[for-linus][PATCH 0/7] tracing: Updates to the last pull request for 5.18

[for-linus][PATCH 0/7] tracing: Updates to the last pull request for 5.18

[Steven Rostedt]

Updates to Tracing:

- Rename the staging files to give them some meaning.
  Just stage1,stag2,etc, does not show what they are for

- Check for NULL from allocation in bootconfig

- Hold event mutex for dyn_event call in user events

- Mark user events to broken (to work on the API)

- Remove eBPF updates from user events

- Remove user events from uapi header to keep it from being installed.

- Move ftrace_graph_is_dead() into inline as it is called from hot paths
  and also convert it into a static branch.


Beau Belgrave (2):
      tracing/user_events: Hold event_mutex during dyn_event_add
      tracing/user_events: Remove eBPF interfaces

Christophe Leroy (1):
      ftrace: Make ftrace_graph_is_dead() a static branch

Lv Ruyi (1):
      proc: bootconfig: Add null pointer check

Steven Rostedt (Google) (3):
      tracing: Rename the staging files for trace_events
      tracing: Set user_events to BROKEN
      tracing: Move user_events.h temporarily out of include/uapi

----
 Documentation/trace/user_events.rst                | 14 +---
 fs/proc/bootconfig.c                               |  2 +
 include/linux/ftrace.h                             | 16 +++-
 include/{uapi => }/linux/user_events.h             | 53 -------------
 .../{stage1_defines.h => stage1_struct_define.h}   |  0
 .../{stage2_defines.h => stage2_data_offsets.h}    |  0
 .../{stage3_defines.h => stage3_trace_output.h}    |  0
 .../{stage4_defines.h => stage4_event_fields.h}    |  0
 .../{stage5_defines.h => stage5_get_offsets.h}     |  0
 .../{stage6_defines.h => stage6_event_callback.h}  |  0
 .../{stage7_defines.h => stage7_class_define.h}    |  0
 include/trace/trace_custom_events.h                | 14 ++--
 include/trace/trace_events.h                       | 14 ++--
 kernel/trace/Kconfig                               |  1 +
 kernel/trace/fgraph.c                              | 17 +----
 kernel/trace/trace_events_user.c                   | 86 +++-------------------
 16 files changed, 50 insertions(+), 167 deletions(-)
 rename include/{uapi => }/linux/user_events.h (58%)
 rename include/trace/stages/{stage1_defines.h => stage1_struct_define.h} (100%)
 rename include/trace/stages/{stage2_defines.h => stage2_data_offsets.h} (100%)
 rename include/trace/stages/{stage3_defines.h => stage3_trace_output.h} (100%)
 rename include/trace/stages/{stage4_defines.h => stage4_event_fields.h} (100%)
 rename include/trace/stages/{stage5_defines.h => stage5_get_offsets.h} (100%)
 rename include/trace/stages/{stage6_defines.h => stage6_event_callback.h} (100%)
 rename include/trace/stages/{stage7_defines.h => stage7_class_define.h} (100%)

[for-linus][PATCH 1/7] tracing: Rename the staging files for trace_events

[Steven Rostedt]

From: "Steven Rostedt (Google)" <rostedt@goodmis.org>

When looking for implementation of different phases of the creation of the
TRACE_EVENT() macro, it is pretty useless when all helper macro
redefinitions are in files labeled "stageX_defines.h". Rename them to
state which phase the files are for. For instance, when looking for the
defines that are used to create the event fields, seeing
"stage4_event_fields.h" gives the developer a good idea that the defines
are in that file.

Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---
 .../{stage1_defines.h => stage1_struct_define.h}   |  0
 .../{stage2_defines.h => stage2_data_offsets.h}    |  0
 .../{stage3_defines.h => stage3_trace_output.h}    |  0
 .../{stage4_defines.h => stage4_event_fields.h}    |  0
 .../{stage5_defines.h => stage5_get_offsets.h}     |  0
 .../{stage6_defines.h => stage6_event_callback.h}  |  0
 .../{stage7_defines.h => stage7_class_define.h}    |  0
 include/trace/trace_custom_events.h                | 14 +++++++-------
 include/trace/trace_events.h                       | 14 +++++++-------
 9 files changed, 14 insertions(+), 14 deletions(-)
 rename include/trace/stages/{stage1_defines.h => stage1_struct_define.h} (100%)
 rename include/trace/stages/{stage2_defines.h => stage2_data_offsets.h} (100%)
 rename include/trace/stages/{stage3_defines.h => stage3_trace_output.h} (100%)
 rename include/trace/stages/{stage4_defines.h => stage4_event_fields.h} (100%)
 rename include/trace/stages/{stage5_defines.h => stage5_get_offsets.h} (100%)
 rename include/trace/stages/{stage6_defines.h => stage6_event_callback.h} (100%)
 rename include/trace/stages/{stage7_defines.h => stage7_class_define.h} (100%)

diff --git a/include/trace/stages/stage1_defines.h b/include/trace/stages/stage1_struct_define.h
similarity index 100%
rename from include/trace/stages/stage1_defines.h
rename to include/trace/stages/stage1_struct_define.h
diff --git a/include/trace/stages/stage2_defines.h b/include/trace/stages/stage2_data_offsets.h
similarity index 100%
rename from include/trace/stages/stage2_defines.h
rename to include/trace/stages/stage2_data_offsets.h
diff --git a/include/trace/stages/stage3_defines.h b/include/trace/stages/stage3_trace_output.h
similarity index 100%
rename from include/trace/stages/stage3_defines.h
rename to include/trace/stages/stage3_trace_output.h
diff --git a/include/trace/stages/stage4_defines.h b/include/trace/stages/stage4_event_fields.h
similarity index 100%
rename from include/trace/stages/stage4_defines.h
rename to include/trace/stages/stage4_event_fields.h
diff --git a/include/trace/stages/stage5_defines.h b/include/trace/stages/stage5_get_offsets.h
similarity index 100%
rename from include/trace/stages/stage5_defines.h
rename to include/trace/stages/stage5_get_offsets.h
diff --git a/include/trace/stages/stage6_defines.h b/include/trace/stages/stage6_event_callback.h
similarity index 100%
rename from include/trace/stages/stage6_defines.h
rename to include/trace/stages/stage6_event_callback.h
diff --git a/include/trace/stages/stage7_defines.h b/include/trace/stages/stage7_class_define.h
similarity index 100%
rename from include/trace/stages/stage7_defines.h
rename to include/trace/stages/stage7_class_define.h
diff --git a/include/trace/trace_custom_events.h b/include/trace/trace_custom_events.h
index b567c7202339..6e492dba96bf 100644
--- a/include/trace/trace_custom_events.h
+++ b/include/trace/trace_custom_events.h
@@ -35,7 +35,7 @@
 
 /* Stage 1 creates the structure of the recorded event layout */
 
-#include "stages/stage1_defines.h"
+#include "stages/stage1_struct_define.h"
 
 #undef DECLARE_CUSTOM_EVENT_CLASS
 #define DECLARE_CUSTOM_EVENT_CLASS(name, proto, args, tstruct, assign, print) \
@@ -56,7 +56,7 @@
 
 /* Stage 2 creates the custom class */
 
-#include "stages/stage2_defines.h"
+#include "stages/stage2_data_offsets.h"
 
 #undef DECLARE_CUSTOM_EVENT_CLASS
 #define DECLARE_CUSTOM_EVENT_CLASS(call, proto, args, tstruct, assign, print)	\
@@ -71,7 +71,7 @@
 
 /* Stage 3 create the way to print the custom event */
 
-#include "stages/stage3_defines.h"
+#include "stages/stage3_trace_output.h"
 
 #undef DECLARE_CUSTOM_EVENT_CLASS
 #define DECLARE_CUSTOM_EVENT_CLASS(call, proto, args, tstruct, assign, print) \
@@ -102,7 +102,7 @@ static struct trace_event_functions trace_custom_event_type_funcs_##call = { \
 
 /* Stage 4 creates the offset layout for the fields */
 
-#include "stages/stage4_defines.h"
+#include "stages/stage4_event_fields.h"
 
 #undef DECLARE_CUSTOM_EVENT_CLASS
 #define DECLARE_CUSTOM_EVENT_CLASS(call, proto, args, tstruct, func, print)	\
@@ -114,7 +114,7 @@ static struct trace_event_fields trace_custom_event_fields_##call[] = {	\
 
 /* Stage 5 creates the helper function for dynamic fields */
 
-#include "stages/stage5_defines.h"
+#include "stages/stage5_get_offsets.h"
 
 #undef DECLARE_CUSTOM_EVENT_CLASS
 #define DECLARE_CUSTOM_EVENT_CLASS(call, proto, args, tstruct, assign, print) \
@@ -134,7 +134,7 @@ static inline notrace int trace_custom_event_get_offsets_##call(	\
 
 /* Stage 6 creates the probe function that records the event */
 
-#include "stages/stage6_defines.h"
+#include "stages/stage6_event_callback.h"
 
 #undef DECLARE_CUSTOM_EVENT_CLASS
 #define DECLARE_CUSTOM_EVENT_CLASS(call, proto, args, tstruct, assign, print) \
@@ -182,7 +182,7 @@ static inline void ftrace_test_custom_probe_##call(void)		\
 
 /* Stage 7 creates the actual class and event structure for the custom event */
 
-#include "stages/stage7_defines.h"
+#include "stages/stage7_class_define.h"
 
 #undef DECLARE_CUSTOM_EVENT_CLASS
 #define DECLARE_CUSTOM_EVENT_CLASS(call, proto, args, tstruct, assign, print) \
diff --git a/include/trace/trace_events.h b/include/trace/trace_events.h
index 8a8cd66cc6d5..c2f9cabf154d 100644
--- a/include/trace/trace_events.h
+++ b/include/trace/trace_events.h
@@ -45,7 +45,7 @@
 			     PARAMS(print));		       \
 	DEFINE_EVENT(name, name, PARAMS(proto), PARAMS(args));
 
-#include "stages/stage1_defines.h"
+#include "stages/stage1_struct_define.h"
 
 #undef DECLARE_EVENT_CLASS
 #define DECLARE_EVENT_CLASS(name, proto, args, tstruct, assign, print)	\
@@ -109,7 +109,7 @@
  * The size of an array is also encoded, in the higher 16 bits of <item>.
  */
 
-#include "stages/stage2_defines.h"
+#include "stages/stage2_data_offsets.h"
 
 #undef DECLARE_EVENT_CLASS
 #define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print)	\
@@ -181,7 +181,7 @@
  * in binary.
  */
 
-#include "stages/stage3_defines.h"
+#include "stages/stage3_trace_output.h"
 
 #undef DECLARE_EVENT_CLASS
 #define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print)	\
@@ -236,7 +236,7 @@ static struct trace_event_functions trace_event_type_funcs_##call = {	\
 
 #include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
 
-#include "stages/stage4_defines.h"
+#include "stages/stage4_event_fields.h"
 
 #undef DECLARE_EVENT_CLASS
 #define DECLARE_EVENT_CLASS(call, proto, args, tstruct, func, print)	\
@@ -249,7 +249,7 @@ static struct trace_event_fields trace_event_fields_##call[] = {	\
 
 #include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
 
-#include "stages/stage5_defines.h"
+#include "stages/stage5_get_offsets.h"
 
 #undef DECLARE_EVENT_CLASS
 #define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print)	\
@@ -372,7 +372,7 @@ static inline notrace int trace_event_get_offsets_##call(		\
 #define _TRACE_PERF_INIT(call)
 #endif /* CONFIG_PERF_EVENTS */
 
-#include "stages/stage6_defines.h"
+#include "stages/stage6_event_callback.h"
 
 #undef DECLARE_EVENT_CLASS
 #define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print)	\
@@ -418,7 +418,7 @@ static inline void ftrace_test_probe_##call(void)			\
 
 #include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
 
-#include "stages/stage7_defines.h"
+#include "stages/stage7_class_define.h"
 
 #undef DECLARE_EVENT_CLASS
 #define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print)	\
-- 
2.35.1

[for-linus][PATCH 2/7] proc: bootconfig: Add null pointer check

[Steven Rostedt]

From: Lv Ruyi <lv.ruyi@zte.com.cn>

kzalloc is a memory allocation function which can return NULL when some
internal memory errors happen. It is safer to add null pointer check.

Link: https://lkml.kernel.org/r/20220329104004.2376879-1-lv.ruyi@zte.com.cn

Cc: stable@vger.kernel.org
Fixes: c1a3c36017d4 ("proc: bootconfig: Add /proc/bootconfig to show boot config list")
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: Lv Ruyi <lv.ruyi@zte.com.cn>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---
 fs/proc/bootconfig.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/fs/proc/bootconfig.c b/fs/proc/bootconfig.c
index 6d8d4bf20837..2e244ada1f97 100644
--- a/fs/proc/bootconfig.c
+++ b/fs/proc/bootconfig.c
@@ -32,6 +32,8 @@ static int __init copy_xbc_key_value_list(char *dst, size_t size)
 	int ret = 0;
 
 	key = kzalloc(XBC_KEYLEN_MAX, GFP_KERNEL);
+	if (!key)
+		return -ENOMEM;
 
 	xbc_for_each_key_value(leaf, val) {
 		ret = xbc_node_compose_key(leaf, key, XBC_KEYLEN_MAX);
-- 
2.35.1

[for-linus][PATCH 3/7] tracing/user_events: Hold event_mutex during dyn_event_add

[Steven Rostedt]

From: Beau Belgrave <beaub@linux.microsoft.com>

Make sure the event_mutex is properly held during dyn_event_add call.
This is required when adding dynamic events.

Link: https://lkml.kernel.org/r/20220328223225.1992-1-beaub@linux.microsoft.com

Reported-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---
 kernel/trace/trace_events_user.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/kernel/trace/trace_events_user.c b/kernel/trace/trace_events_user.c
index 8b3d241a31c2..61d78d64bdf0 100644
--- a/kernel/trace/trace_events_user.c
+++ b/kernel/trace/trace_events_user.c
@@ -1165,11 +1165,11 @@ static int user_event_parse(char *name, char *args, char *flags,
 #endif
 
 	mutex_lock(&event_mutex);
+
 	ret = user_event_trace_register(user);
-	mutex_unlock(&event_mutex);
 
 	if (ret)
-		goto put_user;
+		goto put_user_lock;
 
 	user->index = index;
 
@@ -1181,8 +1181,12 @@ static int user_event_parse(char *name, char *args, char *flags,
 	set_bit(user->index, page_bitmap);
 	hash_add(register_table, &user->node, key);
 
+	mutex_unlock(&event_mutex);
+
 	*newuser = user;
 	return 0;
+put_user_lock:
+	mutex_unlock(&event_mutex);
 put_user:
 	user_event_destroy_fields(user);
 	user_event_destroy_validators(user);
-- 
2.35.1

[for-linus][PATCH 4/7] tracing/user_events: Remove eBPF interfaces

[Steven Rostedt]

From: Beau Belgrave <beaub@linux.microsoft.com>

Remove eBPF interfaces within user_events to ensure they are fully
reviewed.

Link: https://lore.kernel.org/all/20220329165718.GA10381@kbox/
Link: https://lkml.kernel.org/r/20220329173051.10087-1-beaub@linux.microsoft.com

Suggested-by: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---
 Documentation/trace/user_events.rst | 14 ++----
 include/uapi/linux/user_events.h    | 53 ---------------------
 kernel/trace/trace_events_user.c    | 73 +----------------------------
 3 files changed, 4 insertions(+), 136 deletions(-)

diff --git a/Documentation/trace/user_events.rst b/Documentation/trace/user_events.rst
index bddedabaca80..c180936f49fc 100644
--- a/Documentation/trace/user_events.rst
+++ b/Documentation/trace/user_events.rst
@@ -7,7 +7,7 @@ user_events: User-based Event Tracing
 Overview
 --------
 User based trace events allow user processes to create events and trace data
-that can be viewed via existing tools, such as ftrace, perf and eBPF.
+that can be viewed via existing tools, such as ftrace and perf.
 To enable this feature, build your kernel with CONFIG_USER_EVENTS=y.
 
 Programs can view status of the events via
@@ -67,8 +67,7 @@ The command string format is as follows::
 
 Supported Flags
 ^^^^^^^^^^^^^^^
-**BPF_ITER** - EBPF programs attached to this event will get the raw iovec
-struct instead of any data copies for max performance.
+None yet
 
 Field Format
 ^^^^^^^^^^^^
@@ -160,7 +159,7 @@ The following values are defined to aid in checking what has been attached:
 
 **EVENT_STATUS_FTRACE** - Bit set if ftrace has been attached (Bit 0).
 
-**EVENT_STATUS_PERF** - Bit set if perf/eBPF has been attached (Bit 1).
+**EVENT_STATUS_PERF** - Bit set if perf has been attached (Bit 1).
 
 Writing Data
 ------------
@@ -204,13 +203,6 @@ It's advised for user programs to do the following::
 
 **NOTE:** *The write_index is not emitted out into the trace being recorded.*
 
-EBPF
-----
-EBPF programs that attach to a user-based event tracepoint are given a pointer
-to a struct user_bpf_context. The bpf context contains the data type (which can
-be a user or kernel buffer, or can be a pointer to the iovec) and the data
-length that was emitted (minus the write_index).
-
 Example Code
 ------------
 See sample code in samples/user_events.
diff --git a/include/uapi/linux/user_events.h b/include/uapi/linux/user_events.h
index e570840571e1..736e05603463 100644
--- a/include/uapi/linux/user_events.h
+++ b/include/uapi/linux/user_events.h
@@ -32,9 +32,6 @@
 /* Create dynamic location entry within a 32-bit value */
 #define DYN_LOC(offset, size) ((size) << 16 | (offset))
 
-/* Use raw iterator for attached BPF program(s), no affect on ftrace/perf */
-#define FLAG_BPF_ITER (1 << 0)
-
 /*
  * Describes an event registration and stores the results of the registration.
  * This structure is passed to the DIAG_IOCSREG ioctl, callers at a minimum
@@ -63,54 +60,4 @@ struct user_reg {
 /* Requests to delete a user_event */
 #define DIAG_IOCSDEL _IOW(DIAG_IOC_MAGIC, 1, char*)
 
-/* Data type that was passed to the BPF program */
-enum {
-	/* Data resides in kernel space */
-	USER_BPF_DATA_KERNEL,
-
-	/* Data resides in user space */
-	USER_BPF_DATA_USER,
-
-	/* Data is a pointer to a user_bpf_iter structure */
-	USER_BPF_DATA_ITER,
-};
-
-/*
- * Describes an iovec iterator that BPF programs can use to access data for
- * a given user_event write() / writev() call.
- */
-struct user_bpf_iter {
-
-	/* Offset of the data within the first iovec */
-	__u32 iov_offset;
-
-	/* Number of iovec structures */
-	__u32 nr_segs;
-
-	/* Pointer to iovec structures */
-	const struct iovec *iov;
-};
-
-/* Context that BPF programs receive when attached to a user_event */
-struct user_bpf_context {
-
-	/* Data type being passed (see union below) */
-	__u32 data_type;
-
-	/* Length of the data */
-	__u32 data_len;
-
-	/* Pointer to data, varies by data type */
-	union {
-		/* Kernel data (data_type == USER_BPF_DATA_KERNEL) */
-		void *kdata;
-
-		/* User data (data_type == USER_BPF_DATA_USER) */
-		void *udata;
-
-		/* Direct iovec (data_type == USER_BPF_DATA_ITER) */
-		struct user_bpf_iter *iter;
-	};
-};
-
 #endif /* _UAPI_LINUX_USER_EVENTS_H */
diff --git a/kernel/trace/trace_events_user.c b/kernel/trace/trace_events_user.c
index 61d78d64bdf0..846c27bc7aef 100644
--- a/kernel/trace/trace_events_user.c
+++ b/kernel/trace/trace_events_user.c
@@ -42,9 +42,6 @@
 #define MAX_FIELD_ARRAY_SIZE 1024
 #define MAX_FIELD_ARG_NAME 256
 
-#define MAX_BPF_COPY_SIZE PAGE_SIZE
-#define MAX_STACK_BPF_DATA 512
-
 static char *register_page_data;
 
 static DEFINE_MUTEX(reg_mutex);
@@ -405,19 +402,6 @@ static int user_event_parse_field(char *field, struct user_event *user,
 				    type[0] != 'u', FILTER_OTHER);
 }
 
-static void user_event_parse_flags(struct user_event *user, char *flags)
-{
-	char *flag;
-
-	if (flags == NULL)
-		return;
-
-	while ((flag = strsep(&flags, ",")) != NULL) {
-		if (strcmp(flag, "BPF_ITER") == 0)
-			user->flags |= FLAG_BPF_ITER;
-	}
-}
-
 static int user_event_parse_fields(struct user_event *user, char *args)
 {
 	char *field;
@@ -713,64 +697,14 @@ static void user_event_ftrace(struct user_event *user, struct iov_iter *i,
 }
 
 #ifdef CONFIG_PERF_EVENTS
-static void user_event_bpf(struct user_event *user, struct iov_iter *i)
-{
-	struct user_bpf_context context;
-	struct user_bpf_iter bpf_i;
-	char fast_data[MAX_STACK_BPF_DATA];
-	void *temp = NULL;
-
-	if ((user->flags & FLAG_BPF_ITER) && iter_is_iovec(i)) {
-		/* Raw iterator */
-		context.data_type = USER_BPF_DATA_ITER;
-		context.data_len = i->count;
-		context.iter = &bpf_i;
-
-		bpf_i.iov_offset = i->iov_offset;
-		bpf_i.iov = i->iov;
-		bpf_i.nr_segs = i->nr_segs;
-	} else if (i->nr_segs == 1 && iter_is_iovec(i)) {
-		/* Single buffer from user */
-		context.data_type = USER_BPF_DATA_USER;
-		context.data_len = i->count;
-		context.udata = i->iov->iov_base + i->iov_offset;
-	} else {
-		/* Multi buffer from user */
-		struct iov_iter copy = *i;
-		size_t copy_size = min_t(size_t, i->count, MAX_BPF_COPY_SIZE);
-
-		context.data_type = USER_BPF_DATA_KERNEL;
-		context.kdata = fast_data;
-
-		if (unlikely(copy_size > sizeof(fast_data))) {
-			temp = kmalloc(copy_size, GFP_NOWAIT);
-
-			if (temp)
-				context.kdata = temp;
-			else
-				copy_size = sizeof(fast_data);
-		}
-
-		context.data_len = copy_nofault(context.kdata,
-						copy_size, &copy);
-	}
-
-	trace_call_bpf(&user->call, &context);
-
-	kfree(temp);
-}
-
 /*
- * Writes the user supplied payload out to perf ring buffer or eBPF program.
+ * Writes the user supplied payload out to perf ring buffer.
  */
 static void user_event_perf(struct user_event *user, struct iov_iter *i,
 			    void *tpdata, bool *faulted)
 {
 	struct hlist_head *perf_head;
 
-	if (bpf_prog_array_valid(&user->call))
-		user_event_bpf(user, i);
-
 	perf_head = this_cpu_ptr(user->call.perf_events);
 
 	if (perf_head && !hlist_empty(perf_head)) {
@@ -1136,8 +1070,6 @@ static int user_event_parse(char *name, char *args, char *flags,
 
 	user->tracepoint.name = name;
 
-	user_event_parse_flags(user, flags);
-
 	ret = user_event_parse_fields(user, args);
 
 	if (ret)
@@ -1579,9 +1511,6 @@ static int user_seq_show(struct seq_file *m, void *p)
 			busy++;
 		}
 
-		if (flags & FLAG_BPF_ITER)
-			seq_puts(m, " FLAG:BPF_ITER");
-
 		seq_puts(m, "\n");
 		active++;
 	}
-- 
2.35.1

[for-linus][PATCH 5/7] tracing: Set user_events to BROKEN

[Steven Rostedt]

From: "Steven Rostedt (Google)" <rostedt@goodmis.org>

After being merged, user_events become more visible to a wider audience
that have concerns with the current API. It is too late to fix this for
this release, but instead of a full revert, just mark it as BROKEN (which
prevents it from being selected in make config). Then we can work finding
a better API. If that fails, then it will need to be completely reverted.

Link: https://lore.kernel.org/all/2059213643.196683.1648499088753.JavaMail.zimbra@efficios.com/
Link: https://lkml.kernel.org/r/20220330155835.5e1f6669@gandalf.local.home

Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---
 kernel/trace/Kconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
index 16a52a71732d..f83d29adb375 100644
--- a/kernel/trace/Kconfig
+++ b/kernel/trace/Kconfig
@@ -741,6 +741,7 @@ config USER_EVENTS
 	bool "User trace events"
 	select TRACING
 	select DYNAMIC_EVENTS
+	depends on BROKEN || COMPILE_TEST # API needs to be straighten out
 	help
 	  User trace events are user-defined trace events that
 	  can be used like an existing kernel trace event.  User trace
-- 
2.35.1

[for-linus][PATCH 6/7] ftrace: Make ftrace_graph_is_dead() a static branch

[Steven Rostedt]

From: Christophe Leroy <christophe.leroy@csgroup.eu>

ftrace_graph_is_dead() is used on hot paths, it just reads a variable
in memory and is not worth suffering function call constraints.

For instance, at entry of prepare_ftrace_return(), inlining it avoids
saving prepare_ftrace_return() parameters to stack and restoring them
after calling ftrace_graph_is_dead().

While at it using a static branch is even more performant and is
rather well adapted considering that the returned value will almost
never change.

Inline ftrace_graph_is_dead() and replace 'kill_ftrace_graph' bool
by a static branch.

The performance improvement is noticeable.

Link: https://lkml.kernel.org/r/e0411a6a0ed3eafff0ad2bc9cd4b0e202b4617df.1648623570.git.christophe.leroy@csgroup.eu

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---
 include/linux/ftrace.h | 16 +++++++++++++++-
 kernel/trace/fgraph.c  | 17 +++--------------
 2 files changed, 18 insertions(+), 15 deletions(-)

diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index 37b619185ec9..f15a4b76cbfc 100644
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -9,6 +9,7 @@
 
 #include <linux/trace_recursion.h>
 #include <linux/trace_clock.h>
+#include <linux/jump_label.h>
 #include <linux/kallsyms.h>
 #include <linux/linkage.h>
 #include <linux/bitops.h>
@@ -1015,7 +1016,20 @@ unsigned long ftrace_graph_ret_addr(struct task_struct *task, int *idx,
 extern int register_ftrace_graph(struct fgraph_ops *ops);
 extern void unregister_ftrace_graph(struct fgraph_ops *ops);
 
-extern bool ftrace_graph_is_dead(void);
+/**
+ * ftrace_graph_is_dead - returns true if ftrace_graph_stop() was called
+ *
+ * ftrace_graph_stop() is called when a severe error is detected in
+ * the function graph tracing. This function is called by the critical
+ * paths of function graph to keep those paths from doing any more harm.
+ */
+DECLARE_STATIC_KEY_FALSE(kill_ftrace_graph);
+
+static inline bool ftrace_graph_is_dead(void)
+{
+	return static_branch_unlikely(&kill_ftrace_graph);
+}
+
 extern void ftrace_graph_stop(void);
 
 /* The current handlers in use */
diff --git a/kernel/trace/fgraph.c b/kernel/trace/fgraph.c
index 19028e072cdb..8f4fb328133a 100644
--- a/kernel/trace/fgraph.c
+++ b/kernel/trace/fgraph.c
@@ -7,6 +7,7 @@
  *
  * Highly modified by Steven Rostedt (VMware).
  */
+#include <linux/jump_label.h>
 #include <linux/suspend.h>
 #include <linux/ftrace.h>
 #include <linux/slab.h>
@@ -23,24 +24,12 @@
 #define ASSIGN_OPS_HASH(opsname, val)
 #endif
 
-static bool kill_ftrace_graph;
+DEFINE_STATIC_KEY_FALSE(kill_ftrace_graph);
 int ftrace_graph_active;
 
 /* Both enabled by default (can be cleared by function_graph tracer flags */
 static bool fgraph_sleep_time = true;
 
-/**
- * ftrace_graph_is_dead - returns true if ftrace_graph_stop() was called
- *
- * ftrace_graph_stop() is called when a severe error is detected in
- * the function graph tracing. This function is called by the critical
- * paths of function graph to keep those paths from doing any more harm.
- */
-bool ftrace_graph_is_dead(void)
-{
-	return kill_ftrace_graph;
-}
-
 /**
  * ftrace_graph_stop - set to permanently disable function graph tracing
  *
@@ -51,7 +40,7 @@ bool ftrace_graph_is_dead(void)
  */
 void ftrace_graph_stop(void)
 {
-	kill_ftrace_graph = true;
+	static_branch_enable(&kill_ftrace_graph);
 }
 
 /* Add a function return address to the trace stack on thread info.*/
-- 
2.35.1

[for-linus][PATCH 7/7] tracing: Move user_events.h temporarily out of include/uapi

[Steven Rostedt]

From: "Steven Rostedt (Google)" <rostedt@goodmis.org>

While user_events API is under development and has been marked for broken
to not let the API become fixed, move the header file out of the uapi
directory. This is to prevent it from being installed, then later changed,
and then have an old distro user space update with a new kernel, where
applications see the user_events being available, but the old header is in
place, and then they get compiled incorrectly.

Also, surround the include with CONFIG_COMPILE_TEST to the current
location, but when the BROKEN tag is taken off, it will use the uapi
directory, and fail to compile. This is a good way to remind us to move
the header back.

Link: https://lore.kernel.org/all/20220330155835.5e1f6669@gandalf.local.home
Link: https://lkml.kernel.org/r/20220330201755.29319-1-mathieu.desnoyers@efficios.com
Link: https://lkml.kernel.org/r/20220401143903.188384f3@gandalf.local.home

Suggested-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---
 include/{uapi => }/linux/user_events.h | 0
 kernel/trace/trace_events_user.c       | 5 +++++
 2 files changed, 5 insertions(+)
 rename include/{uapi => }/linux/user_events.h (100%)

diff --git a/include/uapi/linux/user_events.h b/include/linux/user_events.h
similarity index 100%
rename from include/uapi/linux/user_events.h
rename to include/linux/user_events.h
diff --git a/kernel/trace/trace_events_user.c b/kernel/trace/trace_events_user.c
index 846c27bc7aef..706e1686b5eb 100644
--- a/kernel/trace/trace_events_user.c
+++ b/kernel/trace/trace_events_user.c
@@ -18,7 +18,12 @@
 #include <linux/tracefs.h>
 #include <linux/types.h>
 #include <linux/uaccess.h>
+/* Reminder to move to uapi when everything works */
+#ifdef CONFIG_COMPILE_TEST
+#include <linux/user_events.h>
+#else
 #include <uapi/linux/user_events.h>
+#endif
 #include "trace.h"
 #include "trace_dynevent.h"
 
-- 
2.35.1