kprobes: introduce weak arch_check_ftrace_location() helper function

Introduce weak arch_check_ftrace_location() helper function which
architectures can override in order to implement handling of kprobes
on function tracer call sites on their own, without depending on
common code or implementing the KPROBES_ON_FTRACE feature.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 11 insertions, 7 deletions

diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index 3995f546d0f3..317eb8ad28dd 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -1410,16 +1410,10 @@ static inline int check_kprobe_rereg(struct kprobe *p)
         return ret;
 }
 
-static int check_kprobe_address_safe(struct kprobe *p,
-                                     struct module **probed_mod)
+int __weak arch_check_ftrace_location(struct kprobe *p)
 {
-        int ret = 0;
         unsigned long ftrace_addr;
 
-        /*
-         * If the address is located on a ftrace nop, set the
-         * breakpoint to the following instruction.
-         */
         ftrace_addr = ftrace_location((unsigned long)p->addr);
         if (ftrace_addr) {
 #ifdef CONFIG_KPROBES_ON_FTRACE
@@ -1431,7 +1425,17 @@ static int check_kprobe_address_safe(struct kprobe *p,
                 return -EINVAL;
 #endif
         }
+        return 0;
+}
 
+static int check_kprobe_address_safe(struct kprobe *p,
+                                     struct module **probed_mod)
+{
+        int ret;
+
+        ret = arch_check_ftrace_location(p);
+        if (ret)
+                return ret;
         jump_label_lock();
         preempt_disable();