value */
 
@@ -186,6 +190,7 @@ static int get_sample(void)
 
 	init_time(last_t2, 0);
 	start = time_get(); /* start timestamp */
+	outer_diff = 0;
 
 	do {
 
@@ -194,14 +199,14 @@ static int get_sample(void)
 
 		if (time_u64(last_t2)) {
 			/* Check the delta from outer loop (t2 to next t1) */
-			diff = time_to_us(time_sub(t1, last_t2));
+			outer_diff = time_to_us(time_sub(t1, last_t2));
 			/* This shouldn't happen */
-			if (diff < 0) {
+			if (outer_diff < 0) {
 				pr_err(BANNER "time running backwards\n");
 				goto out;
 			}
-			if (diff > outer_sample)
-				outer_sample = diff;
+			if (outer_diff > outer_sample)
+				outer_sample = outer_diff;
 		}
 		last_t2 = t2;
 
@@ -217,6 +222,12 @@ static int get_sample(void)
 		/* This checks the inner loop (t1 to t2) */
 		diff = time_to_us(time_sub(t2, t1));     /* current diff */
 
+		if (diff > thresh || outer_diff > thresh) {
+			if (!count)
+				ktime_get_real_ts64(&s.timestamp);
+			count++;
+		}
+
 		/* This shouldn't happen */
 		if (diff < 0) {
 			pr_err(BANNER "time running backwards\n");
@@ -236,7 +247,6 @@ static int get_sample(void)
 
 	/* If we exceed the threshold value, we have found a hardware latency */
 	if (sample > thresh || outer_sample > thresh) {
-		struct hwlat_sample s;
 		u64 latency;
 
 		ret = 1;
@@ -249,9 +259,9 @@ static int get_sample(void)
 		s.seqnum = hwlat_data.count;
 		s.duration = sample;
 		s.outer_duration = outer_sample;
-		ktime_get_real_ts64(&s.timestamp);
 		s.nmi_total_ts = nmi_total_ts;
 		s.nmi_count = nmi_count;
+		s.count = count;
 		trace_hwlat_sample(&s);
 
 		latency = max(sample, outer_sample);

kernel/trace/trace_kprobe.c

@@ -1078,6 +1078,8 @@ static int trace_kprobe_show(struct seq_file *m, struct dyn_event *ev)
 	int i;
 
 	seq_putc(m, trace_kprobe_is_return(tk) ? 'r' : 'p');
+	if (trace_kprobe_is_return(tk) && tk->rp.maxactive)
+		seq_printf(m, "%d", tk->rp.maxactive);
 	seq_printf(m, ":%s/%s", trace_probe_group_name(&tk->tp),
 				trace_probe_name(&tk->tp));
 

kernel/trace/trace_output.c

@@ -617,22 +617,19 @@ int trace_print_context(struct trace_iterator *iter)
 
 int trace_print_lat_context(struct trace_iterator *iter)
 {
+	struct trace_entry *entry, *next_entry;
 	struct trace_array *tr = iter->tr;
-	/* trace_find_next_entry will reset ent_size */
-	int ent_size = iter->ent_size;
 	struct trace_seq *s = &iter->seq;
-	u64 next_ts;
-	struct trace_entry *entry = iter->ent,
-			   *next_entry = trace_find_next_entry(iter, NULL,
-							       &next_ts);
 	unsigned long verbose = (tr->trace_flags & TRACE_ITER_VERBOSE);
+	u64 next_ts;
 
-	/* Restore the original ent_size */
-	iter->ent_size = ent_size;
-
+	next_entry = trace_find_next_entry(iter, NULL, &next_ts);
 	if (!next_entry)
 		next_ts = iter->ts;
 
+	/* trace_find_next_entry() may change iter->ent */
+	entry = iter->ent;
+
 	if (verbose) {
 		char comm[TASK_COMM_LEN];
 
@@ -1158,12 +1155,12 @@ trace_hwlat_print(struct trace_iterator *iter, int flags,
 
 	trace_assign_type(field, entry);
 
-	trace_seq_printf(s, "#%-5u inner/outer(us): %4llu/%-5llu ts:%lld.%09ld",
+	trace_seq_printf(s, "#%-5u inner/outer(us): %4llu/%-5llu ts:%lld.%09ld count:%d",
 			 field->seqnum,
 			 field->duration,
 			 field->outer_duration,
 			 (long long)field->timestamp.tv_sec,
-			 field->timestamp.tv_nsec);
+			 field->timestamp.tv_nsec, field->count);
 
 	if (field->nmi_count) {
 		/*

lib/bootconfig.c

@@ -29,12 +29,14 @@ static int xbc_node_num __initdata;
 static char *xbc_data __initdata;
 static size_t xbc_data_size __initdata;
 static struct xbc_node *last_parent __initdata;
+static const char *xbc_err_msg __initdata;
+static int xbc_err_pos __initdata;
 
 static int __init xbc_parse_error(const char *msg, const char *p)
 {
-	int pos = p - xbc_data;
+	xbc_err_msg = msg;
+	xbc_err_pos = (int)(p - xbc_data);
 
-	pr_err("Parse error at pos %d: %s\n", pos, msg);
 	return -EINVAL;
 }
 
@@ -738,33 +740,44 @@ void __init xbc_destroy_all(void)
 /**
  * xbc_init() - Parse given XBC file and build XBC internal tree
  * @buf: boot config text
+ * @emsg: A pointer of const char * to store the error message
+ * @epos: A pointer of int to store the error position
  *
  * This parses the boot config text in @buf. @buf must be a
  * null terminated string and smaller than XBC_DATA_MAX.
  * Return the number of stored nodes (>0) if succeeded, or -errno
  * if there is any error.
+ * In error cases, @emsg will be updated with an error message and
+ * @epos will be updated with the error position which is the byte offset
+ * of @buf. If the error is not a parser error, @epos will be -1.
  */
-int __init xbc_init(char *buf)
+int __init xbc_init(char *buf, const char **emsg, int *epos)
 {
 	char *p, *q;
 	int ret, c;
 
+	if (epos)
+		*epos = -1;
+
 	if (xbc_data) {
-		pr_err("Error: bootconfig is already initialized.\n");
+		if (emsg)
+			*emsg = "Bootconfig is already initialized";
 		return -EBUSY;
 	}
 
 	ret = strlen(buf);
 	if (ret > XBC_DATA_MAX - 1 || ret == 0) {
-		pr_err("Error: Config data is %s.\n",
-			ret ? "too big" : "empty");
+		if (emsg)
+			*emsg = ret ? "Config data is too big" :
+				"Config data is empty";
 		return -ERANGE;
 	}
 
 	xbc_nodes = memblock_alloc(sizeof(struct xbc_node) * XBC_NODE_MAX,
 				   SMP_CACHE_BYTES);
 	if (!xbc_nodes) {
-		pr_err("Failed to allocate memory for bootconfig nodes.\n");
+		if (emsg)
+			*emsg = "Failed to allocate bootconfig nodes";
 		return -ENOMEM;
 	}
 	memset(xbc_nodes, 0, sizeof(struct xbc_node) * XBC_NODE_MAX);
@@ -814,9 +827,13 @@ int __init xbc_init(char *buf)
 	if (!ret)
 		ret = xbc_verify_tree();
 
-	if (ret < 0)
+	if (ret < 0) {
+		if (epos)
+			*epos = xbc_err_pos;
+		if (emsg)
+			*emsg = xbc_err_msg;
 		xbc_destroy_all();
-	else
+	} else
 		ret = xbc_node_num;
 
 	return ret;

tools/bootconfig/Makefile

 # SPDX-License-Identifier: GPL-2.0
 # Makefile for bootconfig command
+include ../scripts/Makefile.include
 
 bindir ?= /usr/bin
 
-HEADER = include/linux/bootconfig.h
-CFLAGS = -Wall -g -I./include
+ifeq ($(srctree),)
+srctree := $(patsubst %/,%,$(dir $(CURDIR)))
+srctree := $(patsubst %/,%,$(dir $(srctree)))
+endif
 
-PROGS = bootconfig
+LIBSRC = $(srctree)/lib/bootconfig.c $(srctree)/include/linux/bootconfig.h
+CFLAGS = -Wall -g -I$(CURDIR)/include
 
-all: $(PROGS)
+ALL_TARGETS := bootconfig
+ALL_PROGRAMS := $(patsubst %,$(OUTPUT)%,$(ALL_TARGETS))
 
-bootconfig: ../../lib/bootconfig.c main.c $(HEADER)
+all: $(ALL_PROGRAMS)
+
+$(OUTPUT)bootconfig: main.c $(LIBSRC)
 	$(CC) $(filter %.c,$^) $(CFLAGS) -o $@
 
-install: $(PROGS)
-	install bootconfig $(DESTDIR)$(bindir)
+test: $(ALL_PROGRAMS) test-bootconfig.sh
+	./test-bootconfig.sh $(OUTPUT)
 
-test: bootconfig
-	./test-bootconfig.sh
+install: $(ALL_PROGRAMS)
+	install $(OUTPUT)bootconfig $(DESTDIR)$(bindir)
 
 clean:
-	$(RM) -f *.o bootconfig
+	$(RM) -f $(OUTPUT)*.o $(ALL_PROGRAMS)

tools/bootconfig/main.c

@@ -130,6 +130,7 @@ int load_xbc_from_initrd(int fd, char **buf)
 	int ret;
 	u32 size = 0, csum = 0, rcsum;
 	char magic[BOOTCONFIG_MAGIC_LEN];
+	const char *msg;
 
 	ret = fstat(fd, &stat);
 	if (ret < 0)
@@ -182,10 +183,12 @@ int load_xbc_from_initrd(int fd, char **buf)
 		return -EINVAL;
 	}
 
-	ret = xbc_init(*buf);
+	ret = xbc_init(*buf, &msg, NULL);
 	/* Wrong data */
-	if (ret < 0)
+	if (ret < 0) {
+		pr_err("parse error: %s.\n", msg);
 		return ret;
+	}
 
 	return size;
 }
@@ -244,11 +247,34 @@ int delete_xbc(const char *path)
 	return ret;
 }
 
+static void show_xbc_error(const char *data, const char *msg, int pos)
+{
+	int lin = 1, col, i;
+
+	if (pos < 0) {
+		pr_err("Error: %s.\n", msg);
+		return;
+	}
+
+	/* Note that pos starts from 0 but lin and col should start from 1. */
+	col = pos + 1;
+	for (i = 0; i < pos; i++) {
+		if (data[i] == '\n') {
+			lin++;
+			col = pos - i;
+		}
+	}
+	pr_err("Parse Error: %s at %d:%d\n", msg, lin, col);
+
+}
+
 int apply_xbc(const char *path, const char *xbc_path)
 {
 	u32 size, csum;
 	char *buf, *data;
 	int ret, fd;
+	const char *msg;
+	int pos;
 
 	ret = load_xbc_file(xbc_path, &buf);
 	if (ret < 0) {
@@ -267,11 +293,12 @@ int apply_xbc(const char *path, const char *xbc_path)
 	*(u32 *)(data + size + 4) = csum;
 
 	/* Check the data format */
-	ret = xbc_init(buf);
+	ret = xbc_init(buf, &msg, &pos);
 	if (ret < 0) {
-		pr_err("Failed to parse %s: %d\n", xbc_path, ret);
+		show_xbc_error(data, msg, pos);
 		free(data);
 		free(buf);
+
 		return ret;
 	}
 	printf("Apply %s to %s\n", xbc_path, path);

tools/bootconfig/test-bootconfig.sh

@@ -3,9 +3,16 @@
 
 echo "Boot config test script"
 
-BOOTCONF=./bootconfig
-INITRD=`mktemp initrd-XXXX`
-TEMPCONF=`mktemp temp-XXXX.bconf`
+if [ -d "$1" ]; then
+  TESTDIR=$1
+else
+  TESTDIR=.
+fi
+BOOTCONF=${TESTDIR}/bootconfig
+
+INITRD=`mktemp ${TESTDIR}/initrd-XXXX`
+TEMPCONF=`mktemp ${TESTDIR}/temp-XXXX.bconf`
+OUTFILE=`mktemp ${TESTDIR}/tempout-XXXX`
 NG=0
 
 cleanup() {
@@ -65,7 +72,6 @@ new_size=$(stat -c %s $INITRD)
 xpass test $new_size -eq $initrd_size
 
 echo "No error messge while applying"
-OUTFILE=`mktemp tempout-XXXX`
 dd if=/dev/zero of=$INITRD bs=4096 count=1
 printf " \0\0\0 \0\0\0" >> $INITRD
 $BOOTCONF -a $TEMPCONF $INITRD > $OUTFILE 2>&1

tools/testing/selftests/ftrace/test.d/event/event-no-pid.tc

+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+# description: event tracing - restricts events based on pid notrace filtering
+# flags: instance
+
+do_reset() {
+    echo > set_event
+    echo > set_event_pid
+    echo > set_event_notrace_pid
+    echo 0 > options/event-fork
+    echo 0 > events/enable
+    clear_trace
+    echo 1 > tracing_on
+}
+
+fail() { #msg
+    cat trace
+    do_reset
+    echo $1
+    exit_fail
+}
+
+count_pid() {
+    pid=$@
+    cat trace | grep -v '^#' | sed -e 's/[^-]*-\([0-9]*\).*/\1/' | grep $pid | wc -l
+}
+
+count_no_pid() {
+    pid=$1
+    cat trace | grep -v '^#' | sed -e 's/[^-]*-\([0-9]*\).*/\1/' | grep -v $pid | wc -l
+}
+
+enable_system() {
+    system=$1
+
+    if [ -d events/$system ]; then
+	echo 1 > events/$system/enable
+    fi
+}
+
+enable_events() {
+    echo 0 > tracing_on
+    # Enable common groups of events, as all events can allow for
+    # events to be traced via scheduling that we don't care to test.
+    enable_system syscalls
+    enable_system rcu
+    enable_system block
+    enable_system exceptions
+    enable_system irq
+    enable_system net
+    enable_system power
+    enable_system signal
+    enable_system sock
+    enable_system timer
+    enable_system thermal
+    echo 1 > tracing_on
+}
+
+if [ ! -f set_event -o ! -d events/sched ]; then
+    echo "event tracing is not supported"
+    exit_unsupported
+fi
+
+if [ ! -f set_event_pid -o ! -f set_event_notrace_pid ]; then
+    echo "event pid notrace filtering is not supported"
+    exit_unsupported
+fi
+
+echo 0 > options/event-fork
+
+do_reset
+
+read mypid rest < /proc/self/stat
+
+echo $mypid > set_event_notrace_pid
+grep -q $mypid set_event_notrace_pid
+
+enable_events
+
+yield
+
+echo 0 > tracing_on
+
+cnt=`count_pid $mypid`
+if [ $cnt -ne 0 ]; then
+    fail "Filtered out task has events"
+fi
+
+cnt=`count_no_pid $mypid`
+if [ $cnt -eq 0 ]; then
+    fail "No other events were recorded"
+fi
+
+do_reset
+
+echo $mypid > set_event_notrace_pid
+echo 1 > options/event-fork
+
+enable_events
+
+yield &
+child=$!
+echo "child = $child"
+wait $child
+
+echo 0 > tracing_on
+
+cnt=`count_pid $mypid`
+if [ $cnt -ne 0 ]; then
+    fail "Filtered out task has events"
+fi
+
+cnt=`count_pid $child`
+if [ $cnt -ne 0 ]; then
+    fail "Child of filtered out taskhas events"
+fi
+
+cnt=`count_no_pid $mypid`
+if [ $cnt -eq 0 ]; then
+    fail "No other events were recorded"
+fi
+
+do_reset
+
+exit 0

tools/testing/selftests/ftrace/test.d/ftrace/func-filter-notrace-pid.tc

+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+# description: ftrace - function pid notrace filters
+# flags: instance
+
+# Make sure that function pid matching filter with notrace works.
+
+if ! grep -q function available_tracers; then
+    echo "no function tracer configured"
+    exit_unsupported
+fi
+
+if [ ! -f set_ftrace_notrace_pid ]; then
+    echo "set_ftrace_notrace_pid not found? Is function tracer not set?"
+    exit_unsupported
+fi
+
+if [ ! -f set_ftrace_filter ]; then
+    echo "set_ftrace_filter not found? Is function tracer not set?"
+    exit_unsupported
+fi
+
+do_function_fork=1
+
+if [ ! -f options/function-fork ]; then
+    do_function_fork=0
+    echo "no option for function-fork found. Option will not be tested."
+fi
+
+read PID _ < /proc/self/stat
+
+if [ $do_function_fork -eq 1 ]; then
+    # default value of function-fork option
+    orig_value=`grep function-fork trace_options`
+fi
+
+do_reset() {
+    if [ $do_function_fork -eq 0 ]; then
+	return
+    fi
+
+    echo > set_ftrace_notrace_pid
+    echo $orig_value > trace_options
+}
+
+fail() { # msg
+    do_reset
+    echo $1
+    exit_fail
+}
+
+do_test() {
+    disable_tracing
+
+    echo do_execve* > set_ftrace_filter
+    echo *do_fork >> set_ftrace_filter
+
+    echo $PID > set_ftrace_notrace_pid
+    echo function > current_tracer
+
+    if [ $do_function_fork -eq 1 ]; then
+	# don't allow children to be traced
+	echo nofunction-fork > trace_options
+    fi
+
+    enable_tracing
+    yield
+
+    count_pid=`cat trace | grep -v ^# | grep $PID | wc -l`
+    count_other=`cat trace | grep -v ^# | grep -v $PID | wc -l`
+
+    # count_pid should be 0
+    if [ $count_pid -ne 0 -o $count_other -eq 0 ]; then
+	fail "PID filtering not working? traced task = $count_pid; other tasks = $count_other "
+    fi
+
+    disable_tracing
+    clear_trace
+
+    if [ $do_function_fork -eq 0 ]; then
+	return
+    fi
+
+    # allow children to be traced
+    echo function-fork > trace_options
+
+    # With pid in both set_ftrace_pid and set_ftrace_notrace_pid
+    # there should not be any tasks traced.
+
+    echo $PID > set_ftrace_pid
+
+    enable_tracing
+    yield
+
+    count_pid=`cat trace | grep -v ^# | grep $PID | wc -l`
+    count_other=`cat trace | grep -v ^# | grep -v $PID | wc -l`
+
+    # both should be zero
+    if [ $count_pid -ne 0 -o $count_other -ne 0 ]; then
+	fail "PID filtering not following fork? traced task = $count_pid; other tasks = $count_other "
+    fi
+}
+
+do_test
+
+do_reset
+
+exit 0

tools/testing/selftests/ftrace/test.d/ftrace/func_traceonoff_triggers.tc

@@ -41,7 +41,7 @@ fi
 
 echo '** ENABLE EVENTS'
 
-echo 1 > events/enable
+echo 1 > events/sched/enable
 
 echo '** ENABLE TRACING'
 enable_tracing