From d44a4b9df5ff0d660310f3cff76ae16aac14855d Mon Sep 17 00:00:00 2001
From: Josh Poimboeuf <jpoimboe@redhat.com>
Date: Wed, 18 Oct 2017 06:29:10 -0500
Subject: [PATCH] livepatch-patch-hook: clean up version checks

Clean up the kernel version checks a little bit.  Use 'HAVE_*' naming
everywhere for consistency.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
---
 kmod/patch/livepatch-patch-hook.c | 50 ++++++++++++++++---------------
 1 file changed, 26 insertions(+), 24 deletions(-)

diff --git a/kmod/patch/livepatch-patch-hook.c b/kmod/patch/livepatch-patch-hook.c
index c4c6bee..40cb27f 100644
--- a/kmod/patch/livepatch-patch-hook.c
+++ b/kmod/patch/livepatch-patch-hook.c
@@ -35,8 +35,18 @@
 #define UTS_UBUNTU_RELEASE_ABI 0
 #endif
 
-#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 7, 0)
-#define NEED_KLP_RELOCS
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 7, 0)
+#define HAVE_ELF_RELOCS
+#endif
+
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 5, 0) ||			\
+    (LINUX_VERSION_CODE >= KERNEL_VERSION(4, 4, 0) &&			\
+      UTS_UBUNTU_RELEASE_ABI >= 7)
+#define HAVE_SYMPOS
+#endif
+
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 12, 0)
+#define HAVE_IMMEDIATE
 #endif
 
 /*
@@ -87,7 +97,7 @@ static struct patch_object *patch_alloc_new_object(const char *name)
 	if (!object)
 		return NULL;
 	INIT_LIST_HEAD(&object->funcs);
-#ifdef NEED_KLP_RELOCS
+#ifndef HAVE_ELF_RELOCS
 	INIT_LIST_HEAD(&object->relocs);
 #endif
 	if (strcmp(name, "vmlinux"))
@@ -129,7 +139,7 @@ static int patch_add_func_to_object(struct kpatch_patch_func *kfunc)
 	return 0;
 }
 
-#ifdef NEED_KLP_RELOCS
+#ifndef HAVE_ELF_RELOCS
 static int patch_add_reloc_to_object(struct kpatch_patch_dynrela *kdynrela)
 {
 	struct patch_reloc *reloc;
@@ -155,7 +165,7 @@ static int patch_add_reloc_to_object(struct kpatch_patch_dynrela *kdynrela)
 static void patch_free_scaffold(void) {
 	struct patch_func *func, *safefunc;
 	struct patch_object *object, *safeobject;
-#ifdef NEED_KLP_RELOCS
+#ifndef HAVE_ELF_RELOCS
 	struct patch_reloc *reloc, *safereloc;
 #endif
 
@@ -165,7 +175,7 @@ static void patch_free_scaffold(void) {
 			list_del(&func->list);
 			kfree(func);
 		}
-#ifdef NEED_KLP_RELOCS
+#ifndef HAVE_ELF_RELOCS
 		list_for_each_entry_safe(reloc, safereloc,
 		                         &object->relocs, list) {
 			list_del(&reloc->list);
@@ -185,7 +195,7 @@ static void patch_free_livepatch(struct klp_patch *patch)
 		for (object = patch->objs; object && object->funcs; object++) {
 			if (object->funcs)
 				kfree(object->funcs);
-#ifdef NEED_KLP_RELOCS
+#ifndef HAVE_ELF_RELOCS
 			if (object->relocs)
 				kfree(object->relocs);
 #endif
@@ -197,7 +207,7 @@ static void patch_free_livepatch(struct klp_patch *patch)
 }
 
 extern struct kpatch_patch_func __kpatch_funcs[], __kpatch_funcs_end[];
-#ifdef NEED_KLP_RELOCS
+#ifndef HAVE_ELF_RELOCS
 extern struct kpatch_patch_dynrela __kpatch_dynrelas[], __kpatch_dynrelas_end[];
 #endif
 
@@ -209,7 +219,7 @@ static int __init patch_init(void)
 	struct patch_object *object;
 	struct patch_func *func;
 	int ret = 0, i, j;
-#ifdef NEED_KLP_RELOCS
+#ifndef HAVE_ELF_RELOCS
 	struct kpatch_patch_dynrela *kdynrela;
 	struct patch_reloc *reloc;
 	struct klp_reloc *lrelocs, *lreloc;
@@ -224,7 +234,7 @@ static int __init patch_init(void)
 			goto out;
 	}
 
-#ifdef NEED_KLP_RELOCS
+#ifndef HAVE_ELF_RELOCS
 	for (kdynrela = __kpatch_dynrelas;
 	     kdynrela != __kpatch_dynrelas_end;
 	     kdynrela++) {
@@ -248,10 +258,8 @@ static int __init patch_init(void)
 		goto out;
 	lpatch->mod = THIS_MODULE;
 	lpatch->objs = lobjects;
-#if __powerpc__
-#if (LINUX_VERSION_CODE >= KERNEL_VERSION(4, 12, 0))
+#if defined(__powerpc__) && defined(HAVE_IMMEDIATE)
 	lpatch->immediate = true;
-#endif
 #endif
 
 	i = 0;
@@ -268,10 +276,7 @@ static int __init patch_init(void)
 			lfunc = &lfuncs[j];
 			lfunc->old_name = func->kfunc->name;
 			lfunc->new_func = (void *)func->kfunc->new_addr;
-#if (( LINUX_VERSION_CODE >= KERNEL_VERSION(4, 5, 0) ) || \
-     ( LINUX_VERSION_CODE >= KERNEL_VERSION(4, 4, 0) && \
-      UTS_UBUNTU_RELEASE_ABI >= 7 ) \
-    )
+#ifdef HAVE_SYMPOS
 			lfunc->old_sympos = func->kfunc->sympos;
 #else
 			lfunc->old_addr = func->kfunc->old_addr;
@@ -279,7 +284,7 @@ static int __init patch_init(void)
 			j++;
 		}
 
-#ifdef NEED_KLP_RELOCS
+#ifndef HAVE_ELF_RELOCS
 		lrelocs = kzalloc(sizeof(struct klp_reloc) *
 				  (object->relocs_nr+1), GFP_KERNEL);
 		if (!lrelocs)
@@ -289,21 +294,18 @@ static int __init patch_init(void)
 		list_for_each_entry(reloc, &object->relocs, list) {
 			lreloc = &lrelocs[j];
 			lreloc->loc = reloc->kdynrela->dest;
-#if (( LINUX_VERSION_CODE >= KERNEL_VERSION(4, 5, 0) ) || \
-     ( LINUX_VERSION_CODE >= KERNEL_VERSION(4, 4, 0) && \
-      UTS_UBUNTU_RELEASE_ABI >= 7 ) \
-    )
+#ifdef HAVE_SYMPOS
 			lreloc->sympos = reloc->kdynrela->sympos;
 #else
 			lreloc->val = reloc->kdynrela->src;
-#endif /* 4.5.0 */
+#endif /* HAVE_SYMPOS */
 			lreloc->type = reloc->kdynrela->type;
 			lreloc->name = reloc->kdynrela->name;
 			lreloc->addend = reloc->kdynrela->addend;
 			lreloc->external = reloc->kdynrela->external;
 			j++;
 		}
-#endif /* 4.7.0 */
+#endif /* HAVE_ELF_RELOCS */
 
 		i++;
 	}