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