Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / kernel / trace / trace_syscalls.c
diff --git a/kernel/kernel/trace/trace_syscalls.c b/kernel/kernel/trace/trace_syscalls.c
new file mode 100644 (file)
index 0000000..f97f6e3
--- /dev/null
@@ -0,0 +1,750 @@
+#include <trace/syscall.h>
+#include <trace/events/syscalls.h>
+#include <linux/syscalls.h>
+#include <linux/slab.h>
+#include <linux/kernel.h>
+#include <linux/module.h>      /* for MODULE_NAME_LEN via KSYM_SYMBOL_LEN */
+#include <linux/ftrace.h>
+#include <linux/perf_event.h>
+#include <asm/syscall.h>
+
+#include "trace_output.h"
+#include "trace.h"
+
+static DEFINE_MUTEX(syscall_trace_lock);
+
+static int syscall_enter_register(struct ftrace_event_call *event,
+                                enum trace_reg type, void *data);
+static int syscall_exit_register(struct ftrace_event_call *event,
+                                enum trace_reg type, void *data);
+
+static struct list_head *
+syscall_get_enter_fields(struct ftrace_event_call *call)
+{
+       struct syscall_metadata *entry = call->data;
+
+       return &entry->enter_fields;
+}
+
+extern struct syscall_metadata *__start_syscalls_metadata[];
+extern struct syscall_metadata *__stop_syscalls_metadata[];
+
+static struct syscall_metadata **syscalls_metadata;
+
+#ifndef ARCH_HAS_SYSCALL_MATCH_SYM_NAME
+static inline bool arch_syscall_match_sym_name(const char *sym, const char *name)
+{
+       /*
+        * Only compare after the "sys" prefix. Archs that use
+        * syscall wrappers may have syscalls symbols aliases prefixed
+        * with ".SyS" or ".sys" instead of "sys", leading to an unwanted
+        * mismatch.
+        */
+       return !strcmp(sym + 3, name + 3);
+}
+#endif
+
+#ifdef ARCH_TRACE_IGNORE_COMPAT_SYSCALLS
+/*
+ * Some architectures that allow for 32bit applications
+ * to run on a 64bit kernel, do not map the syscalls for
+ * the 32bit tasks the same as they do for 64bit tasks.
+ *
+ *     *cough*x86*cough*
+ *
+ * In such a case, instead of reporting the wrong syscalls,
+ * simply ignore them.
+ *
+ * For an arch to ignore the compat syscalls it needs to
+ * define ARCH_TRACE_IGNORE_COMPAT_SYSCALLS as well as
+ * define the function arch_trace_is_compat_syscall() to let
+ * the tracing system know that it should ignore it.
+ */
+static int
+trace_get_syscall_nr(struct task_struct *task, struct pt_regs *regs)
+{
+       if (unlikely(arch_trace_is_compat_syscall(regs)))
+               return -1;
+
+       return syscall_get_nr(task, regs);
+}
+#else
+static inline int
+trace_get_syscall_nr(struct task_struct *task, struct pt_regs *regs)
+{
+       return syscall_get_nr(task, regs);
+}
+#endif /* ARCH_TRACE_IGNORE_COMPAT_SYSCALLS */
+
+static __init struct syscall_metadata *
+find_syscall_meta(unsigned long syscall)
+{
+       struct syscall_metadata **start;
+       struct syscall_metadata **stop;
+       char str[KSYM_SYMBOL_LEN];
+
+
+       start = __start_syscalls_metadata;
+       stop = __stop_syscalls_metadata;
+       kallsyms_lookup(syscall, NULL, NULL, NULL, str);
+
+       if (arch_syscall_match_sym_name(str, "sys_ni_syscall"))
+               return NULL;
+
+       for ( ; start < stop; start++) {
+               if ((*start)->name && arch_syscall_match_sym_name(str, (*start)->name))
+                       return *start;
+       }
+       return NULL;
+}
+
+static struct syscall_metadata *syscall_nr_to_meta(int nr)
+{
+       if (!syscalls_metadata || nr >= NR_syscalls || nr < 0)
+               return NULL;
+
+       return syscalls_metadata[nr];
+}
+
+static enum print_line_t
+print_syscall_enter(struct trace_iterator *iter, int flags,
+                   struct trace_event *event)
+{
+       struct trace_seq *s = &iter->seq;
+       struct trace_entry *ent = iter->ent;
+       struct syscall_trace_enter *trace;
+       struct syscall_metadata *entry;
+       int i, syscall;
+
+       trace = (typeof(trace))ent;
+       syscall = trace->nr;
+       entry = syscall_nr_to_meta(syscall);
+
+       if (!entry)
+               goto end;
+
+       if (entry->enter_event->event.type != ent->type) {
+               WARN_ON_ONCE(1);
+               goto end;
+       }
+
+       trace_seq_printf(s, "%s(", entry->name);
+
+       for (i = 0; i < entry->nb_args; i++) {
+
+               if (trace_seq_has_overflowed(s))
+                       goto end;
+
+               /* parameter types */
+               if (trace_flags & TRACE_ITER_VERBOSE)
+                       trace_seq_printf(s, "%s ", entry->types[i]);
+
+               /* parameter values */
+               trace_seq_printf(s, "%s: %lx%s", entry->args[i],
+                                trace->args[i],
+                                i == entry->nb_args - 1 ? "" : ", ");
+       }
+
+       trace_seq_putc(s, ')');
+end:
+       trace_seq_putc(s, '\n');
+
+       return trace_handle_return(s);
+}
+
+static enum print_line_t
+print_syscall_exit(struct trace_iterator *iter, int flags,
+                  struct trace_event *event)
+{
+       struct trace_seq *s = &iter->seq;
+       struct trace_entry *ent = iter->ent;
+       struct syscall_trace_exit *trace;
+       int syscall;
+       struct syscall_metadata *entry;
+
+       trace = (typeof(trace))ent;
+       syscall = trace->nr;
+       entry = syscall_nr_to_meta(syscall);
+
+       if (!entry) {
+               trace_seq_putc(s, '\n');
+               goto out;
+       }
+
+       if (entry->exit_event->event.type != ent->type) {
+               WARN_ON_ONCE(1);
+               return TRACE_TYPE_UNHANDLED;
+       }
+
+       trace_seq_printf(s, "%s -> 0x%lx\n", entry->name,
+                               trace->ret);
+
+ out:
+       return trace_handle_return(s);
+}
+
+extern char *__bad_type_size(void);
+
+#define SYSCALL_FIELD(type, name)                                      \
+       sizeof(type) != sizeof(trace.name) ?                            \
+               __bad_type_size() :                                     \
+               #type, #name, offsetof(typeof(trace), name),            \
+               sizeof(trace.name), is_signed_type(type)
+
+static int __init
+__set_enter_print_fmt(struct syscall_metadata *entry, char *buf, int len)
+{
+       int i;
+       int pos = 0;
+
+       /* When len=0, we just calculate the needed length */
+#define LEN_OR_ZERO (len ? len - pos : 0)
+
+       pos += snprintf(buf + pos, LEN_OR_ZERO, "\"");
+       for (i = 0; i < entry->nb_args; i++) {
+               pos += snprintf(buf + pos, LEN_OR_ZERO, "%s: 0x%%0%zulx%s",
+                               entry->args[i], sizeof(unsigned long),
+                               i == entry->nb_args - 1 ? "" : ", ");
+       }
+       pos += snprintf(buf + pos, LEN_OR_ZERO, "\"");
+
+       for (i = 0; i < entry->nb_args; i++) {
+               pos += snprintf(buf + pos, LEN_OR_ZERO,
+                               ", ((unsigned long)(REC->%s))", entry->args[i]);
+       }
+
+#undef LEN_OR_ZERO
+
+       /* return the length of print_fmt */
+       return pos;
+}
+
+static int __init set_syscall_print_fmt(struct ftrace_event_call *call)
+{
+       char *print_fmt;
+       int len;
+       struct syscall_metadata *entry = call->data;
+
+       if (entry->enter_event != call) {
+               call->print_fmt = "\"0x%lx\", REC->ret";
+               return 0;
+       }
+
+       /* First: called with 0 length to calculate the needed length */
+       len = __set_enter_print_fmt(entry, NULL, 0);
+
+       print_fmt = kmalloc(len + 1, GFP_KERNEL);
+       if (!print_fmt)
+               return -ENOMEM;
+
+       /* Second: actually write the @print_fmt */
+       __set_enter_print_fmt(entry, print_fmt, len + 1);
+       call->print_fmt = print_fmt;
+
+       return 0;
+}
+
+static void __init free_syscall_print_fmt(struct ftrace_event_call *call)
+{
+       struct syscall_metadata *entry = call->data;
+
+       if (entry->enter_event == call)
+               kfree(call->print_fmt);
+}
+
+static int __init syscall_enter_define_fields(struct ftrace_event_call *call)
+{
+       struct syscall_trace_enter trace;
+       struct syscall_metadata *meta = call->data;
+       int ret;
+       int i;
+       int offset = offsetof(typeof(trace), args);
+
+       ret = trace_define_field(call, SYSCALL_FIELD(int, nr), FILTER_OTHER);
+       if (ret)
+               return ret;
+
+       for (i = 0; i < meta->nb_args; i++) {
+               ret = trace_define_field(call, meta->types[i],
+                                        meta->args[i], offset,
+                                        sizeof(unsigned long), 0,
+                                        FILTER_OTHER);
+               offset += sizeof(unsigned long);
+       }
+
+       return ret;
+}
+
+static int __init syscall_exit_define_fields(struct ftrace_event_call *call)
+{
+       struct syscall_trace_exit trace;
+       int ret;
+
+       ret = trace_define_field(call, SYSCALL_FIELD(int, nr), FILTER_OTHER);
+       if (ret)
+               return ret;
+
+       ret = trace_define_field(call, SYSCALL_FIELD(long, ret),
+                                FILTER_OTHER);
+
+       return ret;
+}
+
+static void ftrace_syscall_enter(void *data, struct pt_regs *regs, long id)
+{
+       struct trace_array *tr = data;
+       struct ftrace_event_file *ftrace_file;
+       struct syscall_trace_enter *entry;
+       struct syscall_metadata *sys_data;
+       struct ring_buffer_event *event;
+       struct ring_buffer *buffer;
+       unsigned long irq_flags;
+       int pc;
+       int syscall_nr;
+       int size;
+
+       syscall_nr = trace_get_syscall_nr(current, regs);
+       if (syscall_nr < 0 || syscall_nr >= NR_syscalls)
+               return;
+
+       /* Here we're inside tp handler's rcu_read_lock_sched (__DO_TRACE) */
+       ftrace_file = rcu_dereference_sched(tr->enter_syscall_files[syscall_nr]);
+       if (!ftrace_file)
+               return;
+
+       if (ftrace_trigger_soft_disabled(ftrace_file))
+               return;
+
+       sys_data = syscall_nr_to_meta(syscall_nr);
+       if (!sys_data)
+               return;
+
+       size = sizeof(*entry) + sizeof(unsigned long) * sys_data->nb_args;
+
+       local_save_flags(irq_flags);
+       pc = preempt_count();
+
+       buffer = tr->trace_buffer.buffer;
+       event = trace_buffer_lock_reserve(buffer,
+                       sys_data->enter_event->event.type, size, irq_flags, pc);
+       if (!event)
+               return;
+
+       entry = ring_buffer_event_data(event);
+       entry->nr = syscall_nr;
+       syscall_get_arguments(current, regs, 0, sys_data->nb_args, entry->args);
+
+       event_trigger_unlock_commit(ftrace_file, buffer, event, entry,
+                                   irq_flags, pc);
+}
+
+static void ftrace_syscall_exit(void *data, struct pt_regs *regs, long ret)
+{
+       struct trace_array *tr = data;
+       struct ftrace_event_file *ftrace_file;
+       struct syscall_trace_exit *entry;
+       struct syscall_metadata *sys_data;
+       struct ring_buffer_event *event;
+       struct ring_buffer *buffer;
+       unsigned long irq_flags;
+       int pc;
+       int syscall_nr;
+
+       syscall_nr = trace_get_syscall_nr(current, regs);
+       if (syscall_nr < 0 || syscall_nr >= NR_syscalls)
+               return;
+
+       /* Here we're inside tp handler's rcu_read_lock_sched (__DO_TRACE()) */
+       ftrace_file = rcu_dereference_sched(tr->exit_syscall_files[syscall_nr]);
+       if (!ftrace_file)
+               return;
+
+       if (ftrace_trigger_soft_disabled(ftrace_file))
+               return;
+
+       sys_data = syscall_nr_to_meta(syscall_nr);
+       if (!sys_data)
+               return;
+
+       local_save_flags(irq_flags);
+       pc = preempt_count();
+
+       buffer = tr->trace_buffer.buffer;
+       event = trace_buffer_lock_reserve(buffer,
+                       sys_data->exit_event->event.type, sizeof(*entry),
+                       irq_flags, pc);
+       if (!event)
+               return;
+
+       entry = ring_buffer_event_data(event);
+       entry->nr = syscall_nr;
+       entry->ret = syscall_get_return_value(current, regs);
+
+       event_trigger_unlock_commit(ftrace_file, buffer, event, entry,
+                                   irq_flags, pc);
+}
+
+static int reg_event_syscall_enter(struct ftrace_event_file *file,
+                                  struct ftrace_event_call *call)
+{
+       struct trace_array *tr = file->tr;
+       int ret = 0;
+       int num;
+
+       num = ((struct syscall_metadata *)call->data)->syscall_nr;
+       if (WARN_ON_ONCE(num < 0 || num >= NR_syscalls))
+               return -ENOSYS;
+       mutex_lock(&syscall_trace_lock);
+       if (!tr->sys_refcount_enter)
+               ret = register_trace_sys_enter(ftrace_syscall_enter, tr);
+       if (!ret) {
+               rcu_assign_pointer(tr->enter_syscall_files[num], file);
+               tr->sys_refcount_enter++;
+       }
+       mutex_unlock(&syscall_trace_lock);
+       return ret;
+}
+
+static void unreg_event_syscall_enter(struct ftrace_event_file *file,
+                                     struct ftrace_event_call *call)
+{
+       struct trace_array *tr = file->tr;
+       int num;
+
+       num = ((struct syscall_metadata *)call->data)->syscall_nr;
+       if (WARN_ON_ONCE(num < 0 || num >= NR_syscalls))
+               return;
+       mutex_lock(&syscall_trace_lock);
+       tr->sys_refcount_enter--;
+       RCU_INIT_POINTER(tr->enter_syscall_files[num], NULL);
+       if (!tr->sys_refcount_enter)
+               unregister_trace_sys_enter(ftrace_syscall_enter, tr);
+       mutex_unlock(&syscall_trace_lock);
+}
+
+static int reg_event_syscall_exit(struct ftrace_event_file *file,
+                                 struct ftrace_event_call *call)
+{
+       struct trace_array *tr = file->tr;
+       int ret = 0;
+       int num;
+
+       num = ((struct syscall_metadata *)call->data)->syscall_nr;
+       if (WARN_ON_ONCE(num < 0 || num >= NR_syscalls))
+               return -ENOSYS;
+       mutex_lock(&syscall_trace_lock);
+       if (!tr->sys_refcount_exit)
+               ret = register_trace_sys_exit(ftrace_syscall_exit, tr);
+       if (!ret) {
+               rcu_assign_pointer(tr->exit_syscall_files[num], file);
+               tr->sys_refcount_exit++;
+       }
+       mutex_unlock(&syscall_trace_lock);
+       return ret;
+}
+
+static void unreg_event_syscall_exit(struct ftrace_event_file *file,
+                                    struct ftrace_event_call *call)
+{
+       struct trace_array *tr = file->tr;
+       int num;
+
+       num = ((struct syscall_metadata *)call->data)->syscall_nr;
+       if (WARN_ON_ONCE(num < 0 || num >= NR_syscalls))
+               return;
+       mutex_lock(&syscall_trace_lock);
+       tr->sys_refcount_exit--;
+       RCU_INIT_POINTER(tr->exit_syscall_files[num], NULL);
+       if (!tr->sys_refcount_exit)
+               unregister_trace_sys_exit(ftrace_syscall_exit, tr);
+       mutex_unlock(&syscall_trace_lock);
+}
+
+static int __init init_syscall_trace(struct ftrace_event_call *call)
+{
+       int id;
+       int num;
+
+       num = ((struct syscall_metadata *)call->data)->syscall_nr;
+       if (num < 0 || num >= NR_syscalls) {
+               pr_debug("syscall %s metadata not mapped, disabling ftrace event\n",
+                               ((struct syscall_metadata *)call->data)->name);
+               return -ENOSYS;
+       }
+
+       if (set_syscall_print_fmt(call) < 0)
+               return -ENOMEM;
+
+       id = trace_event_raw_init(call);
+
+       if (id < 0) {
+               free_syscall_print_fmt(call);
+               return id;
+       }
+
+       return id;
+}
+
+struct trace_event_functions enter_syscall_print_funcs = {
+       .trace          = print_syscall_enter,
+};
+
+struct trace_event_functions exit_syscall_print_funcs = {
+       .trace          = print_syscall_exit,
+};
+
+struct ftrace_event_class __refdata event_class_syscall_enter = {
+       .system         = "syscalls",
+       .reg            = syscall_enter_register,
+       .define_fields  = syscall_enter_define_fields,
+       .get_fields     = syscall_get_enter_fields,
+       .raw_init       = init_syscall_trace,
+};
+
+struct ftrace_event_class __refdata event_class_syscall_exit = {
+       .system         = "syscalls",
+       .reg            = syscall_exit_register,
+       .define_fields  = syscall_exit_define_fields,
+       .fields         = LIST_HEAD_INIT(event_class_syscall_exit.fields),
+       .raw_init       = init_syscall_trace,
+};
+
+unsigned long __init __weak arch_syscall_addr(int nr)
+{
+       return (unsigned long)sys_call_table[nr];
+}
+
+void __init init_ftrace_syscalls(void)
+{
+       struct syscall_metadata *meta;
+       unsigned long addr;
+       int i;
+
+       syscalls_metadata = kcalloc(NR_syscalls, sizeof(*syscalls_metadata),
+                                   GFP_KERNEL);
+       if (!syscalls_metadata) {
+               WARN_ON(1);
+               return;
+       }
+
+       for (i = 0; i < NR_syscalls; i++) {
+               addr = arch_syscall_addr(i);
+               meta = find_syscall_meta(addr);
+               if (!meta)
+                       continue;
+
+               meta->syscall_nr = i;
+               syscalls_metadata[i] = meta;
+       }
+}
+
+#ifdef CONFIG_PERF_EVENTS
+
+static DECLARE_BITMAP(enabled_perf_enter_syscalls, NR_syscalls);
+static DECLARE_BITMAP(enabled_perf_exit_syscalls, NR_syscalls);
+static int sys_perf_refcount_enter;
+static int sys_perf_refcount_exit;
+
+static void perf_syscall_enter(void *ignore, struct pt_regs *regs, long id)
+{
+       struct syscall_metadata *sys_data;
+       struct syscall_trace_enter *rec;
+       struct hlist_head *head;
+       int syscall_nr;
+       int rctx;
+       int size;
+
+       syscall_nr = trace_get_syscall_nr(current, regs);
+       if (syscall_nr < 0 || syscall_nr >= NR_syscalls)
+               return;
+       if (!test_bit(syscall_nr, enabled_perf_enter_syscalls))
+               return;
+
+       sys_data = syscall_nr_to_meta(syscall_nr);
+       if (!sys_data)
+               return;
+
+       head = this_cpu_ptr(sys_data->enter_event->perf_events);
+       if (hlist_empty(head))
+               return;
+
+       /* get the size after alignment with the u32 buffer size field */
+       size = sizeof(unsigned long) * sys_data->nb_args + sizeof(*rec);
+       size = ALIGN(size + sizeof(u32), sizeof(u64));
+       size -= sizeof(u32);
+
+       rec = (struct syscall_trace_enter *)perf_trace_buf_prepare(size,
+                               sys_data->enter_event->event.type, NULL, &rctx);
+       if (!rec)
+               return;
+
+       rec->nr = syscall_nr;
+       syscall_get_arguments(current, regs, 0, sys_data->nb_args,
+                              (unsigned long *)&rec->args);
+       perf_trace_buf_submit(rec, size, rctx, 0, 1, regs, head, NULL);
+}
+
+static int perf_sysenter_enable(struct ftrace_event_call *call)
+{
+       int ret = 0;
+       int num;
+
+       num = ((struct syscall_metadata *)call->data)->syscall_nr;
+
+       mutex_lock(&syscall_trace_lock);
+       if (!sys_perf_refcount_enter)
+               ret = register_trace_sys_enter(perf_syscall_enter, NULL);
+       if (ret) {
+               pr_info("event trace: Could not activate"
+                               "syscall entry trace point");
+       } else {
+               set_bit(num, enabled_perf_enter_syscalls);
+               sys_perf_refcount_enter++;
+       }
+       mutex_unlock(&syscall_trace_lock);
+       return ret;
+}
+
+static void perf_sysenter_disable(struct ftrace_event_call *call)
+{
+       int num;
+
+       num = ((struct syscall_metadata *)call->data)->syscall_nr;
+
+       mutex_lock(&syscall_trace_lock);
+       sys_perf_refcount_enter--;
+       clear_bit(num, enabled_perf_enter_syscalls);
+       if (!sys_perf_refcount_enter)
+               unregister_trace_sys_enter(perf_syscall_enter, NULL);
+       mutex_unlock(&syscall_trace_lock);
+}
+
+static void perf_syscall_exit(void *ignore, struct pt_regs *regs, long ret)
+{
+       struct syscall_metadata *sys_data;
+       struct syscall_trace_exit *rec;
+       struct hlist_head *head;
+       int syscall_nr;
+       int rctx;
+       int size;
+
+       syscall_nr = trace_get_syscall_nr(current, regs);
+       if (syscall_nr < 0 || syscall_nr >= NR_syscalls)
+               return;
+       if (!test_bit(syscall_nr, enabled_perf_exit_syscalls))
+               return;
+
+       sys_data = syscall_nr_to_meta(syscall_nr);
+       if (!sys_data)
+               return;
+
+       head = this_cpu_ptr(sys_data->exit_event->perf_events);
+       if (hlist_empty(head))
+               return;
+
+       /* We can probably do that at build time */
+       size = ALIGN(sizeof(*rec) + sizeof(u32), sizeof(u64));
+       size -= sizeof(u32);
+
+       rec = (struct syscall_trace_exit *)perf_trace_buf_prepare(size,
+                               sys_data->exit_event->event.type, NULL, &rctx);
+       if (!rec)
+               return;
+
+       rec->nr = syscall_nr;
+       rec->ret = syscall_get_return_value(current, regs);
+       perf_trace_buf_submit(rec, size, rctx, 0, 1, regs, head, NULL);
+}
+
+static int perf_sysexit_enable(struct ftrace_event_call *call)
+{
+       int ret = 0;
+       int num;
+
+       num = ((struct syscall_metadata *)call->data)->syscall_nr;
+
+       mutex_lock(&syscall_trace_lock);
+       if (!sys_perf_refcount_exit)
+               ret = register_trace_sys_exit(perf_syscall_exit, NULL);
+       if (ret) {
+               pr_info("event trace: Could not activate"
+                               "syscall exit trace point");
+       } else {
+               set_bit(num, enabled_perf_exit_syscalls);
+               sys_perf_refcount_exit++;
+       }
+       mutex_unlock(&syscall_trace_lock);
+       return ret;
+}
+
+static void perf_sysexit_disable(struct ftrace_event_call *call)
+{
+       int num;
+
+       num = ((struct syscall_metadata *)call->data)->syscall_nr;
+
+       mutex_lock(&syscall_trace_lock);
+       sys_perf_refcount_exit--;
+       clear_bit(num, enabled_perf_exit_syscalls);
+       if (!sys_perf_refcount_exit)
+               unregister_trace_sys_exit(perf_syscall_exit, NULL);
+       mutex_unlock(&syscall_trace_lock);
+}
+
+#endif /* CONFIG_PERF_EVENTS */
+
+static int syscall_enter_register(struct ftrace_event_call *event,
+                                enum trace_reg type, void *data)
+{
+       struct ftrace_event_file *file = data;
+
+       switch (type) {
+       case TRACE_REG_REGISTER:
+               return reg_event_syscall_enter(file, event);
+       case TRACE_REG_UNREGISTER:
+               unreg_event_syscall_enter(file, event);
+               return 0;
+
+#ifdef CONFIG_PERF_EVENTS
+       case TRACE_REG_PERF_REGISTER:
+               return perf_sysenter_enable(event);
+       case TRACE_REG_PERF_UNREGISTER:
+               perf_sysenter_disable(event);
+               return 0;
+       case TRACE_REG_PERF_OPEN:
+       case TRACE_REG_PERF_CLOSE:
+       case TRACE_REG_PERF_ADD:
+       case TRACE_REG_PERF_DEL:
+               return 0;
+#endif
+       }
+       return 0;
+}
+
+static int syscall_exit_register(struct ftrace_event_call *event,
+                                enum trace_reg type, void *data)
+{
+       struct ftrace_event_file *file = data;
+
+       switch (type) {
+       case TRACE_REG_REGISTER:
+               return reg_event_syscall_exit(file, event);
+       case TRACE_REG_UNREGISTER:
+               unreg_event_syscall_exit(file, event);
+               return 0;
+
+#ifdef CONFIG_PERF_EVENTS
+       case TRACE_REG_PERF_REGISTER:
+               return perf_sysexit_enable(event);
+       case TRACE_REG_PERF_UNREGISTER:
+               perf_sysexit_disable(event);
+               return 0;
+       case TRACE_REG_PERF_OPEN:
+       case TRACE_REG_PERF_CLOSE:
+       case TRACE_REG_PERF_ADD:
+       case TRACE_REG_PERF_DEL:
+               return 0;
+#endif
+       }
+       return 0;
+}