WSL2-Linux-Kernel/mm/damon/dbgfs.c

658 строки
14 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* DAMON Debugfs Interface
*
* Author: SeongJae Park <sjpark@amazon.de>
*/
#define pr_fmt(fmt) "damon-dbgfs: " fmt
#include <linux/damon.h>
#include <linux/debugfs.h>
#include <linux/file.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/page_idle.h>
#include <linux/slab.h>
static struct damon_ctx **dbgfs_ctxs;
static int dbgfs_nr_ctxs;
static struct dentry **dbgfs_dirs;
static DEFINE_MUTEX(damon_dbgfs_lock);
/*
* Returns non-empty string on success, negative error code otherwise.
*/
static char *user_input_str(const char __user *buf, size_t count, loff_t *ppos)
{
char *kbuf;
ssize_t ret;
/* We do not accept continuous write */
if (*ppos)
return ERR_PTR(-EINVAL);
kbuf = kmalloc(count + 1, GFP_KERNEL | __GFP_NOWARN);
if (!kbuf)
return ERR_PTR(-ENOMEM);
ret = simple_write_to_buffer(kbuf, count + 1, ppos, buf, count);
if (ret != count) {
kfree(kbuf);
return ERR_PTR(-EIO);
}
kbuf[ret] = '\0';
return kbuf;
}
static ssize_t dbgfs_attrs_read(struct file *file,
char __user *buf, size_t count, loff_t *ppos)
{
struct damon_ctx *ctx = file->private_data;
char kbuf[128];
int ret;
mutex_lock(&ctx->kdamond_lock);
ret = scnprintf(kbuf, ARRAY_SIZE(kbuf), "%lu %lu %lu %lu %lu\n",
ctx->sample_interval, ctx->aggr_interval,
ctx->primitive_update_interval, ctx->min_nr_regions,
ctx->max_nr_regions);
mutex_unlock(&ctx->kdamond_lock);
return simple_read_from_buffer(buf, count, ppos, kbuf, ret);
}
static ssize_t dbgfs_attrs_write(struct file *file,
const char __user *buf, size_t count, loff_t *ppos)
{
struct damon_ctx *ctx = file->private_data;
unsigned long s, a, r, minr, maxr;
char *kbuf;
ssize_t ret = count;
int err;
kbuf = user_input_str(buf, count, ppos);
if (IS_ERR(kbuf))
return PTR_ERR(kbuf);
if (sscanf(kbuf, "%lu %lu %lu %lu %lu",
&s, &a, &r, &minr, &maxr) != 5) {
ret = -EINVAL;
goto out;
}
mutex_lock(&ctx->kdamond_lock);
if (ctx->kdamond) {
ret = -EBUSY;
goto unlock_out;
}
err = damon_set_attrs(ctx, s, a, r, minr, maxr);
if (err)
ret = err;
unlock_out:
mutex_unlock(&ctx->kdamond_lock);
out:
kfree(kbuf);
return ret;
}
static inline bool targetid_is_pid(const struct damon_ctx *ctx)
{
return ctx->primitive.target_valid == damon_va_target_valid;
}
static ssize_t sprint_target_ids(struct damon_ctx *ctx, char *buf, ssize_t len)
{
struct damon_target *t;
unsigned long id;
int written = 0;
int rc;
damon_for_each_target(t, ctx) {
id = t->id;
if (targetid_is_pid(ctx))
/* Show pid numbers to debugfs users */
id = (unsigned long)pid_vnr((struct pid *)id);
rc = scnprintf(&buf[written], len - written, "%lu ", id);
if (!rc)
return -ENOMEM;
written += rc;
}
if (written)
written -= 1;
written += scnprintf(&buf[written], len - written, "\n");
return written;
}
static ssize_t dbgfs_target_ids_read(struct file *file,
char __user *buf, size_t count, loff_t *ppos)
{
struct damon_ctx *ctx = file->private_data;
ssize_t len;
char ids_buf[320];
mutex_lock(&ctx->kdamond_lock);
len = sprint_target_ids(ctx, ids_buf, 320);
mutex_unlock(&ctx->kdamond_lock);
if (len < 0)
return len;
return simple_read_from_buffer(buf, count, ppos, ids_buf, len);
}
/*
* Converts a string into an array of unsigned long integers
*
* Returns an array of unsigned long integers if the conversion success, or
* NULL otherwise.
*/
static unsigned long *str_to_target_ids(const char *str, ssize_t len,
ssize_t *nr_ids)
{
unsigned long *ids;
const int max_nr_ids = 32;
unsigned long id;
int pos = 0, parsed, ret;
*nr_ids = 0;
ids = kmalloc_array(max_nr_ids, sizeof(id), GFP_KERNEL);
if (!ids)
return NULL;
while (*nr_ids < max_nr_ids && pos < len) {
ret = sscanf(&str[pos], "%lu%n", &id, &parsed);
pos += parsed;
if (ret != 1)
break;
ids[*nr_ids] = id;
*nr_ids += 1;
}
return ids;
}
static void dbgfs_put_pids(unsigned long *ids, int nr_ids)
{
int i;
for (i = 0; i < nr_ids; i++)
put_pid((struct pid *)ids[i]);
}
static ssize_t dbgfs_target_ids_write(struct file *file,
const char __user *buf, size_t count, loff_t *ppos)
{
struct damon_ctx *ctx = file->private_data;
struct damon_target *t, *next_t;
char *kbuf, *nrs;
unsigned long *targets;
ssize_t nr_targets;
ssize_t ret = count;
int i;
int err;
kbuf = user_input_str(buf, count, ppos);
if (IS_ERR(kbuf))
return PTR_ERR(kbuf);
nrs = kbuf;
targets = str_to_target_ids(nrs, ret, &nr_targets);
if (!targets) {
ret = -ENOMEM;
goto out;
}
if (targetid_is_pid(ctx)) {
for (i = 0; i < nr_targets; i++) {
targets[i] = (unsigned long)find_get_pid(
(int)targets[i]);
if (!targets[i]) {
dbgfs_put_pids(targets, i);
ret = -EINVAL;
goto free_targets_out;
}
}
}
mutex_lock(&ctx->kdamond_lock);
if (ctx->kdamond) {
if (targetid_is_pid(ctx))
dbgfs_put_pids(targets, nr_targets);
ret = -EBUSY;
goto unlock_out;
}
/* remove previously set targets */
damon_for_each_target_safe(t, next_t, ctx) {
if (targetid_is_pid(ctx))
put_pid((struct pid *)t->id);
damon_destroy_target(t);
}
err = damon_set_targets(ctx, targets, nr_targets);
if (err) {
if (targetid_is_pid(ctx))
dbgfs_put_pids(targets, nr_targets);
ret = err;
}
unlock_out:
mutex_unlock(&ctx->kdamond_lock);
free_targets_out:
kfree(targets);
out:
kfree(kbuf);
return ret;
}
static ssize_t dbgfs_kdamond_pid_read(struct file *file,
char __user *buf, size_t count, loff_t *ppos)
{
struct damon_ctx *ctx = file->private_data;
char *kbuf;
ssize_t len;
kbuf = kmalloc(count, GFP_KERNEL | __GFP_NOWARN);
if (!kbuf)
return -ENOMEM;
mutex_lock(&ctx->kdamond_lock);
if (ctx->kdamond)
len = scnprintf(kbuf, count, "%d\n", ctx->kdamond->pid);
else
len = scnprintf(kbuf, count, "none\n");
mutex_unlock(&ctx->kdamond_lock);
if (!len)
goto out;
len = simple_read_from_buffer(buf, count, ppos, kbuf, len);
out:
kfree(kbuf);
return len;
}
static int damon_dbgfs_open(struct inode *inode, struct file *file)
{
file->private_data = inode->i_private;
return nonseekable_open(inode, file);
}
static const struct file_operations attrs_fops = {
.open = damon_dbgfs_open,
.read = dbgfs_attrs_read,
.write = dbgfs_attrs_write,
};
static const struct file_operations target_ids_fops = {
.open = damon_dbgfs_open,
.read = dbgfs_target_ids_read,
.write = dbgfs_target_ids_write,
};
static const struct file_operations kdamond_pid_fops = {
.open = damon_dbgfs_open,
.read = dbgfs_kdamond_pid_read,
};
static void dbgfs_fill_ctx_dir(struct dentry *dir, struct damon_ctx *ctx)
{
const char * const file_names[] = {"attrs", "target_ids",
"kdamond_pid"};
const struct file_operations *fops[] = {&attrs_fops, &target_ids_fops,
&kdamond_pid_fops};
int i;
for (i = 0; i < ARRAY_SIZE(file_names); i++)
debugfs_create_file(file_names[i], 0600, dir, ctx, fops[i]);
}
static int dbgfs_before_terminate(struct damon_ctx *ctx)
{
struct damon_target *t, *next;
if (!targetid_is_pid(ctx))
return 0;
mutex_lock(&ctx->kdamond_lock);
damon_for_each_target_safe(t, next, ctx) {
put_pid((struct pid *)t->id);
damon_destroy_target(t);
}
mutex_unlock(&ctx->kdamond_lock);
return 0;
}
static struct damon_ctx *dbgfs_new_ctx(void)
{
struct damon_ctx *ctx;
ctx = damon_new_ctx();
if (!ctx)
return NULL;
damon_va_set_primitives(ctx);
ctx->callback.before_terminate = dbgfs_before_terminate;
return ctx;
}
static void dbgfs_destroy_ctx(struct damon_ctx *ctx)
{
damon_destroy_ctx(ctx);
}
/*
* Make a context of @name and create a debugfs directory for it.
*
* This function should be called while holding damon_dbgfs_lock.
*
* Returns 0 on success, negative error code otherwise.
*/
static int dbgfs_mk_context(char *name)
{
struct dentry *root, **new_dirs, *new_dir;
struct damon_ctx **new_ctxs, *new_ctx;
if (damon_nr_running_ctxs())
return -EBUSY;
new_ctxs = krealloc(dbgfs_ctxs, sizeof(*dbgfs_ctxs) *
(dbgfs_nr_ctxs + 1), GFP_KERNEL);
if (!new_ctxs)
return -ENOMEM;
dbgfs_ctxs = new_ctxs;
new_dirs = krealloc(dbgfs_dirs, sizeof(*dbgfs_dirs) *
(dbgfs_nr_ctxs + 1), GFP_KERNEL);
if (!new_dirs)
return -ENOMEM;
dbgfs_dirs = new_dirs;
root = dbgfs_dirs[0];
if (!root)
return -ENOENT;
new_dir = debugfs_create_dir(name, root);
/* Below check is required for a potential duplicated name case */
if (IS_ERR(new_dir))
return PTR_ERR(new_dir);
dbgfs_dirs[dbgfs_nr_ctxs] = new_dir;
new_ctx = dbgfs_new_ctx();
if (!new_ctx) {
debugfs_remove(new_dir);
dbgfs_dirs[dbgfs_nr_ctxs] = NULL;
return -ENOMEM;
}
dbgfs_ctxs[dbgfs_nr_ctxs] = new_ctx;
dbgfs_fill_ctx_dir(dbgfs_dirs[dbgfs_nr_ctxs],
dbgfs_ctxs[dbgfs_nr_ctxs]);
dbgfs_nr_ctxs++;
return 0;
}
static ssize_t dbgfs_mk_context_write(struct file *file,
const char __user *buf, size_t count, loff_t *ppos)
{
char *kbuf;
char *ctx_name;
ssize_t ret = count;
int err;
kbuf = user_input_str(buf, count, ppos);
if (IS_ERR(kbuf))
return PTR_ERR(kbuf);
ctx_name = kmalloc(count + 1, GFP_KERNEL);
if (!ctx_name) {
kfree(kbuf);
return -ENOMEM;
}
/* Trim white space */
if (sscanf(kbuf, "%s", ctx_name) != 1) {
ret = -EINVAL;
goto out;
}
mutex_lock(&damon_dbgfs_lock);
err = dbgfs_mk_context(ctx_name);
if (err)
ret = err;
mutex_unlock(&damon_dbgfs_lock);
out:
kfree(kbuf);
kfree(ctx_name);
return ret;
}
/*
* Remove a context of @name and its debugfs directory.
*
* This function should be called while holding damon_dbgfs_lock.
*
* Return 0 on success, negative error code otherwise.
*/
static int dbgfs_rm_context(char *name)
{
struct dentry *root, *dir, **new_dirs;
struct inode *inode;
struct damon_ctx **new_ctxs;
int i, j;
int ret = 0;
if (damon_nr_running_ctxs())
return -EBUSY;
root = dbgfs_dirs[0];
if (!root)
return -ENOENT;
dir = debugfs_lookup(name, root);
if (!dir)
return -ENOENT;
inode = d_inode(dir);
if (!S_ISDIR(inode->i_mode)) {
ret = -EINVAL;
goto out_dput;
}
new_dirs = kmalloc_array(dbgfs_nr_ctxs - 1, sizeof(*dbgfs_dirs),
GFP_KERNEL);
if (!new_dirs) {
ret = -ENOMEM;
goto out_dput;
}
new_ctxs = kmalloc_array(dbgfs_nr_ctxs - 1, sizeof(*dbgfs_ctxs),
GFP_KERNEL);
if (!new_ctxs) {
ret = -ENOMEM;
goto out_new_dirs;
}
for (i = 0, j = 0; i < dbgfs_nr_ctxs; i++) {
if (dbgfs_dirs[i] == dir) {
debugfs_remove(dbgfs_dirs[i]);
dbgfs_destroy_ctx(dbgfs_ctxs[i]);
continue;
}
new_dirs[j] = dbgfs_dirs[i];
new_ctxs[j++] = dbgfs_ctxs[i];
}
kfree(dbgfs_dirs);
kfree(dbgfs_ctxs);
dbgfs_dirs = new_dirs;
dbgfs_ctxs = new_ctxs;
dbgfs_nr_ctxs--;
goto out_dput;
out_new_dirs:
kfree(new_dirs);
out_dput:
dput(dir);
return ret;
}
static ssize_t dbgfs_rm_context_write(struct file *file,
const char __user *buf, size_t count, loff_t *ppos)
{
char *kbuf;
ssize_t ret = count;
int err;
char *ctx_name;
kbuf = user_input_str(buf, count, ppos);
if (IS_ERR(kbuf))
return PTR_ERR(kbuf);
ctx_name = kmalloc(count + 1, GFP_KERNEL);
if (!ctx_name) {
kfree(kbuf);
return -ENOMEM;
}
/* Trim white space */
if (sscanf(kbuf, "%s", ctx_name) != 1) {
ret = -EINVAL;
goto out;
}
mutex_lock(&damon_dbgfs_lock);
err = dbgfs_rm_context(ctx_name);
if (err)
ret = err;
mutex_unlock(&damon_dbgfs_lock);
out:
kfree(kbuf);
kfree(ctx_name);
return ret;
}
static ssize_t dbgfs_monitor_on_read(struct file *file,
char __user *buf, size_t count, loff_t *ppos)
{
char monitor_on_buf[5];
bool monitor_on = damon_nr_running_ctxs() != 0;
int len;
len = scnprintf(monitor_on_buf, 5, monitor_on ? "on\n" : "off\n");
return simple_read_from_buffer(buf, count, ppos, monitor_on_buf, len);
}
static ssize_t dbgfs_monitor_on_write(struct file *file,
const char __user *buf, size_t count, loff_t *ppos)
{
ssize_t ret = count;
char *kbuf;
int err;
kbuf = user_input_str(buf, count, ppos);
if (IS_ERR(kbuf))
return PTR_ERR(kbuf);
/* Remove white space */
if (sscanf(kbuf, "%s", kbuf) != 1) {
kfree(kbuf);
return -EINVAL;
}
mutex_lock(&damon_dbgfs_lock);
if (!strncmp(kbuf, "on", count))
err = damon_start(dbgfs_ctxs, dbgfs_nr_ctxs);
else if (!strncmp(kbuf, "off", count))
err = damon_stop(dbgfs_ctxs, dbgfs_nr_ctxs);
else
err = -EINVAL;
mutex_unlock(&damon_dbgfs_lock);
if (err)
ret = err;
kfree(kbuf);
return ret;
}
static const struct file_operations mk_contexts_fops = {
.write = dbgfs_mk_context_write,
};
static const struct file_operations rm_contexts_fops = {
.write = dbgfs_rm_context_write,
};
static const struct file_operations monitor_on_fops = {
.read = dbgfs_monitor_on_read,
.write = dbgfs_monitor_on_write,
};
static int __init __damon_dbgfs_init(void)
{
struct dentry *dbgfs_root;
const char * const file_names[] = {"mk_contexts", "rm_contexts",
"monitor_on"};
const struct file_operations *fops[] = {&mk_contexts_fops,
&rm_contexts_fops, &monitor_on_fops};
int i;
dbgfs_root = debugfs_create_dir("damon", NULL);
for (i = 0; i < ARRAY_SIZE(file_names); i++)
debugfs_create_file(file_names[i], 0600, dbgfs_root, NULL,
fops[i]);
dbgfs_fill_ctx_dir(dbgfs_root, dbgfs_ctxs[0]);
dbgfs_dirs = kmalloc_array(1, sizeof(dbgfs_root), GFP_KERNEL);
if (!dbgfs_dirs) {
debugfs_remove(dbgfs_root);
return -ENOMEM;
}
dbgfs_dirs[0] = dbgfs_root;
return 0;
}
/*
* Functions for the initialization
*/
static int __init damon_dbgfs_init(void)
{
int rc = -ENOMEM;
mutex_lock(&damon_dbgfs_lock);
dbgfs_ctxs = kmalloc(sizeof(*dbgfs_ctxs), GFP_KERNEL);
if (!dbgfs_ctxs)
goto out;
dbgfs_ctxs[0] = dbgfs_new_ctx();
if (!dbgfs_ctxs[0]) {
kfree(dbgfs_ctxs);
goto out;
}
dbgfs_nr_ctxs = 1;
rc = __damon_dbgfs_init();
if (rc) {
kfree(dbgfs_ctxs[0]);
kfree(dbgfs_ctxs);
pr_err("%s: dbgfs init failed\n", __func__);
}
out:
mutex_unlock(&damon_dbgfs_lock);
return rc;
}
module_init(damon_dbgfs_init);
#include "dbgfs-test.h"