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New tracing features:

Browse Source 
- 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 trace 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)
 
 Other minor updates and fixes.
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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
  ...
This commit is contained in:
Linus Torvalds 2020-04-05 10:36:18 -07:00
commit aa1a8ce533
28 changed files with 1196 additions and 258 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

82
Documentation/trace/ftrace.rst
View File

@ -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 event happened.
The absolute timestamp that the first latency was recorded in the window.
nmi-total:4 nmi-count:1
count:6
The number of times a latency was detected during the window.
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

2
drivers/Kconfig
View File

@ -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"

1
drivers/gpu/Makefile
View File

@ -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/

4
drivers/gpu/trace/Kconfig Normal file
View File

@ -0,0 +1,4 @@
# SPDX-License-Identifier: GPL-2.0-only
config TRACE_GPU_MEM
bool

3
drivers/gpu/trace/Makefile Normal file
View File

@ -0,0 +1,3 @@
# SPDX-License-Identifier: GPL-2.0
obj-$(CONFIG_TRACE_GPU_MEM) += trace_gpu_mem.o

13
drivers/gpu/trace/trace_gpu_mem.c Normal file
View File

@ -0,0 +1,13 @@
// 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);

3
include/linux/bootconfig.h
View File

@ -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);

4
include/linux/ring_buffer.h
View File

@ -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);

2
include/linux/trace_events.h
View File

@ -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;

57
include/trace/events/gpu_mem.h Normal file
View File

@ -0,0 +1,57 @@
/* 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>

14
init/main.c
View File

@ -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");

200
kernel/trace/ftrace.c
View File

@ -102,7 +102,7 @@ static bool ftrace_pids_enabled(struct ftrace_ops *ops)
tr = ops->private;
return tr->function_pids != NULL;
return tr->function_pids != NULL || tr->function_no_pids != NULL;
}
static void ftrace_update_trampoline(struct ftrace_ops *ops);
@ -139,13 +139,23 @@ static inline void ftrace_ops_init(struct ftrace_ops *ops)
#endif
}
#define FTRACE_PID_IGNORE -1
#define FTRACE_PID_TRACE -2
static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip,
struct ftrace_ops *op, struct pt_regs *regs)
{
struct trace_array *tr = op->private;
int pid;
if (tr && this_cpu_read(tr->array_buffer.data->ftrace_ignore_pid))
return;
if (tr) {
pid = this_cpu_read(tr->array_buffer.data->ftrace_ignore_pid);
if (pid == FTRACE_PID_IGNORE)
return;
if (pid != FTRACE_PID_TRACE &&
pid != current->pid)
return;
}
op->saved_func(ip, parent_ip, op, regs);
}
@ -6923,11 +6933,17 @@ ftrace_filter_pid_sched_switch_probe(void *data, bool preempt,
{
struct trace_array *tr = data;
struct trace_pid_list *pid_list;
struct trace_pid_list *no_pid_list;
pid_list = rcu_dereference_sched(tr->function_pids);
no_pid_list = rcu_dereference_sched(tr->function_no_pids);
this_cpu_write(tr->array_buffer.data->ftrace_ignore_pid,
trace_ignore_this_task(pid_list, next));
if (trace_ignore_this_task(pid_list, no_pid_list, next))
this_cpu_write(tr->array_buffer.data->ftrace_ignore_pid,
FTRACE_PID_IGNORE);
else
this_cpu_write(tr->array_buffer.data->ftrace_ignore_pid,
next->pid);
}
static void
@ -6940,6 +6956,9 @@ ftrace_pid_follow_sched_process_fork(void *data,
pid_list = rcu_dereference_sched(tr->function_pids);
trace_filter_add_remove_task(pid_list, self, task);
pid_list = rcu_dereference_sched(tr->function_no_pids);
trace_filter_add_remove_task(pid_list, self, task);
}
static void
@ -6950,6 +6969,9 @@ ftrace_pid_follow_sched_process_exit(void *data, struct task_struct *task)
pid_list = rcu_dereference_sched(tr->function_pids);
trace_filter_add_remove_task(pid_list, NULL, task);
pid_list = rcu_dereference_sched(tr->function_no_pids);
trace_filter_add_remove_task(pid_list, NULL, task);
}
void ftrace_pid_follow_fork(struct trace_array *tr, bool enable)
@ -6967,42 +6989,57 @@ void ftrace_pid_follow_fork(struct trace_array *tr, bool enable)
}
}
static void clear_ftrace_pids(struct trace_array *tr)
static void clear_ftrace_pids(struct trace_array *tr, int type)
{
struct trace_pid_list *pid_list;
struct trace_pid_list *no_pid_list;
int cpu;
pid_list = rcu_dereference_protected(tr->function_pids,
lockdep_is_held(&ftrace_lock));
if (!pid_list)
no_pid_list = rcu_dereference_protected(tr->function_no_pids,
lockdep_is_held(&ftrace_lock));
/* Make sure there's something to do */
if (!pid_type_enabled(type, pid_list, no_pid_list))
return;
unregister_trace_sched_switch(ftrace_filter_pid_sched_switch_probe, tr);
/* See if the pids still need to be checked after this */
if (!still_need_pid_events(type, pid_list, no_pid_list)) {
unregister_trace_sched_switch(ftrace_filter_pid_sched_switch_probe, tr);
for_each_possible_cpu(cpu)
per_cpu_ptr(tr->array_buffer.data, cpu)->ftrace_ignore_pid = FTRACE_PID_TRACE;
}
for_each_possible_cpu(cpu)
per_cpu_ptr(tr->array_buffer.data, cpu)->ftrace_ignore_pid = false;
if (type & TRACE_PIDS)
rcu_assign_pointer(tr->function_pids, NULL);
rcu_assign_pointer(tr->function_pids, NULL);
if (type & TRACE_NO_PIDS)
rcu_assign_pointer(tr->function_no_pids, NULL);
/* Wait till all users are no longer using pid filtering */
synchronize_rcu();
trace_free_pid_list(pid_list);
if ((type & TRACE_PIDS) && pid_list)
trace_free_pid_list(pid_list);
if ((type & TRACE_NO_PIDS) && no_pid_list)
trace_free_pid_list(no_pid_list);
}
void ftrace_clear_pids(struct trace_array *tr)
{
mutex_lock(&ftrace_lock);
clear_ftrace_pids(tr);
clear_ftrace_pids(tr, TRACE_PIDS | TRACE_NO_PIDS);
mutex_unlock(&ftrace_lock);
}
static void ftrace_pid_reset(struct trace_array *tr)
static void ftrace_pid_reset(struct trace_array *tr, int type)
{
mutex_lock(&ftrace_lock);
clear_ftrace_pids(tr);
clear_ftrace_pids(tr, type);
ftrace_update_pid_func();
ftrace_startup_all(0);
@ -7066,9 +7103,45 @@ static const struct seq_operations ftrace_pid_sops = {
.show = fpid_show,
};
static int
ftrace_pid_open(struct inode *inode, struct file *file)
static void *fnpid_start(struct seq_file *m, loff_t *pos)
__acquires(RCU)
{
struct trace_pid_list *pid_list;
struct trace_array *tr = m->private;
mutex_lock(&ftrace_lock);
rcu_read_lock_sched();
pid_list = rcu_dereference_sched(tr->function_no_pids);
if (!pid_list)
return !(*pos) ? FTRACE_NO_PIDS : NULL;
return trace_pid_start(pid_list, pos);
}
static void *fnpid_next(struct seq_file *m, void *v, loff_t *pos)
{
struct trace_array *tr = m->private;
struct trace_pid_list *pid_list = rcu_dereference_sched(tr->function_no_pids);
if (v == FTRACE_NO_PIDS) {
(*pos)++;
return NULL;
}
return trace_pid_next(pid_list, v, pos);
}
static const struct seq_operations ftrace_no_pid_sops = {
.start = fnpid_start,
.next = fnpid_next,
.stop = fpid_stop,
.show = fpid_show,
};
static int pid_open(struct inode *inode, struct file *file, int type)
{
const struct seq_operations *seq_ops;
struct trace_array *tr = inode->i_private;
struct seq_file *m;
int ret = 0;
@ -7079,9 +7152,18 @@ ftrace_pid_open(struct inode *inode, struct file *file)
if ((file->f_mode & FMODE_WRITE) &&
(file->f_flags & O_TRUNC))
ftrace_pid_reset(tr);
ftrace_pid_reset(tr, type);
ret = seq_open(file, &ftrace_pid_sops);
switch (type) {
case TRACE_PIDS:
seq_ops = &ftrace_pid_sops;
break;
case TRACE_NO_PIDS:
seq_ops = &ftrace_no_pid_sops;
break;
}
ret = seq_open(file, seq_ops);
if (ret < 0) {
trace_array_put(tr);
} else {
@ -7093,10 +7175,23 @@ ftrace_pid_open(struct inode *inode, struct file *file)
return ret;
}
static int
ftrace_pid_open(struct inode *inode, struct file *file)
{
return pid_open(inode, file, TRACE_PIDS);
}
static int
ftrace_no_pid_open(struct inode *inode, struct file *file)
{
return pid_open(inode, file, TRACE_NO_PIDS);
}
static void ignore_task_cpu(void *data)
{
struct trace_array *tr = data;
struct trace_pid_list *pid_list;
struct trace_pid_list *no_pid_list;
/*
* This function is called by on_each_cpu() while the
@ -7104,18 +7199,25 @@ static void ignore_task_cpu(void *data)
*/
pid_list = rcu_dereference_protected(tr->function_pids,
mutex_is_locked(&ftrace_lock));
no_pid_list = rcu_dereference_protected(tr->function_no_pids,
mutex_is_locked(&ftrace_lock));
this_cpu_write(tr->array_buffer.data->ftrace_ignore_pid,
trace_ignore_this_task(pid_list, current));
if (trace_ignore_this_task(pid_list, no_pid_list, current))
this_cpu_write(tr->array_buffer.data->ftrace_ignore_pid,
FTRACE_PID_IGNORE);
else
this_cpu_write(tr->array_buffer.data->ftrace_ignore_pid,
current->pid);
}
static ssize_t
ftrace_pid_write(struct file *filp, const char __user *ubuf,
size_t cnt, loff_t *ppos)
pid_write(struct file *filp, const char __user *ubuf,
size_t cnt, loff_t *ppos, int type)
{
struct seq_file *m = filp->private_data;
struct trace_array *tr = m->private;
struct trace_pid_list *filtered_pids = NULL;
struct trace_pid_list *filtered_pids;
struct trace_pid_list *other_pids;
struct trace_pid_list *pid_list;
ssize_t ret;
@ -7124,19 +7226,39 @@ ftrace_pid_write(struct file *filp, const char __user *ubuf,
mutex_lock(&ftrace_lock);
filtered_pids = rcu_dereference_protected(tr->function_pids,
switch (type) {
case TRACE_PIDS:
filtered_pids = rcu_dereference_protected(tr->function_pids,
lockdep_is_held(&ftrace_lock));
other_pids = rcu_dereference_protected(tr->function_no_pids,
lockdep_is_held(&ftrace_lock));
break;
case TRACE_NO_PIDS:
filtered_pids = rcu_dereference_protected(tr->function_no_pids,
lockdep_is_held(&ftrace_lock));
other_pids = rcu_dereference_protected(tr->function_pids,
lockdep_is_held(&ftrace_lock));
break;
}
ret = trace_pid_write(filtered_pids, &pid_list, ubuf, cnt);
if (ret < 0)
goto out;
rcu_assign_pointer(tr->function_pids, pid_list);
switch (type) {
case TRACE_PIDS:
rcu_assign_pointer(tr->function_pids, pid_list);
break;
case TRACE_NO_PIDS:
rcu_assign_pointer(tr->function_no_pids, pid_list);
break;
}
if (filtered_pids) {
synchronize_rcu();
trace_free_pid_list(filtered_pids);
} else if (pid_list) {
} else if (pid_list && !other_pids) {
/* Register a probe to set whether to ignore the tracing of a task */
register_trace_sched_switch(ftrace_filter_pid_sched_switch_probe, tr);
}
@ -7159,6 +7281,20 @@ ftrace_pid_write(struct file *filp, const char __user *ubuf,
return ret;
}
static ssize_t
ftrace_pid_write(struct file *filp, const char __user *ubuf,
size_t cnt, loff_t *ppos)
{
return pid_write(filp, ubuf, cnt, ppos, TRACE_PIDS);
}
static ssize_t
ftrace_no_pid_write(struct file *filp, const char __user *ubuf,
size_t cnt, loff_t *ppos)
{
return pid_write(filp, ubuf, cnt, ppos, TRACE_NO_PIDS);
}
static int
ftrace_pid_release(struct inode *inode, struct file *file)
{
@ -7177,10 +7313,20 @@ static const struct file_operations ftrace_pid_fops = {
.release = ftrace_pid_release,
};
static const struct file_operations ftrace_no_pid_fops = {
.open = ftrace_no_pid_open,
.write = ftrace_no_pid_write,
.read = seq_read,
.llseek = tracing_lseek,
.release = ftrace_pid_release,
};
void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d_tracer)
{
trace_create_file("set_ftrace_pid", 0644, d_tracer,
tr, &ftrace_pid_fops);
trace_create_file("set_ftrace_notrace_pid", 0644, d_tracer,
tr, &ftrace_no_pid_fops);
}
void __init ftrace_init_tracefs_toplevel(struct trace_array *tr,

243
kernel/trace/ring_buffer.c
View File

@ -441,6 +441,7 @@ enum {
struct ring_buffer_per_cpu {
int cpu;
atomic_t record_disabled;
atomic_t resize_disabled;
struct trace_buffer *buffer;
raw_spinlock_t reader_lock; /* serialize readers */
arch_spinlock_t lock;
@ -484,7 +485,6 @@ struct trace_buffer {
unsigned flags;
int cpus;
atomic_t record_disabled;
atomic_t resize_disabled;
cpumask_var_t cpumask;
struct lock_class_key *reader_lock_key;
@ -503,10 +503,14 @@ struct trace_buffer {
struct ring_buffer_iter {
struct ring_buffer_per_cpu *cpu_buffer;
unsigned long head;
unsigned long next_event;
struct buffer_page *head_page;
struct buffer_page *cache_reader_page;
unsigned long cache_read;
u64 read_stamp;
u64 page_stamp;
struct ring_buffer_event *event;
int missed_events;
};
/**
@ -1737,18 +1741,24 @@ int ring_buffer_resize(struct trace_buffer *buffer, unsigned long size,
size = nr_pages * BUF_PAGE_SIZE;
/*
* Don't succeed if resizing is disabled, as a reader might be
* manipulating the ring buffer and is expecting a sane state while
* this is true.
*/
if (atomic_read(&buffer->resize_disabled))
return -EBUSY;
/* prevent another thread from changing buffer sizes */
mutex_lock(&buffer->mutex);
if (cpu_id == RING_BUFFER_ALL_CPUS) {
/*
* Don't succeed if resizing is disabled, as a reader might be
* manipulating the ring buffer and is expecting a sane state while
* this is true.
*/
for_each_buffer_cpu(buffer, cpu) {
cpu_buffer = buffer->buffers[cpu];
if (atomic_read(&cpu_buffer->resize_disabled)) {
err = -EBUSY;
goto out_err_unlock;
}
}
/* calculate the pages to update */
for_each_buffer_cpu(buffer, cpu) {
cpu_buffer = buffer->buffers[cpu];
@ -1816,6 +1826,16 @@ int ring_buffer_resize(struct trace_buffer *buffer, unsigned long size,
if (nr_pages == cpu_buffer->nr_pages)
goto out;
/*
* Don't succeed if resizing is disabled, as a reader might be
* manipulating the ring buffer and is expecting a sane state while
* this is true.
*/
if (atomic_read(&cpu_buffer->resize_disabled)) {
err = -EBUSY;
goto out_err_unlock;
}
cpu_buffer->nr_pages_to_update = nr_pages -
cpu_buffer->nr_pages;
@ -1885,6 +1905,7 @@ int ring_buffer_resize(struct trace_buffer *buffer, unsigned long size,
free_buffer_page(bpage);
}
}
out_err_unlock:
mutex_unlock(&buffer->mutex);
return err;
}
@ -1913,17 +1934,65 @@ rb_reader_event(struct ring_buffer_per_cpu *cpu_buffer)
cpu_buffer->reader_page->read);
}
static __always_inline struct ring_buffer_event *
rb_iter_head_event(struct ring_buffer_iter *iter)
{
return __rb_page_index(iter->head_page, iter->head);
}
static __always_inline unsigned rb_page_commit(struct buffer_page *bpage)
{
return local_read(&bpage->page->commit);
}
static struct ring_buffer_event *
rb_iter_head_event(struct ring_buffer_iter *iter)
{
struct ring_buffer_event *event;
struct buffer_page *iter_head_page = iter->head_page;
unsigned long commit;
unsigned length;
if (iter->head != iter->next_event)
return iter->event;
/*
* When the writer goes across pages, it issues a cmpxchg which
* is a mb(), which will synchronize with the rmb here.
* (see rb_tail_page_update() and __rb_reserve_next())
*/
commit = rb_page_commit(iter_head_page);
smp_rmb();
event = __rb_page_index(iter_head_page, iter->head);
length = rb_event_length(event);
/*
* READ_ONCE() doesn't work on functions and we don't want the
* compiler doing any crazy optimizations with length.
*/
barrier();
if ((iter->head + length) > commit || length > BUF_MAX_DATA_SIZE)
/* Writer corrupted the read? */
goto reset;
memcpy(iter->event, event, length);
/*
* If the page stamp is still the same after this rmb() then the
* event was safely copied without the writer entering the page.
*/
smp_rmb();
/* Make sure the page didn't change since we read this */
if (iter->page_stamp != iter_head_page->page->time_stamp ||
commit > rb_page_commit(iter_head_page))
goto reset;
iter->next_event = iter->head + length;
return iter->event;
reset:
/* Reset to the beginning */
iter->page_stamp = iter->read_stamp = iter->head_page->page->time_stamp;
iter->head = 0;
iter->next_event = 0;
iter->missed_events = 1;
return NULL;
}
/* Size is determined by what has been committed */
static __always_inline unsigned rb_page_size(struct buffer_page *bpage)
{
@ -1959,8 +2028,9 @@ static void rb_inc_iter(struct ring_buffer_iter *iter)
else
rb_inc_page(cpu_buffer, &iter->head_page);
iter->read_stamp = iter->head_page->page->time_stamp;
iter->page_stamp = iter->read_stamp = iter->head_page->page->time_stamp;
iter->head = 0;
iter->next_event = 0;
}
/*
@ -3547,14 +3617,18 @@ static void rb_iter_reset(struct ring_buffer_iter *iter)
/* Iterator usage is expected to have record disabled */
iter->head_page = cpu_buffer->reader_page;
iter->head = cpu_buffer->reader_page->read;
iter->next_event = iter->head;
iter->cache_reader_page = iter->head_page;
iter->cache_read = cpu_buffer->read;
if (iter->head)
if (iter->head) {
iter->read_stamp = cpu_buffer->read_stamp;
else
iter->page_stamp = cpu_buffer->reader_page->page->time_stamp;
} else {
iter->read_stamp = iter->head_page->page->time_stamp;
iter->page_stamp = iter->read_stamp;
}
}
/**
@ -3590,17 +3664,38 @@ int ring_buffer_iter_empty(struct ring_buffer_iter *iter)
struct buffer_page *reader;
struct buffer_page *head_page;
struct buffer_page *commit_page;
struct buffer_page *curr_commit_page;
unsigned commit;
u64 curr_commit_ts;
u64 commit_ts;
cpu_buffer = iter->cpu_buffer;
/* Remember, trace recording is off when iterator is in use */
reader = cpu_buffer->reader_page;
head_page = cpu_buffer->head_page;
commit_page = cpu_buffer->commit_page;
commit = rb_page_commit(commit_page);
commit_ts = commit_page->page->time_stamp;
return ((iter->head_page == commit_page && iter->head == commit) ||
/*
* When the writer goes across pages, it issues a cmpxchg which
* is a mb(), which will synchronize with the rmb here.
* (see rb_tail_page_update())
*/
smp_rmb();
commit = rb_page_commit(commit_page);
/* We want to make sure that the commit page doesn't change */
smp_rmb();
/* Make sure commit page didn't change */
curr_commit_page = READ_ONCE(cpu_buffer->commit_page);
curr_commit_ts = READ_ONCE(curr_commit_page->page->time_stamp);
/* If the commit page changed, then there's more data */
if (curr_commit_page != commit_page ||
curr_commit_ts != commit_ts)
return 0;
/* Still racy, as it may return a false positive, but that's OK */
return ((iter->head_page == commit_page && iter->head >= commit) ||
(iter->head_page == reader && commit_page == head_page &&
head_page->read == commit &&
iter->head == rb_page_commit(cpu_buffer->reader_page)));
@ -3828,15 +3923,22 @@ static void rb_advance_reader(struct ring_buffer_per_cpu *cpu_buffer)
static void rb_advance_iter(struct ring_buffer_iter *iter)
{
struct ring_buffer_per_cpu *cpu_buffer;
struct ring_buffer_event *event;
unsigned length;
cpu_buffer = iter->cpu_buffer;
/* If head == next_event then we need to jump to the next event */
if (iter->head == iter->next_event) {
/* If the event gets overwritten again, there's nothing to do */
if (rb_iter_head_event(iter) == NULL)
return;
}
iter->head = iter->next_event;
/*
* Check if we are at the end of the buffer.
*/
if (iter->head >= rb_page_size(iter->head_page)) {
if (iter->next_event >= rb_page_size(iter->head_page)) {
/* discarded commits can make the page empty */
if (iter->head_page == cpu_buffer->commit_page)
return;
@ -3844,27 +3946,7 @@ static void rb_advance_iter(struct ring_buffer_iter *iter)
return;
}
event = rb_iter_head_event(iter);
length = rb_event_length(event);
/*
* This should not be called to advance the header if we are
* at the tail of the buffer.
*/
if (RB_WARN_ON(cpu_buffer,
(iter->head_page == cpu_buffer->commit_page) &&
(iter->head + length > rb_commit_index(cpu_buffer))))
return;
rb_update_iter_read_stamp(iter, event);
iter->head += length;
/* check for end of page padding */
if ((iter->head >= rb_page_size(iter->head_page)) &&
(iter->head_page != cpu_buffer->commit_page))
rb_inc_iter(iter);
rb_update_iter_read_stamp(iter, iter->event);
}
static int rb_lost_events(struct ring_buffer_per_cpu *cpu_buffer)
@ -3952,6 +4034,7 @@ rb_iter_peek(struct ring_buffer_iter *iter, u64 *ts)
struct ring_buffer_per_cpu *cpu_buffer;
struct ring_buffer_event *event;
int nr_loops = 0;
bool failed = false;
if (ts)
*ts = 0;
@ -3978,10 +4061,14 @@ rb_iter_peek(struct ring_buffer_iter *iter, u64 *ts)
* to a data event, we should never loop more than three times.
* Once for going to next page, once on time extend, and
* finally once to get the event.
* (We never hit the following condition more than thrice).
* We should never hit the following condition more than thrice,
* unless the buffer is very small, and there's a writer
* that is causing the reader to fail getting an event.
*/
if (RB_WARN_ON(cpu_buffer, ++nr_loops > 3))
if (++nr_loops > 3) {
RB_WARN_ON(cpu_buffer, !failed);
return NULL;
}
if (rb_per_cpu_empty(cpu_buffer))
return NULL;
@ -3992,6 +4079,10 @@ rb_iter_peek(struct ring_buffer_iter *iter, u64 *ts)
}
event = rb_iter_head_event(iter);
if (!event) {
failed = true;
goto again;
}
switch (event->type_len) {
case RINGBUF_TYPE_PADDING:
@ -4102,6 +4193,20 @@ ring_buffer_peek(struct trace_buffer *buffer, int cpu, u64 *ts,
return event;
}
/** ring_buffer_iter_dropped - report if there are dropped events
* @iter: The ring buffer iterator
*
* Returns true if there was dropped events since the last peek.
*/
bool ring_buffer_iter_dropped(struct ring_buffer_iter *iter)
{
bool ret = iter->missed_events != 0;
iter->missed_events = 0;
return ret;
}
EXPORT_SYMBOL_GPL(ring_buffer_iter_dropped);
/**
* ring_buffer_iter_peek - peek at the next event to be read
* @iter: The ring buffer iterator
@ -4208,16 +4313,21 @@ ring_buffer_read_prepare(struct trace_buffer *buffer, int cpu, gfp_t flags)
if (!cpumask_test_cpu(cpu, buffer->cpumask))
return NULL;
iter = kmalloc(sizeof(*iter), flags);
iter = kzalloc(sizeof(*iter), flags);
if (!iter)
return NULL;
iter->event = kmalloc(BUF_MAX_DATA_SIZE, flags);
if (!iter->event) {
kfree(iter);
return NULL;
}
cpu_buffer = buffer->buffers[cpu];
iter->cpu_buffer = cpu_buffer;
atomic_inc(&buffer->resize_disabled);
atomic_inc(&cpu_buffer->record_disabled);
atomic_inc(&cpu_buffer->resize_disabled);
return iter;
}
@ -4290,42 +4400,31 @@ ring_buffer_read_finish(struct ring_buffer_iter *iter)
rb_check_pages(cpu_buffer);
raw_spin_unlock_irqrestore(&cpu_buffer->reader_lock, flags);
atomic_dec(&cpu_buffer->record_disabled);
atomic_dec(&cpu_buffer->buffer->resize_disabled);
atomic_dec(&cpu_buffer->resize_disabled);
kfree(iter->event);
kfree(iter);
}
EXPORT_SYMBOL_GPL(ring_buffer_read_finish);
/**
* ring_buffer_read - read the next item in the ring buffer by the iterator
* ring_buffer_iter_advance - advance the iterator to the next location
* @iter: The ring buffer iterator
* @ts: The time stamp of the event read.
*
* This reads the next event in the ring buffer and increments the iterator.
* Move the location of the iterator such that the next read will
* be the next location of the iterator.
*/
struct ring_buffer_event *
ring_buffer_read(struct ring_buffer_iter *iter, u64 *ts)
void ring_buffer_iter_advance(struct ring_buffer_iter *iter)
{
struct ring_buffer_event *event;
struct ring_buffer_per_cpu *cpu_buffer = iter->cpu_buffer;
unsigned long flags;
raw_spin_lock_irqsave(&cpu_buffer->reader_lock, flags);
again:
event = rb_iter_peek(iter, ts);
if (!event)
goto out;
if (event->type_len == RINGBUF_TYPE_PADDING)
goto again;
rb_advance_iter(iter);
out:
raw_spin_unlock_irqrestore(&cpu_buffer->reader_lock, flags);
return event;
raw_spin_unlock_irqrestore(&cpu_buffer->reader_lock, flags);
}
EXPORT_SYMBOL_GPL(ring_buffer_read);
EXPORT_SYMBOL_GPL(ring_buffer_iter_advance);
/**
* ring_buffer_size - return the size of the ring buffer (in bytes)
@ -4406,7 +4505,7 @@ void ring_buffer_reset_cpu(struct trace_buffer *buffer, int cpu)
if (!cpumask_test_cpu(cpu, buffer->cpumask))
return;
atomic_inc(&buffer->resize_disabled);
atomic_inc(&cpu_buffer->resize_disabled);
atomic_inc(&cpu_buffer->record_disabled);
/* Make sure all commits have finished */
@ -4427,7 +4526,7 @@ void ring_buffer_reset_cpu(struct trace_buffer *buffer, int cpu)
raw_spin_unlock_irqrestore(&cpu_buffer->reader_lock, flags);
atomic_dec(&cpu_buffer->record_disabled);
atomic_dec(&buffer->resize_disabled);
atomic_dec(&cpu_buffer->resize_disabled);
}
EXPORT_SYMBOL_GPL(ring_buffer_reset_cpu);

110
kernel/trace/trace.c
View File

@ -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();

39
kernel/trace/trace.h
View File

@ -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 \

4
kernel/trace/trace_entries.h
View File

@ -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)
);

280
kernel/trace/trace_events.c
View File

@ -232,10 +232,13 @@ bool trace_event_ignore_this_pid(struct trace_event_file *trace_file)
{
struct trace_array *tr = trace_file->tr;
struct trace_array_cpu *data;
struct trace_pid_list *no_pid_list;
struct trace_pid_list *pid_list;
pid_list = rcu_dereference_raw(tr->filtered_pids);
if (!pid_list)
no_pid_list = rcu_dereference_raw(tr->filtered_no_pids);
if (!pid_list && !no_pid_list)
return false;
data = this_cpu_ptr(tr->array_buffer.data);
@ -510,6 +513,9 @@ event_filter_pid_sched_process_exit(void *data, struct task_struct *task)
pid_list = rcu_dereference_raw(tr->filtered_pids);
trace_filter_add_remove_task(pid_list, NULL, task);
pid_list = rcu_dereference_raw(tr->filtered_no_pids);
trace_filter_add_remove_task(pid_list, NULL, task);
}
static void
@ -522,6 +528,9 @@ event_filter_pid_sched_process_fork(void *data,
pid_list = rcu_dereference_sched(tr->filtered_pids);
trace_filter_add_remove_task(pid_list, self, task);
pid_list = rcu_dereference_sched(tr->filtered_no_pids);
trace_filter_add_remove_task(pid_list, self, task);
}
void trace_event_follow_fork(struct trace_array *tr, bool enable)
@ -544,13 +553,23 @@ event_filter_pid_sched_switch_probe_pre(void *data, bool preempt,
struct task_struct *prev, struct task_struct *next)
{
struct trace_array *tr = data;
struct trace_pid_list *no_pid_list;
struct trace_pid_list *pid_list;
bool ret;
pid_list = rcu_dereference_sched(tr->filtered_pids);
no_pid_list = rcu_dereference_sched(tr->filtered_no_pids);
this_cpu_write(tr->array_buffer.data->ignore_pid,
trace_ignore_this_task(pid_list, prev) &&
trace_ignore_this_task(pid_list, next));
/*
* Sched switch is funny, as we only want to ignore it
* in the notrace case if both prev and next should be ignored.
*/
ret = trace_ignore_this_task(NULL, no_pid_list, prev) &&
trace_ignore_this_task(NULL, no_pid_list, next);
this_cpu_write(tr->array_buffer.data->ignore_pid, ret ||
(trace_ignore_this_task(pid_list, NULL, prev) &&
trace_ignore_this_task(pid_list, NULL, next)));
}
static void
@ -558,18 +577,21 @@ event_filter_pid_sched_switch_probe_post(void *data, bool preempt,
struct task_struct *prev, struct task_struct *next)
{
struct trace_array *tr = data;
struct trace_pid_list *no_pid_list;
struct trace_pid_list *pid_list;
pid_list = rcu_dereference_sched(tr->filtered_pids);
no_pid_list = rcu_dereference_sched(tr->filtered_no_pids);
this_cpu_write(tr->array_buffer.data->ignore_pid,
trace_ignore_this_task(pid_list, next));
trace_ignore_this_task(pid_list, no_pid_list, next));
}
static void
event_filter_pid_sched_wakeup_probe_pre(void *data, struct task_struct *task)
{
struct trace_array *tr = data;
struct trace_pid_list *no_pid_list;
struct trace_pid_list *pid_list;
/* Nothing to do if we are already tracing */
@ -577,15 +599,17 @@ event_filter_pid_sched_wakeup_probe_pre(void *data, struct task_struct *task)
return;
pid_list = rcu_dereference_sched(tr->filtered_pids);
no_pid_list = rcu_dereference_sched(tr->filtered_no_pids);
this_cpu_write(tr->array_buffer.data->ignore_pid,
trace_ignore_this_task(pid_list, task));
trace_ignore_this_task(pid_list, no_pid_list, task));
}
static void
event_filter_pid_sched_wakeup_probe_post(void *data, struct task_struct *task)
{
struct trace_array *tr = data;
struct trace_pid_list *no_pid_list;
struct trace_pid_list *pid_list;
/* Nothing to do if we are not tracing */
@ -593,23 +617,15 @@ event_filter_pid_sched_wakeup_probe_post(void *data, struct task_struct *task)
return;
pid_list = rcu_dereference_sched(tr->filtered_pids);
no_pid_list = rcu_dereference_sched(tr->filtered_no_pids);
/* Set tracing if current is enabled */
this_cpu_write(tr->array_buffer.data->ignore_pid,
trace_ignore_this_task(pid_list, current));
trace_ignore_this_task(pid_list, no_pid_list, current));
}
static void __ftrace_clear_event_pids(struct trace_array *tr)
static void unregister_pid_events(struct trace_array *tr)
{
struct trace_pid_list *pid_list;
struct trace_event_file *file;
int cpu;
pid_list = rcu_dereference_protected(tr->filtered_pids,
lockdep_is_held(&event_mutex));
if (!pid_list)
return;
unregister_trace_sched_switch(event_filter_pid_sched_switch_probe_pre, tr);
unregister_trace_sched_switch(event_filter_pid_sched_switch_probe_post, tr);
@ -621,26 +637,55 @@ static void __ftrace_clear_event_pids(struct trace_array *tr)
unregister_trace_sched_waking(event_filter_pid_sched_wakeup_probe_pre, tr);
unregister_trace_sched_waking(event_filter_pid_sched_wakeup_probe_post, tr);
}
list_for_each_entry(file, &tr->events, list) {
clear_bit(EVENT_FILE_FL_PID_FILTER_BIT, &file->flags);
static void __ftrace_clear_event_pids(struct trace_array *tr, int type)
{
struct trace_pid_list *pid_list;
struct trace_pid_list *no_pid_list;
struct trace_event_file *file;
int cpu;
pid_list = rcu_dereference_protected(tr->filtered_pids,
lockdep_is_held(&event_mutex));
no_pid_list = rcu_dereference_protected(tr->filtered_no_pids,
lockdep_is_held(&event_mutex));
/* Make sure there's something to do */
if (!pid_type_enabled(type, pid_list, no_pid_list))
return;
if (!still_need_pid_events(type, pid_list, no_pid_list)) {
unregister_pid_events(tr);
list_for_each_entry(file, &tr->events, list) {
clear_bit(EVENT_FILE_FL_PID_FILTER_BIT, &file->flags);
}
for_each_possible_cpu(cpu)
per_cpu_ptr(tr->array_buffer.data, cpu)->ignore_pid = false;
}
for_each_possible_cpu(cpu)
per_cpu_ptr(tr->array_buffer.data, cpu)->ignore_pid = false;
if (type & TRACE_PIDS)
rcu_assign_pointer(tr->filtered_pids, NULL);
rcu_assign_pointer(tr->filtered_pids, NULL);
if (type & TRACE_NO_PIDS)
rcu_assign_pointer(tr->filtered_no_pids, NULL);
/* Wait till all users are no longer using pid filtering */
tracepoint_synchronize_unregister();
trace_free_pid_list(pid_list);
if ((type & TRACE_PIDS) && pid_list)
trace_free_pid_list(pid_list);
if ((type & TRACE_NO_PIDS) && no_pid_list)
trace_free_pid_list(no_pid_list);
}
static void ftrace_clear_event_pids(struct trace_array *tr)
static void ftrace_clear_event_pids(struct trace_array *tr, int type)
{
mutex_lock(&event_mutex);
__ftrace_clear_event_pids(tr);
__ftrace_clear_event_pids(tr, type);
mutex_unlock(&event_mutex);
}
@ -1013,15 +1058,32 @@ static void t_stop(struct seq_file *m, void *p)
}
static void *
p_next(struct seq_file *m, void *v, loff_t *pos)
__next(struct seq_file *m, void *v, loff_t *pos, int type)
{
struct trace_array *tr = m->private;
struct trace_pid_list *pid_list = rcu_dereference_sched(tr->filtered_pids);
struct trace_pid_list *pid_list;
if (type == TRACE_PIDS)
pid_list = rcu_dereference_sched(tr->filtered_pids);
else
pid_list = rcu_dereference_sched(tr->filtered_no_pids);
return trace_pid_next(pid_list, v, pos);
}
static void *p_start(struct seq_file *m, loff_t *pos)
static void *
p_next(struct seq_file *m, void *v, loff_t *pos)
{
return __next(m, v, pos, TRACE_PIDS);
}
static void *
np_next(struct seq_file *m, void *v, loff_t *pos)
{
return __next(m, v, pos, TRACE_NO_PIDS);
}
static void *__start(struct seq_file *m, loff_t *pos, int type)
__acquires(RCU)
{
struct trace_pid_list *pid_list;
@ -1036,7 +1098,10 @@ static void *p_start(struct seq_file *m, loff_t *pos)
mutex_lock(&event_mutex);
rcu_read_lock_sched();
pid_list = rcu_dereference_sched(tr->filtered_pids);
if (type == TRACE_PIDS)
pid_list = rcu_dereference_sched(tr->filtered_pids);
else
pid_list = rcu_dereference_sched(tr->filtered_no_pids);
if (!pid_list)
return NULL;
@ -1044,6 +1109,18 @@ static void *p_start(struct seq_file *m, loff_t *pos)
return trace_pid_start(pid_list, pos);
}
static void *p_start(struct seq_file *m, loff_t *pos)
__acquires(RCU)
{
return __start(m, pos, TRACE_PIDS);
}
static void *np_start(struct seq_file *m, loff_t *pos)
__acquires(RCU)
{
return __start(m, pos, TRACE_NO_PIDS);
}
static void p_stop(struct seq_file *m, void *p)
__releases(RCU)
{
@ -1588,6 +1665,7 @@ static void ignore_task_cpu(void *data)
{
struct trace_array *tr = data;
struct trace_pid_list *pid_list;
struct trace_pid_list *no_pid_list;
/*
* This function is called by on_each_cpu() while the
@ -1595,18 +1673,50 @@ static void ignore_task_cpu(void *data)
*/
pid_list = rcu_dereference_protected(tr->filtered_pids,
mutex_is_locked(&event_mutex));
no_pid_list = rcu_dereference_protected(tr->filtered_no_pids,
mutex_is_locked(&event_mutex));
this_cpu_write(tr->array_buffer.data->ignore_pid,
trace_ignore_this_task(pid_list, current));
trace_ignore_this_task(pid_list, no_pid_list, current));
}
static void register_pid_events(struct trace_array *tr)
{
/*
* Register a probe that is called before all other probes
* to set ignore_pid if next or prev do not match.
* Register a probe this is called after all other probes
* to only keep ignore_pid set if next pid matches.
*/
register_trace_prio_sched_switch(event_filter_pid_sched_switch_probe_pre,
tr, INT_MAX);
register_trace_prio_sched_switch(event_filter_pid_sched_switch_probe_post,
tr, 0);
register_trace_prio_sched_wakeup(event_filter_pid_sched_wakeup_probe_pre,
tr, INT_MAX);
register_trace_prio_sched_wakeup(event_filter_pid_sched_wakeup_probe_post,
tr, 0);
register_trace_prio_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_pre,
tr, INT_MAX);
register_trace_prio_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_post,
tr, 0);
register_trace_prio_sched_waking(event_filter_pid_sched_wakeup_probe_pre,
tr, INT_MAX);
register_trace_prio_sched_waking(event_filter_pid_sched_wakeup_probe_post,
tr, 0);
}
static ssize_t
ftrace_event_pid_write(struct file *filp, const char __user *ubuf,
size_t cnt, loff_t *ppos)
event_pid_write(struct file *filp, const char __user *ubuf,
size_t cnt, loff_t *ppos, int type)
{
struct seq_file *m = filp->private_data;
struct trace_array *tr = m->private;
struct trace_pid_list *filtered_pids = NULL;
struct trace_pid_list *other_pids = NULL;
struct trace_pid_list *pid_list;
struct trace_event_file *file;
ssize_t ret;
@ -1620,14 +1730,26 @@ ftrace_event_pid_write(struct file *filp, const char __user *ubuf,
mutex_lock(&event_mutex);
filtered_pids = rcu_dereference_protected(tr->filtered_pids,
lockdep_is_held(&event_mutex));
if (type == TRACE_PIDS) {
filtered_pids = rcu_dereference_protected(tr->filtered_pids,
lockdep_is_held(&event_mutex));
other_pids = rcu_dereference_protected(tr->filtered_no_pids,
lockdep_is_held(&event_mutex));
} else {
filtered_pids = rcu_dereference_protected(tr->filtered_no_pids,
lockdep_is_held(&event_mutex));
other_pids = rcu_dereference_protected(tr->filtered_pids,
lockdep_is_held(&event_mutex));
}
ret = trace_pid_write(filtered_pids, &pid_list, ubuf, cnt);
if (ret < 0)
goto out;
rcu_assign_pointer(tr->filtered_pids, pid_list);
if (type == TRACE_PIDS)
rcu_assign_pointer(tr->filtered_pids, pid_list);
else
rcu_assign_pointer(tr->filtered_no_pids, pid_list);
list_for_each_entry(file, &tr->events, list) {
set_bit(EVENT_FILE_FL_PID_FILTER_BIT, &file->flags);
@ -1636,32 +1758,8 @@ ftrace_event_pid_write(struct file *filp, const char __user *ubuf,
if (filtered_pids) {
tracepoint_synchronize_unregister();
trace_free_pid_list(filtered_pids);
} else if (pid_list) {
/*
* Register a probe that is called before all other probes
* to set ignore_pid if next or prev do not match.
* Register a probe this is called after all other probes
* to only keep ignore_pid set if next pid matches.
*/
register_trace_prio_sched_switch(event_filter_pid_sched_switch_probe_pre,
tr, INT_MAX);
register_trace_prio_sched_switch(event_filter_pid_sched_switch_probe_post,
tr, 0);
register_trace_prio_sched_wakeup(event_filter_pid_sched_wakeup_probe_pre,
tr, INT_MAX);
register_trace_prio_sched_wakeup(event_filter_pid_sched_wakeup_probe_post,
tr, 0);
register_trace_prio_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_pre,
tr, INT_MAX);
register_trace_prio_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_post,
tr, 0);
register_trace_prio_sched_waking(event_filter_pid_sched_wakeup_probe_pre,
tr, INT_MAX);
register_trace_prio_sched_waking(event_filter_pid_sched_wakeup_probe_post,
tr, 0);
} else if (pid_list && !other_pids) {
register_pid_events(tr);
}
/*
@ -1680,9 +1778,24 @@ ftrace_event_pid_write(struct file *filp, const char __user *ubuf,
return ret;
}
static ssize_t
ftrace_event_pid_write(struct file *filp, const char __user *ubuf,
size_t cnt, loff_t *ppos)
{
return event_pid_write(filp, ubuf, cnt, ppos, TRACE_PIDS);
}
static ssize_t
ftrace_event_npid_write(struct file *filp, const char __user *ubuf,
size_t cnt, loff_t *ppos)
{
return event_pid_write(filp, ubuf, cnt, ppos, TRACE_NO_PIDS);
}
static int ftrace_event_avail_open(struct inode *inode, struct file *file);
static int ftrace_event_set_open(struct inode *inode, struct file *file);
static int ftrace_event_set_pid_open(struct inode *inode, struct file *file);
static int ftrace_event_set_npid_open(struct inode *inode, struct file *file);
static int ftrace_event_release(struct inode *inode, struct file *file);
static const struct seq_operations show_event_seq_ops = {
@ -1706,6 +1819,13 @@ static const struct seq_operations show_set_pid_seq_ops = {
.stop = p_stop,
};
static const struct seq_operations show_set_no_pid_seq_ops = {
.start = np_start,
.next = np_next,
.show = trace_pid_show,
.stop = p_stop,
};
static const struct file_operations ftrace_avail_fops = {
.open = ftrace_event_avail_open,
.read = seq_read,
@ -1729,6 +1849,14 @@ static const struct file_operations ftrace_set_event_pid_fops = {
.release = ftrace_event_release,
};
static const struct file_operations ftrace_set_event_notrace_pid_fops = {
.open = ftrace_event_set_npid_open,
.read = seq_read,
.write = ftrace_event_npid_write,
.llseek = seq_lseek,
.release = ftrace_event_release,
};
static const struct file_operations ftrace_enable_fops = {
.open = tracing_open_generic,
.read = event_enable_read,
@ -1858,7 +1986,28 @@ ftrace_event_set_pid_open(struct inode *inode, struct file *file)
if ((file->f_mode & FMODE_WRITE) &&
(file->f_flags & O_TRUNC))
ftrace_clear_event_pids(tr);
ftrace_clear_event_pids(tr, TRACE_PIDS);
ret = ftrace_event_open(inode, file, seq_ops);
if (ret < 0)
trace_array_put(tr);
return ret;
}
static int
ftrace_event_set_npid_open(struct inode *inode, struct file *file)
{
const struct seq_operations *seq_ops = &show_set_no_pid_seq_ops;
struct trace_array *tr = inode->i_private;
int ret;
ret = tracing_check_open_get_tr(tr);
if (ret)
return ret;
if ((file->f_mode & FMODE_WRITE) &&
(file->f_flags & O_TRUNC))
ftrace_clear_event_pids(tr, TRACE_NO_PIDS);
ret = ftrace_event_open(inode, file, seq_ops);
if (ret < 0)
@ -3075,6 +3224,11 @@ create_event_toplevel_files(struct dentry *parent, struct trace_array *tr)
if (!entry)
pr_warn("Could not create tracefs 'set_event_pid' entry\n");
entry = tracefs_create_file("set_event_notrace_pid", 0644, parent,
tr, &ftrace_set_event_notrace_pid_fops);
if (!entry)
pr_warn("Could not create tracefs 'set_event_notrace_pid' entry\n");
/* ring buffer internal formats */
entry = trace_create_file("header_page", 0444, d_events,
ring_buffer_print_page_header,
@ -3158,7 +3312,7 @@ int event_trace_del_tracer(struct trace_array *tr)
clear_event_triggers(tr);
/* Clear the pid list */
__ftrace_clear_event_pids(tr);
__ftrace_clear_event_pids(tr, TRACE_PIDS | TRACE_NO_PIDS);
/* Disable any running events */
__ftrace_set_clr_event_nolock(tr, NULL, NULL, NULL, 0);

2
kernel/trace/trace_functions_graph.c
View File

@ -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;
}

24
kernel/trace/trace_hwlat.c
View File

@ -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);

2
kernel/trace/trace_kprobe.c
View File

@ -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));

19
kernel/trace/trace_output.c
View File

@ -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) {
/*

35
lib/bootconfig.c
View File

@ -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;

27
tools/bootconfig/Makefile
View File

@ -1,23 +1,30 @@
# 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)

35
tools/bootconfig/main.c
View File

@ -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);

14
tools/bootconfig/test-bootconfig.sh
View File

@ -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

125
tools/testing/selftests/ftrace/test.d/event/event-no-pid.tc Normal file
View File

@ -0,0 +1,125 @@
#!/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

108
tools/testing/selftests/ftrace/test.d/ftrace/func-filter-notrace-pid.tc Normal file
View File

@ -0,0 +1,108 @@
#!/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

2
tools/testing/selftests/ftrace/test.d/ftrace/func_traceonoff_triggers.tc
View File

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