[for-next][PATCH 00/14] tracing: More updates for 6.6

[for-next][PATCH 00/14] tracing: More updates for 6.6

[Steven Rostedt]

  git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace.git
trace/for-next

Head SHA1: 8c96b70171584f38940eb2ba65b84eee38b549ba


Eric Vaughn (1):
      tracing/user_events: Optimize safe list traversals

Sishuai Gong (1):
      tracefs: Avoid changing i_mode to a temp value

Steven Rostedt (Google) (1):
      tracefs: Remove kerneldoc from struct eventfs_file

Valentin Schneider (9):
      tracing/filters: Dynamically allocate filter_pred.regex
      tracing/filters: Enable filtering a cpumask field by another cpumask
      tracing/filters: Enable filtering a scalar field by a cpumask
      tracing/filters: Enable filtering the CPU common field by a cpumask
      tracing/filters: Optimise cpumask vs cpumask filtering when user mask is a single CPU
      tracing/filters: Optimise scalar vs cpumask filtering when the user mask is a single CPU
      tracing/filters: Optimise CPU vs cpumask filtering when the user mask is a single CPU
      tracing/filters: Further optimise scalar vs cpumask comparison
      tracing/filters: Document cpumask filtering

Yue Haibing (1):
      tracing: Remove unused function declarations

Zhang Zekun (1):
      ftrace: Remove empty declaration ftrace_enable_daemon() and ftrace_disable_daemon()

----
 Documentation/trace/events.rst     |  14 ++
 fs/tracefs/event_inode.c           |  14 +-
 fs/tracefs/inode.c                 |   6 +-
 include/linux/ftrace.h             |   5 -
 include/linux/trace_events.h       |   1 +
 kernel/trace/trace.h               |   2 -
 kernel/trace/trace_events_filter.c | 302 +++++++++++++++++++++++++++++++++----
 kernel/trace/trace_events_user.c   |  15 +-
 8 files changed, 312 insertions(+), 47 deletions(-)

[for-next][PATCH 01/14] tracing/filters: Dynamically allocate filter_pred.regex

[Steven Rostedt]

From: Valentin Schneider <vschneid@redhat.com>

Every predicate allocation includes a MAX_FILTER_STR_VAL (256) char array
in the regex field, even if the predicate function does not use the field.

A later commit will introduce a dynamically allocated cpumask to struct
filter_pred, which will require a dedicated freeing function. Bite the
bullet and make filter_pred.regex dynamically allocated.

While at it, reorder the fields of filter_pred to fill in the byte
holes. The struct now fits on a single cacheline.

No change in behaviour intended.

The kfree()'s were patched via Coccinelle:
  @@
  struct filter_pred *pred;
  @@

  -kfree(pred);
  +free_predicate(pred);

Link: https://lkml.kernel.org/r/20230707172155.70873-2-vschneid@redhat.com

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Daniel Bristot de Oliveira <bristot@redhat.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Leonardo Bras <leobras@redhat.com>
Cc: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Valentin Schneider <vschneid@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---
 kernel/trace/trace_events_filter.c | 64 ++++++++++++++++++------------
 1 file changed, 39 insertions(+), 25 deletions(-)

diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index 1dad64267878..91fc9990107f 100644
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -70,15 +70,15 @@ enum filter_pred_fn {
 };
 
 struct filter_pred {
-	enum filter_pred_fn 	fn_num;
-	u64 			val;
-	u64 			val2;
-	struct regex		regex;
+	struct regex		*regex;
 	unsigned short		*ops;
 	struct ftrace_event_field *field;
-	int 			offset;
+	u64			val;
+	u64			val2;
+	enum filter_pred_fn	fn_num;
+	int			offset;
 	int			not;
-	int 			op;
+	int			op;
 };
 
 /*
@@ -186,6 +186,14 @@ enum {
 	PROCESS_OR	= 4,
 };
 
+static void free_predicate(struct filter_pred *pred)
+{
+	if (pred) {
+		kfree(pred->regex);
+		kfree(pred);
+	}
+}
+
 /*
  * Without going into a formal proof, this explains the method that is used in
  * parsing the logical expressions.
@@ -623,7 +631,7 @@ predicate_parse(const char *str, int nr_parens, int nr_preds,
 	kfree(inverts);
 	if (prog_stack) {
 		for (i = 0; prog_stack[i].pred; i++)
-			kfree(prog_stack[i].pred);
+			free_predicate(prog_stack[i].pred);
 		kfree(prog_stack);
 	}
 	return ERR_PTR(ret);
@@ -750,7 +758,7 @@ static int filter_pred_string(struct filter_pred *pred, void *event)
 	char *addr = (char *)(event + pred->offset);
 	int cmp, match;
 
-	cmp = pred->regex.match(addr, &pred->regex, pred->regex.field_len);
+	cmp = pred->regex->match(addr, pred->regex, pred->regex->field_len);
 
 	match = cmp ^ pred->not;
 
@@ -763,7 +771,7 @@ static __always_inline int filter_pchar(struct filter_pred *pred, char *str)
 	int len;
 
 	len = strlen(str) + 1;	/* including tailing '\0' */
-	cmp = pred->regex.match(str, &pred->regex, len);
+	cmp = pred->regex->match(str, pred->regex, len);
 
 	match = cmp ^ pred->not;
 
@@ -813,7 +821,7 @@ static int filter_pred_strloc(struct filter_pred *pred, void *event)
 	char *addr = (char *)(event + str_loc);
 	int cmp, match;
 
-	cmp = pred->regex.match(addr, &pred->regex, str_len);
+	cmp = pred->regex->match(addr, pred->regex, str_len);
 
 	match = cmp ^ pred->not;
 
@@ -836,7 +844,7 @@ static int filter_pred_strrelloc(struct filter_pred *pred, void *event)
 	char *addr = (char *)(&item[1]) + str_loc;
 	int cmp, match;
 
-	cmp = pred->regex.match(addr, &pred->regex, str_len);
+	cmp = pred->regex->match(addr, pred->regex, str_len);
 
 	match = cmp ^ pred->not;
 
@@ -874,7 +882,7 @@ static int filter_pred_comm(struct filter_pred *pred, void *event)
 {
 	int cmp;
 
-	cmp = pred->regex.match(current->comm, &pred->regex,
+	cmp = pred->regex->match(current->comm, pred->regex,
 				TASK_COMM_LEN);
 	return cmp ^ pred->not;
 }
@@ -1004,7 +1012,7 @@ enum regex_type filter_parse_regex(char *buff, int len, char **search, int *not)
 
 static void filter_build_regex(struct filter_pred *pred)
 {
-	struct regex *r = &pred->regex;
+	struct regex *r = pred->regex;
 	char *search;
 	enum regex_type type = MATCH_FULL;
 
@@ -1169,7 +1177,7 @@ static void free_prog(struct event_filter *filter)
 		return;
 
 	for (i = 0; prog[i].pred; i++)
-		kfree(prog[i].pred);
+		free_predicate(prog[i].pred);
 	kfree(prog);
 }
 
@@ -1553,9 +1561,12 @@ static int parse_pred(const char *str, void *data,
 			goto err_free;
 		}
 
-		pred->regex.len = len;
-		strncpy(pred->regex.pattern, str + s, len);
-		pred->regex.pattern[len] = 0;
+		pred->regex = kzalloc(sizeof(*pred->regex), GFP_KERNEL);
+		if (!pred->regex)
+			goto err_mem;
+		pred->regex->len = len;
+		strncpy(pred->regex->pattern, str + s, len);
+		pred->regex->pattern[len] = 0;
 
 	/* This is either a string, or an integer */
 	} else if (str[i] == '\'' || str[i] == '"') {
@@ -1597,9 +1608,12 @@ static int parse_pred(const char *str, void *data,
 			goto err_free;
 		}
 
-		pred->regex.len = len;
-		strncpy(pred->regex.pattern, str + s, len);
-		pred->regex.pattern[len] = 0;
+		pred->regex = kzalloc(sizeof(*pred->regex), GFP_KERNEL);
+		if (!pred->regex)
+			goto err_mem;
+		pred->regex->len = len;
+		strncpy(pred->regex->pattern, str + s, len);
+		pred->regex->pattern[len] = 0;
 
 		filter_build_regex(pred);
 
@@ -1608,7 +1622,7 @@ static int parse_pred(const char *str, void *data,
 
 		} else if (field->filter_type == FILTER_STATIC_STRING) {
 			pred->fn_num = FILTER_PRED_FN_STRING;
-			pred->regex.field_len = field->size;
+			pred->regex->field_len = field->size;
 
 		} else if (field->filter_type == FILTER_DYN_STRING) {
 			pred->fn_num = FILTER_PRED_FN_STRLOC;
@@ -1691,10 +1705,10 @@ static int parse_pred(const char *str, void *data,
 	return i;
 
 err_free:
-	kfree(pred);
+	free_predicate(pred);
 	return -EINVAL;
 err_mem:
-	kfree(pred);
+	free_predicate(pred);
 	return -ENOMEM;
 }
 
@@ -2287,8 +2301,8 @@ static int ftrace_function_set_filter_pred(struct filter_pred *pred,
 		return ret;
 
 	return __ftrace_function_set_filter(pred->op == OP_EQ,
-					    pred->regex.pattern,
-					    pred->regex.len,
+					    pred->regex->pattern,
+					    pred->regex->len,
 					    data);
 }
 
-- 
2.40.1

[for-next][PATCH 02/14] tracing/filters: Enable filtering a cpumask field by another cpumask

[Steven Rostedt]

From: Valentin Schneider <vschneid@redhat.com>

The recently introduced ipi_send_cpumask trace event contains a cpumask
field, but it currently cannot be used in filter expressions.

Make event filtering aware of cpumask fields, and allow these to be
filtered by a user-provided cpumask.

The user-provided cpumask is to be given in cpulist format and wrapped as:
"CPUS{$cpulist}". The use of curly braces instead of parentheses is to
prevent predicate_parse() from parsing the contents of CPUS{...} as a
full-fledged predicate subexpression.

This enables e.g.:

$ trace-cmd record -e 'ipi_send_cpumask' -f 'cpumask & CPUS{2,4,6,8-32}'

Link: https://lkml.kernel.org/r/20230707172155.70873-3-vschneid@redhat.com

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Daniel Bristot de Oliveira <bristot@redhat.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Leonardo Bras <leobras@redhat.com>
Cc: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Valentin Schneider <vschneid@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---
 include/linux/trace_events.h       |  1 +
 kernel/trace/trace_events_filter.c | 97 +++++++++++++++++++++++++++++-
 2 files changed, 96 insertions(+), 2 deletions(-)

diff --git a/include/linux/trace_events.h b/include/linux/trace_events.h
index c17623c78029..1600aeb8e1a3 100644
--- a/include/linux/trace_events.h
+++ b/include/linux/trace_events.h
@@ -808,6 +808,7 @@ enum {
 	FILTER_RDYN_STRING,
 	FILTER_PTR_STRING,
 	FILTER_TRACE_FN,
+	FILTER_CPUMASK,
 	FILTER_COMM,
 	FILTER_CPU,
 	FILTER_STACKTRACE,
diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index 91fc9990107f..cb1863dfa280 100644
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -64,6 +64,7 @@ enum filter_pred_fn {
 	FILTER_PRED_FN_PCHAR_USER,
 	FILTER_PRED_FN_PCHAR,
 	FILTER_PRED_FN_CPU,
+	FILTER_PRED_FN_CPUMASK,
 	FILTER_PRED_FN_FUNCTION,
 	FILTER_PRED_FN_,
 	FILTER_PRED_TEST_VISITED,
@@ -71,6 +72,7 @@ enum filter_pred_fn {
 
 struct filter_pred {
 	struct regex		*regex;
+	struct cpumask          *mask;
 	unsigned short		*ops;
 	struct ftrace_event_field *field;
 	u64			val;
@@ -94,6 +96,8 @@ struct filter_pred {
 	C(TOO_MANY_OPEN,	"Too many '('"),			\
 	C(TOO_MANY_CLOSE,	"Too few '('"),				\
 	C(MISSING_QUOTE,	"Missing matching quote"),		\
+	C(MISSING_BRACE_OPEN,   "Missing '{'"),				\
+	C(MISSING_BRACE_CLOSE,  "Missing '}'"),				\
 	C(OPERAND_TOO_LONG,	"Operand too long"),			\
 	C(EXPECT_STRING,	"Expecting string field"),		\
 	C(EXPECT_DIGIT,		"Expecting numeric field"),		\
@@ -103,6 +107,7 @@ struct filter_pred {
 	C(BAD_SUBSYS_FILTER,	"Couldn't find or set field in one of a subsystem's events"), \
 	C(TOO_MANY_PREDS,	"Too many terms in predicate expression"), \
 	C(INVALID_FILTER,	"Meaningless filter expression"),	\
+	C(INVALID_CPULIST,	"Invalid cpulist"),	\
 	C(IP_FIELD_ONLY,	"Only 'ip' field is supported for function trace"), \
 	C(INVALID_VALUE,	"Invalid value (did you forget quotes)?"), \
 	C(NO_FUNCTION,		"Function not found"),			\
@@ -190,6 +195,7 @@ static void free_predicate(struct filter_pred *pred)
 {
 	if (pred) {
 		kfree(pred->regex);
+		kfree(pred->mask);
 		kfree(pred);
 	}
 }
@@ -877,6 +883,26 @@ static int filter_pred_cpu(struct filter_pred *pred, void *event)
 	}
 }
 
+/* Filter predicate for cpumask field vs user-provided cpumask */
+static int filter_pred_cpumask(struct filter_pred *pred, void *event)
+{
+	u32 item = *(u32 *)(event + pred->offset);
+	int loc = item & 0xffff;
+	const struct cpumask *mask = (event + loc);
+	const struct cpumask *cmp = pred->mask;
+
+	switch (pred->op) {
+	case OP_EQ:
+		return cpumask_equal(mask, cmp);
+	case OP_NE:
+		return !cpumask_equal(mask, cmp);
+	case OP_BAND:
+		return cpumask_intersects(mask, cmp);
+	default:
+		return 0;
+	}
+}
+
 /* Filter predicate for COMM. */
 static int filter_pred_comm(struct filter_pred *pred, void *event)
 {
@@ -1244,8 +1270,12 @@ static void filter_free_subsystem_filters(struct trace_subsystem_dir *dir,
 
 int filter_assign_type(const char *type)
 {
-	if (strstr(type, "__data_loc") && strstr(type, "char"))
-		return FILTER_DYN_STRING;
+	if (strstr(type, "__data_loc")) {
+		if (strstr(type, "char"))
+			return FILTER_DYN_STRING;
+		if (strstr(type, "cpumask_t"))
+			return FILTER_CPUMASK;
+		}
 
 	if (strstr(type, "__rel_loc") && strstr(type, "char"))
 		return FILTER_RDYN_STRING;
@@ -1357,6 +1387,8 @@ static int filter_pred_fn_call(struct filter_pred *pred, void *event)
 		return filter_pred_pchar(pred, event);
 	case FILTER_PRED_FN_CPU:
 		return filter_pred_cpu(pred, event);
+	case FILTER_PRED_FN_CPUMASK:
+		return filter_pred_cpumask(pred, event);
 	case FILTER_PRED_FN_FUNCTION:
 		return filter_pred_function(pred, event);
 	case FILTER_PRED_TEST_VISITED:
@@ -1568,6 +1600,67 @@ static int parse_pred(const char *str, void *data,
 		strncpy(pred->regex->pattern, str + s, len);
 		pred->regex->pattern[len] = 0;
 
+	} else if (!strncmp(str + i, "CPUS", 4)) {
+		unsigned int maskstart;
+		char *tmp;
+
+		switch (field->filter_type) {
+		case FILTER_CPUMASK:
+			break;
+		default:
+			parse_error(pe, FILT_ERR_ILLEGAL_FIELD_OP, pos + i);
+			goto err_free;
+		}
+
+		switch (op) {
+		case OP_EQ:
+		case OP_NE:
+		case OP_BAND:
+			break;
+		default:
+			parse_error(pe, FILT_ERR_ILLEGAL_FIELD_OP, pos + i);
+			goto err_free;
+		}
+
+		/* Skip CPUS */
+		i += 4;
+		if (str[i++] != '{') {
+			parse_error(pe, FILT_ERR_MISSING_BRACE_OPEN, pos + i);
+			goto err_free;
+		}
+		maskstart = i;
+
+		/* Walk the cpulist until closing } */
+		for (; str[i] && str[i] != '}'; i++);
+		if (str[i] != '}') {
+			parse_error(pe, FILT_ERR_MISSING_BRACE_CLOSE, pos + i);
+			goto err_free;
+		}
+
+		if (maskstart == i) {
+			parse_error(pe, FILT_ERR_INVALID_CPULIST, pos + i);
+			goto err_free;
+		}
+
+		/* Copy the cpulist between { and } */
+		tmp = kmalloc((i - maskstart) + 1, GFP_KERNEL);
+		strscpy(tmp, str + maskstart, (i - maskstart) + 1);
+
+		pred->mask = kzalloc(cpumask_size(), GFP_KERNEL);
+		if (!pred->mask)
+			goto err_mem;
+
+		/* Now parse it */
+		if (cpulist_parse(tmp, pred->mask)) {
+			parse_error(pe, FILT_ERR_INVALID_CPULIST, pos + i);
+			goto err_free;
+		}
+
+		/* Move along */
+		i++;
+		if (field->filter_type == FILTER_CPUMASK)
+			pred->fn_num = FILTER_PRED_FN_CPUMASK;
+
 	/* This is either a string, or an integer */
 	} else if (str[i] == '\'' || str[i] == '"') {
 		char q = str[i];
-- 
2.40.1

[for-next][PATCH 03/14] tracing/filters: Enable filtering a scalar field by a cpumask

[Steven Rostedt]

From: Valentin Schneider <vschneid@redhat.com>

Several events use a scalar field to denote a CPU:
o sched_wakeup.target_cpu
o sched_migrate_task.orig_cpu,dest_cpu
o sched_move_numa.src_cpu,dst_cpu
o ipi_send_cpu.cpu
o ...

Filtering these currently requires using arithmetic comparison functions,
which can be tedious when dealing with interleaved SMT or NUMA CPU ids.

Allow these to be filtered by a user-provided cpumask, which enables e.g.:

$ trace-cmd record -e 'sched_wakeup' -f 'target_cpu & CPUS{2,4,6,8-32}'

Link: https://lkml.kernel.org/r/20230707172155.70873-4-vschneid@redhat.com

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Daniel Bristot de Oliveira <bristot@redhat.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Leonardo Bras <leobras@redhat.com>
Cc: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Valentin Schneider <vschneid@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---
 kernel/trace/trace_events_filter.c | 92 ++++++++++++++++++++++++++----
 1 file changed, 81 insertions(+), 11 deletions(-)

diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index cb1863dfa280..1e14f801685a 100644
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -46,15 +46,19 @@ static const char * ops[] = { OPS };
 enum filter_pred_fn {
 	FILTER_PRED_FN_NOP,
 	FILTER_PRED_FN_64,
+	FILTER_PRED_FN_64_CPUMASK,
 	FILTER_PRED_FN_S64,
 	FILTER_PRED_FN_U64,
 	FILTER_PRED_FN_32,
+	FILTER_PRED_FN_32_CPUMASK,
 	FILTER_PRED_FN_S32,
 	FILTER_PRED_FN_U32,
 	FILTER_PRED_FN_16,
+	FILTER_PRED_FN_16_CPUMASK,
 	FILTER_PRED_FN_S16,
 	FILTER_PRED_FN_U16,
 	FILTER_PRED_FN_8,
+	FILTER_PRED_FN_8_CPUMASK,
 	FILTER_PRED_FN_S8,
 	FILTER_PRED_FN_U8,
 	FILTER_PRED_FN_COMM,
@@ -643,6 +647,39 @@ predicate_parse(const char *str, int nr_parens, int nr_preds,
 	return ERR_PTR(ret);
 }
 
+static inline int
+do_filter_cpumask(int op, const struct cpumask *mask, const struct cpumask *cmp)
+{
+	switch (op) {
+	case OP_EQ:
+		return cpumask_equal(mask, cmp);
+	case OP_NE:
+		return !cpumask_equal(mask, cmp);
+	case OP_BAND:
+		return cpumask_intersects(mask, cmp);
+	default:
+		return 0;
+	}
+}
+
+/* Optimisation of do_filter_cpumask() for scalar fields */
+static inline int
+do_filter_scalar_cpumask(int op, unsigned int cpu, const struct cpumask *mask)
+{
+	switch (op) {
+	case OP_EQ:
+		return cpumask_test_cpu(cpu, mask) &&
+			cpumask_nth(1, mask) >= nr_cpu_ids;
+	case OP_NE:
+		return !cpumask_test_cpu(cpu, mask) ||
+			cpumask_nth(1, mask) < nr_cpu_ids;
+	case OP_BAND:
+		return cpumask_test_cpu(cpu, mask);
+	default:
+		return 0;
+	}
+}
+
 enum pred_cmp_types {
 	PRED_CMP_TYPE_NOP,
 	PRED_CMP_TYPE_LT,
@@ -686,6 +723,18 @@ static int filter_pred_##type(struct filter_pred *pred, void *event)	\
 	}								\
 }
 
+#define DEFINE_CPUMASK_COMPARISON_PRED(size)					\
+static int filter_pred_##size##_cpumask(struct filter_pred *pred, void *event)	\
+{										\
+	u##size *addr = (u##size *)(event + pred->offset);			\
+	unsigned int cpu = *addr;						\
+										\
+	if (cpu >= nr_cpu_ids)							\
+		return 0;							\
+										\
+	return do_filter_scalar_cpumask(pred->op, cpu, pred->mask);		\
+}
+
 #define DEFINE_EQUALITY_PRED(size)					\
 static int filter_pred_##size(struct filter_pred *pred, void *event)	\
 {									\
@@ -707,6 +756,11 @@ DEFINE_COMPARISON_PRED(u16);
 DEFINE_COMPARISON_PRED(s8);
 DEFINE_COMPARISON_PRED(u8);
 
+DEFINE_CPUMASK_COMPARISON_PRED(64);
+DEFINE_CPUMASK_COMPARISON_PRED(32);
+DEFINE_CPUMASK_COMPARISON_PRED(16);
+DEFINE_CPUMASK_COMPARISON_PRED(8);
+
 DEFINE_EQUALITY_PRED(64);
 DEFINE_EQUALITY_PRED(32);
 DEFINE_EQUALITY_PRED(16);
@@ -891,16 +945,7 @@ static int filter_pred_cpumask(struct filter_pred *pred, void *event)
 	const struct cpumask *mask = (event + loc);
 	const struct cpumask *cmp = pred->mask;
 
-	switch (pred->op) {
-	case OP_EQ:
-		return cpumask_equal(mask, cmp);
-	case OP_NE:
-		return !cpumask_equal(mask, cmp);
-	case OP_BAND:
-		return cpumask_intersects(mask, cmp);
-	default:
-		return 0;
-	}
+	return do_filter_cpumask(pred->op, mask, cmp);
 }
 
 /* Filter predicate for COMM. */
@@ -1351,24 +1396,32 @@ static int filter_pred_fn_call(struct filter_pred *pred, void *event)
 	switch (pred->fn_num) {
 	case FILTER_PRED_FN_64:
 		return filter_pred_64(pred, event);
+	case FILTER_PRED_FN_64_CPUMASK:
+		return filter_pred_64_cpumask(pred, event);
 	case FILTER_PRED_FN_S64:
 		return filter_pred_s64(pred, event);
 	case FILTER_PRED_FN_U64:
 		return filter_pred_u64(pred, event);
 	case FILTER_PRED_FN_32:
 		return filter_pred_32(pred, event);
+	case FILTER_PRED_FN_32_CPUMASK:
+		return filter_pred_32_cpumask(pred, event);
 	case FILTER_PRED_FN_S32:
 		return filter_pred_s32(pred, event);
 	case FILTER_PRED_FN_U32:
 		return filter_pred_u32(pred, event);
 	case FILTER_PRED_FN_16:
 		return filter_pred_16(pred, event);
+	case FILTER_PRED_FN_16_CPUMASK:
+		return filter_pred_16_cpumask(pred, event);
 	case FILTER_PRED_FN_S16:
 		return filter_pred_s16(pred, event);
 	case FILTER_PRED_FN_U16:
 		return filter_pred_u16(pred, event);
 	case FILTER_PRED_FN_8:
 		return filter_pred_8(pred, event);
+	case FILTER_PRED_FN_8_CPUMASK:
+		return filter_pred_8_cpumask(pred, event);
 	case FILTER_PRED_FN_S8:
 		return filter_pred_s8(pred, event);
 	case FILTER_PRED_FN_U8:
@@ -1606,6 +1659,7 @@ static int parse_pred(const char *str, void *data,
 
 		switch (field->filter_type) {
 		case FILTER_CPUMASK:
+		case FILTER_OTHER:
 			break;
 		default:
 			parse_error(pe, FILT_ERR_ILLEGAL_FIELD_OP, pos + i);
@@ -1658,8 +1712,24 @@ static int parse_pred(const char *str, void *data,
 
 		/* Move along */
 		i++;
-		if (field->filter_type == FILTER_CPUMASK)
+		if (field->filter_type == FILTER_CPUMASK) {
 			pred->fn_num = FILTER_PRED_FN_CPUMASK;
+		} else {
+			switch (field->size) {
+			case 8:
+				pred->fn_num = FILTER_PRED_FN_64_CPUMASK;
+				break;
+			case 4:
+				pred->fn_num = FILTER_PRED_FN_32_CPUMASK;
+				break;
+			case 2:
+				pred->fn_num = FILTER_PRED_FN_16_CPUMASK;
+				break;
+			case 1:
+				pred->fn_num = FILTER_PRED_FN_8_CPUMASK;
+				break;
+			}
+		}
 
 	/* This is either a string, or an integer */
 	} else if (str[i] == '\'' || str[i] == '"') {
-- 
2.40.1

[for-next][PATCH 04/14] tracing/filters: Enable filtering the CPU common field by a cpumask

[Steven Rostedt]

From: Valentin Schneider <vschneid@redhat.com>

The tracing_cpumask lets us specify which CPUs are traced in a buffer
instance, but doesn't let us do this on a per-event basis (unless one
creates an instance per event).

A previous commit added filtering scalar fields by a user-given cpumask,
make this work with the CPU common field as well.

This enables doing things like

$ trace-cmd record -e 'sched_switch' -f 'CPU & CPUS{12-52}' \
		   -e 'sched_wakeup' -f 'target_cpu & CPUS{12-52}'

Link: https://lkml.kernel.org/r/20230707172155.70873-5-vschneid@redhat.com

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Daniel Bristot de Oliveira <bristot@redhat.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Leonardo Bras <leobras@redhat.com>
Cc: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Valentin Schneider <vschneid@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---
 kernel/trace/trace_events_filter.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index 1e14f801685a..3009d0c61b53 100644
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -68,6 +68,7 @@ enum filter_pred_fn {
 	FILTER_PRED_FN_PCHAR_USER,
 	FILTER_PRED_FN_PCHAR,
 	FILTER_PRED_FN_CPU,
+	FILTER_PRED_FN_CPU_CPUMASK,
 	FILTER_PRED_FN_CPUMASK,
 	FILTER_PRED_FN_FUNCTION,
 	FILTER_PRED_FN_,
@@ -937,6 +938,14 @@ static int filter_pred_cpu(struct filter_pred *pred, void *event)
 	}
 }
 
+/* Filter predicate for current CPU vs user-provided cpumask */
+static int filter_pred_cpu_cpumask(struct filter_pred *pred, void *event)
+{
+	int cpu = raw_smp_processor_id();
+
+	return do_filter_scalar_cpumask(pred->op, cpu, pred->mask);
+}
+
 /* Filter predicate for cpumask field vs user-provided cpumask */
 static int filter_pred_cpumask(struct filter_pred *pred, void *event)
 {
@@ -1440,6 +1449,8 @@ static int filter_pred_fn_call(struct filter_pred *pred, void *event)
 		return filter_pred_pchar(pred, event);
 	case FILTER_PRED_FN_CPU:
 		return filter_pred_cpu(pred, event);
+	case FILTER_PRED_FN_CPU_CPUMASK:
+		return filter_pred_cpu_cpumask(pred, event);
 	case FILTER_PRED_FN_CPUMASK:
 		return filter_pred_cpumask(pred, event);
 	case FILTER_PRED_FN_FUNCTION:
@@ -1659,6 +1670,7 @@ static int parse_pred(const char *str, void *data,
 
 		switch (field->filter_type) {
 		case FILTER_CPUMASK:
+		case FILTER_CPU:
 		case FILTER_OTHER:
 			break;
 		default:
@@ -1714,6 +1726,8 @@ static int parse_pred(const char *str, void *data,
 		i++;
 		if (field->filter_type == FILTER_CPUMASK) {
 			pred->fn_num = FILTER_PRED_FN_CPUMASK;
+		} else if (field->filter_type == FILTER_CPU) {
+			pred->fn_num = FILTER_PRED_FN_CPU_CPUMASK;
 		} else {
 			switch (field->size) {
 			case 8:
-- 
2.40.1

[for-next][PATCH 05/14] tracing/filters: Optimise cpumask vs cpumask filtering when user mask is a single CPU

[Steven Rostedt]

From: Valentin Schneider <vschneid@redhat.com>

Steven noted that when the user-provided cpumask contains a single CPU,
then the filtering function can use a scalar as input instead of a
full-fledged cpumask.

Reuse do_filter_scalar_cpumask() when the input mask has a weight of one.

Link: https://lkml.kernel.org/r/20230707172155.70873-6-vschneid@redhat.com

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Daniel Bristot de Oliveira <bristot@redhat.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Leonardo Bras <leobras@redhat.com>
Cc: Frederic Weisbecker <frederic@kernel.org>
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Valentin Schneider <vschneid@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---
 kernel/trace/trace_events_filter.c | 35 +++++++++++++++++++++++++++++-
 1 file changed, 34 insertions(+), 1 deletion(-)

diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index 3009d0c61b53..2fe65ddeb34e 100644
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -70,6 +70,7 @@ enum filter_pred_fn {
 	FILTER_PRED_FN_CPU,
 	FILTER_PRED_FN_CPU_CPUMASK,
 	FILTER_PRED_FN_CPUMASK,
+	FILTER_PRED_FN_CPUMASK_CPU,
 	FILTER_PRED_FN_FUNCTION,
 	FILTER_PRED_FN_,
 	FILTER_PRED_TEST_VISITED,
@@ -957,6 +958,22 @@ static int filter_pred_cpumask(struct filter_pred *pred, void *event)
 	return do_filter_cpumask(pred->op, mask, cmp);
 }
 
+/* Filter predicate for cpumask field vs user-provided scalar  */
+static int filter_pred_cpumask_cpu(struct filter_pred *pred, void *event)
+{
+	u32 item = *(u32 *)(event + pred->offset);
+	int loc = item & 0xffff;
+	const struct cpumask *mask = (event + loc);
+	unsigned int cpu = pred->val;
+
+	/*
+	 * This inverts the usual usage of the function (field is first element,
+	 * user parameter is second), but that's fine because the (scalar, mask)
+	 * operations used are symmetric.
+	 */
+	return do_filter_scalar_cpumask(pred->op, cpu, mask);
+}
+
 /* Filter predicate for COMM. */
 static int filter_pred_comm(struct filter_pred *pred, void *event)
 {
@@ -1453,6 +1470,8 @@ static int filter_pred_fn_call(struct filter_pred *pred, void *event)
 		return filter_pred_cpu_cpumask(pred, event);
 	case FILTER_PRED_FN_CPUMASK:
 		return filter_pred_cpumask(pred, event);
+	case FILTER_PRED_FN_CPUMASK_CPU:
+		return filter_pred_cpumask_cpu(pred, event);
 	case FILTER_PRED_FN_FUNCTION:
 		return filter_pred_function(pred, event);
 	case FILTER_PRED_TEST_VISITED:
@@ -1666,6 +1685,7 @@ static int parse_pred(const char *str, void *data,
 
 	} else if (!strncmp(str + i, "CPUS", 4)) {
 		unsigned int maskstart;
+		bool single;
 		char *tmp;
 
 		switch (field->filter_type) {
@@ -1724,8 +1744,21 @@ static int parse_pred(const char *str, void *data,
 
 		/* Move along */
 		i++;
+
+		/*
+		 * Optimisation: if the user-provided mask has a weight of one
+		 * then we can treat it as a scalar input.
+		 */
+		single = cpumask_weight(pred->mask) == 1;
+		if (single && field->filter_type == FILTER_CPUMASK) {
+			pred->val = cpumask_first(pred->mask);
+			kfree(pred->mask);
+		}
+
 		if (field->filter_type == FILTER_CPUMASK) {
-			pred->fn_num = FILTER_PRED_FN_CPUMASK;
+			pred->fn_num = single ?
+				FILTER_PRED_FN_CPUMASK_CPU :
+				FILTER_PRED_FN_CPUMASK;
 		} else if (field->filter_type == FILTER_CPU) {
 			pred->fn_num = FILTER_PRED_FN_CPU_CPUMASK;
 		} else {
-- 
2.40.1

[for-next][PATCH 06/14] tracing/filters: Optimise scalar vs cpumask filtering when the user mask is a single CPU

[Steven Rostedt]

From: Valentin Schneider <vschneid@redhat.com>

Steven noted that when the user-provided cpumask contains a single CPU,
then the filtering function can use a scalar as input instead of a
full-fledged cpumask.

When the mask contains a single CPU, directly re-use the unsigned field
predicate functions. Transform '&' into '==' beforehand.

Link: https://lkml.kernel.org/r/20230707172155.70873-7-vschneid@redhat.com

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Daniel Bristot de Oliveira <bristot@redhat.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Leonardo Bras <leobras@redhat.com>
Cc: Frederic Weisbecker <frederic@kernel.org>
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Valentin Schneider <vschneid@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---
 kernel/trace/trace_events_filter.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index 2fe65ddeb34e..54d642fabb7f 100644
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -1750,7 +1750,7 @@ static int parse_pred(const char *str, void *data,
 		 * then we can treat it as a scalar input.
 		 */
 		single = cpumask_weight(pred->mask) == 1;
-		if (single && field->filter_type == FILTER_CPUMASK) {
+		if (single && field->filter_type != FILTER_CPU) {
 			pred->val = cpumask_first(pred->mask);
 			kfree(pred->mask);
 		}
@@ -1761,6 +1761,11 @@ static int parse_pred(const char *str, void *data,
 				FILTER_PRED_FN_CPUMASK;
 		} else if (field->filter_type == FILTER_CPU) {
 			pred->fn_num = FILTER_PRED_FN_CPU_CPUMASK;
+		} else if (single) {
+			pred->op = pred->op == OP_BAND ? OP_EQ : pred->op;
+			pred->fn_num = select_comparison_fn(pred->op, field->size, false);
+			if (pred->op == OP_NE)
+				pred->not = 1;
 		} else {
 			switch (field->size) {
 			case 8:
-- 
2.40.1

[for-next][PATCH 07/14] tracing/filters: Optimise CPU vs cpumask filtering when the user mask is a single CPU

[Steven Rostedt]

From: Valentin Schneider <vschneid@redhat.com>

Steven noted that when the user-provided cpumask contains a single CPU,
then the filtering function can use a scalar as input instead of a
full-fledged cpumask.

In this case we can directly re-use filter_pred_cpu(), we just need to
transform '&' into '==' before executing it.

Link: https://lkml.kernel.org/r/20230707172155.70873-8-vschneid@redhat.com

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Daniel Bristot de Oliveira <bristot@redhat.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Leonardo Bras <leobras@redhat.com>
Cc: Frederic Weisbecker <frederic@kernel.org>
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Valentin Schneider <vschneid@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---
 kernel/trace/trace_events_filter.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index 54d642fabb7f..fd72dacc5d1b 100644
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -1750,7 +1750,7 @@ static int parse_pred(const char *str, void *data,
 		 * then we can treat it as a scalar input.
 		 */
 		single = cpumask_weight(pred->mask) == 1;
-		if (single && field->filter_type != FILTER_CPU) {
+		if (single) {
 			pred->val = cpumask_first(pred->mask);
 			kfree(pred->mask);
 		}
@@ -1760,7 +1760,12 @@ static int parse_pred(const char *str, void *data,
 				FILTER_PRED_FN_CPUMASK_CPU :
 				FILTER_PRED_FN_CPUMASK;
 		} else if (field->filter_type == FILTER_CPU) {
-			pred->fn_num = FILTER_PRED_FN_CPU_CPUMASK;
+			if (single) {
+				pred->op = pred->op == OP_BAND ? OP_EQ : pred->op;
+				pred->fn_num = FILTER_PRED_FN_CPU;
+			} else {
+				pred->fn_num = FILTER_PRED_FN_CPU_CPUMASK;
+			}
 		} else if (single) {
 			pred->op = pred->op == OP_BAND ? OP_EQ : pred->op;
 			pred->fn_num = select_comparison_fn(pred->op, field->size, false);
-- 
2.40.1

[for-next][PATCH 08/14] tracing/filters: Further optimise scalar vs cpumask comparison

[Steven Rostedt]

From: Valentin Schneider <vschneid@redhat.com>

Per the previous commits, we now only enter do_filter_scalar_cpumask() with
a mask of weight greater than one. Optimise the equality checks.

Link: https://lkml.kernel.org/r/20230707172155.70873-9-vschneid@redhat.com

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Daniel Bristot de Oliveira <bristot@redhat.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Leonardo Bras <leobras@redhat.com>
Cc: Frederic Weisbecker <frederic@kernel.org>
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Valentin Schneider <vschneid@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---
 kernel/trace/trace_events_filter.c | 26 ++++++++++++++++++++------
 1 file changed, 20 insertions(+), 6 deletions(-)

diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index fd72dacc5d1b..3a529214a21b 100644
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -667,6 +667,25 @@ do_filter_cpumask(int op, const struct cpumask *mask, const struct cpumask *cmp)
 /* Optimisation of do_filter_cpumask() for scalar fields */
 static inline int
 do_filter_scalar_cpumask(int op, unsigned int cpu, const struct cpumask *mask)
+{
+	/*
+	 * Per the weight-of-one cpumask optimisations, the mask passed in this
+	 * function has a weight >= 2, so it is never equal to a single scalar.
+	 */
+	switch (op) {
+	case OP_EQ:
+		return false;
+	case OP_NE:
+		return true;
+	case OP_BAND:
+		return cpumask_test_cpu(cpu, mask);
+	default:
+		return 0;
+	}
+}
+
+static inline int
+do_filter_cpumask_scalar(int op, const struct cpumask *mask, unsigned int cpu)
 {
 	switch (op) {
 	case OP_EQ:
@@ -966,12 +985,7 @@ static int filter_pred_cpumask_cpu(struct filter_pred *pred, void *event)
 	const struct cpumask *mask = (event + loc);
 	unsigned int cpu = pred->val;
 
-	/*
-	 * This inverts the usual usage of the function (field is first element,
-	 * user parameter is second), but that's fine because the (scalar, mask)
-	 * operations used are symmetric.
-	 */
-	return do_filter_scalar_cpumask(pred->op, cpu, mask);
+	return do_filter_cpumask_scalar(pred->op, mask, cpu);
 }
 
 /* Filter predicate for COMM. */
-- 
2.40.1

[for-next][PATCH 09/14] tracing/filters: Document cpumask filtering

[Steven Rostedt]

From: Valentin Schneider <vschneid@redhat.com>

Cpumask, scalar and CPU fields can now be filtered by a user-provided
cpumask, document the syntax.

Link: https://lkml.kernel.org/r/20230707172155.70873-10-vschneid@redhat.com

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Daniel Bristot de Oliveira <bristot@redhat.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Leonardo Bras <leobras@redhat.com>
Cc: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Valentin Schneider <vschneid@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---
 Documentation/trace/events.rst | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/Documentation/trace/events.rst b/Documentation/trace/events.rst
index f5fcb8e1218f..34108d5a55b4 100644
--- a/Documentation/trace/events.rst
+++ b/Documentation/trace/events.rst
@@ -219,6 +219,20 @@ the function "security_prepare_creds" and less than the end of that function.
 The ".function" postfix can only be attached to values of size long, and can only
 be compared with "==" or "!=".
 
+Cpumask fields or scalar fields that encode a CPU number can be filtered using
+a user-provided cpumask in cpulist format. The format is as follows::
+
+  CPUS{$cpulist}
+
+Operators available to cpumask filtering are:
+
+& (intersection), ==, !=
+
+For example, this will filter events that have their .target_cpu field present
+in the given cpumask::
+
+  target_cpu & CPUS{17-42}
+
 5.2 Setting filters
 -------------------
 
-- 
2.40.1

[for-next][PATCH 10/14] tracing: Remove unused function declarations

[Steven Rostedt]

From: Yue Haibing <yuehaibing@huawei.com>

Commit 9457158bbc0e ("tracing: Fix reset of time stamps during trace_clock changes")
left behind tracing_reset_current() declaration.
Also commit 6954e415264e ("tracing: Place trace_pid_list logic into abstract functions")
removed trace_free_pid_list() implementation but leave declaration.

Link: https://lore.kernel.org/linux-trace-kernel/20230803144028.25492-1-yuehaibing@huawei.com

Cc: <mhiramat@kernel.org>
Signed-off-by: Yue Haibing <yuehaibing@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---
 kernel/trace/trace.h | 2 --
 1 file changed, 2 deletions(-)

diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 5b1f9e24764a..b6e44a39b4ce 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -604,7 +604,6 @@ trace_buffer_iter(struct trace_iterator *iter, int cpu)
 int tracer_init(struct tracer *t, struct trace_array *tr);
 int tracing_is_enabled(void);
 void tracing_reset_online_cpus(struct array_buffer *buf);
-void tracing_reset_current(int cpu);
 void tracing_reset_all_online_cpus(void);
 void tracing_reset_all_online_cpus_unlocked(void);
 int tracing_open_generic(struct inode *inode, struct file *filp);
@@ -705,7 +704,6 @@ void trace_filter_add_remove_task(struct trace_pid_list *pid_list,
 void *trace_pid_next(struct trace_pid_list *pid_list, void *v, loff_t *pos);
 void *trace_pid_start(struct trace_pid_list *pid_list, loff_t *pos);
 int trace_pid_show(struct seq_file *m, void *v);
-void trace_free_pid_list(struct trace_pid_list *pid_list);
 int trace_pid_write(struct trace_pid_list *filtered_pids,
 		    struct trace_pid_list **new_pid_list,
 		    const char __user *ubuf, size_t cnt);
-- 
2.40.1

[for-next][PATCH 11/14] ftrace: Remove empty declaration ftrace_enable_daemon() and ftrace_disable_daemon()

[Steven Rostedt]

From: Zhang Zekun <zhangzekun11@huawei.com>

The definition of ftrace_enable_daemon() and ftrace_disable_daemon() has
been removed since commit cb7be3b2fc2c ("ftrace: remove daemon"), remain
the declarations in the header files, so remove it.

Link: https://lore.kernel.org/linux-trace-kernel/20230804013636.115940-1-zhangzekun11@huawei.com

Cc: <mhiramat@kernel.org>
Cc: <mark.rutland@arm.com>
Signed-off-by: Zhang Zekun <zhangzekun11@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---
 include/linux/ftrace.h | 5 -----
 1 file changed, 5 deletions(-)

diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index aad9cf8876b5..e8921871ef9a 100644
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -862,13 +862,8 @@ extern int skip_trace(unsigned long ip);
 extern void ftrace_module_init(struct module *mod);
 extern void ftrace_module_enable(struct module *mod);
 extern void ftrace_release_mod(struct module *mod);
-
-extern void ftrace_disable_daemon(void);
-extern void ftrace_enable_daemon(void);
 #else /* CONFIG_DYNAMIC_FTRACE */
 static inline int skip_trace(unsigned long ip) { return 0; }
-static inline void ftrace_disable_daemon(void) { }
-static inline void ftrace_enable_daemon(void) { }
 static inline void ftrace_module_init(struct module *mod) { }
 static inline void ftrace_module_enable(struct module *mod) { }
 static inline void ftrace_release_mod(struct module *mod) { }
-- 
2.40.1

[for-next][PATCH 12/14] tracing/user_events: Optimize safe list traversals

[Steven Rostedt]

From: Eric Vaughn <ervaughn@linux.microsoft.com>

Several of the list traversals in the user_events facility use safe list
traversals where they could be using the unsafe versions instead.

Replace these safe traversals with their unsafe counterparts in the
interest of optimization.

Link: https://lore.kernel.org/linux-trace-kernel/20230810194337.695983-1-ervaughn@linux.microsoft.com

Suggested-by: Beau Belgrave <beaub@linux.microsoft.com>
Signed-off-by: Eric Vaughn <ervaughn@linux.microsoft.com>
Acked-by: Beau Belgrave <beaub@linux.microsoft.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---
 kernel/trace/trace_events_user.c | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/kernel/trace/trace_events_user.c b/kernel/trace/trace_events_user.c
index 33cb6af31f39..6f046650e527 100644
--- a/kernel/trace/trace_events_user.c
+++ b/kernel/trace/trace_events_user.c
@@ -1328,14 +1328,14 @@ static int user_field_set_string(struct ftrace_event_field *field,
 
 static int user_event_set_print_fmt(struct user_event *user, char *buf, int len)
 {
-	struct ftrace_event_field *field, *next;
+	struct ftrace_event_field *field;
 	struct list_head *head = &user->fields;
 	int pos = 0, depth = 0;
 	const char *str_func;
 
 	pos += snprintf(buf + pos, LEN_OR_ZERO, "\"");
 
-	list_for_each_entry_safe_reverse(field, next, head, link) {
+	list_for_each_entry_reverse(field, head, link) {
 		if (depth != 0)
 			pos += snprintf(buf + pos, LEN_OR_ZERO, " ");
 
@@ -1347,7 +1347,7 @@ static int user_event_set_print_fmt(struct user_event *user, char *buf, int len)
 
 	pos += snprintf(buf + pos, LEN_OR_ZERO, "\"");
 
-	list_for_each_entry_safe_reverse(field, next, head, link) {
+	list_for_each_entry_reverse(field, head, link) {
 		if (user_field_is_dyn_string(field->type, &str_func))
 			pos += snprintf(buf + pos, LEN_OR_ZERO,
 					", %s(%s)", str_func, field->name);
@@ -1732,7 +1732,7 @@ static int user_event_create(const char *raw_command)
 static int user_event_show(struct seq_file *m, struct dyn_event *ev)
 {
 	struct user_event *user = container_of(ev, struct user_event, devent);
-	struct ftrace_event_field *field, *next;
+	struct ftrace_event_field *field;
 	struct list_head *head;
 	int depth = 0;
 
@@ -1740,7 +1740,7 @@ static int user_event_show(struct seq_file *m, struct dyn_event *ev)
 
 	head = trace_get_fields(&user->call);
 
-	list_for_each_entry_safe_reverse(field, next, head, link) {
+	list_for_each_entry_reverse(field, head, link) {
 		if (depth == 0)
 			seq_puts(m, " ");
 		else
@@ -1816,13 +1816,14 @@ static bool user_field_match(struct ftrace_event_field *field, int argc,
 static bool user_fields_match(struct user_event *user, int argc,
 			      const char **argv)
 {
-	struct ftrace_event_field *field, *next;
+	struct ftrace_event_field *field;
 	struct list_head *head = &user->fields;
 	int i = 0;
 
-	list_for_each_entry_safe_reverse(field, next, head, link)
+	list_for_each_entry_reverse(field, head, link) {
 		if (!user_field_match(field, argc, argv, &i))
 			return false;
+	}
 
 	if (i != argc)
 		return false;
-- 
2.40.1

[for-next][PATCH 13/14] tracefs: Avoid changing i_mode to a temp value

[Steven Rostedt]

From: Sishuai Gong <sishuai.system@gmail.com>

Right now inode->i_mode is updated twice to reach the desired value
in tracefs_apply_options(). Because there is no lock protecting the two
writes, other threads might read the intermediate value of inode->i_mode.

Thread-1			Thread-2
// tracefs_apply_options()	//e.g., acl_permission_check
inode->i_mode &= ~S_IALLUGO;
				unsigned int mode = inode->i_mode;
inode->i_mode |= opts->mode;

I think there is no need to introduce a lock but it is better to
only update inode->i_mode ONCE, so the readers will either see the old
or latest value, rather than an intermediate/temporary value.

Note, the race is not a security concern as the intermediate value is more
locked down than either the start or end version. This is more just to do
the conversion cleanly.

Link: https://lore.kernel.org/linux-trace-kernel/AB5B0A1C-75D9-4E82-A7F0-CF7D0715587B@gmail.com

Signed-off-by: Sishuai Gong <sishuai.system@gmail.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---
 fs/tracefs/inode.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/fs/tracefs/inode.c b/fs/tracefs/inode.c
index bb6de89eb446..c7a10f965602 100644
--- a/fs/tracefs/inode.c
+++ b/fs/tracefs/inode.c
@@ -310,6 +310,7 @@ static int tracefs_apply_options(struct super_block *sb, bool remount)
 	struct tracefs_fs_info *fsi = sb->s_fs_info;
 	struct inode *inode = d_inode(sb->s_root);
 	struct tracefs_mount_opts *opts = &fsi->mount_opts;
+	umode_t tmp_mode;
 
 	/*
 	 * On remount, only reset mode/uid/gid if they were provided as mount
@@ -317,8 +318,9 @@ static int tracefs_apply_options(struct super_block *sb, bool remount)
 	 */
 
 	if (!remount || opts->opts & BIT(Opt_mode)) {
-		inode->i_mode &= ~S_IALLUGO;
-		inode->i_mode |= opts->mode;
+		tmp_mode = READ_ONCE(inode->i_mode) & ~S_IALLUGO;
+		tmp_mode |= opts->mode;
+		WRITE_ONCE(inode->i_mode, tmp_mode);
 	}
 
 	if (!remount || opts->opts & BIT(Opt_uid))
-- 
2.40.1

[for-next][PATCH 14/14] tracefs: Remove kerneldoc from struct eventfs_file

[Steven Rostedt]

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

The struct eventfs_file is a local structure and should not be parsed by
kernel doc. It also does not fully follow the kerneldoc format and is
causing kerneldoc to spit out errors. Replace the /** to /* so that
kerneldoc no longer processes this structure.

Also format the comments of the delete union of the structure to be a bit
better.

Link: https://lore.kernel.org/linux-trace-kernel/20230818201414.2729745-1-willy@infradead.org/
Link: https://lore.kernel.org/linux-trace-kernel/20230822053313.77aa3397@rorschach.local.home

Cc: Mark Rutland <mark.rutland@arm.com>
Reported-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---
 fs/tracefs/event_inode.c | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/fs/tracefs/event_inode.c b/fs/tracefs/event_inode.c
index da8d2e73cc47..237c6f370ad9 100644
--- a/fs/tracefs/event_inode.c
+++ b/fs/tracefs/event_inode.c
@@ -27,7 +27,7 @@ struct eventfs_inode {
 	struct list_head	e_top_files;
 };
 
-/**
+/*
  * struct eventfs_file - hold the properties of the eventfs files and
  *                       directories.
  * @name:	the name of the file or directory to create
@@ -48,10 +48,16 @@ struct eventfs_file {
 	struct eventfs_inode		*ei;
 	const struct file_operations	*fop;
 	const struct inode_operations	*iop;
+	/*
+	 * Union - used for deletion
+	 * @del_list:	list of eventfs_file to delete
+	 * @rcu:	eventfs_file to delete in RCU
+	 * @is_freed:	node is freed if one of the above is set
+	 */
 	union {
-		struct list_head	del_list; /* list of eventfs_file to delete */
-		struct rcu_head		rcu; /* eventfs_file to delete */
-		unsigned long		is_freed; /* Freed if one of the above is set */
+		struct list_head	del_list;
+		struct rcu_head		rcu;
+		unsigned long		is_freed;
 	};
 	void				*data;
 	umode_t				mode;
-- 
2.40.1