[PATCH v2 3/4] selftests/livepatch: more verification in test-klp-shadow-vars

Yannick Cote
2020-06-03T18:21:50Z

This change makes the test feel more familiar with narrowing to a
typical usage by operating on a number of identical structure instances
and populating the same two new shadow variables symmetrically while
keeping the same testing and verification criteria for the extra
variables.

Reviewed-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Acked-by: Miroslav Benes <mbenes@suse.cz>
Acked-by: Joe Lawrence <joe.lawrence@redhat.com>
Signed-off-by: Yannick Cote <ycote@redhat.com>
---
lib/livepatch/test_klp_shadow_vars.c | 192 +++++++++---------
.../selftests/livepatch/test-shadow-vars.sh | 81 +++++---
2 files changed, 143 insertions(+), 130 deletions(-)

diff --git a/lib/livepatch/test_klp_shadow_vars.c b/lib/livepatch/test_klp_shadow_vars.c
index ec2635cff974..a49265e56917 100644
--- a/lib/livepatch/test_klp_shadow_vars.c
+++ b/lib/livepatch/test_klp_shadow_vars.c
@@ -128,6 +128,11 @@ static int shadow_ctor(void *obj, void *shadow_data, void *ctor_data)
return 0;
}

+/*
+ * With more than one item to free in the list, order is not determined and
+ * shadow_dtor will not be passed to shadow_free_all() which would make the
+ * test fail. (see pass 6)
+ */
static void shadow_dtor(void *obj, void *shadow_data)
{
int **sv = shadow_data;
@@ -136,6 +141,9 @@ static void shadow_dtor(void *obj, void *shadow_data)
__func__, ptr_id(obj), ptr_id(sv));
}

+/* number of objects we simulate that need shadow vars */
+#define NUM_OBJS 3
+
/* dynamically created obj fields have the following shadow var id values */
#define SV_ID1 0x1234
#define SV_ID2 0x1235
@@ -157,122 +165,106 @@ struct test_object {

static int test_klp_shadow_vars_init(void)
{
- struct test_object obj1, obj2, obj3;
- char nfield1, nfield2, *pnfield1, *pnfield2, **sv1, **sv2;
- int nfield3, nfield4, *pnfield3, *pnfield4, **sv3, **sv4;
+ struct test_object objs[NUM_OBJS];
+ char nfields1[NUM_OBJS], *pnfields1[NUM_OBJS], **sv1[NUM_OBJS];
+ char *pndup[NUM_OBJS];
+ int nfields2[NUM_OBJS], *pnfields2[NUM_OBJS], **sv2[NUM_OBJS];
void **sv;
-
- pnfield1 = &nfield1;
- pnfield2 = &nfield2;
- pnfield3 = &nfield3;
- pnfield4 = &nfield4;
+ int i;

ptr_id(NULL);
- ptr_id(pnfield1);
- ptr_id(pnfield2);
- ptr_id(pnfield3);
- ptr_id(pnfield4);

/*
* With an empty shadow variable hash table, expect not to find
* any matches.
*/
- sv = shadow_get(&obj1, SV_ID1);
+ sv = shadow_get(&objs[0], SV_ID1);
if (!sv)
pr_info(" got expected NULL result\n");

- /*
- * Allocate a few shadow variables with different <obj> and <id>.
- */
- sv1 = shadow_alloc(&obj1, SV_ID1, sizeof(pnfield1), GFP_KERNEL, shadow_ctor, &pnfield1);
- if (!sv1)
- return -ENOMEM;
-
- sv2 = shadow_alloc(&obj2, SV_ID1, sizeof(pnfield2), GFP_KERNEL, shadow_ctor, &pnfield2);
- if (!sv2)
- return -ENOMEM;
-
- sv3 = shadow_alloc(&obj1, SV_ID2, sizeof(pnfield3), GFP_KERNEL, shadow_ctor, &pnfield3);
- if (!sv3)
- return -ENOMEM;
-
- /*
- * Verify we can find our new shadow variables and that they point
- * to expected data.
- */
- sv = shadow_get(&obj1, SV_ID1);
- if (!sv)
- return -EINVAL;
- if ((char **)sv == sv1 && *sv1 == pnfield1)
- pr_info(" got expected PTR%d -> PTR%d result\n",
- ptr_id(sv1), ptr_id(*sv1));
-
- sv = shadow_get(&obj2, SV_ID1);
- if (!sv)
- return -EINVAL;
- if ((char **)sv == sv2 && *sv2 == pnfield2)
- pr_info(" got expected PTR%d -> PTR%d result\n",
- ptr_id(sv2), ptr_id(*sv2));
-
- sv = shadow_get(&obj1, SV_ID2);
- if (!sv)
- return -EINVAL;
- if ((int **)sv == sv3 && *sv3 == pnfield3)
- pr_info(" got expected PTR%d -> PTR%d result\n",
- ptr_id(sv3), ptr_id(*sv3));
-
- /*
- * Allocate or get a few more, this time with the same <obj>, <id>.
- * The second invocation should return the same shadow var.
- */
- sv4 = shadow_get_or_alloc(&obj3, SV_ID1, sizeof(pnfield4), GFP_KERNEL, shadow_ctor, &pnfield4);
- if (!sv4)
- return -ENOMEM;
-
- sv = shadow_get_or_alloc(&obj3, SV_ID1, sizeof(pnfield4), GFP_KERNEL, shadow_ctor, &pnfield4);
- if (!sv)
- return -EINVAL;
- if ((int **)sv == sv4 && *sv4 == pnfield4)
- pr_info(" got expected PTR%d -> PTR%d result\n",
- ptr_id(sv4), ptr_id(*sv4));
-
- /*
- * Free the <obj=*, id> shadow variables and check that we can no
- * longer find them.
- */
- shadow_free(&obj1, SV_ID1, shadow_dtor); /* sv1 */
- sv = shadow_get(&obj1, SV_ID1);
- if (!sv)
- pr_info(" got expected NULL result\n");
+ /* pass 1: init & alloc a char+int pair of svars for each objs */
+ for (i = 0; i < NUM_OBJS; i++) {
+ pnfields1[i] = &nfields1[i];
+ ptr_id(pnfields1[i]);
+
+ if (i % 2) {
+ sv1[i] = shadow_alloc(&objs[i], SV_ID1,
+ sizeof(pnfields1[i]), GFP_KERNEL,
+ shadow_ctor, &pnfields1[i]);
+ } else {
+ sv1[i] = shadow_get_or_alloc(&objs[i], SV_ID1,
+ sizeof(pnfields1[i]), GFP_KERNEL,
+ shadow_ctor, &pnfields1[i]);
+ }
+ if (!sv1[i])
+ return -ENOMEM;
+
+ pnfields2[i] = &nfields2[i];
+ ptr_id(pnfields2[i]);
+ sv2[i] = shadow_alloc(&objs[i], SV_ID2, sizeof(pnfields2[i]),
+ GFP_KERNEL, shadow_ctor, &pnfields2[i]);
+ if (!sv2[i])
+ return -ENOMEM;
+ }

- shadow_free(&obj2, SV_ID1, shadow_dtor); /* sv2 */
- sv = shadow_get(&obj2, SV_ID1);
- if (!sv)
- pr_info(" got expected NULL result\n");
+ /* pass 2: verify we find allocated svars and where they point to */
+ for (i = 0; i < NUM_OBJS; i++) {
+ /* check the "char" svar for all objects */
+ sv = shadow_get(&objs[i], SV_ID1);
+ if (!sv)
+ return -EINVAL;
+ if ((char **)sv == sv1[i] && *sv1[i] == pnfields1[i])
+ pr_info(" got expected PTR%d -> PTR%d result\n",
+ ptr_id(sv1[i]), ptr_id(*sv1[i]));
+
+ /* check the "int" svar for all objects */
+ sv = shadow_get(&objs[i], SV_ID2);
+ if (!sv)
+ return -EINVAL;
+ if ((int **)sv == sv2[i] && *sv2[i] == pnfields2[i])
+ pr_info(" got expected PTR%d -> PTR%d result\n",
+ ptr_id(sv2[i]), ptr_id(*sv2[i]));
+ }

- shadow_free(&obj3, SV_ID1, shadow_dtor); /* sv4 */
- sv = shadow_get(&obj3, SV_ID1);
- if (!sv)
- pr_info(" got expected NULL result\n");
+ /* pass 3: verify that 'get_or_alloc' returns already allocated svars */
+ for (i = 0; i < NUM_OBJS; i++) {
+ pndup[i] = &nfields1[i];
+ ptr_id(pndup[i]);
+
+ sv = shadow_get_or_alloc(&objs[i], SV_ID1, sizeof(pndup[i]),
+ GFP_KERNEL, shadow_ctor, &pndup[i]);
+ if (!sv)
+ return -EINVAL;
+ if ((char **)sv == sv1[i] && *sv1[i] == pnfields1[i])
+ pr_info(" got expected PTR%d -> PTR%d result\n",
+ ptr_id(sv1[i]), ptr_id(*sv1[i]));
+ }

- /*
- * We should still find an <id+1> variable.
- */
- sv = shadow_get(&obj1, SV_ID2);
- if (!sv)
- return -EINVAL;
- if ((int **)sv == sv3 && *sv3 == pnfield3)
- pr_info(" got expected PTR%d -> PTR%d result\n",
- ptr_id(sv3), ptr_id(*sv3));
+ /* pass 4: free <objs[*], SV_ID1> pairs of svars, verify removal */
+ for (i = 0; i < NUM_OBJS; i++) {
+ shadow_free(&objs[i], SV_ID1, shadow_dtor); /* 'char' pairs */
+ sv = shadow_get(&objs[i], SV_ID1);
+ if (!sv)
+ pr_info(" got expected NULL result\n");
+ }

- /*
- * Free all the <id+1> variables, too.
- */
- shadow_free_all(SV_ID2, shadow_dtor); /* sv3 */
- sv = shadow_get(&obj1, SV_ID1);
- if (!sv)
- pr_info(" shadow_get() got expected NULL result\n");
+ /* pass 5: check we still find <objs[*], SV_ID2> svar pairs */
+ for (i = 0; i < NUM_OBJS; i++) {
+ sv = shadow_get(&objs[i], SV_ID2); /* 'int' pairs */
+ if (!sv)
+ return -EINVAL;
+ if ((int **)sv == sv2[i] && *sv2[i] == pnfields2[i])
+ pr_info(" got expected PTR%d -> PTR%d result\n",
+ ptr_id(sv2[i]), ptr_id(*sv2[i]));
+ }

+ /* pass 6: free all the <objs[*], SV_ID2> svar pairs too. */
+ shadow_free_all(SV_ID2, NULL); /* 'int' pairs */
+ for (i = 0; i < NUM_OBJS; i++) {
+ sv = shadow_get(&objs[i], SV_ID2);
+ if (!sv)
+ pr_info(" got expected NULL result\n");
+ }

free_ptr_list();

diff --git a/tools/testing/selftests/livepatch/test-shadow-vars.sh b/tools/testing/selftests/livepatch/test-shadow-vars.sh
index 1aae73299114..7c016548c2ea 100755
--- a/tools/testing/selftests/livepatch/test-shadow-vars.sh
+++ b/tools/testing/selftests/livepatch/test-shadow-vars.sh
@@ -19,42 +19,63 @@ load_mod $MOD_TEST
unload_mod $MOD_TEST

check_result "% modprobe $MOD_TEST
-$MOD_TEST: klp_shadow_get(obj=PTR5, id=0x1234) = PTR0
+$MOD_TEST: klp_shadow_get(obj=PTR1, id=0x1234) = PTR0
$MOD_TEST: got expected NULL result
-$MOD_TEST: shadow_ctor: PTR6 -> PTR1
-$MOD_TEST: klp_shadow_alloc(obj=PTR5, id=0x1234, size=8, gfp_flags=GFP_KERNEL), ctor=PTR7, ctor_data=PTR1 = PTR6
-$MOD_TEST: shadow_ctor: PTR8 -> PTR2
-$MOD_TEST: klp_shadow_alloc(obj=PTR9, id=0x1234, size=8, gfp_flags=GFP_KERNEL), ctor=PTR7, ctor_data=PTR2 = PTR8
-$MOD_TEST: shadow_ctor: PTR10 -> PTR3
-$MOD_TEST: klp_shadow_alloc(obj=PTR5, id=0x1235, size=8, gfp_flags=GFP_KERNEL), ctor=PTR7, ctor_data=PTR3 = PTR10
-$MOD_TEST: klp_shadow_get(obj=PTR5, id=0x1234) = PTR6
-$MOD_TEST: got expected PTR6 -> PTR1 result
+$MOD_TEST: shadow_ctor: PTR3 -> PTR2
+$MOD_TEST: klp_shadow_get_or_alloc(obj=PTR1, id=0x1234, size=8, gfp_flags=GFP_KERNEL), ctor=PTR4, ctor_data=PTR2 = PTR3
+$MOD_TEST: shadow_ctor: PTR6 -> PTR5
+$MOD_TEST: klp_shadow_alloc(obj=PTR1, id=0x1235, size=8, gfp_flags=GFP_KERNEL), ctor=PTR4, ctor_data=PTR5 = PTR6
+$MOD_TEST: shadow_ctor: PTR8 -> PTR7
+$MOD_TEST: klp_shadow_alloc(obj=PTR9, id=0x1234, size=8, gfp_flags=GFP_KERNEL), ctor=PTR4, ctor_data=PTR7 = PTR8
+$MOD_TEST: shadow_ctor: PTR11 -> PTR10
+$MOD_TEST: klp_shadow_alloc(obj=PTR9, id=0x1235, size=8, gfp_flags=GFP_KERNEL), ctor=PTR4, ctor_data=PTR10 = PTR11
+$MOD_TEST: shadow_ctor: PTR13 -> PTR12
+$MOD_TEST: klp_shadow_get_or_alloc(obj=PTR14, id=0x1234, size=8, gfp_flags=GFP_KERNEL), ctor=PTR4, ctor_data=PTR12 = PTR13
+$MOD_TEST: shadow_ctor: PTR16 -> PTR15
+$MOD_TEST: klp_shadow_alloc(obj=PTR14, id=0x1235, size=8, gfp_flags=GFP_KERNEL), ctor=PTR4, ctor_data=PTR15 = PTR16
+$MOD_TEST: klp_shadow_get(obj=PTR1, id=0x1234) = PTR3
+$MOD_TEST: got expected PTR3 -> PTR2 result
+$MOD_TEST: klp_shadow_get(obj=PTR1, id=0x1235) = PTR6
+$MOD_TEST: got expected PTR6 -> PTR5 result
$MOD_TEST: klp_shadow_get(obj=PTR9, id=0x1234) = PTR8
-$MOD_TEST: got expected PTR8 -> PTR2 result
-$MOD_TEST: klp_shadow_get(obj=PTR5, id=0x1235) = PTR10
-$MOD_TEST: got expected PTR10 -> PTR3 result
-$MOD_TEST: shadow_ctor: PTR11 -> PTR4
-$MOD_TEST: klp_shadow_get_or_alloc(obj=PTR12, id=0x1234, size=8, gfp_flags=GFP_KERNEL), ctor=PTR7, ctor_data=PTR4 = PTR11
-$MOD_TEST: klp_shadow_get_or_alloc(obj=PTR12, id=0x1234, size=8, gfp_flags=GFP_KERNEL), ctor=PTR7, ctor_data=PTR4 = PTR11
-$MOD_TEST: got expected PTR11 -> PTR4 result
-$MOD_TEST: shadow_dtor(obj=PTR5, shadow_data=PTR6)
-$MOD_TEST: klp_shadow_free(obj=PTR5, id=0x1234, dtor=PTR13)
-$MOD_TEST: klp_shadow_get(obj=PTR5, id=0x1234) = PTR0
+$MOD_TEST: got expected PTR8 -> PTR7 result
+$MOD_TEST: klp_shadow_get(obj=PTR9, id=0x1235) = PTR11
+$MOD_TEST: got expected PTR11 -> PTR10 result
+$MOD_TEST: klp_shadow_get(obj=PTR14, id=0x1234) = PTR13
+$MOD_TEST: got expected PTR13 -> PTR12 result
+$MOD_TEST: klp_shadow_get(obj=PTR14, id=0x1235) = PTR16
+$MOD_TEST: got expected PTR16 -> PTR15 result
+$MOD_TEST: klp_shadow_get_or_alloc(obj=PTR1, id=0x1234, size=8, gfp_flags=GFP_KERNEL), ctor=PTR4, ctor_data=PTR2 = PTR3
+$MOD_TEST: got expected PTR3 -> PTR2 result
+$MOD_TEST: klp_shadow_get_or_alloc(obj=PTR9, id=0x1234, size=8, gfp_flags=GFP_KERNEL), ctor=PTR4, ctor_data=PTR7 = PTR8
+$MOD_TEST: got expected PTR8 -> PTR7 result
+$MOD_TEST: klp_shadow_get_or_alloc(obj=PTR14, id=0x1234, size=8, gfp_flags=GFP_KERNEL), ctor=PTR4, ctor_data=PTR12 = PTR13
+$MOD_TEST: got expected PTR13 -> PTR12 result
+$MOD_TEST: shadow_dtor(obj=PTR1, shadow_data=PTR3)
+$MOD_TEST: klp_shadow_free(obj=PTR1, id=0x1234, dtor=PTR17)
+$MOD_TEST: klp_shadow_get(obj=PTR1, id=0x1234) = PTR0
$MOD_TEST: got expected NULL result
$MOD_TEST: shadow_dtor(obj=PTR9, shadow_data=PTR8)
-$MOD_TEST: klp_shadow_free(obj=PTR9, id=0x1234, dtor=PTR13)
+$MOD_TEST: klp_shadow_free(obj=PTR9, id=0x1234, dtor=PTR17)
$MOD_TEST: klp_shadow_get(obj=PTR9, id=0x1234) = PTR0
$MOD_TEST: got expected NULL result
-$MOD_TEST: shadow_dtor(obj=PTR12, shadow_data=PTR11)
-$MOD_TEST: klp_shadow_free(obj=PTR12, id=0x1234, dtor=PTR13)
-$MOD_TEST: klp_shadow_get(obj=PTR12, id=0x1234) = PTR0
+$MOD_TEST: shadow_dtor(obj=PTR14, shadow_data=PTR13)
+$MOD_TEST: klp_shadow_free(obj=PTR14, id=0x1234, dtor=PTR17)
+$MOD_TEST: klp_shadow_get(obj=PTR14, id=0x1234) = PTR0
$MOD_TEST: got expected NULL result
-$MOD_TEST: klp_shadow_get(obj=PTR5, id=0x1235) = PTR10
-$MOD_TEST: got expected PTR10 -> PTR3 result
-$MOD_TEST: shadow_dtor(obj=PTR5, shadow_data=PTR10)
-$MOD_TEST: klp_shadow_free_all(id=0x1235, dtor=PTR13)
-$MOD_TEST: klp_shadow_get(obj=PTR5, id=0x1234) = PTR0
-$MOD_TEST: shadow_get() got expected NULL result
-% rmmod test_klp_shadow_vars"
+$MOD_TEST: klp_shadow_get(obj=PTR1, id=0x1235) = PTR6
+$MOD_TEST: got expected PTR6 -> PTR5 result
+$MOD_TEST: klp_shadow_get(obj=PTR9, id=0x1235) = PTR11
+$MOD_TEST: got expected PTR11 -> PTR10 result
+$MOD_TEST: klp_shadow_get(obj=PTR14, id=0x1235) = PTR16
+$MOD_TEST: got expected PTR16 -> PTR15 result
+$MOD_TEST: klp_shadow_free_all(id=0x1235, dtor=PTR0)
+$MOD_TEST: klp_shadow_get(obj=PTR1, id=0x1235) = PTR0
+$MOD_TEST: got expected NULL result
+$MOD_TEST: klp_shadow_get(obj=PTR9, id=0x1235) = PTR0
+$MOD_TEST: got expected NULL result
+$MOD_TEST: klp_shadow_get(obj=PTR14, id=0x1235) = PTR0
+$MOD_TEST: got expected NULL result
+% rmmod $MOD_TEST"

exit 0
--
2.25.4