From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from 66-220-155-178.mail-mxout.facebook.com (66-220-155-178.mail-mxout.facebook.com [66.220.155.178]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id CAA711D4606 for ; Sat, 29 Aug 2026 06:16:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=66.220.155.178 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787984171; cv=none; b=IxMR12zATk4Xl0fGAphY6UM5kDCxdZG5osD7ndMLQ9OgyIoehgy0a6F+9uWMhYC7R9JrarKK7Hrh0lPFyFqBSZxnjghHXsyc9WDVIlWxw23nZ+8EdGQc+ir2E5V7EH7iNzDwP1T/RkvVbyBNYBaGsKNjsFjt1AOwKIX2s9RDrQo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787984171; c=relaxed/simple; bh=3mNXNQjRgWYMVs8kxZk8GpsP4ueiVjqvjGes0d06tJM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ORC/ruxPNLn6u3nznO47P365pfD2s+FZbNwKFYgb1qD9Sb9qCuVpw4a55jOW8vP5dEimxD+rfb61A8KiBrAS7WDFynZDx8RMOEZYm16Dua6kXVZhE9DycIoPt5VHgSPQnWq/PBmLjy6qZ1zlxB1+9eS3NsX8WmFwOwg+s6oaTaE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.dev; spf=fail smtp.mailfrom=linux.dev; arc=none smtp.client-ip=66.220.155.178 Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=fail smtp.mailfrom=linux.dev Received: by devvm16039.vll0.facebook.com (Postfix, from userid 128203) id 5694E273BA2FFF; Fri, 28 Aug 2026 23:16:00 -0700 (PDT) From: Yonghong Song To: bpf@vger.kernel.org Cc: Alexei Starovoitov , Andrii Nakryiko , Daniel Borkmann , Eduard Zingerman , kernel-team@fb.com Subject: [PATCH bpf-next v4 09/12] selftests/bpf: Check the member named for an unsupported kfunc return type Date: Fri, 28 Aug 2026 23:16:00 -0700 Message-ID: <20260829061600.1697800-1-yonghong.song@linux.dev> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260829061514.1690730-1-yonghong.song@linux.dev> References: <20260829061514.1690730-1-yonghong.song@linux.dev> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Add tests to cover cases where a kfunc return type is rejected with proper messages including member names and array types. Signed-off-by: Yonghong Song --- .../selftests/bpf/progs/aggregate_ret_kfunc.c | 82 +++++++++++++++++++ .../selftests/bpf/test_kmods/bpf_testmod.c | 40 +++++++++ .../bpf/test_kmods/bpf_testmod_kfunc.h | 42 ++++++++++ 3 files changed, 164 insertions(+) diff --git a/tools/testing/selftests/bpf/progs/aggregate_ret_kfunc.c b/to= ols/testing/selftests/bpf/progs/aggregate_ret_kfunc.c index f10e5cf6fd89..0361a7b42c9b 100644 --- a/tools/testing/selftests/bpf/progs/aggregate_ret_kfunc.c +++ b/tools/testing/selftests/bpf/progs/aggregate_ret_kfunc.c @@ -19,6 +19,11 @@ void __kfunc_btf_root(void) "r"(&bpf_kfunc_call_test_ret_fastcall), "r"(&bpf_kfunc_call_test_ret_ptr), "r"(&bpf_kfunc_call_test_ret_ii), + "r"(&bpf_kfunc_call_test_ret_nested), + "r"(&bpf_kfunc_call_test_ret_ptr_arr), + "r"(&bpf_kfunc_call_test_ret_deep), + "r"(&bpf_kfunc_call_test_ret_arr_struct), + "r"(&bpf_kfunc_call_test_ret_arr2d), "r"(&bpf_kfunc_call_test_ret_big)); } =20 @@ -72,6 +77,7 @@ __naked int aggregate_ret_kfunc_fastcall_fail(void) SEC("tc") __arch_x86_64 __arch_arm64 __failure __msg("is not composed of scalars or arena pointers") +__msg("member 'p' has type PTR") __naked int aggregate_ret_kfunc_ptr_fail(void) { asm volatile ( @@ -84,6 +90,82 @@ __naked int aggregate_ret_kfunc_ptr_fail(void) : __clobber_all); } =20 +SEC("tc") +__arch_x86_64 __arch_arm64 +__failure __msg("is not composed of scalars or arena pointers") +__msg("member 'in.p' has type PTR") +__naked int aggregate_ret_kfunc_nested_ptr_fail(void) +{ + asm volatile ( + "r1 =3D 0;" + "call %[bpf_kfunc_call_test_ret_nested];" + "r0 =3D 0;" + "exit;" + : + : __imm(bpf_kfunc_call_test_ret_nested) + : __clobber_all); +} + +SEC("tc") +__arch_x86_64 __arch_arm64 +__failure __msg("is not composed of scalars or arena pointers") +__msg("member 'p[]' has type PTR") +__naked int aggregate_ret_kfunc_ptr_arr_fail(void) +{ + asm volatile ( + "call %[bpf_kfunc_call_test_ret_ptr_arr];" + "r0 =3D 0;" + "exit;" + : + : __imm(bpf_kfunc_call_test_ret_ptr_arr) + : __clobber_all); +} + +SEC("tc") +__arch_x86_64 __arch_arm64 +__failure __msg("is not composed of scalars or arena pointers") +__msg("member 'in1[].in2.p' has type PTR") +__naked int aggregate_ret_kfunc_arr_struct_fail(void) +{ + asm volatile ( + "call %[bpf_kfunc_call_test_ret_arr_struct];" + "r0 =3D 0;" + "exit;" + : + : __imm(bpf_kfunc_call_test_ret_arr_struct) + : __clobber_all); +} + +SEC("tc") +__arch_x86_64 __arch_arm64 +__failure __msg("is not composed of scalars or arena pointers") +__msg("member 'a[].p' has type PTR") +__naked int aggregate_ret_kfunc_arr2d_fail(void) +{ + asm volatile ( + "call %[bpf_kfunc_call_test_ret_arr2d];" + "r0 =3D 0;" + "exit;" + : + : __imm(bpf_kfunc_call_test_ret_arr2d) + : __clobber_all); +} + +SEC("tc") +__arch_x86_64 __arch_arm64 +__failure __msg("max struct nesting depth exceeded") +__naked int aggregate_ret_kfunc_too_deep_fail(void) +{ + asm volatile ( + "r1 =3D 0;" + "call %[bpf_kfunc_call_test_ret_deep];" + "r0 =3D 0;" + "exit;" + : + : __imm(bpf_kfunc_call_test_ret_deep) + : __clobber_all); +} + SEC("tc") __arch_x86_64 __arch_arm64 __failure __msg("R2 !read_ok") diff --git a/tools/testing/selftests/bpf/test_kmods/bpf_testmod.c b/tools= /testing/selftests/bpf/test_kmods/bpf_testmod.c index 850cf4f830c4..dff1ad6f491f 100644 --- a/tools/testing/selftests/bpf/test_kmods/bpf_testmod.c +++ b/tools/testing/selftests/bpf/test_kmods/bpf_testmod.c @@ -981,6 +981,41 @@ __bpf_kfunc struct prog_test_ret_ptr bpf_kfunc_call_= test_ret_ptr(u64 tag) return r; } =20 +__bpf_kfunc struct prog_test_ret_nested bpf_kfunc_call_test_ret_nested(u= 64 tag) +{ + struct prog_test_ret_nested r =3D { .in =3D { .p =3D NULL }, .tag =3D t= ag }; + + return r; +} + +__bpf_kfunc struct prog_test_ret_ptr_arr bpf_kfunc_call_test_ret_ptr_arr= (void) +{ + struct prog_test_ret_ptr_arr r =3D { .p =3D { NULL, NULL } }; + + return r; +} + +__bpf_kfunc struct prog_test_ret_arr_struct bpf_kfunc_call_test_ret_arr_= struct(void) +{ + struct prog_test_ret_arr_struct r =3D {}; + + return r; +} + +__bpf_kfunc struct prog_test_ret_arr2d bpf_kfunc_call_test_ret_arr2d(voi= d) +{ + struct prog_test_ret_arr2d r =3D {}; + + return r; +} + +__bpf_kfunc struct prog_test_ret_deep bpf_kfunc_call_test_ret_deep(u64 v= ) +{ + struct prog_test_ret_deep r =3D { .l1 =3D { .l2 =3D { .l3 =3D { .l4 =3D= { .v =3D v } } } } }; + + return r; +} + __bpf_kfunc struct prog_test_ret_ii bpf_kfunc_call_test_ret_ii(int a, in= t b) { struct prog_test_ret_ii r =3D { .a =3D a, .b =3D b }; @@ -1539,6 +1574,11 @@ BTF_ID_FLAGS(func, bpf_kfunc_call_test_i128) BTF_ID_FLAGS(func, bpf_kfunc_call_test_ret_pair) BTF_ID_FLAGS(func, bpf_kfunc_call_test_ret_fastcall, KF_FASTCALL) BTF_ID_FLAGS(func, bpf_kfunc_call_test_ret_ptr) +BTF_ID_FLAGS(func, bpf_kfunc_call_test_ret_nested) +BTF_ID_FLAGS(func, bpf_kfunc_call_test_ret_ptr_arr) +BTF_ID_FLAGS(func, bpf_kfunc_call_test_ret_arr_struct) +BTF_ID_FLAGS(func, bpf_kfunc_call_test_ret_arr2d) +BTF_ID_FLAGS(func, bpf_kfunc_call_test_ret_deep) BTF_ID_FLAGS(func, bpf_kfunc_call_test_ret_ii) #endif BTF_ID_FLAGS(func, bpf_kfunc_call_test_ret_big) 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 65e693ada736..9202c31ba6c9 100644 --- a/tools/testing/selftests/bpf/test_kmods/bpf_testmod_kfunc.h +++ b/tools/testing/selftests/bpf/test_kmods/bpf_testmod_kfunc.h @@ -70,6 +70,43 @@ struct prog_test_ret_ptr { /* 16 bytes: contains a poi= nter */ __u64 tag; }; =20 +struct prog_test_ret_nested { /* 16 bytes: the pointer hides one level d= own */ + struct { + void *p; + } in; + __u64 tag; +}; + +struct prog_test_ret_ptr_arr { /* 16 bytes: an array of pointers */ + void *p[2]; +}; + +struct prog_test_ret_arr_struct { /* 16 bytes: the pointer is under an a= rray of structs */ + struct { + struct { + void *p; + } in2; + } in1[2]; +}; + +struct prog_test_ret_arr2d { /* 16 bytes: a two dimensional array of str= ucts */ + struct { + void *p; + } a[1][2]; +}; + +struct prog_test_ret_deep { /* 8 bytes, but nested past the 4-level walk= limit */ + struct { + struct { + struct { + struct { + __u64 v; + } l4; + } l3; + } l2; + } l1; +}; + struct prog_test_ret_big { /* 24 bytes: too large for R0:R2 */ __u64 a; __u64 b; @@ -159,6 +196,11 @@ struct prog_test_ret_pair bpf_kfunc_call_test_ret_pa= ir(__u64 a, __u64 b) __ksym; struct prog_test_ret_pair bpf_kfunc_call_test_ret_fastcall(__u64 a, __u6= 4 b) __ksym; struct prog_test_ret_ii bpf_kfunc_call_test_ret_ii(int a, int b) __ksym; struct prog_test_ret_ptr bpf_kfunc_call_test_ret_ptr(__u64 tag) __ksym; +struct prog_test_ret_nested bpf_kfunc_call_test_ret_nested(__u64 tag) __= ksym; +struct prog_test_ret_ptr_arr bpf_kfunc_call_test_ret_ptr_arr(void) __ksy= m; +struct prog_test_ret_arr_struct bpf_kfunc_call_test_ret_arr_struct(void)= __ksym; +struct prog_test_ret_arr2d bpf_kfunc_call_test_ret_arr2d(void) __ksym; +struct prog_test_ret_deep bpf_kfunc_call_test_ret_deep(__u64 v) __ksym; struct prog_test_ret_big bpf_kfunc_call_test_ret_big(void) __ksym; __u64 bpf_kfunc_call_stack_arg(__u64 a, __u64 b, __u64 c, __u64 d, __u64 e, __u64 f, __u64 g, __u64 h, --=20 2.53.0-Meta