From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793692801; b=mMMEbIbZhq/k7OYkCvPmTAwRenbPxZGXZBBh14G1UX2XsKsTLrgDVsHPQE46Lnc3yWXm KHtFbM9u8Wt9zir8C+T/ZdpFWQG1RzEQFeLRKTOOzOnihEGyn1EhA7rN9wLdxsBqGMpCm I+upnjRxJvzVIXVVyd/S0BwatyKhKh+b+u/MnS1u9cbogzu7utpxAxPVWXHxzJ/W3g3U7 uEvza8sjOqWu8RLrOGaGdm+7KR5Ht+tE7cU/eg2FnqgWVzXyhWqknwFvmoVwSRgcTpyzk SFOGpjOL5DS1IxZ1Zk1mnP1XS0WIuyy7wYEFhVBzIBqBmL1uyCMDUiqXiNIFvSzFH/A== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793692801; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:Content-Transfer-Encoding; bh=aWC1fpeZM+QP/64/LlbIQvYUrFOSEHGeQ7yKHlmi7Q4=; b=nLc/lGd5hLAJ7iD6ksENWAGAm1mlItU9XVzzW4KRq3qo4D0a2HxSYnixNfCzC1Gy07EF omd55vyKo1gGtVNVT1nGQpDMUNjriTEvEqhzK4BZGTz+btwYqdqCx8KduEkWFfhudVB1t SUgyu3TtqRqa0LdKnptQODFajg84sgodg7nxF8u0f8j2NLYOFlytfNBOfyx1XQyWjevg7 FiCKSVry7pspbd52FNDnnGNTQ6CoNavrr1bMykNfLronRxisImo9h0gbYYiNMUX0QmX14 hKsk8LasuFn0pTT+hCEP0wX8UAzs0c+0/ej4khZG9MTAMXWRjLtp+sJRMlurYQwDxbQ== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=LhgrJq3L; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 58471606A324 for ; Tue, 3 Nov 2026 08:00:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=LhgrJq3L Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0491A1F000C1; Tue, 3 Nov 2026 07:59:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793692801; bh=aWC1fpeZM+QP/64/LlbIQvYUrFOSEHGeQ7yKHlmi7Q4=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=LhgrJq3Lq6X3P/irxArdBkEOP1l46e/U5W/V+lvXpkBKvL3zyLBFe9p3tB2NSEKSl yazFsLx/fur+/hQM3kHlHfDA9v8sHNvR6cRJmc77AWV7Upvkb78uyJtqsbxZIf5gzw 0lu4axk7HAPsWxqX5ucfkxNgl1tpdPiM2szhA5/FBywItXnmPdNLEWSZ9ay2Ko6SE2 dMb2gAUbUHQOoUeyVT+VulTtEhRLd9ci5miucT72lkrzDYi9q3k27NLixNNkyJrTLp MonutnN2PQMA0rOAZvWU8htC/2WaKOv8lbKNEnJKKEzXNtDfpqy4hfUYbo8w1E19kd sZvzrTX6iY7HQ== From: Jiri Olsa To: Alexei Starovoitov , Daniel Borkmann Cc: bpf@vger.kernel.org, linux-mm@kvack.org, Andrii Nakryiko , Eduard Zingerman , Kumar Kartikeya Dwivedi , Lorenzo Stoakes , John Fastabend , Federico Di Pierro Subject: [PATCHv2 bpf-next 4/8] selftests/bpf: Test const kfunc memory arguments Date: Tue, 3 Nov 2026 08:59:11 +0100 Message-ID: <20261103075916.100050-5-jolsa@kernel.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261103075916.100050-1-jolsa@kernel.org> References: <20261103075916.100050-1-jolsa@kernel.org> X-Mailing-List: bpf@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Verify that const kfunc arguments accept read-only global data, writable stack data, and const scalar structs. Check that read-only data is rejected when passed to a writable memory argument. Assisted-by: Codex:GPT-6 Signed-off-by: Jiri Olsa --- .../testing/selftests/bpf/prog_tests/kfunc_call.c | 2 ++ .../testing/selftests/bpf/progs/kfunc_call_fail.c | 10 ++++++++++ .../testing/selftests/bpf/progs/kfunc_call_test.c | 14 ++++++++++++++ .../testing/selftests/bpf/test_kmods/bpf_testmod.c | 10 ++++++++++ .../selftests/bpf/test_kmods/bpf_testmod_kfunc.h | 2 ++ 5 files changed, 38 insertions(+) diff --git a/tools/testing/selftests/bpf/prog_tests/kfunc_call.c b/tools/testing/selftests/bpf/prog_tests/kfunc_call.c index 0063e60d6f2f..f2152591982b 100644 --- a/tools/testing/selftests/bpf/prog_tests/kfunc_call.c +++ b/tools/testing/selftests/bpf/prog_tests/kfunc_call.c @@ -63,6 +63,7 @@ static struct kfunc_test_params kfunc_tests[] = { */ SYSCALL_NULL_CTX_FAIL(kfunc_syscall_test_fail, -EINVAL, "processed 4 insns"), SYSCALL_NULL_CTX_FAIL(kfunc_syscall_test_null_fail, -EINVAL, "processed 4 insns"), + TC_FAIL(kfunc_call_test_mem_len_fail_readonly, 0, "write into map forbidden"), TC_FAIL(kfunc_call_test_get_mem_fail_rdonly, 0, "R0 cannot write into rdonly_mem"), TC_FAIL(kfunc_call_test_get_mem_fail_use_after_free, 0, "invalid mem access 'scalar'"), TC_FAIL(kfunc_call_test_get_mem_fail_oob, 0, "min value is outside of the allowed memory range"), @@ -82,6 +83,7 @@ static struct kfunc_test_params kfunc_tests[] = { TC_TEST(kfunc_call_test5_asm, 0), TC_TEST(kfunc_call_test_ref_btf_id, 0), TC_TEST(kfunc_call_test_get_mem, 42), + TC_TEST(kfunc_call_test_const_mem, 0), SYSCALL_TEST(kfunc_syscall_test, 0), SYSCALL_NULL_CTX_TEST(kfunc_syscall_test_null, 0), TC_TEST(kfunc_call_test_static_unused_arg, 0), diff --git a/tools/testing/selftests/bpf/progs/kfunc_call_fail.c b/tools/testing/selftests/bpf/progs/kfunc_call_fail.c index 7e93f7fb1329..bef956d3f89e 100644 --- a/tools/testing/selftests/bpf/progs/kfunc_call_fail.c +++ b/tools/testing/selftests/bpf/progs/kfunc_call_fail.c @@ -4,6 +4,8 @@ #include #include "../test_kmods/bpf_testmod_kfunc.h" +static const char kfunc_mem_rodata[] = "read-only data"; + static struct bpf_spin_lock kfunc_call_lock SEC(".data.A"); SEC("?tc") @@ -47,6 +49,14 @@ int kfunc_syscall_test_null_fail(struct syscall_test_args *args) return 0; } +SEC("?tc") +int kfunc_call_test_mem_len_fail_readonly(struct __sk_buff *skb) +{ + bpf_kfunc_call_test_mem_len_pass1((void *)kfunc_mem_rodata, + sizeof(kfunc_mem_rodata)); + return 0; +} + SEC("?tc") int kfunc_call_test_get_mem_fail_rdonly(struct __sk_buff *skb) { diff --git a/tools/testing/selftests/bpf/progs/kfunc_call_test.c b/tools/testing/selftests/bpf/progs/kfunc_call_test.c index 8e6560c31e78..4f4a6713aa6e 100644 --- a/tools/testing/selftests/bpf/progs/kfunc_call_test.c +++ b/tools/testing/selftests/bpf/progs/kfunc_call_test.c @@ -5,6 +5,9 @@ #include "bpf_misc.h" #include "../test_kmods/bpf_testmod_kfunc.h" +static const char kfunc_const_data[] = "read-only source"; +static const struct prog_test_pass1 kfunc_const_struct = { .x0 = 1 }; + static struct bpf_spin_lock kfunc_call_lock SEC(".data.A"); SEC("tc") @@ -208,6 +211,17 @@ int kfunc_call_test_pass(struct __sk_buff *skb) return 0; } +SEC("tc") +int kfunc_call_test_const_mem(struct __sk_buff *skb) +{ + char stack_data[] = "read-write"; + + bpf_kfunc_call_test_const_mem(kfunc_const_data, sizeof(kfunc_const_data)); + bpf_kfunc_call_test_const_mem(stack_data, sizeof(stack_data)); + bpf_kfunc_call_test_const_struct(&kfunc_const_struct); + return 0; +} + struct syscall_test_args { __u8 data[16]; size_t size; diff --git a/tools/testing/selftests/bpf/test_kmods/bpf_testmod.c b/tools/testing/selftests/bpf/test_kmods/bpf_testmod.c index 76fbe64755ef..41ff36f0ca77 100644 --- a/tools/testing/selftests/bpf/test_kmods/bpf_testmod.c +++ b/tools/testing/selftests/bpf/test_kmods/bpf_testmod.c @@ -1049,6 +1049,8 @@ BTF_ID_FLAGS(func, bpf_kfunc_arena_args5_test) BTF_ID_FLAGS(func, bpf_kfunc_arena_stack_arg_test) BTF_ID_FLAGS(func, bpf_kfunc_arena_mixed_test) BTF_ID_FLAGS(func, bpf_kfunc_call_test_mem_len_pass1) +BTF_ID_FLAGS(func, bpf_kfunc_call_test_const_mem) +BTF_ID_FLAGS(func, bpf_kfunc_call_test_const_struct) BTF_ID_FLAGS(func, bpf_kfunc_dynptr_test) BTF_ID_FLAGS(func, bpf_kfunc_nested_acquire_nonzero_offset_test, KF_ACQUIRE) BTF_ID_FLAGS(func, bpf_kfunc_nested_acquire_zero_offset_test, KF_ACQUIRE) @@ -1552,6 +1554,14 @@ __bpf_kfunc void bpf_kfunc_call_test_mem_len_pass1(void *mem, int mem__sz) { } +__bpf_kfunc void bpf_kfunc_call_test_const_mem(const void *mem, int mem__sz) +{ +} + +__bpf_kfunc void bpf_kfunc_call_test_const_struct(const struct prog_test_pass1 *p) +{ +} + __bpf_kfunc void bpf_kfunc_call_test_mem_len_fail1(void *mem, int len) { } diff --git a/tools/testing/selftests/bpf/test_kmods/bpf_testmod_kfunc.h b/tools/testing/selftests/bpf/test_kmods/bpf_testmod_kfunc.h index e9902e651d72..0a7df1798603 100644 --- a/tools/testing/selftests/bpf/test_kmods/bpf_testmod_kfunc.h +++ b/tools/testing/selftests/bpf/test_kmods/bpf_testmod_kfunc.h @@ -203,6 +203,8 @@ void bpf_kfunc_call_test_release(struct prog_test_ref_kfunc *p) __ksym; void bpf_kfunc_call_test_ref(struct prog_test_ref_kfunc *p) __ksym; void bpf_kfunc_call_test_mem_len_pass1(void *mem, int len) __ksym; +void bpf_kfunc_call_test_const_mem(const void *mem, int mem__sz) __ksym; +void bpf_kfunc_call_test_const_struct(const struct prog_test_pass1 *p) __ksym; __u64 bpf_kfunc_arena_arg_test(__u64 *val__arena) __ksym; __u64 bpf_kfunc_arena_cap_test(__u64 *val__arena) __ksym; __u64 bpf_kfunc_arena_cap_nullable_test(__u64 *val__arena__nullable) __ksym; -- 2.43.0