X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=kernel%2Ftrace%2Fftrace.c;h=6c508ff33c6206df8e028e1eab43e913565f927e;hb=1bb539ca36e21c2f4fce0865e11df384bc7b7656;hp=8a5c017bb50c141bfca4d8206ac2a1805d224185;hpb=14a9e5c09d13aa36b88ea54b8b6134b60ff2a410;p=firefly-linux-kernel-4.4.55.git diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 8a5c017bb50c..6c508ff33c62 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -64,6 +64,13 @@ #define FL_GLOBAL_CONTROL_MASK (FTRACE_OPS_FL_GLOBAL | FTRACE_OPS_FL_CONTROL) +#ifdef CONFIG_DYNAMIC_FTRACE +#define INIT_REGEX_LOCK(opsname) \ + .regex_lock = __MUTEX_INITIALIZER(opsname.regex_lock), +#else +#define INIT_REGEX_LOCK(opsname) +#endif + static struct ftrace_ops ftrace_list_end __read_mostly = { .func = ftrace_stub, .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_STUB, @@ -113,24 +120,34 @@ static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip); /* * Traverse the ftrace_global_list, invoking all entries. The reason that we - * can use rcu_dereference_raw() is that elements removed from this list + * can use rcu_dereference_raw_notrace() is that elements removed from this list * are simply leaked, so there is no need to interact with a grace-period - * mechanism. The rcu_dereference_raw() calls are needed to handle + * mechanism. The rcu_dereference_raw_notrace() calls are needed to handle * concurrent insertions into the ftrace_global_list. * * Silly Alpha and silly pointer-speculation compiler optimizations! */ #define do_for_each_ftrace_op(op, list) \ - op = rcu_dereference_raw(list); \ + op = rcu_dereference_raw_notrace(list); \ do /* * Optimized for just a single item in the list (as that is the normal case). */ #define while_for_each_ftrace_op(op) \ - while (likely(op = rcu_dereference_raw((op)->next)) && \ + while (likely(op = rcu_dereference_raw_notrace((op)->next)) && \ unlikely((op) != &ftrace_list_end)) +static inline void ftrace_ops_init(struct ftrace_ops *ops) +{ +#ifdef CONFIG_DYNAMIC_FTRACE + if (!(ops->flags & FTRACE_OPS_FL_INITIALIZED)) { + mutex_init(&ops->regex_lock); + ops->flags |= FTRACE_OPS_FL_INITIALIZED; + } +#endif +} + /** * ftrace_nr_registered_ops - return number of ops registered * @@ -762,7 +779,7 @@ ftrace_find_profiled_func(struct ftrace_profile_stat *stat, unsigned long ip) if (hlist_empty(hhd)) return NULL; - hlist_for_each_entry_rcu(rec, hhd, node) { + hlist_for_each_entry_rcu_notrace(rec, hhd, node) { if (rec->ip == ip) return rec; } @@ -907,7 +924,8 @@ static void unregister_ftrace_profiler(void) #else static struct ftrace_ops ftrace_profile_ops __read_mostly = { .func = function_profile_call, - .flags = FTRACE_OPS_FL_RECURSION_SAFE, + .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_INITIALIZED, + INIT_REGEX_LOCK(ftrace_profile_ops) }; static int register_ftrace_profiler(void) @@ -1103,11 +1121,10 @@ static struct ftrace_ops global_ops = { .func = ftrace_stub, .notrace_hash = EMPTY_HASH, .filter_hash = EMPTY_HASH, - .flags = FTRACE_OPS_FL_RECURSION_SAFE, + .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_INITIALIZED, + INIT_REGEX_LOCK(global_ops) }; -static DEFINE_MUTEX(ftrace_regex_lock); - struct ftrace_page { struct ftrace_page *next; struct dyn_ftrace *records; @@ -1148,7 +1165,7 @@ ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip) hhd = &hash->buckets[key]; - hlist_for_each_entry_rcu(entry, hhd, hlist) { + hlist_for_each_entry_rcu_notrace(entry, hhd, hlist) { if (entry->ip == ip) return entry; } @@ -1247,6 +1264,7 @@ static void free_ftrace_hash_rcu(struct ftrace_hash *hash) void ftrace_free_filter(struct ftrace_ops *ops) { + ftrace_ops_init(ops); free_ftrace_hash(ops->filter_hash); free_ftrace_hash(ops->notrace_hash); } @@ -1404,8 +1422,8 @@ ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip) struct ftrace_hash *notrace_hash; int ret; - filter_hash = rcu_dereference_raw(ops->filter_hash); - notrace_hash = rcu_dereference_raw(ops->notrace_hash); + filter_hash = rcu_dereference_raw_notrace(ops->filter_hash); + notrace_hash = rcu_dereference_raw_notrace(ops->notrace_hash); if ((ftrace_hash_empty(filter_hash) || ftrace_lookup_ip(filter_hash, ip)) && @@ -2441,7 +2459,7 @@ t_next(struct seq_file *m, void *v, loff_t *pos) !ftrace_lookup_ip(ops->notrace_hash, rec->ip)) || ((iter->flags & FTRACE_ITER_ENABLED) && - !(rec->flags & ~FTRACE_FL_MASK))) { + !(rec->flags & FTRACE_FL_ENABLED))) { rec = NULL; goto retry; @@ -2624,6 +2642,8 @@ ftrace_regex_open(struct ftrace_ops *ops, int flag, struct ftrace_hash *hash; int ret = 0; + ftrace_ops_init(ops); + if (unlikely(ftrace_disabled)) return -ENODEV; @@ -2636,28 +2656,26 @@ ftrace_regex_open(struct ftrace_ops *ops, int flag, return -ENOMEM; } + iter->ops = ops; + iter->flags = flag; + + mutex_lock(&ops->regex_lock); + if (flag & FTRACE_ITER_NOTRACE) hash = ops->notrace_hash; else hash = ops->filter_hash; - iter->ops = ops; - iter->flags = flag; - if (file->f_mode & FMODE_WRITE) { - mutex_lock(&ftrace_lock); iter->hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, hash); - mutex_unlock(&ftrace_lock); - if (!iter->hash) { trace_parser_put(&iter->parser); kfree(iter); - return -ENOMEM; + ret = -ENOMEM; + goto out_unlock; } } - mutex_lock(&ftrace_regex_lock); - if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) ftrace_filter_reset(iter->hash); @@ -2677,7 +2695,9 @@ ftrace_regex_open(struct ftrace_ops *ops, int flag, } } else file->private_data = iter; - mutex_unlock(&ftrace_regex_lock); + + out_unlock: + mutex_unlock(&ops->regex_lock); return ret; } @@ -2900,7 +2920,7 @@ static void function_trace_probe_call(unsigned long ip, unsigned long parent_ip, * on the hash. rcu_read_lock is too dangerous here. */ preempt_disable_notrace(); - hlist_for_each_entry_rcu(entry, hhd, node) { + hlist_for_each_entry_rcu_notrace(entry, hhd, node) { if (entry->ip == ip) entry->ops->func(ip, parent_ip, &entry->data); } @@ -2910,6 +2930,8 @@ static void function_trace_probe_call(unsigned long ip, unsigned long parent_ip, static struct ftrace_ops trace_probe_ops __read_mostly = { .func = function_trace_probe_call, + .flags = FTRACE_OPS_FL_INITIALIZED, + INIT_REGEX_LOCK(trace_probe_ops) }; static int ftrace_probe_registered; @@ -2919,8 +2941,12 @@ static void __enable_ftrace_function_probe(void) int ret; int i; - if (ftrace_probe_registered) + if (ftrace_probe_registered) { + /* still need to update the function call sites */ + if (ftrace_enabled) + ftrace_run_update_code(FTRACE_UPDATE_CALLS); return; + } for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { struct hlist_head *hhd = &ftrace_func_hash[i]; @@ -2990,19 +3016,21 @@ register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, if (WARN_ON(not)) return -EINVAL; - mutex_lock(&ftrace_lock); + mutex_lock(&trace_probe_ops.regex_lock); hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash); if (!hash) { count = -ENOMEM; - goto out_unlock; + goto out; } if (unlikely(ftrace_disabled)) { count = -ENODEV; - goto out_unlock; + goto out; } + mutex_lock(&ftrace_lock); + do_for_each_ftrace_rec(pg, rec) { if (!ftrace_match_record(rec, NULL, search, len, type)) @@ -3056,6 +3084,8 @@ register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, out_unlock: mutex_unlock(&ftrace_lock); + out: + mutex_unlock(&trace_probe_ops.regex_lock); free_ftrace_hash(hash); return count; @@ -3095,7 +3125,7 @@ __unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, return; } - mutex_lock(&ftrace_lock); + mutex_lock(&trace_probe_ops.regex_lock); hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash); if (!hash) @@ -3133,6 +3163,7 @@ __unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, list_add(&entry->free_list, &free_list); } } + mutex_lock(&ftrace_lock); __disable_ftrace_function_probe(); /* * Remove after the disable is called. Otherwise, if the last @@ -3144,9 +3175,10 @@ __unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, list_del(&entry->free_list); ftrace_free_entry(entry); } + mutex_unlock(&ftrace_lock); out_unlock: - mutex_unlock(&ftrace_lock); + mutex_unlock(&trace_probe_ops.regex_lock); free_ftrace_hash(hash); } @@ -3256,18 +3288,17 @@ ftrace_regex_write(struct file *file, const char __user *ubuf, if (!cnt) return 0; - mutex_lock(&ftrace_regex_lock); - - ret = -ENODEV; - if (unlikely(ftrace_disabled)) - goto out_unlock; - if (file->f_mode & FMODE_READ) { struct seq_file *m = file->private_data; iter = m->private; } else iter = file->private_data; + if (unlikely(ftrace_disabled)) + return -ENODEV; + + /* iter->hash is a local copy, so we don't need regex_lock */ + parser = &iter->parser; read = trace_get_user(parser, ubuf, cnt, ppos); @@ -3276,14 +3307,12 @@ ftrace_regex_write(struct file *file, const char __user *ubuf, ret = ftrace_process_regex(iter->hash, parser->buffer, parser->idx, enable); trace_parser_clear(parser); - if (ret) - goto out_unlock; + if (ret < 0) + goto out; } ret = read; -out_unlock: - mutex_unlock(&ftrace_regex_lock); - + out: return ret; } @@ -3335,16 +3364,19 @@ ftrace_set_hash(struct ftrace_ops *ops, unsigned char *buf, int len, if (unlikely(ftrace_disabled)) return -ENODEV; + mutex_lock(&ops->regex_lock); + if (enable) orig_hash = &ops->filter_hash; else orig_hash = &ops->notrace_hash; hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash); - if (!hash) - return -ENOMEM; + if (!hash) { + ret = -ENOMEM; + goto out_regex_unlock; + } - mutex_lock(&ftrace_regex_lock); if (reset) ftrace_filter_reset(hash); if (buf && !ftrace_match_records(hash, buf, len)) { @@ -3366,7 +3398,7 @@ ftrace_set_hash(struct ftrace_ops *ops, unsigned char *buf, int len, mutex_unlock(&ftrace_lock); out_regex_unlock: - mutex_unlock(&ftrace_regex_lock); + mutex_unlock(&ops->regex_lock); free_ftrace_hash(hash); return ret; @@ -3392,6 +3424,7 @@ ftrace_set_addr(struct ftrace_ops *ops, unsigned long ip, int remove, int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip, int remove, int reset) { + ftrace_ops_init(ops); return ftrace_set_addr(ops, ip, remove, reset, 1); } EXPORT_SYMBOL_GPL(ftrace_set_filter_ip); @@ -3416,6 +3449,7 @@ ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len, int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf, int len, int reset) { + ftrace_ops_init(ops); return ftrace_set_regex(ops, buf, len, reset, 1); } EXPORT_SYMBOL_GPL(ftrace_set_filter); @@ -3434,6 +3468,7 @@ EXPORT_SYMBOL_GPL(ftrace_set_filter); int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf, int len, int reset) { + ftrace_ops_init(ops); return ftrace_set_regex(ops, buf, len, reset, 0); } EXPORT_SYMBOL_GPL(ftrace_set_notrace); @@ -3524,6 +3559,8 @@ ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable) { char *func; + ftrace_ops_init(ops); + while (buf) { func = strsep(&buf, ","); ftrace_set_regex(ops, func, strlen(func), 0, enable); @@ -3551,10 +3588,8 @@ int ftrace_regex_release(struct inode *inode, struct file *file) int filter_hash; int ret; - mutex_lock(&ftrace_regex_lock); if (file->f_mode & FMODE_READ) { iter = m->private; - seq_release(inode, file); } else iter = file->private_data; @@ -3567,6 +3602,8 @@ int ftrace_regex_release(struct inode *inode, struct file *file) trace_parser_put(parser); + mutex_lock(&iter->ops->regex_lock); + if (file->f_mode & FMODE_WRITE) { filter_hash = !!(iter->flags & FTRACE_ITER_FILTER); @@ -3584,10 +3621,11 @@ int ftrace_regex_release(struct inode *inode, struct file *file) mutex_unlock(&ftrace_lock); } + + mutex_unlock(&iter->ops->regex_lock); free_ftrace_hash(iter->hash); kfree(iter); - mutex_unlock(&ftrace_regex_lock); return 0; } @@ -4126,7 +4164,8 @@ void __init ftrace_init(void) static struct ftrace_ops global_ops = { .func = ftrace_stub, - .flags = FTRACE_OPS_FL_RECURSION_SAFE, + .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_INITIALIZED, + INIT_REGEX_LOCK(global_ops) }; static int __init ftrace_nodyn_init(void) @@ -4180,8 +4219,9 @@ ftrace_ops_control_func(unsigned long ip, unsigned long parent_ip, } static struct ftrace_ops control_ops = { - .func = ftrace_ops_control_func, - .flags = FTRACE_OPS_FL_RECURSION_SAFE, + .func = ftrace_ops_control_func, + .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_INITIALIZED, + INIT_REGEX_LOCK(control_ops) }; static inline void @@ -4539,6 +4579,8 @@ int register_ftrace_function(struct ftrace_ops *ops) { int ret = -1; + ftrace_ops_init(ops); + mutex_lock(&ftrace_lock); ret = __register_ftrace_function(ops);