// SPDX-License-Identifier: GPL-2.0 /* * DAMON Debugfs Interface * * Author: SeongJae Park */ #define pr_fmt(fmt) "damon-dbgfs: " fmt #include #include #include #include #include #include #include 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->ops_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; 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; } ret = damon_set_attrs(ctx, s, a, r, minr, maxr); if (!ret) ret = count; unlock_out: mutex_unlock(&ctx->kdamond_lock); out: kfree(kbuf); return ret; } /* * Return corresponding dbgfs' scheme action value (int) for the given * damos_action if the given damos_action value is valid and supported by * dbgfs, negative error code otherwise. */ static int damos_action_to_dbgfs_scheme_action(enum damos_action action) { switch (action) { case DAMOS_WILLNEED: return 0; case DAMOS_COLD: return 1; case DAMOS_PAGEOUT: return 2; case DAMOS_HUGEPAGE: return 3; case DAMOS_NOHUGEPAGE: return 4; case DAMOS_STAT: return 5; default: return -EINVAL; } } static ssize_t sprint_schemes(struct damon_ctx *c, char *buf, ssize_t len) { struct damos *s; int written = 0; int rc; damon_for_each_scheme(s, c) { rc = scnprintf(&buf[written], len - written, "%lu %lu %u %u %u %u %d %lu %lu %lu %u %u %u %d %lu %lu %lu %lu %lu %lu %lu %lu %lu\n", s->min_sz_region, s->max_sz_region, s->min_nr_accesses, s->max_nr_accesses, s->min_age_region, s->max_age_region, damos_action_to_dbgfs_scheme_action(s->action), s->quota.ms, s->quota.sz, s->quota.reset_interval, s->quota.weight_sz, s->quota.weight_nr_accesses, s->quota.weight_age, s->wmarks.metric, s->wmarks.interval, s->wmarks.high, s->wmarks.mid, s->wmarks.low, s->stat.nr_tried, s->stat.sz_tried, s->stat.nr_applied, s->stat.sz_applied, s->stat.qt_exceeds); if (!rc) return -ENOMEM; written += rc; } return written; } static ssize_t dbgfs_schemes_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); len = sprint_schemes(ctx, kbuf, count); mutex_unlock(&ctx->kdamond_lock); if (len < 0) goto out; len = simple_read_from_buffer(buf, count, ppos, kbuf, len); out: kfree(kbuf); return len; } static void free_schemes_arr(struct damos **schemes, ssize_t nr_schemes) { ssize_t i; for (i = 0; i < nr_schemes; i++) kfree(schemes[i]); kfree(schemes); } /* * Return corresponding damos_action for the given dbgfs input for a scheme * action if the input is valid, negative error code otherwise. */ static enum damos_action dbgfs_scheme_action_to_damos_action(int dbgfs_action) { switch (dbgfs_action) { case 0: return DAMOS_WILLNEED; case 1: return DAMOS_COLD; case 2: return DAMOS_PAGEOUT; case 3: return DAMOS_HUGEPAGE; case 4: return DAMOS_NOHUGEPAGE; case 5: return DAMOS_STAT; default: return -EINVAL; } } /* * Converts a string into an array of struct damos pointers * * Returns an array of struct damos pointers that converted if the conversion * success, or NULL otherwise. */ static struct damos **str_to_schemes(const char *str, ssize_t len, ssize_t *nr_schemes) { struct damos *scheme, **schemes; const int max_nr_schemes = 256; int pos = 0, parsed, ret; unsigned long min_sz, max_sz; unsigned int min_nr_a, max_nr_a, min_age, max_age; unsigned int action_input; enum damos_action action; schemes = kmalloc_array(max_nr_schemes, sizeof(scheme), GFP_KERNEL); if (!schemes) return NULL; *nr_schemes = 0; while (pos < len && *nr_schemes < max_nr_schemes) { struct damos_quota quota = {}; struct damos_watermarks wmarks; ret = sscanf(&str[pos], "%lu %lu %u %u %u %u %u %lu %lu %lu %u %u %u %u %lu %lu %lu %lu%n", &min_sz, &max_sz, &min_nr_a, &max_nr_a, &min_age, &max_age, &action_input, "a.ms, "a.sz, "a.reset_interval, "a.weight_sz, "a.weight_nr_accesses, "a.weight_age, &wmarks.metric, &wmarks.interval, &wmarks.high, &wmarks.mid, &wmarks.low, &parsed); if (ret != 18) break; action = dbgfs_scheme_action_to_damos_action(action_input); if ((int)action < 0) goto fail; if (min_sz > max_sz || min_nr_a > max_nr_a || min_age > max_age) goto fail; if (wmarks.high < wmarks.mid || wmarks.high < wmarks.low || wmarks.mid < wmarks.low) goto fail; pos += parsed; scheme = damon_new_scheme(min_sz, max_sz, min_nr_a, max_nr_a, min_age, max_age, action, "a, &wmarks); if (!scheme) goto fail; schemes[*nr_schemes] = scheme; *nr_schemes += 1; } return schemes; fail: free_schemes_arr(schemes, *nr_schemes); return NULL; } static ssize_t dbgfs_schemes_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) { struct damon_ctx *ctx = file->private_data; char *kbuf; struct damos **schemes; ssize_t nr_schemes = 0, ret; kbuf = user_input_str(buf, count, ppos); if (IS_ERR(kbuf)) return PTR_ERR(kbuf); schemes = str_to_schemes(kbuf, count, &nr_schemes); if (!schemes) { ret = -EINVAL; goto out; } mutex_lock(&ctx->kdamond_lock); if (ctx->kdamond) { ret = -EBUSY; goto unlock_out; } ret = damon_set_schemes(ctx, schemes, nr_schemes); if (!ret) { ret = count; nr_schemes = 0; } unlock_out: mutex_unlock(&ctx->kdamond_lock); free_schemes_arr(schemes, nr_schemes); out: kfree(kbuf); return ret; } static ssize_t sprint_target_ids(struct damon_ctx *ctx, char *buf, ssize_t len) { struct damon_target *t; int id; int written = 0; int rc; damon_for_each_target(t, ctx) { if (damon_target_has_pid(ctx)) /* Show pid numbers to debugfs users */ id = pid_vnr(t->pid); else /* Show 42 for physical address space, just for fun */ id = 42; rc = scnprintf(&buf[written], len - written, "%d ", 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 integers array * * Returns an array of integers array if the conversion success, or NULL * otherwise. */ static int *str_to_ints(const char *str, ssize_t len, ssize_t *nr_ints) { int *array; const int max_nr_ints = 32; int nr; int pos = 0, parsed, ret; *nr_ints = 0; array = kmalloc_array(max_nr_ints, sizeof(*array), GFP_KERNEL); if (!array) return NULL; while (*nr_ints < max_nr_ints && pos < len) { ret = sscanf(&str[pos], "%d%n", &nr, &parsed); pos += parsed; if (ret != 1) break; array[*nr_ints] = nr; *nr_ints += 1; } return array; } static void dbgfs_put_pids(struct pid **pids, int nr_pids) { int i; for (i = 0; i < nr_pids; i++) put_pid(pids[i]); } /* * Converts a string into an struct pid pointers array * * Returns an array of struct pid pointers if the conversion success, or NULL * otherwise. */ static struct pid **str_to_pids(const char *str, ssize_t len, ssize_t *nr_pids) { int *ints; ssize_t nr_ints; struct pid **pids; *nr_pids = 0; ints = str_to_ints(str, len, &nr_ints); if (!ints) return NULL; pids = kmalloc_array(nr_ints, sizeof(*pids), GFP_KERNEL); if (!pids) goto out; for (; *nr_pids < nr_ints; (*nr_pids)++) { pids[*nr_pids] = find_get_pid(ints[*nr_pids]); if (!pids[*nr_pids]) { dbgfs_put_pids(pids, *nr_pids); kfree(ints); kfree(pids); return NULL; } } out: kfree(ints); return pids; } /* * dbgfs_set_targets() - Set monitoring targets. * @ctx: monitoring context * @nr_targets: number of targets * @pids: array of target pids (size is same to @nr_targets) * * This function should not be called while the kdamond is running. @pids is * ignored if the context is not configured to have pid in each target. On * failure, reference counts of all pids in @pids are decremented. * * Return: 0 on success, negative error code otherwise. */ static int dbgfs_set_targets(struct damon_ctx *ctx, ssize_t nr_targets, struct pid **pids) { ssize_t i; struct damon_target *t, *next; damon_for_each_target_safe(t, next, ctx) { if (damon_target_has_pid(ctx)) put_pid(t->pid); damon_destroy_target(t); } for (i = 0; i < nr_targets; i++) { t = damon_new_target(); if (!t) { damon_for_each_target_safe(t, next, ctx) damon_destroy_target(t); if (damon_target_has_pid(ctx)) dbgfs_put_pids(pids, nr_targets); return -ENOMEM; } if (damon_target_has_pid(ctx)) t->pid = pids[i]; damon_add_target(ctx, t); } return 0; } 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; bool id_is_pid = true; char *kbuf; struct pid **target_pids = NULL; ssize_t nr_targets; ssize_t ret; kbuf = user_input_str(buf, count, ppos); if (IS_ERR(kbuf)) return PTR_ERR(kbuf); if (!strncmp(kbuf, "paddr\n", count)) { id_is_pid = false; nr_targets = 1; } if (id_is_pid) { target_pids = str_to_pids(kbuf, count, &nr_targets); if (!target_pids) { ret = -ENOMEM; goto out; } } mutex_lock(&ctx->kdamond_lock); if (ctx->kdamond) { if (id_is_pid) dbgfs_put_pids(target_pids, nr_targets); ret = -EBUSY; goto unlock_out; } /* remove previously set targets */ dbgfs_set_targets(ctx, 0, NULL); if (!nr_targets) { ret = count; goto unlock_out; } /* Configure the context for the address space type */ if (id_is_pid) ret = damon_select_ops(ctx, DAMON_OPS_VADDR); else ret = damon_select_ops(ctx, DAMON_OPS_PADDR); if (ret) goto unlock_out; ret = dbgfs_set_targets(ctx, nr_targets, target_pids); if (!ret) ret = count; unlock_out: mutex_unlock(&ctx->kdamond_lock); kfree(target_pids); out: kfree(kbuf); return ret; } static ssize_t sprint_init_regions(struct damon_ctx *c, char *buf, ssize_t len) { struct damon_target *t; struct damon_region *r; int target_idx = 0; int written = 0; int rc; damon_for_each_target(t, c) { damon_for_each_region(r, t) { rc = scnprintf(&buf[written], len - written, "%d %lu %lu\n", target_idx, r->ar.start, r->ar.end); if (!rc) return -ENOMEM; written += rc; } target_idx++; } return written; } static ssize_t dbgfs_init_regions_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) { mutex_unlock(&ctx->kdamond_lock); len = -EBUSY; goto out; } len = sprint_init_regions(ctx, kbuf, count); mutex_unlock(&ctx->kdamond_lock); if (len < 0) goto out; len = simple_read_from_buffer(buf, count, ppos, kbuf, len); out: kfree(kbuf); return len; } static int add_init_region(struct damon_ctx *c, int target_idx, struct damon_addr_range *ar) { struct damon_target *t; struct damon_region *r, *prev; unsigned long idx = 0; int rc = -EINVAL; if (ar->start >= ar->end) return -EINVAL; damon_for_each_target(t, c) { if (idx++ == target_idx) { r = damon_new_region(ar->start, ar->end); if (!r) return -ENOMEM; damon_add_region(r, t); if (damon_nr_regions(t) > 1) { prev = damon_prev_region(r); if (prev->ar.end > r->ar.start) { damon_destroy_region(r, t); return -EINVAL; } } rc = 0; } } return rc; } static int set_init_regions(struct damon_ctx *c, const char *str, ssize_t len) { struct damon_target *t; struct damon_region *r, *next; int pos = 0, parsed, ret; int target_idx; struct damon_addr_range ar; int err; damon_for_each_target(t, c) { damon_for_each_region_safe(r, next, t) damon_destroy_region(r, t); } while (pos < len) { ret = sscanf(&str[pos], "%d %lu %lu%n", &target_idx, &ar.start, &ar.end, &parsed); if (ret != 3) break; err = add_init_region(c, target_idx, &ar); if (err) goto fail; pos += parsed; } return 0; fail: damon_for_each_target(t, c) { damon_for_each_region_safe(r, next, t) damon_destroy_region(r, t); } return err; } static ssize_t dbgfs_init_regions_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) { struct damon_ctx *ctx = file->private_data; char *kbuf; ssize_t ret = count; int err; kbuf = user_input_str(buf, count, ppos); if (IS_ERR(kbuf)) return PTR_ERR(kbuf); mutex_lock(&ctx->kdamond_lock); if (ctx->kdamond) { ret = -EBUSY; goto unlock_out; } err = set_init_regions(ctx, kbuf, ret); if (err) ret = err; unlock_out: mutex_unlock(&ctx->kdamond_lock); 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 schemes_fops = { .open = damon_dbgfs_open, .read = dbgfs_schemes_read, .write = dbgfs_schemes_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 init_regions_fops = { .open = damon_dbgfs_open, .read = dbgfs_init_regions_read, .write = dbgfs_init_regions_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", "schemes", "target_ids", "init_regions", "kdamond_pid"}; const struct file_operations *fops[] = {&attrs_fops, &schemes_fops, &target_ids_fops, &init_regions_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 void dbgfs_before_terminate(struct damon_ctx *ctx) { struct damon_target *t, *next; if (!damon_target_has_pid(ctx)) return; mutex_lock(&ctx->kdamond_lock); damon_for_each_target_safe(t, next, ctx) { put_pid(t->pid); damon_destroy_target(t); } mutex_unlock(&ctx->kdamond_lock); } static struct damon_ctx *dbgfs_new_ctx(void) { struct damon_ctx *ctx; ctx = damon_new_ctx(); if (!ctx) return NULL; if (damon_select_ops(ctx, DAMON_OPS_VADDR) && damon_select_ops(ctx, DAMON_OPS_PADDR)) { damon_destroy_ctx(ctx); return NULL; } 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; 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); ret = dbgfs_mk_context(ctx_name); if (!ret) ret = count; 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 damon_ctx **new_ctxs; int i, j; if (damon_nr_running_ctxs()) return -EBUSY; root = dbgfs_dirs[0]; if (!root) return -ENOENT; dir = debugfs_lookup(name, root); if (!dir) return -ENOENT; new_dirs = kmalloc_array(dbgfs_nr_ctxs - 1, sizeof(*dbgfs_dirs), GFP_KERNEL); if (!new_dirs) return -ENOMEM; new_ctxs = kmalloc_array(dbgfs_nr_ctxs - 1, sizeof(*dbgfs_ctxs), GFP_KERNEL); if (!new_ctxs) { kfree(new_dirs); return -ENOMEM; } 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--; return 0; } 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; 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); ret = dbgfs_rm_context(ctx_name); if (!ret) ret = count; 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; char *kbuf; 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)) { int i; for (i = 0; i < dbgfs_nr_ctxs; i++) { if (damon_targets_empty(dbgfs_ctxs[i])) { kfree(kbuf); mutex_unlock(&damon_dbgfs_lock); return -EINVAL; } } ret = damon_start(dbgfs_ctxs, dbgfs_nr_ctxs, true); } else if (!strncmp(kbuf, "off", count)) { ret = damon_stop(dbgfs_ctxs, dbgfs_nr_ctxs); } else { ret = -EINVAL; } mutex_unlock(&damon_dbgfs_lock); if (!ret) ret = count; 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(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"