path: root/lib/alloc_tag.c

// SPDX-License-Identifier: GPL-2.0-only
#include <linux/alloc_tag.h>
#include <linux/execmem.h>
#include <linux/fs.h>
#include <linux/gfp.h>
#include <linux/kallsyms.h>
#include <linux/module.h>
#include <linux/page_ext.h>
#include <linux/proc_fs.h>
#include <linux/seq_buf.h>
#include <linux/seq_file.h>
#include <linux/string_choices.h>
#include <linux/vmalloc.h>
#include <linux/kmemleak.h>

#define ALLOCINFO_FILE_NAME		"allocinfo"
#define MODULE_ALLOC_TAG_VMAP_SIZE	(100000UL * sizeof(struct alloc_tag))
#define SECTION_START(NAME)		(CODETAG_SECTION_START_PREFIX NAME)
#define SECTION_STOP(NAME)		(CODETAG_SECTION_STOP_PREFIX NAME)

#ifdef CONFIG_MEM_ALLOC_PROFILING_ENABLED_BY_DEFAULT
static bool mem_profiling_support = true;
#else
static bool mem_profiling_support;
#endif

static struct codetag_type *alloc_tag_cttype;

#ifdef CONFIG_ARCH_MODULE_NEEDS_WEAK_PER_CPU
DEFINE_PER_CPU(struct alloc_tag_counters, _shared_alloc_tag);
EXPORT_SYMBOL(_shared_alloc_tag);
#endif

DEFINE_STATIC_KEY_MAYBE(CONFIG_MEM_ALLOC_PROFILING_ENABLED_BY_DEFAULT,
			mem_alloc_profiling_key);
EXPORT_SYMBOL(mem_alloc_profiling_key);

DEFINE_STATIC_KEY_FALSE(mem_profiling_compressed);

struct alloc_tag_kernel_section kernel_tags = { NULL, 0 };
unsigned long alloc_tag_ref_mask;
int alloc_tag_ref_offs;

struct allocinfo_private {
	struct codetag_iterator iter;
	bool print_header;
};

static void *allocinfo_start(struct seq_file *m, loff_t *pos)
{
	struct allocinfo_private *priv;
	loff_t node = *pos;

	priv = (struct allocinfo_private *)m->private;
	codetag_lock_module_list(alloc_tag_cttype, true);
	if (node == 0) {
		priv->print_header = true;
		priv->iter = codetag_get_ct_iter(alloc_tag_cttype);
		codetag_next_ct(&priv->iter);
	}
	return priv->iter.ct ? priv : NULL;
}

static void *allocinfo_next(struct seq_file *m, void *arg, loff_t *pos)
{
	struct allocinfo_private *priv = (struct allocinfo_private *)arg;
	struct codetag *ct = codetag_next_ct(&priv->iter);

	(*pos)++;
	if (!ct)
		return NULL;

	return priv;
}

static void allocinfo_stop(struct seq_file *m, void *arg)
{
	codetag_lock_module_list(alloc_tag_cttype, false);
}

static void print_allocinfo_header(struct seq_buf *buf)
{
	/* Output format version, so we can change it. */
	seq_buf_printf(buf, "allocinfo - version: 2.0\n");
	seq_buf_printf(buf, "#     <size>  <calls> <tag info>\n");
}

static void alloc_tag_to_text(struct seq_buf *out, struct codetag *ct)
{
	struct alloc_tag *tag = ct_to_alloc_tag(ct);
	struct alloc_tag_counters counter = alloc_tag_read(tag);
	s64 bytes = counter.bytes;

	seq_buf_printf(out, "%12lli %8llu ", bytes, counter.calls);
	codetag_to_text(out, ct);
	if (unlikely(alloc_tag_is_inaccurate(tag)))
		seq_buf_printf(out, " accurate:no");
	seq_buf_putc(out, ' ');
	seq_buf_putc(out, '\n');
}

static int allocinfo_show(struct seq_file *m, void *arg)
{
	struct allocinfo_private *priv = (struct allocinfo_private *)arg;
	char *bufp;
	size_t n = seq_get_buf(m, &bufp);
	struct seq_buf buf;

	seq_buf_init(&buf, bufp, n);
	if (priv->print_header) {
		print_allocinfo_header(&buf);
		priv->print_header = false;
	}
	alloc_tag_to_text(&buf, priv->iter.ct);
	seq_commit(m, seq_buf_used(&buf));
	return 0;
}

static const struct seq_operations allocinfo_seq_op = {
	.start	= allocinfo_start,
	.next	= allocinfo_next,
	.stop	= allocinfo_stop,
	.show	= allocinfo_show,
};

size_t alloc_tag_top_users(struct codetag_bytes *tags, size_t count, bool can_sleep)
{
	struct codetag_iterator iter;
	struct codetag *ct;
	struct codetag_bytes n;
	unsigned int i, nr = 0;

	if (IS_ERR_OR_NULL(alloc_tag_cttype))
		return 0;

	if (can_sleep)
		codetag_lock_module_list(alloc_tag_cttype, true);
	else if (!codetag_trylock_module_list(alloc_tag_cttype))
		return 0;

	iter = codetag_get_ct_iter(alloc_tag_cttype);
	while ((ct = codetag_next_ct(&iter))) {
		struct alloc_tag_counters counter = alloc_tag_read(ct_to_alloc_tag(ct));

		n.ct	= ct;
		n.bytes = counter.bytes;

		for (i = 0; i < nr; i++)
			if (n.bytes > tags[i].bytes)
				break;

		if (i < count) {
			nr -= nr == count;
			memmove(&tags[i + 1],
				&tags[i],
				sizeof(tags[0]) * (nr - i));
			nr++;
			tags[i] = n;
		}