livepatch/selftest: Clean up shadow variable names and type

The shadow variable selftest is quite tricky. Especially it is problematic
to understand what values are stored, returned, and printed.

Make it easier to understand by using "int *var, **sv" variables
consistently everywhere instead of the generic "void *", "ret",
and "ctor_data".

Signed-off-by: Petr Mladek <pmladek@suse.com>
Reviewed-by: Joe Lawrence <joe.lawrence@redhat.com>
Acked-by: Miroslav Benes <mbenes@suse.cz>
Reviewed-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

Author: pmladek

lib/livepatch/test_klp_shadow_vars.c

@@ -60,36 +60,43 @@ static int ptr_id(void *ptr)
  */
 static void *shadow_get(void *obj, unsigned long id)
 {
-	void *ret = klp_shadow_get(obj, id);
+	int **sv;
 
+	sv = klp_shadow_get(obj, id);
 	pr_info("klp_%s(obj=PTR%d, id=0x%lx) = PTR%d\n",
-		__func__, ptr_id(obj), id, ptr_id(ret));
+		__func__, ptr_id(obj), id, ptr_id(sv));
 
-	return ret;
+	return sv;
 }
 
 static void *shadow_alloc(void *obj, unsigned long id, size_t size,
 			  gfp_t gfp_flags, klp_shadow_ctor_t ctor,
 			  void *ctor_data)
 {
-	void *ret = klp_shadow_alloc(obj, id, size, gfp_flags, ctor,
-				     ctor_data);
+	int *var = ctor_data;
+	int **sv;
+
+	sv = klp_shadow_alloc(obj, id, size, gfp_flags, ctor, var);
 	pr_info("klp_%s(obj=PTR%d, id=0x%lx, size=%zx, gfp_flags=%pGg), ctor=PTR%d, ctor_data=PTR%d = PTR%d\n",
 		__func__, ptr_id(obj), id, size, &gfp_flags, ptr_id(ctor),
-		ptr_id(ctor_data), ptr_id(ret));
-	return ret;
+		ptr_id(var), ptr_id(sv));
+
+	return sv;
 }
 
 static void *shadow_get_or_alloc(void *obj, unsigned long id, size_t size,
 				 gfp_t gfp_flags, klp_shadow_ctor_t ctor,
 				 void *ctor_data)
 {
-	void *ret = klp_shadow_get_or_alloc(obj, id, size, gfp_flags, ctor,
-					    ctor_data);
+	int *var = ctor_data;
+	int **sv;
+
+	sv = klp_shadow_get_or_alloc(obj, id, size, gfp_flags, ctor, var);
 	pr_info("klp_%s(obj=PTR%d, id=0x%lx, size=%zx, gfp_flags=%pGg), ctor=PTR%d, ctor_data=PTR%d = PTR%d\n",
 		__func__, ptr_id(obj), id, size, &gfp_flags, ptr_id(ctor),
-		ptr_id(ctor_data), ptr_id(ret));
-	return ret;
+		ptr_id(var), ptr_id(sv));
+
+	return sv;
 }
 
 static void shadow_free(void *obj, unsigned long id, klp_shadow_dtor_t dtor)
@@ -110,18 +117,22 @@ static void shadow_free_all(unsigned long id, klp_shadow_dtor_t dtor)
 /* Shadow variable constructor - remember simple pointer data */
 static int shadow_ctor(void *obj, void *shadow_data, void *ctor_data)
 {
-	int **shadow_int = shadow_data;
-	*shadow_int = ctor_data;
+	int **sv = shadow_data;
+	int *var = ctor_data;
+
+	*sv = var;
 	pr_info("%s: PTR%d -> PTR%d\n",
-		__func__, ptr_id(shadow_int), ptr_id(ctor_data));
+		__func__, ptr_id(sv), ptr_id(var));
 
 	return 0;
 }
 
 static void shadow_dtor(void *obj, void *shadow_data)
 {
+	int **sv = shadow_data;
+
 	pr_info("%s(obj=PTR%d, shadow_data=PTR%d)\n",
-		__func__, ptr_id(obj), ptr_id(shadow_data));
+		__func__, ptr_id(obj), ptr_id(sv));
 }
 
 static int test_klp_shadow_vars_init(void)
@@ -134,7 +145,7 @@ static int test_klp_shadow_vars_init(void)
 	int var1, var2, var3, var4;
 	int **sv1, **sv2, **sv3, **sv4;
 
-	void *ret;
+	int **sv;
 
 	ptr_id(NULL);
 	ptr_id(&var1);
@@ -146,8 +157,8 @@ static int test_klp_shadow_vars_init(void)
 	 * With an empty shadow variable hash table, expect not to find
 	 * any matches.
 	 */
-	ret = shadow_get(obj, id);
-	if (!ret)
+	sv = shadow_get(obj, id);
+	if (!sv)
 		pr_info("  got expected NULL result\n");
 
 	/*
@@ -169,23 +180,23 @@ static int test_klp_shadow_vars_init(void)
 	 * Verify we can find our new shadow variables and that they point
 	 * to expected data.
 	 */
-	ret = shadow_get(obj, id);
-	if (!ret)
+	sv = shadow_get(obj, id);
+	if (!sv)
 		return -EINVAL;
-	if (ret == sv1 && *sv1 == &var1)
+	if (sv == sv1 && *sv1 == &var1)
 		pr_info("  got expected PTR%d -> PTR%d result\n",
 			ptr_id(sv1), ptr_id(*sv1));
 
-	ret = shadow_get(obj + 1, id);
-	if (!ret)
+	sv = shadow_get(obj + 1, id);
+	if (!sv)
 		return -EINVAL;
-	if (ret == sv2 && *sv2 == &var2)
+	if (sv == sv2 && *sv2 == &var2)
 		pr_info("  got expected PTR%d -> PTR%d result\n",
 			ptr_id(sv2), ptr_id(*sv2));
-	ret = shadow_get(obj, id + 1);
-	if (!ret)
+	sv = shadow_get(obj, id + 1);
+	if (!sv)
 		return -EINVAL;
-	if (ret == sv3 && *sv3 == &var3)
+	if (sv == sv3 && *sv3 == &var3)
 		pr_info("  got expected PTR%d -> PTR%d result\n",
 			ptr_id(sv3), ptr_id(*sv3));
 
@@ -197,10 +208,10 @@ static int test_klp_shadow_vars_init(void)
 	if (!sv4)
 		return -ENOMEM;
 
-	ret = shadow_get_or_alloc(obj + 2, id, size, gfp_flags, shadow_ctor, &var4);
-	if (!ret)
+	sv = shadow_get_or_alloc(obj + 2, id, size, gfp_flags, shadow_ctor, &var4);
+	if (!sv)
 		return -EINVAL;
-	if (ret == sv4 && *sv4 == &var4)
+	if (sv == sv4 && *sv4 == &var4)
 		pr_info("  got expected PTR%d -> PTR%d result\n",
 			ptr_id(sv4), ptr_id(*sv4));
 
@@ -209,36 +220,36 @@ static int test_klp_shadow_vars_init(void)
 	 * longer find them.
 	 */
 	shadow_free(obj, id, shadow_dtor);			/* sv1 */
-	ret = shadow_get(obj, id);
-	if (!ret)
+	sv = shadow_get(obj, id);
+	if (!sv)
 		pr_info("  got expected NULL result\n");
 
 	shadow_free(obj + 1, id, shadow_dtor);			/* sv2 */
-	ret = shadow_get(obj + 1, id);
-	if (!ret)
+	sv = shadow_get(obj + 1, id);
+	if (!sv)
 		pr_info("  got expected NULL result\n");
 
 	shadow_free(obj + 2, id, shadow_dtor);			/* sv4 */
-	ret = shadow_get(obj + 2, id);
-	if (!ret)
+	sv = shadow_get(obj + 2, id);
+	if (!sv)
 		pr_info("  got expected NULL result\n");
 
 	/*
 	 * We should still find an <id+1> variable.
 	 */
-	ret = shadow_get(obj, id + 1);
-	if (!ret)
+	sv = shadow_get(obj, id + 1);
+	if (!sv)
 		return -EINVAL;
-	if (ret == sv3 && *sv3 == &var3)
+	if (sv == sv3 && *sv3 == &var3)
 		pr_info("  got expected PTR%d -> PTR%d result\n",
 			ptr_id(sv3), ptr_id(*sv3));
 
 	/*
 	 * Free all the <id+1> variables, too.
 	 */
 	shadow_free_all(id + 1, shadow_dtor);			/* sv3 */
-	ret = shadow_get(obj, id);
-	if (!ret)
+	sv = shadow_get(obj, id);
+	if (!sv)
 		pr_info("  shadow_get() got expected NULL result\n");