From 1ec3a81a0cf4236b644282794932c4eda9c1714a Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (VMware)" Date: Tue, 4 Apr 2017 18:16:29 -0400 Subject: [PATCH] ftrace: Have each function probe use its own ftrace_ops Have the function probes have their own ftrace_ops, and remove the trace_probe_ops. This simplifies some of the ftrace infrastructure code. Individual entries for each function is still allocated for the use of the output for set_ftrace_filter, but they will be removed soon too. Signed-off-by: Steven Rostedt (VMware) --- kernel/trace/ftrace.c | 246 +++++++++++++++++------------------------- kernel/trace/trace.h | 1 + 2 files changed, 99 insertions(+), 148 deletions(-) diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index cbae7fb1be15..cf6b7263199a 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -3789,63 +3789,6 @@ static void function_trace_probe_call(unsigned long ip, unsigned long parent_ip, preempt_enable_notrace(); } -static struct ftrace_ops trace_probe_ops __read_mostly = -{ - .func = function_trace_probe_call, - .flags = FTRACE_OPS_FL_INITIALIZED, - INIT_OPS_HASH(trace_probe_ops) -}; - -static int ftrace_probe_registered; - -static void __enable_ftrace_function_probe(struct ftrace_ops_hash *old_hash) -{ - int ret; - int i; - - if (ftrace_probe_registered) { - /* still need to update the function call sites */ - if (ftrace_enabled) - ftrace_run_modify_code(&trace_probe_ops, FTRACE_UPDATE_CALLS, - old_hash); - return; - } - - for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { - struct hlist_head *hhd = &ftrace_func_hash[i]; - if (hhd->first) - break; - } - /* Nothing registered? */ - if (i == FTRACE_FUNC_HASHSIZE) - return; - - ret = ftrace_startup(&trace_probe_ops, 0); - - ftrace_probe_registered = 1; -} - -static bool __disable_ftrace_function_probe(void) -{ - int i; - - if (!ftrace_probe_registered) - return false; - - for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { - struct hlist_head *hhd = &ftrace_func_hash[i]; - if (hhd->first) - return false; - } - - /* no more funcs left */ - ftrace_shutdown(&trace_probe_ops, 0); - - ftrace_probe_registered = 0; - return true; -} - - static void ftrace_free_entry(struct ftrace_func_probe *entry) { if (entry->ops->free) @@ -3996,110 +3939,110 @@ void free_ftrace_func_mapper(struct ftrace_func_mapper *mapper, int register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, - void *data) + void *data) { - struct ftrace_ops_hash old_hash_ops; - struct ftrace_func_probe *entry; - struct ftrace_glob func_g; - struct ftrace_hash **orig_hash = &trace_probe_ops.func_hash->filter_hash; - struct ftrace_hash *old_hash = *orig_hash; + struct ftrace_func_entry *entry; + struct ftrace_func_probe *probe; + struct ftrace_hash **orig_hash; + struct ftrace_hash *old_hash; struct ftrace_hash *hash; - struct ftrace_page *pg; - struct dyn_ftrace *rec; - int not; + struct hlist_head hl; + struct hlist_node *n; unsigned long key; int count = 0; + int size; int ret; + int i; - func_g.type = filter_parse_regex(glob, strlen(glob), - &func_g.search, ¬); - func_g.len = strlen(func_g.search); - - /* we do not support '!' for function probes */ - if (WARN_ON(not)) + /* We do not support '!' for function probes */ + if (WARN_ON(glob[0] == '!')) return -EINVAL; - mutex_lock(&trace_probe_ops.func_hash->regex_lock); - - old_hash_ops.filter_hash = old_hash; - /* Probes only have filters */ - old_hash_ops.notrace_hash = NULL; - - hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, old_hash); - if (!hash) { - count = -ENOMEM; - goto out; + if (!(ops->ops.flags & FTRACE_OPS_FL_INITIALIZED)) { + ops->ops.func = function_trace_probe_call; + ftrace_ops_init(&ops->ops); } - if (unlikely(ftrace_disabled)) { - count = -ENODEV; - goto out; - } - - mutex_lock(&ftrace_lock); + mutex_lock(&ops->ops.func_hash->regex_lock); - do_for_each_ftrace_rec(pg, rec) { + orig_hash = &ops->ops.func_hash->filter_hash; + old_hash = *orig_hash; + hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, old_hash); - if (rec->flags & FTRACE_FL_DISABLED) - continue; + ret = ftrace_match_records(hash, glob, strlen(glob)); - if (!ftrace_match_record(rec, &func_g, NULL, 0)) - continue; + /* Nothing found? */ + if (!ret) + ret = -EINVAL; - entry = kmalloc(sizeof(*entry), GFP_KERNEL); - if (!entry) { - /* If we did not process any, then return error */ - if (!count) - count = -ENOMEM; - goto out_unlock; - } + if (ret < 0) + goto out; - count++; + INIT_HLIST_HEAD(&hl); - /* - * The caller might want to do something special - * for each function we find. We call the callback - * to give the caller an opportunity to do so. - */ - if (ops->init) { - if (ops->init(ops, rec->ip, data) < 0) { - /* caller does not like this func */ - kfree(entry); + size = 1 << hash->size_bits; + for (i = 0; i < size; i++) { + hlist_for_each_entry(entry, &hash->buckets[i], hlist) { + if (ftrace_lookup_ip(old_hash, entry->ip)) continue; + probe = kmalloc(sizeof(*probe), GFP_KERNEL); + if (!probe) { + count = -ENOMEM; + goto err_free; } - } + probe->ops = ops; + probe->ip = entry->ip; + /* + * The caller might want to do something special + * for each function we find. We call the callback + * to give the caller an opportunity to do so. + */ + if (ops->init && ops->init(ops, entry->ip, data) < 0) { + kfree(probe); + goto err_free; + } + hlist_add_head(&probe->node, &hl); - ret = enter_record(hash, rec, 0); - if (ret < 0) { - kfree(entry); - count = ret; - goto out_unlock; + count++; } + } - entry->ops = ops; - entry->ip = rec->ip; + mutex_lock(&ftrace_lock); - key = hash_long(entry->ip, FTRACE_HASH_BITS); - hlist_add_head_rcu(&entry->node, &ftrace_func_hash[key]); + ret = ftrace_hash_move_and_update_ops(&ops->ops, orig_hash, + hash, 1); + if (ret < 0) + goto err_free_unlock; - } while_for_each_ftrace_rec(); + hlist_for_each_entry_safe(probe, n, &hl, node) { + hlist_del(&probe->node); + key = hash_long(probe->ip, FTRACE_HASH_BITS); + hlist_add_head_rcu(&probe->node, &ftrace_func_hash[key]); + } - ret = ftrace_hash_move(&trace_probe_ops, 1, orig_hash, hash); + if (!(ops->ops.flags & FTRACE_OPS_FL_ENABLED)) + ret = ftrace_startup(&ops->ops, 0); - __enable_ftrace_function_probe(&old_hash_ops); + mutex_unlock(&ftrace_lock); if (!ret) - free_ftrace_hash_rcu(old_hash); - else - count = ret; - - out_unlock: - mutex_unlock(&ftrace_lock); + ret = count; out: - mutex_unlock(&trace_probe_ops.func_hash->regex_lock); + mutex_unlock(&ops->ops.func_hash->regex_lock); free_ftrace_hash(hash); - return count; + return ret; + + err_free_unlock: + mutex_unlock(&ftrace_lock); + err_free: + hlist_for_each_entry_safe(probe, n, &hl, node) { + hlist_del(&probe->node); + if (ops->free) + ops->free(ops, probe->ip, NULL); + kfree(probe); + } + goto out; } int @@ -4110,14 +4053,16 @@ unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops) struct ftrace_func_probe *entry; struct ftrace_func_probe *p; struct ftrace_glob func_g; - struct ftrace_hash **orig_hash = &trace_probe_ops.func_hash->filter_hash; - struct ftrace_hash *old_hash = *orig_hash; + struct ftrace_hash **orig_hash; + struct ftrace_hash *old_hash; struct list_head free_list; - struct ftrace_hash *hash; + struct ftrace_hash *hash = NULL; struct hlist_node *tmp; char str[KSYM_SYMBOL_LEN]; int i, ret; - bool disabled; + + if (!(ops->ops.flags & FTRACE_OPS_FL_INITIALIZED)) + return -EINVAL; if (glob && (strcmp(glob, "*") == 0 || !strlen(glob))) func_g.search = NULL; @@ -4134,14 +4079,21 @@ unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops) return -EINVAL; } - mutex_lock(&trace_probe_ops.func_hash->regex_lock); + mutex_lock(&ops->ops.func_hash->regex_lock); + + orig_hash = &ops->ops.func_hash->filter_hash; + old_hash = *orig_hash; + + ret = -EINVAL; + if (ftrace_hash_empty(old_hash)) + goto out_unlock; old_hash_ops.filter_hash = old_hash; /* Probes only have filters */ old_hash_ops.notrace_hash = NULL; ret = -ENOMEM; - hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash); + hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, old_hash); if (!hash) goto out_unlock; @@ -4181,20 +4133,18 @@ unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops) } mutex_lock(&ftrace_lock); - disabled = __disable_ftrace_function_probe(); - /* - * Remove after the disable is called. Otherwise, if the last - * probe is removed, a null hash means *all enabled*. - */ - ret = ftrace_hash_move(&trace_probe_ops, 1, orig_hash, hash); + + if (ftrace_hash_empty(hash)) + ftrace_shutdown(&ops->ops, 0); + + ret = ftrace_hash_move_and_update_ops(&ops->ops, orig_hash, + hash, 1); /* still need to update the function call sites */ - if (ftrace_enabled && !disabled) - ftrace_run_modify_code(&trace_probe_ops, FTRACE_UPDATE_CALLS, + if (ftrace_enabled && !ftrace_hash_empty(hash)) + ftrace_run_modify_code(&ops->ops, FTRACE_UPDATE_CALLS, &old_hash_ops); synchronize_sched(); - if (!ret) - free_ftrace_hash_rcu(old_hash); list_for_each_entry_safe(entry, p, &free_list, free_list) { list_del(&entry->free_list); @@ -4203,7 +4153,7 @@ unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops) mutex_unlock(&ftrace_lock); out_unlock: - mutex_unlock(&trace_probe_ops.func_hash->regex_lock); + mutex_unlock(&ops->ops.func_hash->regex_lock); free_ftrace_hash(hash); return ret; } diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 31d80bff9ee6..e16c67c49de4 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -932,6 +932,7 @@ static inline void ftrace_pid_follow_fork(struct trace_array *tr, bool enable) { #if defined(CONFIG_FUNCTION_TRACER) && defined(CONFIG_DYNAMIC_FTRACE) struct ftrace_probe_ops { + struct ftrace_ops ops; void (*func)(unsigned long ip, unsigned long parent_ip, struct ftrace_probe_ops *ops, -- 2.20.1