ftrace: use probe_kernel
Andrew Morton suggested using the proper API for reading and writing
kernel areas that might fault.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c
index 7834554..da4fb0d 100644
--- a/arch/x86/kernel/ftrace.c
+++ b/arch/x86/kernel/ftrace.c
@@ -67,15 +67,14 @@
* Note: Due to modules and __init, code can
* disappear and change, we need to protect against faulting
* as well as code changing. We do this by using the
- * __copy_*_user functions.
+ * probe_kernel_* functions.
*
* No real locking needed, this code is run through
* kstop_machine, or before SMP starts.
*/
/* read the text we want to modify */
- if (__copy_from_user_inatomic(replaced, (char __user *)ip,
- MCOUNT_INSN_SIZE))
+ if (probe_kernel_read(replaced, (void *)ip, MCOUNT_INSN_SIZE))
return -EFAULT;
/* Make sure it is what we expect it to be */
@@ -83,8 +82,7 @@
return -EINVAL;
/* replace the text with the new text */
- if (__copy_to_user_inatomic((char __user *)ip, new_code,
- MCOUNT_INSN_SIZE))
+ if (probe_kernel_write((void *)ip, new_code, MCOUNT_INSN_SIZE))
return -EPERM;
sync_core();