1 files changed, 10 insertions, 12 deletions

diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index 5c19b8c41c7e..9eaf07f99212 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -607,11 +607,17 @@ static int trace_kprobe_create(int argc, const char *argv[])
         char buf[MAX_EVENT_NAME_LEN];
         unsigned int flags = TPARG_FL_KERNEL;
 
-        /* argc must be >= 1 */
-        if (argv[0][0] == 'r') {
+        switch (argv[0][0]) {
+        case 'r':
                 is_return = true;
                 flags |= TPARG_FL_RETURN;
-        } else if (argv[0][0] != 'p' || argc < 2)
+                break;
+        case 'p':
+                break;
+        default:
+                return -ECANCELED;
+        }
+        if (argc < 2)
                 return -ECANCELED;
 
         event = strchr(&argv[0][1], ':');
@@ -855,22 +861,14 @@ static const struct file_operations kprobe_profile_ops = {
 static nokprobe_inline int
 fetch_store_strlen(unsigned long addr)
 {
-        mm_segment_t old_fs;
         int ret, len = 0;
         u8 c;
 
-        old_fs = get_fs();
-        set_fs(KERNEL_DS);
-        pagefault_disable();
-
         do {
-                ret = __copy_from_user_inatomic(&c, (u8 *)addr + len, 1);
+                ret = probe_mem_read(&c, (u8 *)addr + len, 1);
                 len++;
         } while (c && ret == 0 && len < MAX_STRING_SIZE);
 
-        pagefault_enable();
-        set_fs(old_fs);
-
         return (ret < 0) ? ret : len;
 }