tracing: Call arch_init_ftrace_syscalls at boot

Call arch_init_ftrace_syscalls at boot, so we can determine early the
set of syscalls for the syscall trace events.

Signed-off-by: Jason Baron <jbaron@redhat.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Jiaying Zhang <jiayingz@google.com>
Cc: Martin Bligh <mbligh@google.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Masami Hiramatsu <mhiramat@redhat.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>

1 files changed, 4 insertions, 11 deletions

diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c
index afb31d72618..0d93d409b8d 100644
--- a/arch/x86/kernel/ftrace.c
+++ b/arch/x86/kernel/ftrace.c
@@ -516,31 +516,24 @@ int syscall_name_to_nr(char *name)
         return -1;
 }
 
-void arch_init_ftrace_syscalls(void)
+static int __init arch_init_ftrace_syscalls(void)
 {
         int i;
         struct syscall_metadata *meta;
         unsigned long **psys_syscall_table = &sys_call_table;
-        static atomic_t refs;
-
-        if (atomic_inc_return(&refs) != 1)
-                goto end;
 
         syscalls_metadata = kzalloc(sizeof(*syscalls_metadata) *
                                         FTRACE_SYSCALL_MAX, GFP_KERNEL);
         if (!syscalls_metadata) {
                 WARN_ON(1);
-                return;
+                return -ENOMEM;
         }
 
         for (i = 0; i < FTRACE_SYSCALL_MAX; i++) {
                 meta = find_syscall_meta(psys_syscall_table[i]);
                 syscalls_metadata[i] = meta;
         }
-        return;
-
-        /* Paranoid: avoid overflow */
-end:
-        atomic_dec(&refs);
+        return 0;
 }
+arch_initcall(arch_init_ftrace_syscalls);
 #endif