From b62fdae0388dd8fdf4f4915ab4312ddbc0ea7cb2 Mon Sep 17 00:00:00 2001
From: Geoffrey McRae <geoff@hostfission.com>
Date: Thu, 12 Nov 2020 12:09:43 +1100
Subject: [PATCH] [core] split hook code out of module.c

---
 src/Makefile            |  2 +-
 src/{hooks.c => hook.c} | 47 +++++++++++++++++++++++++++++++++++------
 src/{hooks.h => hook.h} | 11 +++++-----
 src/module.c            | 21 ++++--------------
 4 files changed, 51 insertions(+), 30 deletions(-)
 rename src/{hooks.c => hook.c} (62%)
 rename src/{hooks.h => hook.h} (85%)

diff --git a/src/Makefile b/src/Makefile
index 77db1cf..420e98e 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -3,6 +3,6 @@ vendor-reset-y += \
 	src/vendor-reset-dev.o \
 	src/ioctl.o \
 	src/ftrace.o \
-	src/hooks.o
+	src/hook.o
 
 ccflags-y += -I$(src)/src
diff --git a/src/hooks.c b/src/hook.c
similarity index 62%
rename from src/hooks.c
rename to src/hook.c
index c36793c..6cb9ae3 100644
--- a/src/hooks.c
+++ b/src/hook.c
@@ -17,12 +17,19 @@ this program; if not, write to the Free Software Foundation, Inc., 59 Temple
 Place, Suite 330, Boston, MA 02111-1307 USA
 */
 
-#include <linux/kernel.h>
-#include <linux/pci.h>
-#include "vendor-reset-dev.h"
+#include "hook.h"
 #include "ftrace.h"
-#include "hooks.h"
+#include "vendor-reset-dev.h"
 
+#include <linux/module.h>
+
+#define vr_info(fmt, args...) pr_info("vendor-reset-hook: " fmt, ##args)
+#define vr_warn(fmt, args...) pr_warn("vendor-reset-hook: " fmt, ##args)
+
+static bool install_hook = true;
+module_param(install_hook, bool, 0);
+
+static bool hook_installed = false;
 static int (*orig_pci_dev_specific_reset)(struct pci_dev *dev, int probe);
 
 static int hooked_pci_dev_specific_reset(struct pci_dev *dev, int probe)
@@ -42,6 +49,34 @@ static int hooked_pci_dev_specific_reset(struct pci_dev *dev, int probe)
 }
 
 struct ftrace_hook fh_hooks[] = {
-    HOOK("pci_dev_specific_reset", &orig_pci_dev_specific_reset, hooked_pci_dev_specific_reset),
-    {0},
+  HOOK("pci_dev_specific_reset", &orig_pci_dev_specific_reset, hooked_pci_dev_specific_reset),
+  {0},
 };
+
+long vendor_reset_hook_init(void)
+{
+  int ret = 0;
+
+  if (install_hook)
+  {
+     ret = fh_install_hooks(fh_hooks);
+     if (ret)
+       vr_warn("install failed");
+     else
+     {
+       vr_info("installed");
+       hook_installed = true;
+     }
+  }
+
+  return ret;
+}
+
+void vendor_reset_hook_exit(void)
+{
+  if (hook_installed)
+  {
+    fh_remove_hooks(fh_hooks);
+    hook_installed = false;
+  }
+}
diff --git a/src/hooks.h b/src/hook.h
similarity index 85%
rename from src/hooks.h
rename to src/hook.h
index 5ddafb3..3a055ec 100644
--- a/src/hooks.h
+++ b/src/hook.h
@@ -17,11 +17,10 @@ this program; if not, write to the Free Software Foundation, Inc., 59 Temple
 Place, Suite 330, Boston, MA 02111-1307 USA
 */
 
-#ifndef __VENDOR_RESET_HOOKS_H__
-#define __VENDOR_RESET_HOOKS_H__
+#ifndef __VENDOR_RESET_HOOK_H__
+#define __VENDOR_RESET_HOOK_H__
 
-#include <linux/types.h>
+long vendor_reset_hook_init(void);
+void vendor_reset_hook_exit(void);
 
-extern struct ftrace_hook fh_hooks[];
-
-#endif
\ No newline at end of file
+#endif
diff --git a/src/module.c b/src/module.c
index 112b984..cfda59e 100644
--- a/src/module.c
+++ b/src/module.c
@@ -20,13 +20,8 @@ Place, Suite 330, Boston, MA 02111-1307 USA
 #include <linux/module.h>
 
 #include "ioctl.h"
-#include "ftrace.h"
 #include "hooks.h"
 
-#define vr_info(fmt, args...) pr_info("vendor-reset: " fmt, ##args)
-
-static bool install_hook = true;
-
 static int __init vendor_reset_init(void)
 {
   int ret;
@@ -35,14 +30,9 @@ static int __init vendor_reset_init(void)
   if (ret)
     return ret;
 
-  if (install_hook)
-  {
-    ret = fh_install_hooks(fh_hooks);
-    if (ret)
-      goto err;
-
-    vr_info("hooks installed\n");
-  }
+  ret = vendor_reset_hook_init();
+  if (ret)
+    goto err;
 
   return 0;
 
@@ -53,15 +43,12 @@ err:
 
 static void __exit vendor_reset_exit(void)
 {
-  if (install_hook)
-    fh_remove_hooks(fh_hooks);
-
+  vendor_reset_hook_exit();
   vendor_reset_ioctl_exit();
 }
 
 module_init(vendor_reset_init);
 module_exit(vendor_reset_exit);
-module_param(install_hook, bool, 0);
 
 MODULE_LICENSE("GPL v2");
 MODULE_AUTHOR("Geoffrey McRae <geoff@hostfission.com>");