From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7742E46C4C4; Tue, 21 Jul 2026 15:59:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784649569; cv=none; b=POQe3kT2mz5r67wbc4ygmF/HIhMC+KZtk7Mjzicl6NWAS9oHODvZqq1LXzWxVuCGpOZl8R4/UFoMO1QMIMline+aV+nMfu5duSz3K3lbpkwkLZn/wz82s/lxTS+Y3MF4a1/hd7u56EY/fd2/uXtDGQravVVdDt+hzgBjW1BNofE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784649569; c=relaxed/simple; bh=/w0FsNQHEdY3kZtIwXptRpl8FZPu8qKRFkDwxOhf/yo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Z0uJ5bbMhIphjD9IuDAl58XFzo8JLK5rrye85H7uvW1aamdU3IA44avHxCtG3LwM4pVcg47cZbaLZ+22MlAg3rYzk1XBTWYQMkdqE3CPvY1/xhwGm7Vv4mbzXJUDS7BAPY2pRDwkmgTcOdC+u+xjrrDvCsOdrXQ6bJmOGTQbV4M= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=RrRe5VOi; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="RrRe5VOi" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 97CDC1F000E9; Tue, 21 Jul 2026 15:59:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784649567; bh=CJoZRRzzG3UTrdoQwItbeDCNE4aO19XiB62bNc7/YX4=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=RrRe5VOiVEmOjy3rmkDDSIWFywbT6z1RY/NFEptsT1/l+71E6o8fqE+9zmzEfnyFF wdKzTcmUWQ2C/jTulCNc+QK/jAombL960xSFYGKYnKHjNEDUV3z7zR2Hina6ObJV8h LgUnc2Io+plKEX/uYWfUjuJ7L2FzkXL9ERolEe3M= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Justin Suess , Kumar Kartikeya Dwivedi , Alexei Starovoitov , Sasha Levin Subject: [PATCH 7.1 0626/2077] bpf: Cancel special fields on map value recycle Date: Tue, 21 Jul 2026 17:04:59 +0200 Message-ID: <20260721152607.569275709@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260721152552.646164743@linuxfoundation.org> References: <20260721152552.646164743@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 7.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Justin Suess [ Upstream commit a3a81d247651218e47153f2d2afd7aee236726fd ] Map update and delete paths currently call bpf_obj_free_fields() when a value is being replaced or recycled. That makes field destruction depend on the context of the update/delete operation. For tracing programs this can include NMI context, where referenced kptr destructors, uptr unpinning, and graph root destruction are not generally safe. Introduce bpf_obj_cancel_fields() for the reusable-value path. It only performs NMI-safe cleanup for timer, workqueue, and task_work fields. Fields that need full destruction are left attached to the recycled value and are destroyed by the final cleanup path instead. Switch array and hashtab update/delete/recycle paths to this cancel helper. Keep bpf_obj_free_fields() for final map destruction and for bpf_mem_alloc destructors. Preallocated hashtabs do not have allocator destructors, so teardown continues to walk the normal and extra elements and fully destroy their fields. This deliberately relaxes the eager-free semantics of map update/delete for special fields. Programs that relied on a recycled map slot becoming empty immediately after update/delete were relying on behavior that cannot be implemented safely from every BPF execution context without offloading arbitrary destructors. There is a chance this change breaks programs making assumptions regarding the eager freeing of fields. If so, we can relax semantics to cancellation only when irqs_disabled() is true in the future. However, theoretically, map values that get reused eagerly already have weaker guarantees as parallel users can recreate freed fields before the new element becomes visible again. Fixes: 14a324f6a67e ("bpf: Wire up freeing of referenced kptr") Signed-off-by: Justin Suess Co-developed-by: Kumar Kartikeya Dwivedi Signed-off-by: Kumar Kartikeya Dwivedi Link: https://lore.kernel.org/r/20260609202548.3571690-3-memxor@gmail.com Signed-off-by: Alexei Starovoitov Signed-off-by: Sasha Levin --- include/linux/bpf.h | 1 + kernel/bpf/arraymap.c | 8 +-- kernel/bpf/hashtab.c | 32 +++++---- kernel/bpf/syscall.c | 5 ++ .../selftests/bpf/prog_tests/htab_update.c | 4 +- .../selftests/bpf/prog_tests/linked_list.c | 33 ++++----- .../selftests/bpf/prog_tests/map_kptr.c | 10 +-- .../bpf/prog_tests/refcounted_kptr.c | 8 ++- .../testing/selftests/bpf/progs/htab_update.c | 4 +- .../testing/selftests/bpf/progs/linked_list.c | 71 +++++++++++++++++++ .../selftests/bpf/progs/refcounted_kptr.c | 20 +++++- 11 files changed, 146 insertions(+), 50 deletions(-) diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 487f4653d8a669..a2cf24d1688020 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -2596,6 +2596,7 @@ bool btf_record_equal(const struct btf_record *rec_a, const struct btf_record *r void bpf_obj_free_timer(const struct btf_record *rec, void *obj); void bpf_obj_free_workqueue(const struct btf_record *rec, void *obj); void bpf_obj_free_task_work(const struct btf_record *rec, void *obj); +void bpf_obj_cancel_fields(struct bpf_map *map, void *obj); void bpf_obj_free_fields(const struct btf_record *rec, void *obj); void __bpf_obj_drop_impl(void *p, const struct btf_record *rec, bool percpu); diff --git a/kernel/bpf/arraymap.c b/kernel/bpf/arraymap.c index dfb2110ab73357..4b68d7a2b90ea7 100644 --- a/kernel/bpf/arraymap.c +++ b/kernel/bpf/arraymap.c @@ -386,7 +386,7 @@ static long array_map_update_elem(struct bpf_map *map, void *key, void *value, if (array->map.map_type == BPF_MAP_TYPE_PERCPU_ARRAY) { val = this_cpu_ptr(array->pptrs[index & array->index_mask]); copy_map_value(map, val, value); - bpf_obj_free_fields(array->map.record, val); + bpf_obj_cancel_fields(map, val); } else { val = array->value + (u64)array->elem_size * (index & array->index_mask); @@ -394,7 +394,7 @@ static long array_map_update_elem(struct bpf_map *map, void *key, void *value, copy_map_value_locked(map, val, value, false); else copy_map_value(map, val, value); - bpf_obj_free_fields(array->map.record, val); + bpf_obj_cancel_fields(map, val); } return 0; } @@ -434,14 +434,14 @@ int bpf_percpu_array_update(struct bpf_map *map, void *key, void *value, cpu = map_flags >> 32; ptr = per_cpu_ptr(pptr, cpu); copy_map_value(map, ptr, value); - bpf_obj_free_fields(array->map.record, ptr); + bpf_obj_cancel_fields(map, ptr); goto unlock; } for_each_possible_cpu(cpu) { ptr = per_cpu_ptr(pptr, cpu); val = (map_flags & BPF_F_ALL_CPUS) ? value : value + size * cpu; copy_map_value(map, ptr, val); - bpf_obj_free_fields(array->map.record, ptr); + bpf_obj_cancel_fields(map, ptr); } unlock: rcu_read_unlock(); diff --git a/kernel/bpf/hashtab.c b/kernel/bpf/hashtab.c index 3dd9b4924ae4fb..74c5ced74032bb 100644 --- a/kernel/bpf/hashtab.c +++ b/kernel/bpf/hashtab.c @@ -242,6 +242,10 @@ static void htab_free_prealloced_fields(struct bpf_htab *htab) if (IS_ERR_OR_NULL(htab->map.record)) return; + /* + * Preallocated maps do not have a bpf_mem_alloc destructor, so fully + * destroy every element, including the extra elements. + */ if (htab_has_extra_elems(htab)) num_entries += num_possible_cpus(); for (i = 0; i < num_entries; i++) { @@ -834,8 +838,8 @@ static int htab_lru_map_gen_lookup(struct bpf_map *map, return insn - insn_buf; } -static void check_and_free_fields(struct bpf_htab *htab, - struct htab_elem *elem) +static void check_and_cancel_fields(struct bpf_htab *htab, + struct htab_elem *elem) { if (IS_ERR_OR_NULL(htab->map.record)) return; @@ -845,11 +849,11 @@ static void check_and_free_fields(struct bpf_htab *htab, int cpu; for_each_possible_cpu(cpu) - bpf_obj_free_fields(htab->map.record, per_cpu_ptr(pptr, cpu)); + bpf_obj_cancel_fields(&htab->map, per_cpu_ptr(pptr, cpu)); } else { void *map_value = htab_elem_value(elem, htab->map.key_size); - bpf_obj_free_fields(htab->map.record, map_value); + bpf_obj_cancel_fields(&htab->map, map_value); } } @@ -884,7 +888,7 @@ static bool htab_lru_map_delete_node(void *arg, struct bpf_lru_node *node) htab_unlock_bucket(b, flags); if (l == tgt_l) - check_and_free_fields(htab, l); + check_and_cancel_fields(htab, l); return l == tgt_l; } @@ -949,7 +953,7 @@ static int htab_map_get_next_key(struct bpf_map *map, void *key, void *next_key) static void htab_elem_free(struct bpf_htab *htab, struct htab_elem *l) { - check_and_free_fields(htab, l); + check_and_cancel_fields(htab, l); if (htab->map.map_type == BPF_MAP_TYPE_PERCPU_HASH) bpf_mem_cache_free(&htab->pcpu_ma, l->ptr_to_pptr); @@ -1002,7 +1006,7 @@ static void free_htab_elem(struct bpf_htab *htab, struct htab_elem *l) if (htab_is_prealloc(htab)) { bpf_map_dec_elem_count(&htab->map); - check_and_free_fields(htab, l); + check_and_cancel_fields(htab, l); pcpu_freelist_push(&htab->freelist, &l->fnode); } else { dec_elem_count(htab); @@ -1019,7 +1023,7 @@ static void pcpu_copy_value(struct bpf_htab *htab, void __percpu *pptr, /* copy true value_size bytes */ ptr = this_cpu_ptr(pptr); copy_map_value(&htab->map, ptr, value); - bpf_obj_free_fields(htab->map.record, ptr); + bpf_obj_cancel_fields(&htab->map, ptr); } else { u32 size = round_up(htab->map.value_size, 8); void *val; @@ -1029,7 +1033,7 @@ static void pcpu_copy_value(struct bpf_htab *htab, void __percpu *pptr, cpu = map_flags >> 32; ptr = per_cpu_ptr(pptr, cpu); copy_map_value(&htab->map, ptr, value); - bpf_obj_free_fields(htab->map.record, ptr); + bpf_obj_cancel_fields(&htab->map, ptr); return; } @@ -1037,7 +1041,7 @@ static void pcpu_copy_value(struct bpf_htab *htab, void __percpu *pptr, ptr = per_cpu_ptr(pptr, cpu); val = (map_flags & BPF_F_ALL_CPUS) ? value : value + size * cpu; copy_map_value(&htab->map, ptr, val); - bpf_obj_free_fields(htab->map.record, ptr); + bpf_obj_cancel_fields(&htab->map, ptr); } } } @@ -1253,11 +1257,11 @@ static long htab_map_update_elem(struct bpf_map *map, void *key, void *value, if (l_old) { hlist_nulls_del_rcu(&l_old->hash_node); - /* l_old has already been stashed in htab->extra_elems, free - * its special fields before it is available for reuse. + /* l_old has already been stashed in htab->extra_elems, cancel + * its reusable special fields before it is available for reuse. */ if (htab_is_prealloc(htab)) - check_and_free_fields(htab, l_old); + check_and_cancel_fields(htab, l_old); } htab_unlock_bucket(b, flags); if (l_old && !htab_is_prealloc(htab)) @@ -1270,7 +1274,7 @@ static long htab_map_update_elem(struct bpf_map *map, void *key, void *value, static void htab_lru_push_free(struct bpf_htab *htab, struct htab_elem *elem) { - check_and_free_fields(htab, elem); + check_and_cancel_fields(htab, elem); bpf_map_dec_elem_count(&htab->map); bpf_lru_push_free(&htab->lru, &elem->lru_node); } diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index d3667970885580..ddf0571f476bf1 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -807,6 +807,11 @@ void bpf_obj_free_task_work(const struct btf_record *rec, void *obj) bpf_task_work_cancel_and_free(obj + rec->task_work_off); } +void bpf_obj_cancel_fields(struct bpf_map *map, void *obj) +{ + bpf_map_free_internal_structs(map, obj); +} + void bpf_obj_free_fields(const struct btf_record *rec, void *obj) { const struct btf_field *fields; diff --git a/tools/testing/selftests/bpf/prog_tests/htab_update.c b/tools/testing/selftests/bpf/prog_tests/htab_update.c index ea1a6766fbe987..0a28d434692404 100644 --- a/tools/testing/selftests/bpf/prog_tests/htab_update.c +++ b/tools/testing/selftests/bpf/prog_tests/htab_update.c @@ -23,7 +23,7 @@ static void test_reenter_update(void) if (!ASSERT_OK_PTR(skel, "htab_update__open")) return; - bpf_program__set_autoload(skel->progs.bpf_obj_free_fields, true); + bpf_program__set_autoload(skel->progs.bpf_obj_cancel_fields, true); err = htab_update__load(skel); if (!ASSERT_TRUE(!err, "htab_update__load") || err) goto out; @@ -50,7 +50,7 @@ static void test_reenter_update(void) /* * Second update: replace existing element with same key and trigger * the reentrancy of bpf_map_update_elem(). - * check_and_free_fields() calls bpf_obj_free_fields() on the old + * check_and_cancel_fields() calls bpf_obj_cancel_fields() on the old * value, which is where fentry program runs and performs a nested * bpf_map_update_elem(), triggering -EDEADLK. */ diff --git a/tools/testing/selftests/bpf/prog_tests/linked_list.c b/tools/testing/selftests/bpf/prog_tests/linked_list.c index 6f25b5f39a79cd..62d974a1987fff 100644 --- a/tools/testing/selftests/bpf/prog_tests/linked_list.c +++ b/tools/testing/selftests/bpf/prog_tests/linked_list.c @@ -131,13 +131,14 @@ static void test_linked_list_fail_prog(const char *prog_name, const char *err_ms linked_list_fail__destroy(skel); } -static void clear_fields(struct bpf_map *map) +static void clear_fields(struct bpf_program *prog) { - char buf[24]; - int key = 0; + LIBBPF_OPTS(bpf_test_run_opts, opts); + int ret; - memset(buf, 0xff, sizeof(buf)); - ASSERT_OK(bpf_map__update_elem(map, &key, sizeof(key), buf, sizeof(buf), 0), "check_and_free_fields"); + ret = bpf_prog_test_run_opts(bpf_program__fd(prog), &opts); + ASSERT_OK(ret, "clear_fields"); + ASSERT_OK(opts.retval, "clear_fields retval"); } enum { @@ -170,31 +171,31 @@ static void test_linked_list_success(int mode, bool leave_in_map) ASSERT_OK(ret, "map_list_push_pop"); ASSERT_OK(opts.retval, "map_list_push_pop retval"); if (!leave_in_map) - clear_fields(skel->maps.array_map); + clear_fields(skel->progs.clear_map_list); ret = bpf_prog_test_run_opts(bpf_program__fd(skel->progs.inner_map_list_push_pop), &opts); ASSERT_OK(ret, "inner_map_list_push_pop"); ASSERT_OK(opts.retval, "inner_map_list_push_pop retval"); if (!leave_in_map) - clear_fields(skel->maps.inner_map); + clear_fields(skel->progs.clear_inner_map_list); ret = bpf_prog_test_run_opts(bpf_program__fd(skel->progs.global_list_push_pop), &opts); ASSERT_OK(ret, "global_list_push_pop"); ASSERT_OK(opts.retval, "global_list_push_pop retval"); if (!leave_in_map) - clear_fields(skel->maps.bss_A); + clear_fields(skel->progs.clear_global_list); ret = bpf_prog_test_run_opts(bpf_program__fd(skel->progs.global_list_push_pop_nested), &opts); ASSERT_OK(ret, "global_list_push_pop_nested"); ASSERT_OK(opts.retval, "global_list_push_pop_nested retval"); if (!leave_in_map) - clear_fields(skel->maps.bss_A); + clear_fields(skel->progs.clear_global_nested_list); ret = bpf_prog_test_run_opts(bpf_program__fd(skel->progs.global_list_array_push_pop), &opts); ASSERT_OK(ret, "global_list_array_push_pop"); ASSERT_OK(opts.retval, "global_list_array_push_pop retval"); if (!leave_in_map) - clear_fields(skel->maps.bss_A); + clear_fields(skel->progs.clear_global_array_list); if (mode == PUSH_POP) goto end; @@ -204,19 +205,19 @@ static void test_linked_list_success(int mode, bool leave_in_map) ASSERT_OK(ret, "map_list_push_pop_multiple"); ASSERT_OK(opts.retval, "map_list_push_pop_multiple retval"); if (!leave_in_map) - clear_fields(skel->maps.array_map); + clear_fields(skel->progs.clear_map_list); ret = bpf_prog_test_run_opts(bpf_program__fd(skel->progs.inner_map_list_push_pop_multiple), &opts); ASSERT_OK(ret, "inner_map_list_push_pop_multiple"); ASSERT_OK(opts.retval, "inner_map_list_push_pop_multiple retval"); if (!leave_in_map) - clear_fields(skel->maps.inner_map); + clear_fields(skel->progs.clear_inner_map_list); ret = bpf_prog_test_run_opts(bpf_program__fd(skel->progs.global_list_push_pop_multiple), &opts); ASSERT_OK(ret, "global_list_push_pop_multiple"); ASSERT_OK(opts.retval, "global_list_push_pop_multiple retval"); if (!leave_in_map) - clear_fields(skel->maps.bss_A); + clear_fields(skel->progs.clear_global_list); if (mode == PUSH_POP_MULT) goto end; @@ -226,19 +227,19 @@ static void test_linked_list_success(int mode, bool leave_in_map) ASSERT_OK(ret, "map_list_in_list"); ASSERT_OK(opts.retval, "map_list_in_list retval"); if (!leave_in_map) - clear_fields(skel->maps.array_map); + clear_fields(skel->progs.clear_map_list); ret = bpf_prog_test_run_opts(bpf_program__fd(skel->progs.inner_map_list_in_list), &opts); ASSERT_OK(ret, "inner_map_list_in_list"); ASSERT_OK(opts.retval, "inner_map_list_in_list retval"); if (!leave_in_map) - clear_fields(skel->maps.inner_map); + clear_fields(skel->progs.clear_inner_map_list); ret = bpf_prog_test_run_opts(bpf_program__fd(skel->progs.global_list_in_list), &opts); ASSERT_OK(ret, "global_list_in_list"); ASSERT_OK(opts.retval, "global_list_in_list retval"); if (!leave_in_map) - clear_fields(skel->maps.bss_A); + clear_fields(skel->progs.clear_global_list); end: linked_list__destroy(skel); } diff --git a/tools/testing/selftests/bpf/prog_tests/map_kptr.c b/tools/testing/selftests/bpf/prog_tests/map_kptr.c index 03b46f17cf5375..ec6f2f2e830896 100644 --- a/tools/testing/selftests/bpf/prog_tests/map_kptr.c +++ b/tools/testing/selftests/bpf/prog_tests/map_kptr.c @@ -51,7 +51,6 @@ static void test_map_kptr_success(bool test_run) ret = bpf_map__update_elem(skel->maps.array_map, &key, sizeof(key), buf, sizeof(buf), 0); ASSERT_OK(ret, "array_map update"); - skel->data->ref--; ret = bpf_prog_test_run_opts(bpf_program__fd(skel->progs.test_map_kptr_ref3), &opts); ASSERT_OK(ret, "test_map_kptr_ref3 refcount"); ASSERT_OK(opts.retval, "test_map_kptr_ref3 retval"); @@ -59,49 +58,42 @@ static void test_map_kptr_success(bool test_run) ret = bpf_map__update_elem(skel->maps.pcpu_array_map, &key, sizeof(key), pbuf, cpu * sizeof(buf), 0); ASSERT_OK(ret, "pcpu_array_map update"); - skel->data->ref--; ret = bpf_prog_test_run_opts(bpf_program__fd(skel->progs.test_map_kptr_ref3), &opts); ASSERT_OK(ret, "test_map_kptr_ref3 refcount"); ASSERT_OK(opts.retval, "test_map_kptr_ref3 retval"); ret = bpf_map__delete_elem(skel->maps.hash_map, &key, sizeof(key), 0); ASSERT_OK(ret, "hash_map delete"); - skel->data->ref--; ret = bpf_prog_test_run_opts(bpf_program__fd(skel->progs.test_map_kptr_ref3), &opts); ASSERT_OK(ret, "test_map_kptr_ref3 refcount"); ASSERT_OK(opts.retval, "test_map_kptr_ref3 retval"); ret = bpf_map__delete_elem(skel->maps.pcpu_hash_map, &key, sizeof(key), 0); ASSERT_OK(ret, "pcpu_hash_map delete"); - skel->data->ref--; ret = bpf_prog_test_run_opts(bpf_program__fd(skel->progs.test_map_kptr_ref3), &opts); ASSERT_OK(ret, "test_map_kptr_ref3 refcount"); ASSERT_OK(opts.retval, "test_map_kptr_ref3 retval"); ret = bpf_map__delete_elem(skel->maps.hash_malloc_map, &key, sizeof(key), 0); ASSERT_OK(ret, "hash_malloc_map delete"); - skel->data->ref--; ret = bpf_prog_test_run_opts(bpf_program__fd(skel->progs.test_map_kptr_ref3), &opts); ASSERT_OK(ret, "test_map_kptr_ref3 refcount"); ASSERT_OK(opts.retval, "test_map_kptr_ref3 retval"); ret = bpf_map__delete_elem(skel->maps.pcpu_hash_malloc_map, &key, sizeof(key), 0); ASSERT_OK(ret, "pcpu_hash_malloc_map delete"); - skel->data->ref--; ret = bpf_prog_test_run_opts(bpf_program__fd(skel->progs.test_map_kptr_ref3), &opts); ASSERT_OK(ret, "test_map_kptr_ref3 refcount"); ASSERT_OK(opts.retval, "test_map_kptr_ref3 retval"); ret = bpf_map__delete_elem(skel->maps.lru_hash_map, &key, sizeof(key), 0); ASSERT_OK(ret, "lru_hash_map delete"); - skel->data->ref--; ret = bpf_prog_test_run_opts(bpf_program__fd(skel->progs.test_map_kptr_ref3), &opts); ASSERT_OK(ret, "test_map_kptr_ref3 refcount"); ASSERT_OK(opts.retval, "test_map_kptr_ref3 retval"); ret = bpf_map__delete_elem(skel->maps.lru_pcpu_hash_map, &key, sizeof(key), 0); ASSERT_OK(ret, "lru_pcpu_hash_map delete"); - skel->data->ref--; ret = bpf_prog_test_run_opts(bpf_program__fd(skel->progs.test_map_kptr_ref3), &opts); ASSERT_OK(ret, "test_map_kptr_ref3 refcount"); ASSERT_OK(opts.retval, "test_map_kptr_ref3 retval"); @@ -175,7 +167,7 @@ void serial_test_map_kptr(void) ASSERT_OK(kern_sync_rcu(), "sync rcu"); wait_for_map_release(); - /* Observe refcount dropping to 1 on synchronous delete elem */ + /* Observe refcount dropping to 1 on map release. */ test_map_kptr_success(true); } diff --git a/tools/testing/selftests/bpf/prog_tests/refcounted_kptr.c b/tools/testing/selftests/bpf/prog_tests/refcounted_kptr.c index d2c0542716a848..1737eba3432343 100644 --- a/tools/testing/selftests/bpf/prog_tests/refcounted_kptr.c +++ b/tools/testing/selftests/bpf/prog_tests/refcounted_kptr.c @@ -57,6 +57,7 @@ void test_percpu_hash_refcounted_kptr_refcount_leak(void) .data_size_in = sizeof(pkt_v4), .repeat = 1, ); + LIBBPF_OPTS(bpf_test_run_opts, syscall_opts); cpu_nr = libbpf_num_possible_cpus(); if (!ASSERT_GT(cpu_nr, 0, "libbpf_num_possible_cpus")) @@ -87,8 +88,11 @@ void test_percpu_hash_refcounted_kptr_refcount_leak(void) if (!ASSERT_EQ(opts.retval, 2, "opts.retval")) goto out; - err = bpf_map__update_elem(map, &key, sizeof(key), values, values_sz, 0); - if (!ASSERT_OK(err, "bpf_map__update_elem")) + fd = bpf_program__fd(skel->progs.clear_percpu_hash_kptr); + err = bpf_prog_test_run_opts(fd, &syscall_opts); + if (!ASSERT_OK(err, "bpf_prog_test_run_opts")) + goto out; + if (!ASSERT_EQ(syscall_opts.retval, 1, "syscall_opts.retval")) goto out; fd = bpf_program__fd(skel->progs.check_percpu_hash_refcount); diff --git a/tools/testing/selftests/bpf/progs/htab_update.c b/tools/testing/selftests/bpf/progs/htab_update.c index 195d3b2fba00c5..62c1b1325ec27b 100644 --- a/tools/testing/selftests/bpf/progs/htab_update.c +++ b/tools/testing/selftests/bpf/progs/htab_update.c @@ -22,8 +22,8 @@ struct { int pid = 0; int update_err = 0; -SEC("?fentry/bpf_obj_free_fields") -int bpf_obj_free_fields(void *ctx) +SEC("?fentry/bpf_obj_cancel_fields") +int bpf_obj_cancel_fields(void *ctx) { __u32 key = 0; struct val value = { .payload = 1 }; diff --git a/tools/testing/selftests/bpf/progs/linked_list.c b/tools/testing/selftests/bpf/progs/linked_list.c index 421f40835acd75..fa97faa5358bca 100644 --- a/tools/testing/selftests/bpf/progs/linked_list.c +++ b/tools/testing/selftests/bpf/progs/linked_list.c @@ -290,6 +290,77 @@ int test_list_in_list(struct bpf_spin_lock *lock, struct bpf_list_head *head) return list_in_list(lock, head, true); } +#define MAX_LIST_CLEAR_NODES 256 + +static __always_inline +int clear_list(struct bpf_spin_lock *lock, struct bpf_list_head *head) +{ + struct bpf_list_node *n; + int i; + + for (i = 0; i < MAX_LIST_CLEAR_NODES; i++) { + bpf_spin_lock(lock); + n = bpf_list_pop_front(head); + bpf_spin_unlock(lock); + if (!n) + return 0; + bpf_obj_drop(container_of(n, struct foo, node2)); + } + return 1; +} + +SEC("syscall") +int clear_map_list(void *ctx) +{ + struct map_value *v; + + v = bpf_map_lookup_elem(&array_map, &(int){0}); + if (!v) + return 1; + return clear_list(&v->lock, &v->head); +} + +SEC("syscall") +int clear_inner_map_list(void *ctx) +{ + struct map_value *v; + void *map; + + map = bpf_map_lookup_elem(&map_of_maps, &(int){0}); + if (!map) + return 1; + v = bpf_map_lookup_elem(map, &(int){0}); + if (!v) + return 1; + return clear_list(&v->lock, &v->head); +} + +SEC("syscall") +int clear_global_list(void *ctx) +{ + return clear_list(&glock, &ghead); +} + +SEC("syscall") +int clear_global_nested_list(void *ctx) +{ + return clear_list(&ghead_nested.inner.lock, &ghead_nested.inner.head); +} + +SEC("syscall") +int clear_global_array_list(void *ctx) +{ + int ret; + + ret = clear_list(&glock_c, &ghead_array[0]); + if (ret) + return ret; + ret = clear_list(&glock_c, &ghead_array[1]); + if (ret) + return ret; + return clear_list(&glock_c, &ghead_array_one[0]); +} + SEC("tc") int map_list_push_pop(void *ctx) { diff --git a/tools/testing/selftests/bpf/progs/refcounted_kptr.c b/tools/testing/selftests/bpf/progs/refcounted_kptr.c index c847398837ccd7..9837dccfc141c6 100644 --- a/tools/testing/selftests/bpf/progs/refcounted_kptr.c +++ b/tools/testing/selftests/bpf/progs/refcounted_kptr.c @@ -615,13 +615,31 @@ int percpu_hash_refcount_leak(void *ctx) struct map_value *v; int key = 0; - v = bpf_map_lookup_elem(&percpu_hash, &key); + v = bpf_map_lookup_percpu_elem(&percpu_hash, &key, 0); if (!v) return 0; return __insert_in_list(&head, &lock, &v->node); } +SEC("syscall") +int clear_percpu_hash_kptr(void *ctx) +{ + struct node_data *n; + struct map_value *v; + int key = 0; + + v = bpf_map_lookup_percpu_elem(&percpu_hash, &key, 0); + if (!v) + return 0; + + n = bpf_kptr_xchg(&v->node, NULL); + if (!n) + return 0; + bpf_obj_drop(n); + return probe_read_refcount(); +} + SEC("tc") int check_percpu_hash_refcount(void *ctx) { -- 2.53.0