ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub;
struct ftrace_ops global_ops;
-#if ARCH_SUPPORTS_FTRACE_OPS
-static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
- struct ftrace_ops *op, struct ftrace_regs *fregs);
-#else
-/* See comment below, where ftrace_ops_list_func is defined */
-static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip);
-#define ftrace_ops_list_func ((ftrace_func_t)ftrace_ops_no_ops)
-#endif
+/* Defined by vmlinux.lds.h see the commment above arch_ftrace_ops_list_func for details */
+void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
+ struct ftrace_ops *op, struct ftrace_regs *fregs);
static inline void ftrace_ops_init(struct ftrace_ops *ops)
{
FTRACE_PROFILE_HASH_SIZE * sizeof(struct hlist_head));
}
-int ftrace_profile_pages_init(struct ftrace_profile_stat *stat)
+static int ftrace_profile_pages_init(struct ftrace_profile_stat *stat)
{
struct ftrace_profile_page *pg;
int functions;
}
}
- entry = tracefs_create_file("function_profile_enabled", 0644,
- d_tracer, NULL, &ftrace_profile_fops);
+ entry = tracefs_create_file("function_profile_enabled",
+ TRACE_MODE_WRITE, d_tracer, NULL,
+ &ftrace_profile_fops);
if (!entry)
pr_warn("Could not create tracefs 'function_profile_enabled' entry\n");
}
return entry->direct;
}
+static struct ftrace_func_entry*
+ftrace_add_rec_direct(unsigned long ip, unsigned long addr,
+ struct ftrace_hash **free_hash)
+{
+ struct ftrace_func_entry *entry;
+
+ if (ftrace_hash_empty(direct_functions) ||
+ direct_functions->count > 2 * (1 << direct_functions->size_bits)) {
+ struct ftrace_hash *new_hash;
+ int size = ftrace_hash_empty(direct_functions) ? 0 :
+ direct_functions->count + 1;
+
+ if (size < 32)
+ size = 32;
+
+ new_hash = dup_hash(direct_functions, size);
+ if (!new_hash)
+ return NULL;
+
+ *free_hash = direct_functions;
+ direct_functions = new_hash;
+ }
+
+ entry = kmalloc(sizeof(*entry), GFP_KERNEL);
+ if (!entry)
+ return NULL;
+
+ entry->ip = ip;
+ entry->direct = addr;
+ __add_hash_entry(direct_functions, entry);
+ return entry;
+}
+
static void call_direct_funcs(unsigned long ip, unsigned long pip,
struct ftrace_ops *ops, struct ftrace_regs *fregs)
{
}
ret = -ENOMEM;
- if (ftrace_hash_empty(direct_functions) ||
- direct_functions->count > 2 * (1 << direct_functions->size_bits)) {
- struct ftrace_hash *new_hash;
- int size = ftrace_hash_empty(direct_functions) ? 0 :
- direct_functions->count + 1;
-
- if (size < 32)
- size = 32;
-
- new_hash = dup_hash(direct_functions, size);
- if (!new_hash)
- goto out_unlock;
-
- free_hash = direct_functions;
- direct_functions = new_hash;
- }
-
- entry = kmalloc(sizeof(*entry), GFP_KERNEL);
- if (!entry)
- goto out_unlock;
-
direct = ftrace_find_direct_func(addr);
if (!direct) {
direct = ftrace_alloc_direct_func(addr);
- if (!direct) {
- kfree(entry);
+ if (!direct)
goto out_unlock;
- }
}
- entry->ip = ip;
- entry->direct = addr;
- __add_hash_entry(direct_functions, entry);
+ entry = ftrace_add_rec_direct(ip, addr, &free_hash);
+ if (!entry)
+ goto out_unlock;
ret = ftrace_set_filter_ip(&direct_ops, ip, 0, 0);
if (ret)
return ret;
}
EXPORT_SYMBOL_GPL(modify_ftrace_direct);
+
+#define MULTI_FLAGS (FTRACE_OPS_FL_IPMODIFY | FTRACE_OPS_FL_DIRECT | \
+ FTRACE_OPS_FL_SAVE_REGS)
+
+static int check_direct_multi(struct ftrace_ops *ops)
+{
+ if (!(ops->flags & FTRACE_OPS_FL_INITIALIZED))
+ return -EINVAL;
+ if ((ops->flags & MULTI_FLAGS) != MULTI_FLAGS)
+ return -EINVAL;
+ return 0;
+}
+
+static void remove_direct_functions_hash(struct ftrace_hash *hash, unsigned long addr)
+{
+ struct ftrace_func_entry *entry, *del;
+ int size, i;
+
+ size = 1 << hash->size_bits;
+ for (i = 0; i < size; i++) {
+ hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
+ del = __ftrace_lookup_ip(direct_functions, entry->ip);
+ if (del && del->direct == addr) {
+ remove_hash_entry(direct_functions, del);
+ kfree(del);
+ }
+ }
+ }
+}
+
+/**
+ * register_ftrace_direct_multi - Call a custom trampoline directly
+ * for multiple functions registered in @ops
+ * @ops: The address of the struct ftrace_ops object
+ * @addr: The address of the trampoline to call at @ops functions
+ *
+ * This is used to connect a direct calls to @addr from the nop locations
+ * of the functions registered in @ops (with by ftrace_set_filter_ip
+ * function).
+ *
+ * The location that it calls (@addr) must be able to handle a direct call,
+ * and save the parameters of the function being traced, and restore them
+ * (or inject new ones if needed), before returning.
+ *
+ * Returns:
+ * 0 on success
+ * -EINVAL - The @ops object was already registered with this call or
+ * when there are no functions in @ops object.
+ * -EBUSY - Another direct function is already attached (there can be only one)
+ * -ENODEV - @ip does not point to a ftrace nop location (or not supported)
+ * -ENOMEM - There was an allocation failure.
+ */
+int register_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr)
+{
+ struct ftrace_hash *hash, *free_hash = NULL;
+ struct ftrace_func_entry *entry, *new;
+ int err = -EBUSY, size, i;
+
+ if (ops->func || ops->trampoline)
+ return -EINVAL;
+ if (!(ops->flags & FTRACE_OPS_FL_INITIALIZED))
+ return -EINVAL;
+ if (ops->flags & FTRACE_OPS_FL_ENABLED)
+ return -EINVAL;
+
+ hash = ops->func_hash->filter_hash;
+ if (ftrace_hash_empty(hash))
+ return -EINVAL;
+
+ mutex_lock(&direct_mutex);
+
+ /* Make sure requested entries are not already registered.. */
+ size = 1 << hash->size_bits;
+ for (i = 0; i < size; i++) {
+ hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
+ if (ftrace_find_rec_direct(entry->ip))
+ goto out_unlock;
+ }
+ }
+
+ /* ... and insert them to direct_functions hash. */
+ err = -ENOMEM;
+ for (i = 0; i < size; i++) {
+ hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
+ new = ftrace_add_rec_direct(entry->ip, addr, &free_hash);
+ if (!new)
+ goto out_remove;
+ entry->direct = addr;
+ }
+ }
+
+ ops->func = call_direct_funcs;
+ ops->flags = MULTI_FLAGS;
+ ops->trampoline = FTRACE_REGS_ADDR;
+
+ err = register_ftrace_function(ops);
+
+ out_remove:
+ if (err)
+ remove_direct_functions_hash(hash, addr);
+
+ out_unlock:
+ mutex_unlock(&direct_mutex);
+
+ if (free_hash) {
+ synchronize_rcu_tasks();
+ free_ftrace_hash(free_hash);
+ }
+ return err;
+}
+EXPORT_SYMBOL_GPL(register_ftrace_direct_multi);
+
+/**
+ * unregister_ftrace_direct_multi - Remove calls to custom trampoline
+ * previously registered by register_ftrace_direct_multi for @ops object.
+ * @ops: The address of the struct ftrace_ops object
+ *
+ * This is used to remove a direct calls to @addr from the nop locations
+ * of the functions registered in @ops (with by ftrace_set_filter_ip
+ * function).
+ *
+ * Returns:
+ * 0 on success
+ * -EINVAL - The @ops object was not properly registered.
+ */
+int unregister_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr)
+{
+ struct ftrace_hash *hash = ops->func_hash->filter_hash;
+ int err;
+
+ if (check_direct_multi(ops))
+ return -EINVAL;
+ if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
+ return -EINVAL;
+
+ mutex_lock(&direct_mutex);
+ err = unregister_ftrace_function(ops);
+ remove_direct_functions_hash(hash, addr);
+ mutex_unlock(&direct_mutex);
+ return err;
+}
+EXPORT_SYMBOL_GPL(unregister_ftrace_direct_multi);
+
+/**
+ * modify_ftrace_direct_multi - Modify an existing direct 'multi' call
+ * to call something else
+ * @ops: The address of the struct ftrace_ops object
+ * @addr: The address of the new trampoline to call at @ops functions
+ *
+ * This is used to unregister currently registered direct caller and
+ * register new one @addr on functions registered in @ops object.
+ *
+ * Note there's window between ftrace_shutdown and ftrace_startup calls
+ * where there will be no callbacks called.
+ *
+ * Returns: zero on success. Non zero on error, which includes:
+ * -EINVAL - The @ops object was not properly registered.
+ */
+int modify_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr)
+{
+ struct ftrace_hash *hash;
+ struct ftrace_func_entry *entry, *iter;
+ static struct ftrace_ops tmp_ops = {
+ .func = ftrace_stub,
+ .flags = FTRACE_OPS_FL_STUB,
+ };
+ int i, size;
+ int err;
+
+ if (check_direct_multi(ops))
+ return -EINVAL;
+ if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
+ return -EINVAL;
+
+ mutex_lock(&direct_mutex);
+
+ /* Enable the tmp_ops to have the same functions as the direct ops */
+ ftrace_ops_init(&tmp_ops);
+ tmp_ops.func_hash = ops->func_hash;
+
+ err = register_ftrace_function(&tmp_ops);
+ if (err)
+ goto out_direct;
+
+ /*
+ * Now the ftrace_ops_list_func() is called to do the direct callers.
+ * We can safely change the direct functions attached to each entry.
+ */
+ mutex_lock(&ftrace_lock);
+
+ hash = ops->func_hash->filter_hash;
+ size = 1 << hash->size_bits;
+ for (i = 0; i < size; i++) {
+ hlist_for_each_entry(iter, &hash->buckets[i], hlist) {
+ entry = __ftrace_lookup_ip(direct_functions, iter->ip);
+ if (!entry)
+ continue;
+ entry->direct = addr;
+ }
+ }
+
+ /* Removing the tmp_ops will add the updated direct callers to the functions */
+ unregister_ftrace_function(&tmp_ops);
+
+ mutex_unlock(&ftrace_lock);
+ out_direct:
+ mutex_unlock(&direct_mutex);
+ return err;
+}
+EXPORT_SYMBOL_GPL(modify_ftrace_direct_multi);
#endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */
/**
struct dentry *parent)
{
- trace_create_file("set_ftrace_filter", 0644, parent,
+ trace_create_file("set_ftrace_filter", TRACE_MODE_WRITE, parent,
ops, &ftrace_filter_fops);
- trace_create_file("set_ftrace_notrace", 0644, parent,
+ trace_create_file("set_ftrace_notrace", TRACE_MODE_WRITE, parent,
ops, &ftrace_notrace_fops);
}
static __init int ftrace_init_dyn_tracefs(struct dentry *d_tracer)
{
- trace_create_file("available_filter_functions", 0444,
+ trace_create_file("available_filter_functions", TRACE_MODE_READ,
d_tracer, NULL, &ftrace_avail_fops);
- trace_create_file("enabled_functions", 0444,
+ trace_create_file("enabled_functions", TRACE_MODE_READ,
d_tracer, NULL, &ftrace_enabled_fops);
ftrace_create_filter_files(&global_ops, d_tracer);
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
- trace_create_file("set_graph_function", 0644, d_tracer,
+ trace_create_file("set_graph_function", TRACE_MODE_WRITE, d_tracer,
NULL,
&ftrace_graph_fops);
- trace_create_file("set_graph_notrace", 0644, d_tracer,
+ trace_create_file("set_graph_notrace", TRACE_MODE_WRITE, d_tracer,
NULL,
&ftrace_graph_notrace_fops);
#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
ftrace_free_mem(NULL, start, end);
}
+int __init __weak ftrace_dyn_arch_init(void)
+{
+ return 0;
+}
+
void __init ftrace_init(void)
{
extern unsigned long __start_mcount_loc[];
struct ftrace_ops *op;
int bit;
+ /*
+ * The ftrace_test_and_set_recursion() will disable preemption,
+ * which is required since some of the ops may be dynamically
+ * allocated, they must be freed after a synchronize_rcu().
+ */
bit = trace_test_and_set_recursion(ip, parent_ip, TRACE_LIST_START);
if (bit < 0)
return;
- /*
- * Some of the ops may be dynamically allocated,
- * they must be freed after a synchronize_rcu().
- */
- preempt_disable_notrace();
-
do_for_each_ftrace_op(op, ftrace_ops_list) {
/* Stub functions don't need to be called nor tested */
if (op->flags & FTRACE_OPS_FL_STUB)
}
} while_for_each_ftrace_op(op);
out:
- preempt_enable_notrace();
trace_clear_recursion(bit);
}
* Note, CONFIG_DYNAMIC_FTRACE_WITH_REGS expects a full regs to be saved.
* An architecture can pass partial regs with ftrace_ops and still
* set the ARCH_SUPPORTS_FTRACE_OPS.
+ *
+ * In vmlinux.lds.h, ftrace_ops_list_func() is defined to be
+ * arch_ftrace_ops_list_func.
*/
#if ARCH_SUPPORTS_FTRACE_OPS
-static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
- struct ftrace_ops *op, struct ftrace_regs *fregs)
+void arch_ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
+ struct ftrace_ops *op, struct ftrace_regs *fregs)
{
__ftrace_ops_list_func(ip, parent_ip, NULL, fregs);
}
-NOKPROBE_SYMBOL(ftrace_ops_list_func);
#else
-static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip)
+void arch_ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip)
{
__ftrace_ops_list_func(ip, parent_ip, NULL, NULL);
}
-NOKPROBE_SYMBOL(ftrace_ops_no_ops);
#endif
+NOKPROBE_SYMBOL(arch_ftrace_ops_list_func);
/*
* If there's only one function registered but it does not support
if (bit < 0)
return;
- preempt_disable_notrace();
-
if (!(op->flags & FTRACE_OPS_FL_RCU) || rcu_is_watching())
op->func(ip, parent_ip, op, fregs);
- preempt_enable_notrace();
trace_clear_recursion(bit);
}
NOKPROBE_SYMBOL(ftrace_ops_assist_func);
synchronize_rcu();
if ((type & TRACE_PIDS) && pid_list)
- trace_free_pid_list(pid_list);
+ trace_pid_list_free(pid_list);
if ((type & TRACE_NO_PIDS) && no_pid_list)
- trace_free_pid_list(no_pid_list);
+ trace_pid_list_free(no_pid_list);
}
void ftrace_clear_pids(struct trace_array *tr)
if (filtered_pids) {
synchronize_rcu();
- trace_free_pid_list(filtered_pids);
+ trace_pid_list_free(filtered_pids);
} else if (pid_list && !other_pids) {
/* Register a probe to set whether to ignore the tracing of a task */
register_trace_sched_switch(ftrace_filter_pid_sched_switch_probe, tr);
void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d_tracer)
{
- trace_create_file("set_ftrace_pid", 0644, d_tracer,
+ trace_create_file("set_ftrace_pid", TRACE_MODE_WRITE, d_tracer,
tr, &ftrace_pid_fops);
- trace_create_file("set_ftrace_notrace_pid", 0644, d_tracer,
- tr, &ftrace_no_pid_fops);
+ trace_create_file("set_ftrace_notrace_pid", TRACE_MODE_WRITE,
+ d_tracer, tr, &ftrace_no_pid_fops);
}
void __init ftrace_init_tracefs_toplevel(struct trace_array *tr,
projects / platform / kernel / linux-rpi.git / blobdiff