selftests/bpf: Modify linked_list tests to work with macro-ified inserts

The linked_list tests use macros and function pointers to reduce code
duplication. Earlier in the series, bpf_list_push_{front,back} were
modified to be macros, expanding to invoke actual kfuncs
bpf_list_push_{front,back}_impl. Due to this change, a code snippet
like:

  void (*p)(void *, void *) = (void *)&bpf_list_##op;
  p(hexpr, nexpr);

meant to do bpf_list_push_{front,back}(hexpr, nexpr), will no longer
work as it's no longer valid to do &bpf_list_push_{front,back} since
they're no longer functions.

This patch fixes issues of this type, along with two other minor changes
- one improvement and one fix - both related to the node argument to
list_push_{front,back}.

  * The fix: migration of list_push tests away from (void *, void *)
    func ptr uncovered that some tests were incorrectly passing pointer
    to node, not pointer to struct bpf_list_node within the node. This
    patch fixes such issues (CHECK(..., f) -> CHECK(..., &f->node))

  * The improvement: In linked_list tests, the struct foo type has two
    list_node fields: node and node2, at byte offsets 0 and 40 within
    the struct, respectively. Currently node is used in ~all tests
    involving struct foo and lists. The verifier needs to do some work
    to account for the offset of bpf_list_node within the node type, so
    using node2 instead of node exercises that logic more in the tests.
    This patch migrates linked_list tests to use node2 instead of node.

Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com>
Link: https://lore.kernel.org/r/20230415201811.343116-7-davemarchevsky@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

diff --git a/tools/testing/selftests/bpf/prog_tests/linked_list.c b/tools/testing/selftests/bpf/prog_tests/linked_list.c
index 0ed8132..872e4bd 100644 (file)
--- a/tools/testing/selftests/bpf/prog_tests/linked_list.c
+++ b/tools/testing/selftests/bpf/prog_tests/linked_list.c
@@ -84,11 +84,11 @@ static struct {
        { "double_push_back", "arg#1 expected pointer to allocated object" },
        { "no_node_value_type", "bpf_list_node not found at offset=0" },
        { "incorrect_value_type",
-         "operation on bpf_list_head expects arg#1 bpf_list_node at offset=0 in struct foo, "
+         "operation on bpf_list_head expects arg#1 bpf_list_node at offset=40 in struct foo, "
          "but arg is at offset=0 in struct bar" },
        { "incorrect_node_var_off", "variable ptr_ access var_off=(0x0; 0xffffffff) disallowed" },
-       { "incorrect_node_off1", "bpf_list_node not found at offset=1" },
-       { "incorrect_node_off2", "arg#1 offset=40, but expected bpf_list_node at offset=0 in struct foo" },
+       { "incorrect_node_off1", "bpf_list_node not found at offset=41" },
+       { "incorrect_node_off2", "arg#1 offset=0, but expected bpf_list_node at offset=40 in struct foo" },
        { "no_head_type", "bpf_list_head not found at offset=0" },
        { "incorrect_head_var_off1", "R1 doesn't have constant offset" },
        { "incorrect_head_var_off2", "variable ptr_ access var_off=(0x0; 0xffffffff) disallowed" },

diff --git a/tools/testing/selftests/bpf/progs/linked_list.c b/tools/testing/selftests/bpf/progs/linked_list.c
index 53ded51..57440a5 100644 (file)
--- a/tools/testing/selftests/bpf/progs/linked_list.c
+++ b/tools/testing/selftests/bpf/progs/linked_list.c
@@ -25,7 +25,7 @@ int list_push_pop(struct bpf_spin_lock *lock, struct bpf_list_head *head, bool l
        n = bpf_list_pop_front(head);
        bpf_spin_unlock(lock);
        if (n) {
-               bpf_obj_drop(container_of(n, struct foo, node));
+               bpf_obj_drop(container_of(n, struct foo, node2));
                bpf_obj_drop(f);
                return 3;
        }
@@ -34,7 +34,7 @@ int list_push_pop(struct bpf_spin_lock *lock, struct bpf_list_head *head, bool l
        n = bpf_list_pop_back(head);
        bpf_spin_unlock(lock);
        if (n) {
-               bpf_obj_drop(container_of(n, struct foo, node));
+               bpf_obj_drop(container_of(n, struct foo, node2));
                bpf_obj_drop(f);
                return 4;
        }
@@ -42,7 +42,7 @@ int list_push_pop(struct bpf_spin_lock *lock, struct bpf_list_head *head, bool l
 
        bpf_spin_lock(lock);
        f->data = 42;
-       bpf_list_push_front(head, &f->node);
+       bpf_list_push_front(head, &f->node2);
        bpf_spin_unlock(lock);
        if (leave_in_map)
                return 0;
@@ -51,7 +51,7 @@ int list_push_pop(struct bpf_spin_lock *lock, struct bpf_list_head *head, bool l
        bpf_spin_unlock(lock);
        if (!n)
                return 5;
-       f = container_of(n, struct foo, node);
+       f = container_of(n, struct foo, node2);
        if (f->data != 42) {
                bpf_obj_drop(f);
                return 6;
@@ -59,14 +59,14 @@ int list_push_pop(struct bpf_spin_lock *lock, struct bpf_list_head *head, bool l
 
        bpf_spin_lock(lock);
        f->data = 13;
-       bpf_list_push_front(head, &f->node);
+       bpf_list_push_front(head, &f->node2);
        bpf_spin_unlock(lock);
        bpf_spin_lock(lock);
        n = bpf_list_pop_front(head);
        bpf_spin_unlock(lock);
        if (!n)
                return 7;
-       f = container_of(n, struct foo, node);
+       f = container_of(n, struct foo, node2);
        if (f->data != 13) {
                bpf_obj_drop(f);
                return 8;
@@ -77,7 +77,7 @@ int list_push_pop(struct bpf_spin_lock *lock, struct bpf_list_head *head, bool l
        n = bpf_list_pop_front(head);
        bpf_spin_unlock(lock);
        if (n) {
-               bpf_obj_drop(container_of(n, struct foo, node));
+               bpf_obj_drop(container_of(n, struct foo, node2));
                return 9;
        }
 
@@ -85,7 +85,7 @@ int list_push_pop(struct bpf_spin_lock *lock, struct bpf_list_head *head, bool l
        n = bpf_list_pop_back(head);
        bpf_spin_unlock(lock);
        if (n) {
-               bpf_obj_drop(container_of(n, struct foo, node));
+               bpf_obj_drop(container_of(n, struct foo, node2));
                return 10;
        }
        return 0;
@@ -119,8 +119,8 @@ int list_push_pop_multiple(struct bpf_spin_lock *lock, struct bpf_list_head *hea
                f[i + 1]->data = i + 1;
 
                bpf_spin_lock(lock);
-               bpf_list_push_front(head, &f[i]->node);
-               bpf_list_push_front(head, &f[i + 1]->node);
+               bpf_list_push_front(head, &f[i]->node2);
+               bpf_list_push_front(head, &f[i + 1]->node2);
                bpf_spin_unlock(lock);
        }
 
@@ -130,13 +130,13 @@ int list_push_pop_multiple(struct bpf_spin_lock *lock, struct bpf_list_head *hea
                bpf_spin_unlock(lock);
                if (!n)
                        return 3;
-               pf = container_of(n, struct foo, node);
+               pf = container_of(n, struct foo, node2);
                if (pf->data != (ARRAY_SIZE(f) - i - 1)) {
                        bpf_obj_drop(pf);
                        return 4;
                }
                bpf_spin_lock(lock);
-               bpf_list_push_back(head, &pf->node);
+               bpf_list_push_back(head, &pf->node2);
                bpf_spin_unlock(lock);
        }
 
@@ -149,7 +149,7 @@ int list_push_pop_multiple(struct bpf_spin_lock *lock, struct bpf_list_head *hea
                bpf_spin_unlock(lock);
                if (!n)
                        return 5;
-               pf = container_of(n, struct foo, node);
+               pf = container_of(n, struct foo, node2);
                if (pf->data != i) {
                        bpf_obj_drop(pf);
                        return 6;
@@ -160,7 +160,7 @@ int list_push_pop_multiple(struct bpf_spin_lock *lock, struct bpf_list_head *hea
        n = bpf_list_pop_back(head);
        bpf_spin_unlock(lock);
        if (n) {
-               bpf_obj_drop(container_of(n, struct foo, node));
+               bpf_obj_drop(container_of(n, struct foo, node2));
                return 7;
        }
 
@@ -168,7 +168,7 @@ int list_push_pop_multiple(struct bpf_spin_lock *lock, struct bpf_list_head *hea
        n = bpf_list_pop_front(head);
        bpf_spin_unlock(lock);
        if (n) {
-               bpf_obj_drop(container_of(n, struct foo, node));
+               bpf_obj_drop(container_of(n, struct foo, node2));
                return 8;
        }
        return 0;
@@ -199,7 +199,7 @@ int list_in_list(struct bpf_spin_lock *lock, struct bpf_list_head *head, bool le
 
        bpf_spin_lock(lock);
        f->data = 42;
-       bpf_list_push_front(head, &f->node);
+       bpf_list_push_front(head, &f->node2);
        bpf_spin_unlock(lock);
 
        if (leave_in_map)
@@ -210,7 +210,7 @@ int list_in_list(struct bpf_spin_lock *lock, struct bpf_list_head *head, bool le
        bpf_spin_unlock(lock);
        if (!n)
                return 4;
-       f = container_of(n, struct foo, node);
+       f = container_of(n, struct foo, node2);
        if (f->data != 42) {
                bpf_obj_drop(f);
                return 5;

diff --git a/tools/testing/selftests/bpf/progs/linked_list.h b/tools/testing/selftests/bpf/progs/linked_list.h
index 3fb2412..c0f3609 100644 (file)
--- a/tools/testing/selftests/bpf/progs/linked_list.h
+++ b/tools/testing/selftests/bpf/progs/linked_list.h
@@ -22,7 +22,7 @@ struct foo {
 struct map_value {
        struct bpf_spin_lock lock;
        int data;
-       struct bpf_list_head head __contains(foo, node);
+       struct bpf_list_head head __contains(foo, node2);
 };
 
 struct array_map {
@@ -50,7 +50,7 @@ struct {
 #define private(name) SEC(".bss." #name) __hidden __attribute__((aligned(8)))
 
 private(A) struct bpf_spin_lock glock;
-private(A) struct bpf_list_head ghead __contains(foo, node);
+private(A) struct bpf_list_head ghead __contains(foo, node2);
 private(B) struct bpf_spin_lock glock2;
 
 #endif

diff --git a/tools/testing/selftests/bpf/progs/linked_list_fail.c b/tools/testing/selftests/bpf/progs/linked_list_fail.c
index 41978b4..f4c63da 100644 (file)
--- a/tools/testing/selftests/bpf/progs/linked_list_fail.c
+++ b/tools/testing/selftests/bpf/progs/linked_list_fail.c
@@ -73,22 +73,21 @@ CHECK(inner_map, pop_back, &iv->head);
        int test##_missing_lock_##op(void *ctx)                         \
        {                                                               \
                INIT;                                                   \
-               void (*p)(void *, void *) = (void *)&bpf_list_##op;     \
-               p(hexpr, nexpr);                                        \
+               bpf_list_##op(hexpr, nexpr);                            \
                return 0;                                               \
        }
 
-CHECK(kptr, push_front, &f->head, b);
-CHECK(kptr, push_back, &f->head, b);
+CHECK(kptr, push_front, &f->head, &b->node);
+CHECK(kptr, push_back, &f->head, &b->node);
 
-CHECK(global, push_front, &ghead, f);
-CHECK(global, push_back, &ghead, f);
+CHECK(global, push_front, &ghead, &f->node2);
+CHECK(global, push_back, &ghead, &f->node2);
 
-CHECK(map, push_front, &v->head, f);
-CHECK(map, push_back, &v->head, f);
+CHECK(map, push_front, &v->head, &f->node2);
+CHECK(map, push_back, &v->head, &f->node2);
 
-CHECK(inner_map, push_front, &iv->head, f);
-CHECK(inner_map, push_back, &iv->head, f);
+CHECK(inner_map, push_front, &iv->head, &f->node2);
+CHECK(inner_map, push_back, &iv->head, &f->node2);
 
 #undef CHECK
 
@@ -135,32 +134,31 @@ CHECK_OP(pop_back);
        int test##_incorrect_lock_##op(void *ctx)                       \
        {                                                               \
                INIT;                                                   \
-               void (*p)(void *, void*) = (void *)&bpf_list_##op;      \
                bpf_spin_lock(lexpr);                                   \
-               p(hexpr, nexpr);                                        \
+               bpf_list_##op(hexpr, nexpr);                            \
                return 0;                                               \
        }
 
 #define CHECK_OP(op)                                                   \
-       CHECK(kptr_kptr, op, &f1->lock, &f2->head, b);                  \
-       CHECK(kptr_global, op, &f1->lock, &ghead, f);                   \
-       CHECK(kptr_map, op, &f1->lock, &v->head, f);                    \
-       CHECK(kptr_inner_map, op, &f1->lock, &iv->head, f);             \
+       CHECK(kptr_kptr, op, &f1->lock, &f2->head, &b->node);           \
+       CHECK(kptr_global, op, &f1->lock, &ghead, &f->node2);           \
+       CHECK(kptr_map, op, &f1->lock, &v->head, &f->node2);            \
+       CHECK(kptr_inner_map, op, &f1->lock, &iv->head, &f->node2);     \
                                                                        \
-       CHECK(global_global, op, &glock2, &ghead, f);                   \
-       CHECK(global_kptr, op, &glock, &f1->head, b);                   \
-       CHECK(global_map, op, &glock, &v->head, f);                     \
-       CHECK(global_inner_map, op, &glock, &iv->head, f);              \
+       CHECK(global_global, op, &glock2, &ghead, &f->node2);           \
+       CHECK(global_kptr, op, &glock, &f1->head, &b->node);            \
+       CHECK(global_map, op, &glock, &v->head, &f->node2);             \
+       CHECK(global_inner_map, op, &glock, &iv->head, &f->node2);      \
                                                                        \
-       CHECK(map_map, op, &v->lock, &v2->head, f);                     \
-       CHECK(map_kptr, op, &v->lock, &f2->head, b);                    \
-       CHECK(map_global, op, &v->lock, &ghead, f);                     \
-       CHECK(map_inner_map, op, &v->lock, &iv->head, f);               \
+       CHECK(map_map, op, &v->lock, &v2->head, &f->node2);             \
+       CHECK(map_kptr, op, &v->lock, &f2->head, &b->node);             \
+       CHECK(map_global, op, &v->lock, &ghead, &f->node2);             \
+       CHECK(map_inner_map, op, &v->lock, &iv->head, &f->node2);       \
                                                                        \
-       CHECK(inner_map_inner_map, op, &iv->lock, &iv2->head, f);       \
-       CHECK(inner_map_kptr, op, &iv->lock, &f2->head, b);             \
-       CHECK(inner_map_global, op, &iv->lock, &ghead, f);              \
-       CHECK(inner_map_map, op, &iv->lock, &v->head, f);
+       CHECK(inner_map_inner_map, op, &iv->lock, &iv2->head, &f->node2);\
+       CHECK(inner_map_kptr, op, &iv->lock, &f2->head, &b->node);      \
+       CHECK(inner_map_global, op, &iv->lock, &ghead, &f->node2);      \
+       CHECK(inner_map_map, op, &iv->lock, &v->head, &f->node2);
 
 CHECK_OP(push_front);
 CHECK_OP(push_back);
@@ -340,7 +338,7 @@ int direct_read_node(void *ctx)
        f = bpf_obj_new(typeof(*f));
        if (!f)
                return 0;
-       return *(int *)&f->node;
+       return *(int *)&f->node2;
 }
 
 SEC("?tc")
@@ -351,12 +349,12 @@ int direct_write_node(void *ctx)
        f = bpf_obj_new(typeof(*f));
        if (!f)
                return 0;
-       *(int *)&f->node = 0;
+       *(int *)&f->node2 = 0;
        return 0;
 }
 
 static __always_inline
-int use_after_unlock(void (*op)(void *head, void *node))
+int use_after_unlock(bool push_front)
 {
        struct foo *f;
 
@@ -365,7 +363,10 @@ int use_after_unlock(void (*op)(void *head, void *node))
                return 0;
        bpf_spin_lock(&glock);
        f->data = 42;
-       op(&ghead, &f->node);
+       if (push_front)
+               bpf_list_push_front(&ghead, &f->node2);
+       else
+               bpf_list_push_back(&ghead, &f->node2);
        bpf_spin_unlock(&glock);
 
        return f->data;
@@ -374,17 +375,17 @@ int use_after_unlock(void (*op)(void *head, void *node))
 SEC("?tc")
 int use_after_unlock_push_front(void *ctx)
 {
-       return use_after_unlock((void *)bpf_list_push_front);
+       return use_after_unlock(true);
 }
 
 SEC("?tc")
 int use_after_unlock_push_back(void *ctx)
 {
-       return use_after_unlock((void *)bpf_list_push_back);
+       return use_after_unlock(false);
 }
 
 static __always_inline
-int list_double_add(void (*op)(void *head, void *node))
+int list_double_add(bool push_front)
 {
        struct foo *f;
 
@@ -392,8 +393,13 @@ int list_double_add(void (*op)(void *head, void *node))
        if (!f)
                return 0;
        bpf_spin_lock(&glock);
-       op(&ghead, &f->node);
-       op(&ghead, &f->node);
+       if (push_front) {
+               bpf_list_push_front(&ghead, &f->node2);
+               bpf_list_push_front(&ghead, &f->node2);
+       } else {
+               bpf_list_push_back(&ghead, &f->node2);
+               bpf_list_push_back(&ghead, &f->node2);
+       }
        bpf_spin_unlock(&glock);
 
        return 0;
@@ -402,13 +408,13 @@ int list_double_add(void (*op)(void *head, void *node))
 SEC("?tc")
 int double_push_front(void *ctx)
 {
-       return list_double_add((void *)bpf_list_push_front);
+       return list_double_add(true);
 }
 
 SEC("?tc")
 int double_push_back(void *ctx)
 {
-       return list_double_add((void *)bpf_list_push_back);
+       return list_double_add(false);
 }
 
 SEC("?tc")
@@ -450,7 +456,7 @@ int incorrect_node_var_off(struct __sk_buff *ctx)
        if (!f)
                return 0;
        bpf_spin_lock(&glock);
-       bpf_list_push_front(&ghead, (void *)&f->node + ctx->protocol);
+       bpf_list_push_front(&ghead, (void *)&f->node2 + ctx->protocol);
        bpf_spin_unlock(&glock);
 
        return 0;
@@ -465,7 +471,7 @@ int incorrect_node_off1(void *ctx)
        if (!f)
                return 0;
        bpf_spin_lock(&glock);
-       bpf_list_push_front(&ghead, (void *)&f->node + 1);
+       bpf_list_push_front(&ghead, (void *)&f->node2 + 1);
        bpf_spin_unlock(&glock);
 
        return 0;
@@ -480,7 +486,7 @@ int incorrect_node_off2(void *ctx)
        if (!f)
                return 0;
        bpf_spin_lock(&glock);
-       bpf_list_push_front(&ghead, &f->node2);
+       bpf_list_push_front(&ghead, &f->node);
        bpf_spin_unlock(&glock);
 
        return 0;
@@ -510,7 +516,7 @@ int incorrect_head_var_off1(struct __sk_buff *ctx)
        if (!f)
                return 0;
        bpf_spin_lock(&glock);
-       bpf_list_push_front((void *)&ghead + ctx->protocol, &f->node);
+       bpf_list_push_front((void *)&ghead + ctx->protocol, &f->node2);
        bpf_spin_unlock(&glock);
 
        return 0;
@@ -525,7 +531,7 @@ int incorrect_head_var_off2(struct __sk_buff *ctx)
        if (!f)
                return 0;
        bpf_spin_lock(&glock);
-       bpf_list_push_front((void *)&f->head + ctx->protocol, &f->node);
+       bpf_list_push_front((void *)&f->head + ctx->protocol, &f->node2);
        bpf_spin_unlock(&glock);
 
        return 0;
@@ -563,7 +569,7 @@ int incorrect_head_off2(void *ctx)
                return 0;
 
        bpf_spin_lock(&glock);
-       bpf_list_push_front((void *)&ghead + 1, &f->node);
+       bpf_list_push_front((void *)&ghead + 1, &f->node2);
        bpf_spin_unlock(&glock);
 
        return 0;