[PATCH 2/4] livepatch/selftest: Clean up shadow variable names and type

From: Petr Mladek
Date: Thu Jan 16 2020 - 10:32:31 EST


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@xxxxxxxx>
---
lib/livepatch/test_klp_shadow_vars.c | 93 ++++++++++++++++++++----------------
1 file changed, 52 insertions(+), 41 deletions(-)

diff --git a/lib/livepatch/test_klp_shadow_vars.c b/lib/livepatch/test_klp_shadow_vars.c
index fe5c413efe96..4e94f46234e8 100644
--- a/lib/livepatch/test_klp_shadow_vars.c
+++ b/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));

@@ -209,27 +220,27 @@ 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));

@@ -237,8 +248,8 @@ static int test_klp_shadow_vars_init(void)
* 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");


--
2.16.4