Merge branch 'tracing/urgent' into tracing/core

[linux-2.6-block.git] / kernel / trace / trace_syscalls.c

diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c
index 527e17eae57516a1f36932d13e1799d1244ef03f..ddee9c593732557b5451e741e0d58d9046f76ae6 100644 (file)
--- a/kernel/trace/trace_syscalls.c
+++ b/kernel/trace/trace_syscalls.c
@@ -14,6 +14,69 @@ static int sys_refcount_exit;
 static DECLARE_BITMAP(enabled_enter_syscalls, NR_syscalls);
 static DECLARE_BITMAP(enabled_exit_syscalls, NR_syscalls);
 
+extern unsigned long __start_syscalls_metadata[];
+extern unsigned long __stop_syscalls_metadata[];
+
+static struct syscall_metadata **syscalls_metadata;
+
+static struct syscall_metadata *find_syscall_meta(unsigned long syscall)
+{
+       struct syscall_metadata *start;
+       struct syscall_metadata *stop;
+       char str[KSYM_SYMBOL_LEN];
+
+
+       start = (struct syscall_metadata *)__start_syscalls_metadata;
+       stop = (struct syscall_metadata *)__stop_syscalls_metadata;
+       kallsyms_lookup(syscall, NULL, NULL, NULL, str);
+
+       for ( ; start < stop; start++) {
+               /*
+                * Only compare after the "sys" prefix. Archs that use
+                * syscall wrappers may have syscalls symbols aliases prefixed
+                * with "SyS" instead of "sys", leading to an unwanted
+                * mismatch.
+                */
+               if (start->name && !strcmp(start->name + 3, str + 3))
+                       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];
+}
+
+int syscall_name_to_nr(char *name)
+{
+       int i;
+
+       if (!syscalls_metadata)
+               return -1;
+
+       for (i = 0; i < NR_syscalls; i++) {
+               if (syscalls_metadata[i]) {
+                       if (!strcmp(syscalls_metadata[i]->name, name))
+                               return i;
+               }
+       }
+       return -1;
+}
+
+void set_syscall_enter_id(int num, int id)
+{
+       syscalls_metadata[num]->enter_id = id;
+}
+
+void set_syscall_exit_id(int num, int id)
+{
+       syscalls_metadata[num]->exit_id = id;
+}
+
 enum print_line_t
 print_syscall_enter(struct trace_iterator *iter, int flags)
 {
@@ -375,6 +438,29 @@ struct trace_event event_syscall_exit = {
        .trace                  = print_syscall_exit,
 };
 
+int __init init_ftrace_syscalls(void)
+{
+       struct syscall_metadata *meta;
+       unsigned long addr;
+       int i;
+
+       syscalls_metadata = kzalloc(sizeof(*syscalls_metadata) *
+                                       NR_syscalls, GFP_KERNEL);
+       if (!syscalls_metadata) {
+               WARN_ON(1);
+               return -ENOMEM;
+       }
+
+       for (i = 0; i < NR_syscalls; i++) {
+               addr = arch_syscall_addr(i);
+               meta = find_syscall_meta(addr);
+               syscalls_metadata[i] = meta;
+       }
+
+       return 0;
+}
+core_initcall(init_ftrace_syscalls);
+
 #ifdef CONFIG_EVENT_PROFILE
 
 static DECLARE_BITMAP(enabled_prof_enter_syscalls, NR_syscalls);