[GIT PULL] tracing: Updates for 6.2

From: Steven Rostedt
Date: Thu Jan 26 2023 - 19:35:30 EST

Next message: Chun-Kuang Hu: "Re: [PATCH v2] drm/mediatek: stop using 0 as NULL pointer"
Previous message: Luis Chamberlain: "Re: [PATCH 1/2] wifi: ath11k: Use platform_get_irq() to get the interrupt"
Next in thread: Linus Torvalds: "Re: [GIT PULL] tracing: Updates for 6.2"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]

Linus,

Tracing updates for 6.2:

- Fix filter memory leak by calling ftrace_free_filter()

- Initialize trace_printk() earlier so that ftrace_dump_on_oops shows data
on early crashes.

- Update the outdated instructions in scripts/tracing/ftrace-bisect.sh

- Add lockdep_is_held() to fix lockdep warning

- Add allocation failure check in create_hist_field()

- Don't initialize pointer that gets set right away in enabled_monitors_write()

- Update MAINTAINER entries

- Fix help messages in Kconfigs

- Fix kernel-doc header for update_preds()

Please pull the latest trace-v6.2-rc5 tree, which can be found at:

git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace.git
trace-v6.2-rc5

Tag SHA1: 08c8ae3bc6ff93089952df685713118aad717c3c
Head SHA1: 78020233418518faa72fba11f40e1d53b9e88a2e

Chuang Wang (1):
tracing/osnoise: Use built-in RCU list checking

Colin Ian King (1):
rv: remove redundant initialization of pointer ptr

Mark Rutland (2):
ftrace: Export ftrace_free_filter() to modules
ftrace: Maintain samples/ftrace

Masami Hiramatsu (Google) (1):
bootconfig: Update MAINTAINERS file to add tree and mailing list

Natalia Petrova (1):
trace_events_hist: add check for return value of 'create_hist_field'

Randy Dunlap (3):
tracing: Kconfig: Fix spelling/grammar/punctuation
lib: Kconfig: fix spellos
tracing/filter: fix kernel-doc warnings

Steven Rostedt (Google) (2):
tracing: Make sure trace_printk() can output as soon as it can be used
ftrace/scripts: Update the instructions for ftrace-bisect.sh

----
MAINTAINERS | 5 +++++
kernel/trace/Kconfig | 8 +++----
kernel/trace/ftrace.c | 23 ++++++++++++++++++-
kernel/trace/rv/rv.c | 2 +-
kernel/trace/trace.c | 2 ++
kernel/trace/trace.h | 1 +
kernel/trace/trace_events_filter.c | 8 +++----
kernel/trace/trace_events_hist.c | 2 ++
kernel/trace/trace_osnoise.c | 5 ++---
kernel/trace/trace_output.c | 3 +--
lib/Kconfig.debug | 2 +-
lib/Kconfig.kcsan | 2 +-
samples/ftrace/ftrace-direct-multi-modify.c | 1 +
samples/ftrace/ftrace-direct-multi.c | 1 +
scripts/tracing/ftrace-bisect.sh | 34 ++++++++++++++++++++++-------
15 files changed, 74 insertions(+), 25 deletions(-)
---------------------------
diff --git a/MAINTAINERS b/MAINTAINERS
index f781f936ae35..e64ba36ced78 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -7894,7 +7894,11 @@ F: include/linux/extcon/

EXTRA BOOT CONFIG
M: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
+L: linux-kernel@xxxxxxxxxxxxxxx
+L: linux-trace-kernel@xxxxxxxxxxxxxxx
+Q: https://patchwork.kernel.org/project/linux-trace-kernel/list/
S: Maintained
+T: git git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace.git
F: Documentation/admin-guide/bootconfig.rst
F: fs/proc/bootconfig.c
F: include/linux/bootconfig.h
@@ -8570,6 +8574,7 @@ F: kernel/trace/fgraph.c
F: arch/*/*/*/*ftrace*
F: arch/*/*/*ftrace*
F: include/*/ftrace.h
+F: samples/ftrace

FUNGIBLE ETHERNET DRIVERS
M: Dimitris Michailidis <dmichail@xxxxxxxxxxxx>
diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
index 197545241ab8..d7043043f59c 100644
--- a/kernel/trace/Kconfig
+++ b/kernel/trace/Kconfig
@@ -933,8 +933,8 @@ config RING_BUFFER_RECORD_RECURSION
default y
help
The ring buffer has its own internal recursion. Although when
- recursion happens it wont cause harm because of the protection,
- but it does cause an unwanted overhead. Enabling this option will
+ recursion happens it won't cause harm because of the protection,
+ but it does cause unwanted overhead. Enabling this option will
place where recursion was detected into the ftrace "recursed_functions"
file.

@@ -1017,8 +1017,8 @@ config RING_BUFFER_STARTUP_TEST
The test runs for 10 seconds. This will slow your boot time
by at least 10 more seconds.

- At the end of the test, statics and more checks are done.
- It will output the stats of each per cpu buffer. What
+ At the end of the test, statistics and more checks are done.
+ It will output the stats of each per cpu buffer: What
was written, the sizes, what was read, what was lost, and
other similar details.

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 442438b93fe9..750aa3f08b25 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -1248,12 +1248,17 @@ static void free_ftrace_hash_rcu(struct ftrace_hash *hash)
call_rcu(&hash->rcu, __free_ftrace_hash_rcu);
}

+/**
+ * ftrace_free_filter - remove all filters for an ftrace_ops
+ * @ops - the ops to remove the filters from
+ */
void ftrace_free_filter(struct ftrace_ops *ops)
{
ftrace_ops_init(ops);
free_ftrace_hash(ops->func_hash->filter_hash);
free_ftrace_hash(ops->func_hash->notrace_hash);
}
+EXPORT_SYMBOL_GPL(ftrace_free_filter);

static struct ftrace_hash *alloc_ftrace_hash(int size_bits)
{
@@ -5839,6 +5844,10 @@ EXPORT_SYMBOL_GPL(modify_ftrace_direct_multi);
*
* Filters denote which functions should be enabled when tracing is enabled
* If @ip is NULL, it fails to update filter.
+ *
+ * This can allocate memory which must be freed before @ops can be freed,
+ * either by removing each filtered addr or by using
+ * ftrace_free_filter(@ops).
*/
int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip,
int remove, int reset)
@@ -5858,7 +5867,11 @@ EXPORT_SYMBOL_GPL(ftrace_set_filter_ip);
*
* Filters denote which functions should be enabled when tracing is enabled
* If @ips array or any ip specified within is NULL , it fails to update filter.
- */
+ *
+ * This can allocate memory which must be freed before @ops can be freed,
+ * either by removing each filtered addr or by using
+ * ftrace_free_filter(@ops).
+*/
int ftrace_set_filter_ips(struct ftrace_ops *ops, unsigned long *ips,
unsigned int cnt, int remove, int reset)
{
@@ -5900,6 +5913,10 @@ ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len,
*
* Filters denote which functions should be enabled when tracing is enabled.
* If @buf is NULL and reset is set, all functions will be enabled for tracing.
+ *
+ * This can allocate memory which must be freed before @ops can be freed,
+ * either by removing each filtered addr or by using
+ * ftrace_free_filter(@ops).
*/
int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf,
int len, int reset)
@@ -5919,6 +5936,10 @@ EXPORT_SYMBOL_GPL(ftrace_set_filter);
* Notrace Filters denote which functions should not be enabled when tracing
* is enabled. If @buf is NULL and reset is set, all functions will be enabled
* for tracing.
+ *
+ * This can allocate memory which must be freed before @ops can be freed,
+ * either by removing each filtered addr or by using
+ * ftrace_free_filter(@ops).
*/
int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf,
int len, int reset)
diff --git a/kernel/trace/rv/rv.c b/kernel/trace/rv/rv.c
index 6c97cc2d754a..7e9061828c24 100644
--- a/kernel/trace/rv/rv.c
+++ b/kernel/trace/rv/rv.c
@@ -516,7 +516,7 @@ static ssize_t enabled_monitors_write(struct file *filp, const char __user *user
struct rv_monitor_def *mdef;
int retval = -EINVAL;
bool enable = true;
- char *ptr = buff;
+ char *ptr;
int len;

if (count < 1 || count > MAX_RV_MONITOR_NAME_SIZE + 1)
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index a555a861b978..78ed5f1baa8c 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -10295,6 +10295,8 @@ void __init early_trace_init(void)
static_key_enable(&tracepoint_printk_key.key);
}
tracer_alloc_buffers();
+
+ init_events();
}

void __init trace_init(void)
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index e46a49269be2..4eb6d6b97a9f 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -1490,6 +1490,7 @@ extern void trace_event_enable_cmd_record(bool enable);
extern void trace_event_enable_tgid_record(bool enable);

extern int event_trace_init(void);
+extern int init_events(void);
extern int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr);
extern int event_trace_del_tracer(struct trace_array *tr);
extern void __trace_early_add_events(struct trace_array *tr);
diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index 96acc2b71ac7..e095c3b3a50d 100644
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -128,7 +128,7 @@ static bool is_not(const char *str)
}

/**
- * prog_entry - a singe entry in the filter program
+ * struct prog_entry - a singe entry in the filter program
* @target: Index to jump to on a branch (actually one minus the index)
* @when_to_branch: The value of the result of the predicate to do a branch
* @pred: The predicate to execute.
@@ -140,16 +140,16 @@ struct prog_entry {
};

/**
- * update_preds- assign a program entry a label target
+ * update_preds - assign a program entry a label target
* @prog: The program array
* @N: The index of the current entry in @prog
- * @when_to_branch: What to assign a program entry for its branch condition
+ * @invert: What to assign a program entry for its branch condition
*
* The program entry at @N has a target that points to the index of a program
* entry that can have its target and when_to_branch fields updated.
* Update the current program entry denoted by index @N target field to be
* that of the updated entry. This will denote the entry to update if
- * we are processing an "||" after an "&&"
+ * we are processing an "||" after an "&&".
*/
static void update_preds(struct prog_entry *prog, int N, int invert)
{
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index fcaf226b7744..5edbf6b1da3f 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -1988,6 +1988,8 @@ static struct hist_field *create_hist_field(struct hist_trigger_data *hist_data,
hist_field->fn_num = flags & HIST_FIELD_FL_LOG2 ? HIST_FIELD_FN_LOG2 :
HIST_FIELD_FN_BUCKET;
hist_field->operands[0] = create_hist_field(hist_data, field, fl, NULL);
+ if (!hist_field->operands[0])
+ goto free;
hist_field->size = hist_field->operands[0]->size;
hist_field->type = kstrdup_const(hist_field->operands[0]->type, GFP_KERNEL);
if (!hist_field->type)
diff --git a/kernel/trace/trace_osnoise.c b/kernel/trace/trace_osnoise.c
index 94c1b5eb1dc0..210e1f168392 100644
--- a/kernel/trace/trace_osnoise.c
+++ b/kernel/trace/trace_osnoise.c
@@ -147,9 +147,8 @@ static void osnoise_unregister_instance(struct trace_array *tr)
* register/unregister serialization is provided by trace's
* trace_types_lock.
*/
- lockdep_assert_held(&trace_types_lock);
-
- list_for_each_entry_rcu(inst, &osnoise_instances, list) {
+ list_for_each_entry_rcu(inst, &osnoise_instances, list,
+ lockdep_is_held(&trace_types_lock)) {
if (inst->tr == tr) {
list_del_rcu(&inst->list);
found = 1;
diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
index 57a13b61f186..bd475a00f96d 100644
--- a/kernel/trace/trace_output.c
+++ b/kernel/trace/trace_output.c
@@ -1535,7 +1535,7 @@ static struct trace_event *events[] __initdata = {
NULL
};

-__init static int init_events(void)
+__init int init_events(void)
{
struct trace_event *event;
int i, ret;
@@ -1548,4 +1548,3 @@ __init static int init_events(void)

return 0;
}
-early_initcall(init_events);
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 881c3f84e88a..6426dbf99c12 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -1917,7 +1917,7 @@ config FUNCTION_ERROR_INJECTION
help
Add fault injections into various functions that are annotated with
ALLOW_ERROR_INJECTION() in the kernel. BPF may also modify the return
- value of theses functions. This is useful to test error paths of code.
+ value of these functions. This is useful to test error paths of code.

If unsure, say N

diff --git a/lib/Kconfig.kcsan b/lib/Kconfig.kcsan
index 375575a5a0e3..4dedd61e5192 100644
--- a/lib/Kconfig.kcsan
+++ b/lib/Kconfig.kcsan
@@ -194,7 +194,7 @@ config KCSAN_WEAK_MEMORY
Enable support for modeling a subset of weak memory, which allows
detecting a subset of data races due to missing memory barriers.

- Depends on KCSAN_STRICT, because the options strenghtening certain
+ Depends on KCSAN_STRICT, because the options strengthening certain
plain accesses by default (depending on !KCSAN_STRICT) reduce the
ability to detect any data races invoving reordered accesses, in
particular reordered writes.
diff --git a/samples/ftrace/ftrace-direct-multi-modify.c b/samples/ftrace/ftrace-direct-multi-modify.c
index d52370cad0b6..a825dbd2c9cf 100644
--- a/samples/ftrace/ftrace-direct-multi-modify.c
+++ b/samples/ftrace/ftrace-direct-multi-modify.c
@@ -152,6 +152,7 @@ static void __exit ftrace_direct_multi_exit(void)
{
kthread_stop(simple_tsk);
unregister_ftrace_direct_multi(&direct, my_tramp);
+ ftrace_free_filter(&direct);
}

module_init(ftrace_direct_multi_init);
diff --git a/samples/ftrace/ftrace-direct-multi.c b/samples/ftrace/ftrace-direct-multi.c
index ec1088922517..d955a2650605 100644
--- a/samples/ftrace/ftrace-direct-multi.c
+++ b/samples/ftrace/ftrace-direct-multi.c
@@ -79,6 +79,7 @@ static int __init ftrace_direct_multi_init(void)
static void __exit ftrace_direct_multi_exit(void)
{
unregister_ftrace_direct_multi(&direct, (unsigned long) my_tramp);
+ ftrace_free_filter(&direct);
}

module_init(ftrace_direct_multi_init);
diff --git a/scripts/tracing/ftrace-bisect.sh b/scripts/tracing/ftrace-bisect.sh
index 926701162bc8..bb4f59262bbe 100755
--- a/scripts/tracing/ftrace-bisect.sh
+++ b/scripts/tracing/ftrace-bisect.sh
@@ -12,7 +12,7 @@
# (note, if this is a problem with function_graph tracing, then simply
# replace "function" with "function_graph" in the following steps).
#
-# # cd /sys/kernel/debug/tracing
+# # cd /sys/kernel/tracing
# # echo schedule > set_ftrace_filter
# # echo function > current_tracer
#
@@ -20,22 +20,40 @@
#
# # echo nop > current_tracer
#
-# # cat available_filter_functions > ~/full-file
+# Starting with v5.1 this can be done with numbers, making it much faster:
+#
+# The old (slow) way, for kernels before v5.1.
+#
+# [old-way] # cat available_filter_functions > ~/full-file
+#
+# [old-way] *** Note *** this process will take several minutes to update the
+# [old-way] filters. Setting multiple functions is an O(n^2) operation, and we
+# [old-way] are dealing with thousands of functions. So go have coffee, talk
+# [old-way] with your coworkers, read facebook. And eventually, this operation
+# [old-way] will end.
+#
+# The new way (using numbers) is an O(n) operation, and usually takes less than a second.
+#
+# seq `wc -l available_filter_functions | cut -d' ' -f1` > ~/full-file
+#
+# This will create a sequence of numbers that match the functions in
+# available_filter_functions, and when echoing in a number into the
+# set_ftrace_filter file, it will enable the corresponding function in
+# O(1) time. Making enabling all functions O(n) where n is the number of
+# functions to enable.
+#
+# For either the new or old way, the rest of the operations remain the same.
+#
# # ftrace-bisect ~/full-file ~/test-file ~/non-test-file
# # cat ~/test-file > set_ftrace_filter
#
-# *** Note *** this will take several minutes. Setting multiple functions is
-# an O(n^2) operation, and we are dealing with thousands of functions. So go
-# have coffee, talk with your coworkers, read facebook. And eventually, this
-# operation will end.
-#
# # echo function > current_tracer
#
# If it crashes, we know that ~/test-file has a bad function.
#
# Reboot back to test kernel.
#
-# # cd /sys/kernel/debug/tracing
+# # cd /sys/kernel/tracing
# # mv ~/test-file ~/full-file
#
# If it didn't crash.

Next message: Chun-Kuang Hu: "Re: [PATCH v2] drm/mediatek: stop using 0 as NULL pointer"
Previous message: Luis Chamberlain: "Re: [PATCH 1/2] wifi: ath11k: Use platform_get_irq() to get the interrupt"
Next in thread: Linus Torvalds: "Re: [GIT PULL] tracing: Updates for 6.2"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]