sh: ftrace: Fix up syscall tracepoint support.

Sync up with latest core changes in the syscalls tracing area:

- tracing: Map syscall name to number (syscall_name_to_nr())
- tracing: Call arch_init_ftrace_syscalls at boot
- tracing: add support tracepoint ids (set_syscall_{enter,exit}_id())

Taken from the s390 change.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

1 files changed, 27 insertions, 10 deletions

diff --git a/arch/sh/kernel/ftrace.c b/arch/sh/kernel/ftrace.c
index a3dcc6d5d253..2c48e267256e 100644
--- a/arch/sh/kernel/ftrace.c
+++ b/arch/sh/kernel/ftrace.c
@@ -291,31 +291,48 @@ struct syscall_metadata *syscall_nr_to_meta(int nr)
         return syscalls_metadata[nr];
 }
 
-void arch_init_ftrace_syscalls(void)
+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;
+}
+
+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 /* CONFIG_FTRACE_SYSCALLS */