From 62e9cb43c324c933b2934ce9d2923097b96dab1e Mon Sep 17 00:00:00 2001
From: Zhipeng Xie <xiezhipeng1@huawei.com>
Date: Wed, 26 Feb 2020 20:43:34 -0500
Subject: [PATCH 14/23] livepatch-patch-hook: support force enable/disable

we use force to indicate function which bypass stack check

Signed-off-by: Zhipeng Xie <xiezhipeng1@huawei.com>
---
 kmod/patch/kpatch-patch.h         |  1 +
 kmod/patch/livepatch-patch-hook.c | 18 ++++++++++++++++++
 kpatch-build/kpatch-build         |  4 ++++
 3 files changed, 23 insertions(+)

diff --git a/kmod/patch/kpatch-patch.h b/kmod/patch/kpatch-patch.h
index 9df7818..6e39364 100644
--- a/kmod/patch/kpatch-patch.h
+++ b/kmod/patch/kpatch-patch.h
@@ -64,4 +64,5 @@ struct kpatch_post_unpatch_callback {
 	char *objname;
 };
 
+extern unsigned long __kpatch_force_funcs[], __kpatch_force_funcs_end[];
 #endif /* _KPATCH_PATCH_H_ */
diff --git a/kmod/patch/livepatch-patch-hook.c b/kmod/patch/livepatch-patch-hook.c
index fb23a94..5a0de7f 100644
--- a/kmod/patch/livepatch-patch-hook.c
+++ b/kmod/patch/livepatch-patch-hook.c
@@ -239,6 +239,17 @@ extern struct kpatch_post_patch_callback __kpatch_callbacks_post_patch[], __kpat
 extern struct kpatch_pre_unpatch_callback __kpatch_callbacks_pre_unpatch[], __kpatch_callbacks_pre_unpatch_end[];
 extern struct kpatch_post_unpatch_callback __kpatch_callbacks_post_unpatch[], __kpatch_callbacks_post_unpatch_end[];
 
+static int patch_is_func_forced(unsigned long addr)
+{
+	unsigned long *a;
+
+	for (a = __kpatch_force_funcs; a < __kpatch_force_funcs_end; a++)
+		if (*a == addr)
+			return 1;
+	return 0;
+}
+
+
 #ifdef HAVE_CALLBACKS
 static int add_callbacks_to_patch_objects(void)
 {
@@ -403,6 +414,13 @@ static int __init patch_init(void)
 			lfunc = &lfuncs[j];
 			lfunc->old_name = func->kfunc->name;
 			lfunc->new_func = (void *)func->kfunc->new_addr;
+#if defined(__KLP_SUPPORT_FORCE__)
+#ifdef __ALL_FORCE__
+			lfunc->force = 1;
+#else
+			lfunc->force = patch_is_func_forced(func->kfunc->new_addr);
+#endif
+#endif
 #ifdef HAVE_SYMPOS
 			lfunc->old_sympos = func->kfunc->sympos;
 #else
diff --git a/kpatch-build/kpatch-build b/kpatch-build/kpatch-build
index 8bef7fb..57487b1 100755
--- a/kpatch-build/kpatch-build
+++ b/kpatch-build/kpatch-build
@@ -1079,6 +1079,10 @@ if "$KPATCH_MODULE"; then
 	export KCPPFLAGS="-D__KPATCH_MODULE__"
 fi
 
+if [[ -n "$NO_STACK_CHECK" ]];then
+	export KCPPFLAGS="-D__ALL_FORCE__ $KCPPFLAGS"
+fi
+
 if [[ -n "$KLP_SUPPORT_FORCE" ]];then
 	export KCPPFLAGS="-D__KLP_SUPPORT_FORCE__ $KCPPFLAGS"
 fi
-- 
2.18.1