X-Git-Url: http://git.lttng.org/?a=blobdiff_plain;f=include%2Flttng%2Fprobe-user.h;h=40b91461838f7675fbb0dacf0f1d0b147e58d10c;hb=9f2d2694cf0655682a1f0c29a7f3b868680524a5;hp=6b7f38dc98afdea2fa006fee0f8504c25c8c5e24;hpb=3b4aafcbbef722c5d04f2fe06a47c47d4d23eda0;p=lttng-modules.git

diff --git a/include/lttng/probe-user.h b/include/lttng/probe-user.h
index 6b7f38dc..40b91461 100644
--- a/include/lttng/probe-user.h
+++ b/include/lttng/probe-user.h
@@ -8,10 +8,33 @@
 #ifndef _LTTNG_PROBE_USER_H
 #define _LTTNG_PROBE_USER_H
 
+#include <wrapper/uaccess.h>
+
 /*
  * Calculate string length. Include final null terminating character if there is
  * one, or ends at first fault.
  */
 long lttng_strlen_user_inatomic(const char *addr);
 
+/*
+ * We use __copy_from_user_inatomic to copy userspace data after
+ * checking with access_ok() and disabling page faults.
+ *
+ * Return 0 if OK, nonzero on error.
+ */
+static inline
+unsigned long lttng_copy_from_user_check_nofault(void *dest,
+						 const void __user *src,
+						 unsigned long len)
+{
+	unsigned long ret;
+
+	if (!lttng_access_ok(VERIFY_READ, src, len))
+		return 1;
+	pagefault_disable();
+	ret = __copy_from_user_inatomic(dest, src, len);
+	pagefault_enable();
+	return ret;
+}
+
 #endif /* _LTTNG_PROBE_USER_H */