linux/mm/mmap_lock.c

// SPDX-License-Identifier: GPL-2.0
#define CREATE_TRACE_POINTS
#include <trace/events/mmap_lock.h>

#include <linux/mm.h>
#include <linux/cgroup.h>
#include <linux/memcontrol.h>
#include <linux/mmap_lock.h>
#include <linux/mutex.h>
#include <linux/percpu.h>
#include <linux/rcupdate.h>
#include <linux/smp.h>
#include <linux/trace_events.h>
#include <linux/local_lock.h>

EXPORT_TRACEPOINT_SYMBOL(…);
EXPORT_TRACEPOINT_SYMBOL(…);
EXPORT_TRACEPOINT_SYMBOL(…);

#ifdef CONFIG_MEMCG

static atomic_t reg_refcount;

/*
 * Size of the buffer for memcg path names. Ignoring stack trace support,
 * trace_events_hist.c uses MAX_FILTER_STR_VAL for this, so we also use it.
 */
#define MEMCG_PATH_BUF_SIZE …

int trace_mmap_lock_reg(void)
{ … }

void trace_mmap_lock_unreg(void)
{ … }

#define TRACE_MMAP_LOCK_EVENT(type, mm, ...) …

#else /* !CONFIG_MEMCG */

int trace_mmap_lock_reg(void)
{
	return 0;
}

void trace_mmap_lock_unreg(void)
{
}

#define TRACE_MMAP_LOCK_EVENT …

#endif /* CONFIG_MEMCG */

#ifdef CONFIG_TRACING
#ifdef CONFIG_MEMCG
/*
 * Write the given mm_struct's memcg path to a buffer. If the path cannot be
 * determined or the trace event is being unregistered, empty string is written.
 */
static void get_mm_memcg_path(struct mm_struct *mm, char *buf, size_t buflen)
{ … }

#endif /* CONFIG_MEMCG */

/*
 * Trace calls must be in a separate file, as otherwise there's a circular
 * dependency between linux/mmap_lock.h and trace/events/mmap_lock.h.
 */

void __mmap_lock_do_trace_start_locking(struct mm_struct *mm, bool write)
{ … }
EXPORT_SYMBOL(…);

void __mmap_lock_do_trace_acquire_returned(struct mm_struct *mm, bool write,
					   bool success)
{ … }
EXPORT_SYMBOL(…);

void __mmap_lock_do_trace_released(struct mm_struct *mm, bool write)
{ … }
EXPORT_SYMBOL(…);
#endif /* CONFIG_TRACING */