From c9a70dd5923ea075c8401455afa7cca79118282b Mon Sep 17 00:00:00 2001
From: Suren Baghdasaryan <surenb@google.com>
Date: Wed, 27 Jul 2022 01:05:51 -0700
Subject: [PATCH] ANDROID: GKI: allow mm vendor hooks header inclusion from
 header files

Introduce PROTECT_TRACE_INCLUDE_PATH to allow trace/hooks/mm.h to be
included from a header file. When trace/hooks/mm.h is included from a
header file PROTECT_TRACE_INCLUDE_PATH should be defined before the
inclusion so that the existing TRACE_INCLUDE_PATH gets preserved.

Bug: 236578020
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Change-Id: Ia5890ba51675de41ff3ea4ab38bcb458202df5fb
---
 include/trace/hooks/mm.h              | 11 +++++++++
 include/trace/hooks/restore_incpath.h | 32 +++++++++++++++++++++++++++
 include/trace/hooks/save_incpath.h    | 29 ++++++++++++++++++++++++
 3 files changed, 72 insertions(+)
 create mode 100644 include/trace/hooks/restore_incpath.h
 create mode 100644 include/trace/hooks/save_incpath.h

diff --git a/include/trace/hooks/mm.h b/include/trace/hooks/mm.h
index ae6e379fb487..742862fc5134 100644
--- a/include/trace/hooks/mm.h
+++ b/include/trace/hooks/mm.h
@@ -1,4 +1,13 @@
 /* SPDX-License-Identifier: GPL-2.0 */
+#ifdef PROTECT_TRACE_INCLUDE_PATH
+#undef PROTECT_TRACE_INCLUDE_PATH
+
+#include <trace/hooks/save_incpath.h>
+#include <trace/hooks/mm.h>
+#include <trace/hooks/restore_incpath.h>
+
+#else /* PROTECT_TRACE_INCLUDE_PATH */
+
 #undef TRACE_SYSTEM
 #define TRACE_SYSTEM mm
 
@@ -230,3 +239,5 @@ DECLARE_HOOK(android_vh_set_shmem_page_flag,
 
 /* This part must be outside protection */
 #include <trace/define_trace.h>
+
+#endif /* PROTECT_TRACE_INCLUDE_PATH */
diff --git a/include/trace/hooks/restore_incpath.h b/include/trace/hooks/restore_incpath.h
new file mode 100644
index 000000000000..3a97e4572007
--- /dev/null
+++ b/include/trace/hooks/restore_incpath.h
@@ -0,0 +1,32 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Include this file from a header declaring vendor hooks to preserve and later
+ * restore TRACE_INCLUDE_PATH value. Typical usage:
+ *
+ *   #ifdef PROTECT_TRACE_INCLUDE_PATH
+ *   #undef PROTECT_TRACE_INCLUDE_PATH
+ *
+ *   #include <trace/hooks/save_incpath.h>
+ *   #include <vendor hooks header>
+ *   #include <trace/hooks/restore_incpath.h>
+ *
+ *   #else
+ *
+ *   <vendor hook definitions>
+ *
+ *   #endif
+ *
+ * The header that includes vendor hooks header file should define
+ * PROTECT_TRACE_INCLUDE_PATH before including the vendor hook file like this:
+ *
+ *   #define PROTECT_TRACE_INCLUDE_PATH
+ *   #include <vendor hooks header>
+ */
+#ifdef STORED_TRACE_INCLUDE_PATH
+# undef TRACE_INCLUDE_PATH
+# define TRACE_INCLUDE_PATH STORED_TRACE_INCLUDE_PATH
+# undef STORED_TRACE_INCLUDE_PATH
+#else
+# undef TRACE_INCLUDE_PATH
+#endif
+
diff --git a/include/trace/hooks/save_incpath.h b/include/trace/hooks/save_incpath.h
new file mode 100644
index 000000000000..3b4621a47275
--- /dev/null
+++ b/include/trace/hooks/save_incpath.h
@@ -0,0 +1,29 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Include this file from a header declaring vendor hooks to preserve and later
+ * restore TRACE_INCLUDE_PATH value. Typical usage:
+ *
+ *   #ifdef PROTECT_TRACE_INCLUDE_PATH
+ *   #undef PROTECT_TRACE_INCLUDE_PATH
+ *
+ *   #include <trace/hooks/save_incpath.h>
+ *   #include <vendor hooks header>
+ *   #include <trace/hooks/restore_incpath.h>
+ *
+ *   #else
+ *
+ *   <vendor hook definitions>
+ *
+ *   #endif
+ *
+ * The header that includes vendor hooks header file should define
+ * PROTECT_TRACE_INCLUDE_PATH before including the vendor hook file like this:
+ *
+ *   #define PROTECT_TRACE_INCLUDE_PATH
+ *   #include <vendor hooks header>
+ */
+#ifdef TRACE_INCLUDE_PATH
+#define STORED_TRACE_INCLUDE_PATH TRACE_INCLUDE_PATH
+#undef TRACE_INCLUDE_PATH
+#endif
+