On 3/29/21 5:57 AM, Denis Salopek wrote:
Extend the existing bpf_map_lookup_and_delete_elem() functionality to
hashtab maps, in addition to stacks and queues.
Add bpf_map_lookup_and_delete_elem_flags() libbpf API in order to use
the BPF_F_LOCK flag.
Create a new hashtab bpf_map_ops function that does lookup and deletion
of the element under the same bucket lock and add the created map_ops to
bpf.h.
Add the appropriate test cases to 'maps' and 'lru_map' selftests
accompanied with new test_progs.
Cc: Juraj Vijtiuk <juraj.vijtiuk@xxxxxxxxxx>
Cc: Luka Oreskovic <luka.oreskovic@xxxxxxxxxx>
Cc: Luka Perkov <luka.perkov@xxxxxxxxxx>
Signed-off-by: Denis Salopek <denis.salopek@xxxxxxxxxx>
---
v2: Add functionality for LRU/per-CPU, add test_progs tests.
v3: Add bpf_map_lookup_and_delete_elem_flags() and enable BPF_F_LOCK
flag, change CHECKs to ASSERT_OKs, initialize variables to 0.
v4: Fix the return value for unsupported map types.
---
include/linux/bpf.h | 2 +
kernel/bpf/hashtab.c | 97 ++++++
kernel/bpf/syscall.c | 27 +-
tools/lib/bpf/bpf.c | 13 +
tools/lib/bpf/bpf.h | 2 +
tools/lib/bpf/libbpf.map | 1 +
.../bpf/prog_tests/lookup_and_delete.c | 279 ++++++++++++++++++
.../bpf/progs/test_lookup_and_delete.c | 26 ++
tools/testing/selftests/bpf/test_lru_map.c | 8 +
tools/testing/selftests/bpf/test_maps.c | 19 +-
10 files changed, 469 insertions(+), 5 deletions(-)
create mode 100644 tools/testing/selftests/bpf/prog_tests/lookup_and_delete.c
create mode 100644 tools/testing/selftests/bpf/progs/test_lookup_and_delete.c
Since another revision is needed, could you break the patch to several
commits which will make it easy to review?
Patch 1: kernel + uapi header:
include/linux/bpf.h
kernel/bpf/hashtab.c
kernel/bpf/syscall.c
include/uapi/linux/bpf.h and tools/include/uapi/linux/bpf.h (see below)
Patch 2: libbpf change
tools/lib/bpf/bpf.{c,h}, libbpf.map
Patch 3: selftests/bpf change
tools/testing/selftests/bpf/...
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index 9fdd839b418c..8af4bd7c7229 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -68,6 +68,8 @@ struct bpf_map_ops {
void *(*map_lookup_elem_sys_only)(struct bpf_map *map, void *key);
int (*map_lookup_batch)(struct bpf_map *map, const union bpf_attr *attr,
union bpf_attr __user *uattr);
+ int (*map_lookup_and_delete_elem)(struct bpf_map *map, void *key,
+ void *value, u64 flags);
int (*map_lookup_and_delete_batch)(struct bpf_map *map,
const union bpf_attr *attr,
union bpf_attr __user *uattr);
diff --git a/kernel/bpf/hashtab.c b/kernel/bpf/hashtab.c
index d7ebb12ffffc..0d2085ce9a38 100644
--- a/kernel/bpf/hashtab.c
+++ b/kernel/bpf/hashtab.c
@@ -1401,6 +1401,99 @@ static void htab_map_seq_show_elem(struct bpf_map *map, void *key,
rcu_read_unlock();
}
+static int __htab_map_lookup_and_delete_elem(struct bpf_map *map, void *key,
+ void *value, bool is_lru_map,
+ bool is_percpu, u64 flags)
+{
+ struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
+ u32 hash, key_size, value_size;
+ struct hlist_nulls_head *head;
+ int cpu, off = 0, ret;
+ struct htab_elem *l;
+ unsigned long bflags;
+ void __percpu *pptr;
+ struct bucket *b;
+
+ if ((flags & ~BPF_F_LOCK) ||
+ ((flags & BPF_F_LOCK) && !map_value_has_spin_lock(map)))
+ return -EINVAL;
+
+ key_size = map->key_size;
+ value_size = round_up(map->value_size, 8);
This value_size is actually a round_up size, so maybe
rename it as "roundup_size". Also, I see it is only
used in is_percpu case. It would be good if it can be
moved inside is_percpu branch.
+
+ hash = htab_map_hash(key, key_size, htab->hashrnd);
+ b = __select_bucket(htab, hash);
+ head = &b->head;
+
+ ret = htab_lock_bucket(htab, b, hash, &bflags);
+ if (ret)
+ return ret;
+
+ l = lookup_elem_raw(head, hash, key, key_size);
+ if (l) {
+ if (is_percpu) {
+ pptr = htab_elem_get_ptr(l, key_size);
+ for_each_possible_cpu(cpu) {
+ bpf_long_memcpy(value + off,
+ per_cpu_ptr(pptr, cpu),
+ value_size);
+ off += value_size;
+ }
+ } else {
+ if (flags & BPF_F_LOCK)
+ copy_map_value_locked(map, value, l->key +
+ round_up(key_size, 8),
+ true);
+ else
+ copy_map_value(map, value, l->key +
+ round_up(key_size, 8));
+ check_and_init_map_lock(map, value);
+ }
+
+ hlist_nulls_del_rcu(&l->hash_node);
+ if (!is_lru_map)
+ free_htab_elem(htab, l);
+ } else
+ ret = -ENOENT;
+
+ htab_unlock_bucket(htab, b, hash, bflags);
+
+ if (is_lru_map && l)
+ bpf_lru_push_free(&htab->lru, &l->lru_node);
+
+ return ret;
+}
+
+static int htab_map_lookup_and_delete_elem(struct bpf_map *map, void *key,
+ void *value, u64 flags)
+{
+ return __htab_map_lookup_and_delete_elem(map, key, value, false, false,
+ flags);
+}
+
+static int htab_percpu_map_lookup_and_delete_elem(struct bpf_map *map,
+ void *key, void *value,
+ u64 flags)
+{
+ return __htab_map_lookup_and_delete_elem(map, key, value, false, true,
+ flags);
+}
+
+static int htab_lru_map_lookup_and_delete_elem(struct bpf_map *map, void *key,
+ void *value, u64 flags)
+{
+ return __htab_map_lookup_and_delete_elem(map, key, value, true, false,
+ flags);
+}
+
+static int htab_lru_percpu_map_lookup_and_delete_elem(struct bpf_map *map,
+ void *key, void *value,
+ u64 flags)
+{
+ return __htab_map_lookup_and_delete_elem(map, key, value, true, true,
+ flags);
+}
+
static int
__htab_map_lookup_and_delete_batch(struct bpf_map *map,
const union bpf_attr *attr,
@@ -1934,6 +2027,7 @@ const struct bpf_map_ops htab_map_ops = {
.map_free = htab_map_free,
.map_get_next_key = htab_map_get_next_key,
.map_lookup_elem = htab_map_lookup_elem,
+ .map_lookup_and_delete_elem = htab_map_lookup_and_delete_elem,
.map_update_elem = htab_map_update_elem,
.map_delete_elem = htab_map_delete_elem,
.map_gen_lookup = htab_map_gen_lookup,
@@ -1954,6 +2048,7 @@ const struct bpf_map_ops htab_lru_map_ops = {
.map_free = htab_map_free,
.map_get_next_key = htab_map_get_next_key,
.map_lookup_elem = htab_lru_map_lookup_elem,
+ .map_lookup_and_delete_elem = htab_lru_map_lookup_and_delete_elem,
.map_lookup_elem_sys_only = htab_lru_map_lookup_elem_sys,
.map_update_elem = htab_lru_map_update_elem,
.map_delete_elem = htab_lru_map_delete_elem,
@@ -2077,6 +2172,7 @@ const struct bpf_map_ops htab_percpu_map_ops = {
.map_free = htab_map_free,
.map_get_next_key = htab_map_get_next_key,
.map_lookup_elem = htab_percpu_map_lookup_elem,
+ .map_lookup_and_delete_elem = htab_percpu_map_lookup_and_delete_elem,
.map_update_elem = htab_percpu_map_update_elem,
.map_delete_elem = htab_map_delete_elem,
.map_seq_show_elem = htab_percpu_map_seq_show_elem,
@@ -2096,6 +2192,7 @@ const struct bpf_map_ops htab_lru_percpu_map_ops = {
.map_free = htab_map_free,
.map_get_next_key = htab_map_get_next_key,
.map_lookup_elem = htab_lru_percpu_map_lookup_elem,
+ .map_lookup_and_delete_elem = htab_lru_percpu_map_lookup_and_delete_elem,
.map_update_elem = htab_lru_percpu_map_update_elem,
.map_delete_elem = htab_lru_map_delete_elem,
.map_seq_show_elem = htab_percpu_map_seq_show_elem,
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 9603de81811a..e3851bafb603 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -1468,7 +1468,7 @@ int generic_map_lookup_batch(struct bpf_map *map,
return err;
}
-#define BPF_MAP_LOOKUP_AND_DELETE_ELEM_LAST_FIELD value
+#define BPF_MAP_LOOKUP_AND_DELETE_ELEM_LAST_FIELD flags
static int map_lookup_and_delete_elem(union bpf_attr *attr)
{
@@ -1484,6 +1484,9 @@ static int map_lookup_and_delete_elem(union bpf_attr *attr)
if (CHECK_ATTR(BPF_MAP_LOOKUP_AND_DELETE_ELEM))
return -EINVAL;
+ if (attr->flags & ~BPF_F_LOCK)
+ return -EINVAL; > +
f = fdget(ufd);
map = __bpf_map_get(f);
if (IS_ERR(map))
@@ -1494,24 +1497,40 @@ static int map_lookup_and_delete_elem(union bpf_attr *attr)
goto err_put;
}
Previously, for QUEUE and STACK map, flags are not allowed, and libbpf
sets it as 0. Let us enforce attr->flags with 0 here for QUEUE and STACK.
+ if ((attr->flags & BPF_F_LOCK) &&
+ !map_value_has_spin_lock(map)) {
+ err = -EINVAL;
+ goto err_put;
+ }
+
key = __bpf_copy_key(ukey, map->key_size);
if (IS_ERR(key)) {
err = PTR_ERR(key);
goto err_put;
}
- value_size = map->value_size;
+ value_size = bpf_map_value_size(map);
err = -ENOMEM;
value = kmalloc(value_size, GFP_USER | __GFP_NOWARN);
if (!value)
goto free_key;
+ err = -ENOTSUPP;
if (map->map_type == BPF_MAP_TYPE_QUEUE ||
map->map_type == BPF_MAP_TYPE_STACK) {
err = map->ops->map_pop_elem(map, value);
- } else {
- err = -ENOTSUPP;
+ } else if (map->map_type == BPF_MAP_TYPE_HASH ||
+ map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
+ map->map_type == BPF_MAP_TYPE_LRU_HASH ||
+ map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) {
Since we added four new map support for lookup_and_delete, we should
update documentation in uapi bpf.h.
Currently, it is:
* BPF_MAP_LOOKUP_AND_DELETE_ELEM
* Description
* Look up an element with the given *key* in the map
referred to
* by the file descriptor *fd*, and if found, delete the
element.
*
* The **BPF_MAP_TYPE_QUEUE** and **BPF_MAP_TYPE_STACK**
map types
* implement this command as a "pop" operation, deleting
the top
* element rather than one corresponding to *key*.
* The *key* and *key_len* parameters should be zeroed when
* issuing this operation for these map types.
*
* This command is only valid for the following map types:
* * **BPF_MAP_TYPE_QUEUE**
* * **BPF_MAP_TYPE_STACK**
*
* Return
* Returns zero on success. On error, -1 is returned and
*errno*
* is set appropriately.
Please remember to sync updated linux/include/uapi/linux/bpf.h to
linux/tools/include/uapi/linux/bpf.h.
+ if (!bpf_map_is_dev_bound(map)) {
+ bpf_disable_instrumentation();
+ rcu_read_lock();
+ err = map->ops->map_lookup_and_delete_elem(map, key, value, attr->flags);
+ rcu_read_unlock();
+ bpf_enable_instrumentation();
+ }
}
if (err)
diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c
index bba48ff4c5c0..b7c2cc12034c 100644
--- a/tools/lib/bpf/bpf.c
+++ b/tools/lib/bpf/bpf.c
@@ -458,6 +458,19 @@ int bpf_map_lookup_and_delete_elem(int fd, const void *key, void *value)
return sys_bpf(BPF_MAP_LOOKUP_AND_DELETE_ELEM, &attr, sizeof(attr));
}
+int bpf_map_lookup_and_delete_elem_flags(int fd, const void *key, void *value, __u64 flags)
+{
+ union bpf_attr attr;
+
+ memset(&attr, 0, sizeof(attr));
+ attr.map_fd = fd;
+ attr.key = ptr_to_u64(key);
+ attr.value = ptr_to_u64(value);
+ attr.flags = flags;
+
+ return sys_bpf(BPF_MAP_LOOKUP_AND_DELETE_ELEM, &attr, sizeof(attr));
+}
This looks okay to me. It mimics bpf_map_lookup_elem_flags().
Andrii, could you take a look as well?
+
int bpf_map_delete_elem(int fd, const void *key)
{
union bpf_attr attr;
diff --git a/tools/lib/bpf/bpf.h b/tools/lib/bpf/bpf.h
index 875dde20d56e..4f758f8f50cd 100644
--- a/tools/lib/bpf/bpf.h
+++ b/tools/lib/bpf/bpf.h
@@ -124,6 +124,8 @@ LIBBPF_API int bpf_map_lookup_elem_flags(int fd, const void *key, void *value,
__u64 flags);
LIBBPF_API int bpf_map_lookup_and_delete_elem(int fd, const void *key,
void *value);
+LIBBPF_API int bpf_map_lookup_and_delete_elem_flags(int fd, const void *key,
+ void *value, __u64 flags);
LIBBPF_API int bpf_map_delete_elem(int fd, const void *key);
LIBBPF_API int bpf_map_get_next_key(int fd, const void *key, void *next_key);
LIBBPF_API int bpf_map_freeze(int fd);
diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map
index f5990f7208ce..589dde8311e1 100644
--- a/tools/lib/bpf/libbpf.map
+++ b/tools/lib/bpf/libbpf.map
@@ -132,6 +132,7 @@ LIBBPF_0.0.2 {
bpf_probe_prog_type;
bpf_map__resize;
bpf_map_lookup_elem_flags;
+ bpf_map_lookup_and_delete_elem_flags;
bpf_object__btf;
bpf_object__find_map_fd_by_name;
bpf_get_link_xdp_id;
Please don't put it in 0.0.2. Put it in the latest version which is 0.4.0.
diff --git a/tools/testing/selftests/bpf/prog_tests/lookup_and_delete.c b/tools/testing/selftests/bpf/prog_tests/lookup_and_delete.c
new file mode 100644
index 000000000000..8ace0e4a2349
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/lookup_and_delete.c
@@ -0,0 +1,279 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <test_progs.h>
+#include "test_lookup_and_delete.skel.h"
+
+#define START_VALUE 1234
+#define NEW_VALUE 4321
+#define MAX_ENTRIES 2
+
+static int duration;
+static int nr_cpus;
+
+static int fill_values(int map_fd)
+{
+ __u64 key, value = START_VALUE;
+ int err;
+
+ for (key = 1; key < MAX_ENTRIES + 1; key++) {
+ err = bpf_map_update_elem(map_fd, &key, &value, BPF_NOEXIST);
+ if (!ASSERT_OK(err, "bpf_map_update_elem"))
+ return -1;
+ }
+
+ return 0;
+}
+
+static int fill_values_percpu(int map_fd)
+{
+ BPF_DECLARE_PERCPU(__u64, value);
+ int i, err;
+ u64 key;
+
+ for (i = 0; i < nr_cpus; i++)
+ bpf_percpu(value, i) = START_VALUE;
+
+ for (key = 1; key < MAX_ENTRIES + 1; key++) {
+ err = bpf_map_update_elem(map_fd, &key, value, BPF_NOEXIST);
+ if (!ASSERT_OK(err, "bpf_map_update_elem"))
+ return -1;
+ }
+
+ return 0;
+}
+
+static struct test_lookup_and_delete *setup_prog(enum bpf_map_type map_type,
+ int *map_fd)
+{
+ struct test_lookup_and_delete *skel;
+ int err;
+
+ skel = test_lookup_and_delete__open();
+ if (!ASSERT_OK(!skel, "test_lookup_and_delete__open"))
+ return NULL;
+
+ err = bpf_map__set_type(skel->maps.hash_map, map_type);
+ if (!ASSERT_OK(err, "bpf_map__set_type"))
+ goto error;
Maybe change "error" to "cleanup"? The "cleanup" is
used in other places.
+
+ err = test_lookup_and_delete__load(skel);
+ if (!ASSERT_OK(err, "test_lookup_and_delete__load"))
+ goto error;
+
+ *map_fd = bpf_map__fd(skel->maps.hash_map);
+ if (CHECK(*map_fd < 0, "bpf_map__fd", "failed\n"))
+ goto error;
A new ASSERT variant ASSERT_LT was added recently.
Maybe you can use it?
+
+ return skel;
+
+error:
+ test_lookup_and_delete__destroy(skel);
+ return NULL;
+}
+
+/* Triggers BPF program that updates map with given key and value */
+static int trigger_tp(struct test_lookup_and_delete *skel, __u64 key,
+ __u64 value)
+{
+ int err;
+
+ skel->bss->set_pid = getpid();
+ skel->bss->set_key = key;
+ skel->bss->set_value = value;
+
+ err = test_lookup_and_delete__attach(skel);
+ if (!ASSERT_OK(err, "test_lookup_and_delete__attach"))
+ return -1;
+
+ syscall(__NR_getpgid);
+
+ test_lookup_and_delete__detach(skel);
+
+ return 0;
+}
+
+static void test_lookup_and_delete_hash(void)
+{
+ struct test_lookup_and_delete *skel;
+ __u64 key, value;
+ int map_fd, err;
+
+ /* Setup program and fill the map. */
+ skel = setup_prog(BPF_MAP_TYPE_HASH, &map_fd);
+ if (!ASSERT_OK_PTR(skel, "setup_prog"))
+ return;
+
+ err = fill_values(map_fd);
+ if (!ASSERT_OK(err, "fill_values"))
+ goto cleanup;
+
+ /* Lookup and delete element. */
+ key = 1;
+ err = bpf_map_lookup_and_delete_elem(map_fd, &key, &value);
+ if (!ASSERT_OK(err, "bpf_map_lookup_and_delete_elem"))
+ goto cleanup;
+
+ /* Fetched value should match the initially set value. */
+ if (CHECK(value != START_VALUE, "bpf_map_lookup_and_delete_elem",
+ "unexpected value=%lld\n", value))
+ goto cleanup;
+
+ /* Check that the entry is non existent. */
+ err = bpf_map_lookup_elem(map_fd, &key, &value);
+ if (!ASSERT_OK(!err, "bpf_map_lookup_elem"))
There is a macro ASSERT_ERR, maybe that is better?
+ goto cleanup;
+
+cleanup:
+ test_lookup_and_delete__destroy(skel);
+}
+
+static void test_lookup_and_delete_percpu_hash(void)
+{
+ struct test_lookup_and_delete *skel;
+ BPF_DECLARE_PERCPU(__u64, value);
+ int map_fd, err, i;
+ __u64 key, val;
+
+ /* Setup program and fill the map. */
+ skel = setup_prog(BPF_MAP_TYPE_PERCPU_HASH, &map_fd);
+ if (!ASSERT_OK_PTR(skel, "setup_prog"))
+ return;
+
+ err = fill_values_percpu(map_fd);
+ if (!ASSERT_OK(err, "fill_values_percpu"))
+ goto cleanup;
+
+ /* Lookup and delete element. */
+ key = 1;
+ err = bpf_map_lookup_and_delete_elem(map_fd, &key, value);
+ if (!ASSERT_OK(err, "bpf_map_lookup_and_delete_elem"))
+ goto cleanup;
+
+ for (i = 0; i < nr_cpus; i++) {
+ if (bpf_percpu(value, i))
+ val = bpf_percpu(value, i);
Maybe do the below inside the loop?
val = bpf_percpu(value, i);
if (CHECK(val && val != START_VALUE, ...)
+ }
+
+ /* Fetched value should match the initially set value. */
+ if (CHECK(val != START_VALUE, "bpf_map_lookup_and_delete_elem",
+ "unexpected value=%lld\n", val))
+ goto cleanup;
See the above, do this CHECK inside the loop?
+
+ /* Check that the entry is non existent. */
+ err = bpf_map_lookup_elem(map_fd, &key, value);
+ if (!ASSERT_OK(!err, "bpf_map_lookup_elem"))
+ goto cleanup;
ASSERT_ERR?
+
+cleanup:
+ test_lookup_and_delete__destroy(skel);
+}
+
+static void test_lookup_and_delete_lru_hash(void)
+{
+ struct test_lookup_and_delete *skel;
+ __u64 key, value;
+ int map_fd, err;
+
+ /* Setup program and fill the LRU map. */
+ skel = setup_prog(BPF_MAP_TYPE_LRU_HASH, &map_fd);
+ if (!ASSERT_OK_PTR(skel, "setup_prog"))
+ return;
+
+ err = fill_values(map_fd);
+ if (!ASSERT_OK(err, "fill_values"))
+ goto cleanup;
+
+ /* Insert new element at key=3, should reuse LRU element. */
+ key = 3;
+ err = trigger_tp(skel, key, NEW_VALUE);
+ if (!ASSERT_OK(err, "trigger_tp"))
+ goto cleanup;
+
+ /* Lookup and delete element 3. */
+ err = bpf_map_lookup_and_delete_elem(map_fd, &key, &value);
+ if (!ASSERT_OK(err, "bpf_map_lookup_and_delete_elem"))
+ goto cleanup;
+
+ /* Value should match the new value. */
+ if (CHECK(value != NEW_VALUE, "bpf_map_lookup_and_delete_elem",
+ "unexpected value=%lld\n", value))
+ goto cleanup;
+
+ /* Check that entries 3 and 1 are non existent. */
+ err = bpf_map_lookup_elem(map_fd, &key, &value);
+ if (!ASSERT_OK(!err, "bpf_map_lookup_elem"))
+ goto cleanup;
ASSERT_ERR?
+
+ key = 1;
+ err = bpf_map_lookup_elem(map_fd, &key, &value);
+ if (!ASSERT_OK(!err, "bpf_map_lookup_elem"))
+ goto cleanup;
ASSERT_ERR?
+
+cleanup:
+ test_lookup_and_delete__destroy(skel);
+}
+
+static void test_lookup_and_delete_lru_percpu_hash(void)
+{
+ struct test_lookup_and_delete *skel;
+ BPF_DECLARE_PERCPU(__u64, value);
+ int map_fd, err, i;
+ __u64 key, val;
+
+ /* Setup program and fill the LRU map. */
+ skel = setup_prog(BPF_MAP_TYPE_LRU_PERCPU_HASH, &map_fd);
+ if (!ASSERT_OK_PTR(skel, "setup_prog"))
+ return;
+
+ err = fill_values_percpu(map_fd);
+ if (!ASSERT_OK(err, "fill_values_percpu"))
+ goto cleanup;
+
+ /* Insert new element at key=3, should reuse LRU element. */
+ key = 3;
+ err = trigger_tp(skel, key, NEW_VALUE);
+ if (!ASSERT_OK(err, "trigger_tp"))
+ goto cleanup;
+
+ /* Lookup and delete element 3. */
+ err = bpf_map_lookup_and_delete_elem(map_fd, &key, &value);
+ if (!ASSERT_OK(err, "bpf_map_lookup_and_delete_elem"))
+ goto cleanup;
+
+ for (i = 0; i < nr_cpus; i++) {
+ if (bpf_percpu(value, i))
+ val = bpf_percpu(value, i);
See previous bpf_percpu comments...
+ }
+
+ /* Value should match the new value. */
+ if (CHECK(val != NEW_VALUE, "bpf_map_lookup_and_delete_elem",
+ "unexpected value=%lld\n", val))
+ goto cleanup;
+
+ /* Check that entries 3 and 1 are non existent. */
+ err = bpf_map_lookup_elem(map_fd, &key, &value);
+ if (!ASSERT_OK(!err, "bpf_map_lookup_elem"))
+ goto cleanup;
ASSERT_ERR?
+
+ key = 1;
+ err = bpf_map_lookup_elem(map_fd, &key, &value);
+ if (!ASSERT_OK(!err, "bpf_map_lookup_elem"))
+ goto cleanup;
ASSERT_ERR?
+
+cleanup:
+ test_lookup_and_delete__destroy(skel);
+}
+
+void test_lookup_and_delete(void)
+{
+ nr_cpus = bpf_num_possible_cpus();
+
+ if (test__start_subtest("lookup_and_delete"))
+ test_lookup_and_delete_hash();
+ if (test__start_subtest("lookup_and_delete_percpu"))
+ test_lookup_and_delete_percpu_hash();
+ if (test__start_subtest("lookup_and_delete_lru"))
+ test_lookup_and_delete_lru_hash();
+ if (test__start_subtest("lookup_and_delete_lru_percpu"))
+ test_lookup_and_delete_lru_percpu_hash();
+}
diff --git a/tools/testing/selftests/bpf/progs/test_lookup_and_delete.c b/tools/testing/selftests/bpf/progs/test_lookup_and_delete.c
new file mode 100644
index 000000000000..3a193f42c7e7
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/test_lookup_and_delete.c
@@ -0,0 +1,26 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include "vmlinux.h"
+#include <bpf/bpf_helpers.h>
+
+__u32 set_pid = 0;
+__u64 set_key = 0;
+__u64 set_value = 0;
+
+struct {
+ __uint(type, BPF_MAP_TYPE_HASH);
+ __uint(max_entries, 2);
+ __type(key, __u64);
+ __type(value, __u64);
+} hash_map SEC(".maps");
+
+SEC("tp/syscalls/sys_enter_getpgid")
+int bpf_lookup_and_delete_test(const void *ctx)
+{
+ if (set_pid == bpf_get_current_pid_tgid() >> 32)
+ bpf_map_update_elem(&hash_map, &set_key, &set_value, BPF_NOEXIST);
+
+ return 0;
+}
+
+char _license[] SEC("license") = "GPL";
diff --git a/tools/testing/selftests/bpf/test_lru_map.c b/tools/testing/selftests/bpf/test_lru_map.c
index 6a5349f9eb14..f33fb6de76bc 100644
--- a/tools/testing/selftests/bpf/test_lru_map.c
+++ b/tools/testing/selftests/bpf/test_lru_map.c
@@ -231,6 +231,14 @@ static void test_lru_sanity0(int map_type, int map_flags)
assert(bpf_map_lookup_elem(lru_map_fd, &key, value) == -1 &&
errno == ENOENT);
+ /* lookup elem key=3 and delete it, than check it doesn't exist */
+ key = 1;
+ assert(!bpf_map_lookup_and_delete_elem(lru_map_fd, &key, &value));
+ assert(value[0] == 1234);
+
+ /* remove the same element from the expected map */
+ assert(!bpf_map_delete_elem(expected_map_fd, &key));
+
assert(map_equal(lru_map_fd, expected_map_fd));
close(expected_map_fd);
diff --git a/tools/testing/selftests/bpf/test_maps.c b/tools/testing/selftests/bpf/test_maps.c
index 51adc42b2b40..dbd5f95e8bde 100644
--- a/tools/testing/selftests/bpf/test_maps.c
+++ b/tools/testing/selftests/bpf/test_maps.c
@@ -65,6 +65,13 @@ static void test_hashmap(unsigned int task, void *data)
assert(bpf_map_lookup_elem(fd, &key, &value) == 0 && value == 1234);
key = 2;
+ value = 1234;
+ /* Insert key=2 element. */
+ assert(bpf_map_update_elem(fd, &key, &value, BPF_ANY) == 0);
+
+ /* Check that key=2 matches the value and delete it */
+ assert(bpf_map_lookup_and_delete_elem(fd, &key, &value) == 0 && value == 1234);
+
/* Check that key=2 is not found. */
assert(bpf_map_lookup_elem(fd, &key, &value) == -1 && errno == ENOENT);
@@ -164,8 +171,18 @@ static void test_hashmap_percpu(unsigned int task, void *data)
key = 1;
/* Insert key=1 element. */
- assert(!(expected_key_mask & key));
assert(bpf_map_update_elem(fd, &key, value, BPF_ANY) == 0);
+
+ /* Lookup and delete elem key=1 and check value. */
+ assert(bpf_map_lookup_and_delete_elem(fd, &key, value) == 0 &&
+ bpf_percpu(value, 0) == 100);
+
+ for (i = 0; i < nr_cpus; i++)
+ bpf_percpu(value, i) = i + 100;
+
+ /* Insert key=1 element which should not exist. */
+ assert(!(expected_key_mask & key));
+ assert(bpf_map_update_elem(fd, &key, value, BPF_NOEXIST) == 0);
expected_key_mask |= key;
/* BPF_NOEXIST means add new element if it doesn't exist. */
