linux/kernel/trace/trace_sched_switch.c

// SPDX-License-Identifier: GPL-2.0
/*
 * trace context switch
 *
 * Copyright (C) 2007 Steven Rostedt <[email protected]>
 *
 */
#include <linux/module.h>
#include <linux/kallsyms.h>
#include <linux/uaccess.h>
#include <linux/kmemleak.h>
#include <linux/ftrace.h>
#include <trace/events/sched.h>

#include "trace.h"

#define RECORD_CMDLINE …
#define RECORD_TGID …

static int		sched_cmdline_ref;
static int		sched_tgid_ref;
static DEFINE_MUTEX(sched_register_mutex);

static void
probe_sched_switch(void *ignore, bool preempt,
		   struct task_struct *prev, struct task_struct *next,
		   unsigned int prev_state)
{ … }

static void
probe_sched_wakeup(void *ignore, struct task_struct *wakee)
{ … }

static int tracing_sched_register(void)
{ … }

static void tracing_sched_unregister(void)
{ … }

static void tracing_start_sched_switch(int ops)
{ … }

static void tracing_stop_sched_switch(int ops)
{ … }

void tracing_start_cmdline_record(void)
{ … }

void tracing_stop_cmdline_record(void)
{ … }

void tracing_start_tgid_record(void)
{ … }

void tracing_stop_tgid_record(void)
{ … }

/*
 * The tgid_map array maps from pid to tgid; i.e. the value stored at index i
 * is the tgid last observed corresponding to pid=i.
 */
static int *tgid_map;

/* The maximum valid index into tgid_map. */
static size_t tgid_map_max;

#define SAVED_CMDLINES_DEFAULT …
#define NO_CMDLINE_MAP …
/*
 * Preemption must be disabled before acquiring trace_cmdline_lock.
 * The various trace_arrays' max_lock must be acquired in a context
 * where interrupt is disabled.
 */
static arch_spinlock_t trace_cmdline_lock = …;
struct saved_cmdlines_buffer { … };
static struct saved_cmdlines_buffer *savedcmd;

/* Holds the size of a cmdline and pid element */
#define SAVED_CMDLINE_MAP_ELEMENT_SIZE(s) …

static inline char *get_saved_cmdlines(int idx)
{ … }

static inline void set_cmdline(int idx, const char *cmdline)
{ … }

static void free_saved_cmdlines_buffer(struct saved_cmdlines_buffer *s)
{ … }

static struct saved_cmdlines_buffer *allocate_cmdlines_buffer(unsigned int val)
{ … }

int trace_create_savedcmd(void)
{ … }

int trace_save_cmdline(struct task_struct *tsk)
{ … }

static void __trace_find_cmdline(int pid, char comm[])
{ … }

void trace_find_cmdline(int pid, char comm[])
{ … }

static int *trace_find_tgid_ptr(int pid)
{ … }

int trace_find_tgid(int pid)
{ … }

static int trace_save_tgid(struct task_struct *tsk)
{ … }

static bool tracing_record_taskinfo_skip(int flags)
{ … }

/**
 * tracing_record_taskinfo - record the task info of a task
 *
 * @task:  task to record
 * @flags: TRACE_RECORD_CMDLINE for recording comm
 *         TRACE_RECORD_TGID for recording tgid
 */
void tracing_record_taskinfo(struct task_struct *task, int flags)
{ … }

/**
 * tracing_record_taskinfo_sched_switch - record task info for sched_switch
 *
 * @prev: previous task during sched_switch
 * @next: next task during sched_switch
 * @flags: TRACE_RECORD_CMDLINE for recording comm
 *         TRACE_RECORD_TGID for recording tgid
 */
void tracing_record_taskinfo_sched_switch(struct task_struct *prev,
					  struct task_struct *next, int flags)
{ … }

/* Helpers to record a specific task information */
void tracing_record_cmdline(struct task_struct *task)
{ … }

void tracing_record_tgid(struct task_struct *task)
{ … }

int trace_alloc_tgid_map(void)
{ … }

static void *saved_tgids_next(struct seq_file *m, void *v, loff_t *pos)
{ … }

static void *saved_tgids_start(struct seq_file *m, loff_t *pos)
{ … }

static void saved_tgids_stop(struct seq_file *m, void *v)
{ … }

static int saved_tgids_show(struct seq_file *m, void *v)
{ … }

static const struct seq_operations tracing_saved_tgids_seq_ops = …;

static int tracing_saved_tgids_open(struct inode *inode, struct file *filp)
{ … }


const struct file_operations tracing_saved_tgids_fops = …;

static void *saved_cmdlines_next(struct seq_file *m, void *v, loff_t *pos)
{ … }

static void *saved_cmdlines_start(struct seq_file *m, loff_t *pos)
{ … }

static void saved_cmdlines_stop(struct seq_file *m, void *v)
{ … }

static int saved_cmdlines_show(struct seq_file *m, void *v)
{ … }

static const struct seq_operations tracing_saved_cmdlines_seq_ops = …;

static int tracing_saved_cmdlines_open(struct inode *inode, struct file *filp)
{ … }

const struct file_operations tracing_saved_cmdlines_fops = …;

static ssize_t
tracing_saved_cmdlines_size_read(struct file *filp, char __user *ubuf,
				 size_t cnt, loff_t *ppos)
{ … }

void trace_free_saved_cmdlines_buffer(void)
{ … }

static int tracing_resize_saved_cmdlines(unsigned int val)
{ … }

static ssize_t
tracing_saved_cmdlines_size_write(struct file *filp, const char __user *ubuf,
				  size_t cnt, loff_t *ppos)
{ … }

const struct file_operations tracing_saved_cmdlines_size_fops = …;