From nobody Sat Feb 7 17:01:42 2026 Received: from out-184.mta1.migadu.com (out-184.mta1.migadu.com [95.215.58.184]) (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 481711F1506; Fri, 21 Feb 2025 16:36:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.184 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740155771; cv=none; b=DoIXPkXYdR4Pb77BUtVGu6Ip92VW+t9flzLf1/Kwymx+nESgL2D6k6Wqu5nNfQ9AR7/EEt561rXDIpjAqAmrm6mb/nB/IbTHB3vV80amTBgifsGNXFmZ2EItBMyDKLB7KBqJ8nLlzzEaNT+Ens/RE/UYJuEGQYQ0mfL57qZv3eQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740155771; c=relaxed/simple; bh=jm9V/uGdHxg5OBS/aN+olvdgGrxxL3p39+/oZgyyRrw=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=CXtO7D4GWpppYOpLsiSc/cbUcbtuhxEHA0V25tBrPFRWJNwG9vFUOVZPjHUR3SXNJXwYaE9OLDLh8x1ypnU1mp8RUnzb6NMoYQnrXKccOWMpPBr4iXrSuZPrwgv+ykwW2RhWzHpYf6nHCagEqyBOcviqtfh/e/uxZ94i9zBghoM= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=qisBFz5n; arc=none smtp.client-ip=95.215.58.184 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="qisBFz5n" X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1740155767; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=sXImHF+AatB2zWehHEZzkP3DgCbk67G0CTnxuxdEVxE=; b=qisBFz5noL7qnwLJNeIFAsuJpLJMjvNTyFWWXTZOESyGgzYo+FXdgsqGbx0EzlRQPJ8imU Gut8jIIQV1qLtUJ0TLBY2NZiYeybIkYrvwlvbruWSjEMmqkXBKEu1HxK7VTj6wciyh2aNb BYrqt9siwdvYe4nHRAib9J0tnqM5YTA= From: Tao Chen To: ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, eddyz87@gmail.com, haoluo@google.com, jolsa@kernel.org, qmo@kernel.org Cc: bpf@vger.kernel.org, linux-kernel@vger.kernel.org, chen.dylane@gmail.com, Tao Chen , Tao Chen Subject: [PATCH bpf-next v8 1/4] libbpf: Extract prog load type check from libbpf_probe_bpf_helper Date: Sat, 22 Feb 2025 00:33:32 +0800 Message-Id: <20250221163335.262143-2-chen.dylane@linux.dev> In-Reply-To: <20250221163335.262143-1-chen.dylane@linux.dev> References: <20250221163335.262143-1-chen.dylane@linux.dev> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Migadu-Flow: FLOW_OUT Content-Type: text/plain; charset="utf-8" Extract prog load type check part from libbpf_probe_bpf_helper suggested by Andrii, which will be used in both libbpf_probe_bpf_{helper, kfunc}. Cc: Tao Chen Reviewed-by: Jiri Olsa Reviewed-by: Eduard Zingerman Signed-off-by: Tao Chen --- tools/lib/bpf/libbpf_probes.c | 31 +++++++++++++++++++------------ 1 file changed, 19 insertions(+), 12 deletions(-) diff --git a/tools/lib/bpf/libbpf_probes.c b/tools/lib/bpf/libbpf_probes.c index 9dfbe7750f56..a48a557314f6 100644 --- a/tools/lib/bpf/libbpf_probes.c +++ b/tools/lib/bpf/libbpf_probes.c @@ -413,6 +413,23 @@ int libbpf_probe_bpf_map_type(enum bpf_map_type map_ty= pe, const void *opts) return libbpf_err(ret); } =20 +static bool can_probe_prog_type(enum bpf_prog_type prog_type) +{ + /* we can't successfully load all prog types to check for BPF helper + * and kfunc support. + */ + switch (prog_type) { + case BPF_PROG_TYPE_TRACING: + case BPF_PROG_TYPE_EXT: + case BPF_PROG_TYPE_LSM: + case BPF_PROG_TYPE_STRUCT_OPS: + return false; + default: + break; + } + return true; +} + int libbpf_probe_bpf_helper(enum bpf_prog_type prog_type, enum bpf_func_id= helper_id, const void *opts) { @@ -427,18 +444,8 @@ int libbpf_probe_bpf_helper(enum bpf_prog_type prog_ty= pe, enum bpf_func_id helpe if (opts) return libbpf_err(-EINVAL); =20 - /* we can't successfully load all prog types to check for BPF helper - * support, so bail out with -EOPNOTSUPP error - */ - switch (prog_type) { - case BPF_PROG_TYPE_TRACING: - case BPF_PROG_TYPE_EXT: - case BPF_PROG_TYPE_LSM: - case BPF_PROG_TYPE_STRUCT_OPS: - return -EOPNOTSUPP; - default: - break; - } + if (!can_probe_prog_type(prog_type)) + return libbpf_err(-EOPNOTSUPP); =20 buf[0] =3D '\0'; ret =3D probe_prog_load(prog_type, insns, insn_cnt, buf, sizeof(buf)); --=20 2.43.0 From nobody Sat Feb 7 17:01:42 2026 Received: from out-173.mta0.migadu.com (out-173.mta0.migadu.com [91.218.175.173]) (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 31505204F79 for ; Fri, 21 Feb 2025 16:36:15 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.173 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740155777; cv=none; b=fMZHpcwd9Z5aAXfI5sdsTT/vmc/2e2/6fCzOKYfKy/6Dcc+S9wZvySTkoZL0UfYrWzNjpJ6EbZyQy583U36yRzkA2gLtpnuIhoBcUP12o6LzdBAOeAAF52YtSQyrixLOD0Ue4PoGVVycBH07Rrq3j5Sr4OPLHpm8+ml4rjMFYec= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740155777; c=relaxed/simple; bh=aG8o/kahVF1tm5V+3pDDlV1oJXm/dksJNGytP15/dhA=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=ELI+WFoGfkKoBH/UnQuU/wZZ5EfSQCEPvB+Gs72PscJrqWKUc/55xmQLwvg/ejUoYykWcBhAvFMtNoWiWbueox076uVWjn0A29iXgCueBDZnnQRUXzLxPa98mXxfsSlcx0mVclWrJrqMpLZSPZWDzRHADGsr5TTHBglN6bAYIHk= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=lBHMiiM0; arc=none smtp.client-ip=91.218.175.173 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="lBHMiiM0" X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1740155773; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=7PGzrKBqkUWVbwyFTBIov9XC7SmgDrzD5PuL2n2Yx4M=; b=lBHMiiM0jqYTuuYKSlMsV398//EFh4ZUOseuAj9KLMk11Ij/mApLJlc401rmWFzWJW++W3 BHd0mdHqQE8BN3hE9mKX7bcnKvpUGZxKjnbEPSM+pS8xPM/Ns9OyO42qdXVz9Ig+g+ZL+z e3Wl/YRd9PgVQRa45IV63VECNRWeZ5g= From: Tao Chen To: ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, eddyz87@gmail.com, haoluo@google.com, jolsa@kernel.org, qmo@kernel.org Cc: bpf@vger.kernel.org, linux-kernel@vger.kernel.org, chen.dylane@gmail.com, Tao Chen , Tao Chen Subject: [PATCH bpf-next v8 2/4] libbpf: Init fd_array when prog probe load Date: Sat, 22 Feb 2025 00:33:33 +0800 Message-Id: <20250221163335.262143-3-chen.dylane@linux.dev> In-Reply-To: <20250221163335.262143-1-chen.dylane@linux.dev> References: <20250221163335.262143-1-chen.dylane@linux.dev> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Migadu-Flow: FLOW_OUT Content-Type: text/plain; charset="utf-8" fd_array used to store module btf fd, which will be used for kfunc probe in module btf. Cc: Tao Chen Reviewed-by: Jiri Olsa Reviewed-by: Eduard Zingerman Signed-off-by: Tao Chen --- tools/lib/bpf/libbpf_probes.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/tools/lib/bpf/libbpf_probes.c b/tools/lib/bpf/libbpf_probes.c index a48a557314f6..de2b1205b436 100644 --- a/tools/lib/bpf/libbpf_probes.c +++ b/tools/lib/bpf/libbpf_probes.c @@ -102,12 +102,13 @@ __u32 get_kernel_version(void) =20 static int probe_prog_load(enum bpf_prog_type prog_type, const struct bpf_insn *insns, size_t insns_cnt, - char *log_buf, size_t log_buf_sz) + int *fd_array, char *log_buf, size_t log_buf_sz) { LIBBPF_OPTS(bpf_prog_load_opts, opts, .log_buf =3D log_buf, .log_size =3D log_buf_sz, .log_level =3D log_buf ? 1 : 0, + .fd_array =3D fd_array, ); int fd, err, exp_err =3D 0; const char *exp_msg =3D NULL; @@ -214,7 +215,7 @@ int libbpf_probe_bpf_prog_type(enum bpf_prog_type prog_= type, const void *opts) if (opts) return libbpf_err(-EINVAL); =20 - ret =3D probe_prog_load(prog_type, insns, insn_cnt, NULL, 0); + ret =3D probe_prog_load(prog_type, insns, insn_cnt, NULL, NULL, 0); return libbpf_err(ret); } =20 @@ -448,7 +449,7 @@ int libbpf_probe_bpf_helper(enum bpf_prog_type prog_typ= e, enum bpf_func_id helpe return libbpf_err(-EOPNOTSUPP); =20 buf[0] =3D '\0'; - ret =3D probe_prog_load(prog_type, insns, insn_cnt, buf, sizeof(buf)); + ret =3D probe_prog_load(prog_type, insns, insn_cnt, NULL, buf, sizeof(buf= )); if (ret < 0) return libbpf_err(ret); =20 --=20 2.43.0 From nobody Sat Feb 7 17:01:42 2026 Received: from out-171.mta1.migadu.com (out-171.mta1.migadu.com [95.215.58.171]) (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 778B320FA86 for ; Fri, 21 Feb 2025 16:36:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.171 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740155793; cv=none; b=CpQUDv4eR6I+qABlMMB3XHTSkcOD3Lf80FEUw3oNuwykP9LGh6ZgV2hN2DdQlGHfjzUicZlHFmMnN2r2l4l+TGShpqMFVsz9U+XrZTuPLw12WA6zjcRemxQYEjuCjQqRD1xr9yYzaCPsSpKMqv7DMujMf2nyX9UGexHNRoQYw1s= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740155793; c=relaxed/simple; bh=pWXtRo6gHo4DEJYISY33x6GfcFgrTWBD7e3ZWdUBELE=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=BJNGLsLRCWUe5T+hAVd2eOgW7j1v76tclTiLxRUTkK00QJ8GmZ0IXoFNdWkaBDnr929la4yDP7deLr+2tsxxriulxry3LOtU4vW7gUGDuHnUdXVuTTECfv8lIJVhzgNiN3baLRwsXvxgUXvHWoI0r+MdE/6Id3K7NniNxnooy18= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=kDCLDEcF; arc=none smtp.client-ip=95.215.58.171 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="kDCLDEcF" X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1740155789; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=vB83pcYOlAu6TvcgZccjSdqVZZ3UtGjDlwpT4jeGmb0=; b=kDCLDEcFzNmdb93Nm5TYmHvhLUoeyk70BPC12DJ75fHQSkmqpW/CvtrD0z0NTJBcSAKB+m GG72WyeMITRgC0dTq3RnT14bobqFvGdZe6N5jophG4izfinGCV9hs74j7+A9S/kb1LZ6AN QAx026QBlwhel5knRCgUjGlH4QrB7xE= From: Tao Chen To: ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, eddyz87@gmail.com, haoluo@google.com, jolsa@kernel.org, qmo@kernel.org Cc: bpf@vger.kernel.org, linux-kernel@vger.kernel.org, chen.dylane@gmail.com, Tao Chen , Tao Chen Subject: [PATCH bpf-next v8 3/4] libbpf: Add libbpf_probe_bpf_kfunc API Date: Sat, 22 Feb 2025 00:33:34 +0800 Message-Id: <20250221163335.262143-4-chen.dylane@linux.dev> In-Reply-To: <20250221163335.262143-1-chen.dylane@linux.dev> References: <20250221163335.262143-1-chen.dylane@linux.dev> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Migadu-Flow: FLOW_OUT Content-Type: text/plain; charset="utf-8" Similarly to libbpf_probe_bpf_helper, the libbpf_probe_bpf_kfunc used to test the availability of the different eBPF kfuncs on the current system. Cc: Tao Chen Reviewed-by: Jiri Olsa Reviewed-by: Eduard Zingerman Signed-off-by: Tao Chen --- tools/lib/bpf/libbpf.h | 19 ++++++++++++- tools/lib/bpf/libbpf.map | 1 + tools/lib/bpf/libbpf_probes.c | 51 +++++++++++++++++++++++++++++++++++ 3 files changed, 70 insertions(+), 1 deletion(-) diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h index 3020ee45303a..c79b4475b956 100644 --- a/tools/lib/bpf/libbpf.h +++ b/tools/lib/bpf/libbpf.h @@ -1680,7 +1680,24 @@ LIBBPF_API int libbpf_probe_bpf_map_type(enum bpf_ma= p_type map_type, const void */ LIBBPF_API int libbpf_probe_bpf_helper(enum bpf_prog_type prog_type, enum bpf_func_id helper_id, const void *opts); - +/** + * @brief **libbpf_probe_bpf_kfunc()** detects if host kernel supports the + * use of a given BPF kfunc from specified BPF program type. + * @param prog_type BPF program type used to check the support of BPF kfunc + * @param kfunc_id The btf ID of BPF kfunc to check support for + * @param btf_fd The module BTF FD, if kfunc is defined in kernel module, + * btf_fd is used to point to module's BTF, which is >=3D 0, and < 0 means= kfunc + * defined in vmlinux. + * @param opts reserved for future extensibility, should be NULL + * @return 1, if given combination of program type and kfunc is supported;= 0, + * if the combination is not supported; negative error code if feature + * detection for provided input arguments failed or can't be performed + * + * Make sure the process has required set of CAP_* permissions (or runs as + * root) when performing feature checking. + */ +LIBBPF_API int libbpf_probe_bpf_kfunc(enum bpf_prog_type prog_type, + int kfunc_id, int btf_fd, const void *opts); /** * @brief **libbpf_num_possible_cpus()** is a helper function to get the * number of possible CPUs that the host kernel supports and expects. diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map index b5a838de6f47..3bbfe13aeb6a 100644 --- a/tools/lib/bpf/libbpf.map +++ b/tools/lib/bpf/libbpf.map @@ -438,4 +438,5 @@ LIBBPF_1.6.0 { bpf_linker__new_fd; btf__add_decl_attr; btf__add_type_attr; + libbpf_probe_bpf_kfunc; } LIBBPF_1.5.0; diff --git a/tools/lib/bpf/libbpf_probes.c b/tools/lib/bpf/libbpf_probes.c index de2b1205b436..8efebc18a215 100644 --- a/tools/lib/bpf/libbpf_probes.c +++ b/tools/lib/bpf/libbpf_probes.c @@ -431,6 +431,57 @@ static bool can_probe_prog_type(enum bpf_prog_type pro= g_type) return true; } =20 +int libbpf_probe_bpf_kfunc(enum bpf_prog_type prog_type, int kfunc_id, int= btf_fd, + const void *opts) +{ + struct bpf_insn insns[] =3D { + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, BPF_PSEUDO_KFUNC_CALL, 1, kfunc_id), + BPF_EXIT_INSN(), + }; + const size_t insn_cnt =3D ARRAY_SIZE(insns); + char buf[4096]; + int fd_array[2] =3D {-1}; + int ret; + + if (opts) + return libbpf_err(-EINVAL); + + if (!can_probe_prog_type(prog_type)) + return libbpf_err(-EOPNOTSUPP); + + if (btf_fd >=3D 0) + fd_array[1] =3D btf_fd; + else + /* insn.off =3D 0, means vmlinux btf */ + insns[0].off =3D 0; + + buf[0] =3D '\0'; + ret =3D probe_prog_load(prog_type, insns, insn_cnt, btf_fd >=3D 0 ? fd_ar= ray : NULL, + buf, sizeof(buf)); + if (ret < 0) + return libbpf_err(ret); + + if (ret > 0) + return 1; /* assume supported */ + + /* If BPF verifier recognizes BPF kfunc but it's not supported for + * given BPF program type, it will emit "calling kernel function + * is not allowed". If the kfunc id is invalid, + * it will emit "kernel btf_id is not a function". If BTF fd + * invalid in module BTF, it will emit "invalid module BTF fd specified" = or + * "negative offset disallowed for kernel module function call". If + * kfunc prog not dev buound, it will emit "metadata kfuncs require + * device-bound program". + */ + if (strstr(buf, "not allowed") || strstr(buf, "not a function") || + strstr(buf, "invalid module BTF fd") || + strstr(buf, "negative offset disallowed") || + strstr(buf, "device-bound program")) + return 0; + + return 1; +} + int libbpf_probe_bpf_helper(enum bpf_prog_type prog_type, enum bpf_func_id= helper_id, const void *opts) { --=20 2.43.0 From nobody Sat Feb 7 17:01:42 2026 Received: from out-184.mta0.migadu.com (out-184.mta0.migadu.com [91.218.175.184]) (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 4FDF6216619 for ; Fri, 21 Feb 2025 16:36:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.184 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740155799; cv=none; b=gJbJJSbzR3t8kUQLXZnSOcDmYfRfOKw3n1Iny/z+A8m5qGYVUJUHbp93X3BBCrBUmpqJRCDNld48wQsMo9/P22fKuhkrpSzIwY2FJXYFrdrdnKLDOK9d2Dy2UJzMZyBXvyZAYlwc/OHJgnLO197ysGAJejYjzU3vjrX9z7gDDl4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740155799; c=relaxed/simple; bh=iX7YqtTQujLLqaNAUh00iVuqffF/jAbti+QBntYH1tk=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=mX2oOSrq7sa66+JFWdOGhJYxmZgTMkr59vYKuPEy00pDzLH7HQXbbmRSuDoEJjzlREiL/I7TV/AsZa0cUKeQbY369Tiz0LhH6gjtPre3CuYGgl8v6tPY0ZYkLwcl928xCnCIA4iUIKpL8Ojc51ggi9WdSu/4e/1fUI5YZb1Gi6Y= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=ZGo9rfnH; arc=none smtp.client-ip=91.218.175.184 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="ZGo9rfnH" X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1740155795; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=v8rj6X3iOa/EdVnWOpvJZa4qIATKiMnTI+AiRDP2lgg=; b=ZGo9rfnHFOI2ll6L/pxZZNSZSsn/4h5DSdVFjyEdQYLlc8UnhLe5XY82bobN1nzc0oazwH Bxv1OuqV3p7zEmae3s83rtmCfkTtjMLZnTBdyW7hxlCYzltskSzIZ4x4lunPZKSsAuXs8N mcwAGJOeM0BBuTogYobqSZmAbSDmuiE= From: Tao Chen To: ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, eddyz87@gmail.com, haoluo@google.com, jolsa@kernel.org, qmo@kernel.org Cc: bpf@vger.kernel.org, linux-kernel@vger.kernel.org, chen.dylane@gmail.com, Tao Chen , Tao Chen Subject: [PATCH bpf-next v8 4/4] selftests/bpf: Add libbpf_probe_bpf_kfunc API selftests Date: Sat, 22 Feb 2025 00:33:35 +0800 Message-Id: <20250221163335.262143-5-chen.dylane@linux.dev> In-Reply-To: <20250221163335.262143-1-chen.dylane@linux.dev> References: <20250221163335.262143-1-chen.dylane@linux.dev> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Migadu-Flow: FLOW_OUT Content-Type: text/plain; charset="utf-8" Add selftests for prog_kfunc feature probing. Thanks for Eduard providing the libbpf_probe_func_many test case. ./test_progs -t libbpf_probe_kfuncs #153 libbpf_probe_kfuncs:OK Summary: 1/0 PASSED, 0 SKIPPED, 0 FAILED ./test_progs -t libbpf_probe_kfuncs_many #154 libbpf_probe_kfuncs_many:OK Summary: 1/0 PASSED, 0 SKIPPED, 0 FAILED Cc: Tao Chen Reviewed-by: Jiri Olsa Co-developed-by: Eduard Zingerman Signed-off-by: Eduard Zingerman Signed-off-by: Tao Chen --- .../selftests/bpf/prog_tests/libbpf_probes.c | 173 ++++++++++++++++++ 1 file changed, 173 insertions(+) diff --git a/tools/testing/selftests/bpf/prog_tests/libbpf_probes.c b/tools= /testing/selftests/bpf/prog_tests/libbpf_probes.c index 4ed46ed58a7b..db408fd67add 100644 --- a/tools/testing/selftests/bpf/prog_tests/libbpf_probes.c +++ b/tools/testing/selftests/bpf/prog_tests/libbpf_probes.c @@ -126,3 +126,176 @@ void test_libbpf_probe_helpers(void) ASSERT_EQ(res, d->supported, buf); } } + +static int module_btf_fd(char *module) +{ + int fd, err; + __u32 id =3D 0, len; + struct bpf_btf_info info; + char name[64]; + + while (true) { + err =3D bpf_btf_get_next_id(id, &id); + if (err) + return -1; + + fd =3D bpf_btf_get_fd_by_id(id); + if (fd < 0) { + if (errno =3D=3D ENOENT) + continue; + return -1; + } + len =3D sizeof(info); + memset(&info, 0, sizeof(info)); + info.name =3D ptr_to_u64(name); + info.name_len =3D sizeof(name); + err =3D bpf_btf_get_info_by_fd(fd, &info, &len); + if (err) { + close(fd); + return -1; + } + /* find target module BTF */ + if (!strcmp(name, module)) + break; + + close(fd); + } + + return fd; +} + +void test_libbpf_probe_kfuncs(void) +{ + int ret, kfunc_id, fd; + char *kfunc =3D "bpf_cpumask_create"; + struct btf *vmlinux_btf =3D NULL; + struct btf *module_btf =3D NULL; + + vmlinux_btf =3D btf__parse("/sys/kernel/btf/vmlinux", NULL); + if (!ASSERT_OK_PTR(vmlinux_btf, "btf_parse")) + return; + + kfunc_id =3D btf__find_by_name_kind(vmlinux_btf, kfunc, BTF_KIND_FUNC); + if (!ASSERT_GT(kfunc_id, 0, kfunc)) + goto cleanup; + + /* prog BPF_PROG_TYPE_SYSCALL supports kfunc bpf_cpumask_create */ + ret =3D libbpf_probe_bpf_kfunc(BPF_PROG_TYPE_SYSCALL, kfunc_id, -1, NULL); + if (!ASSERT_EQ(ret, 1, "kfunc in vmlinux support")) + goto cleanup; + + /* prog BPF_PROG_TYPE_KPROBE does not support kfunc bpf_cpumask_create */ + ret =3D libbpf_probe_bpf_kfunc(BPF_PROG_TYPE_KPROBE, kfunc_id, -1, NULL); + if (!ASSERT_EQ(ret, 0, "kfunc in vmlinux not suuport")) + goto cleanup; + + ret =3D libbpf_probe_bpf_kfunc(BPF_PROG_TYPE_KPROBE, -1, -1, NULL); + if (!ASSERT_EQ(ret, 0, "invalid kfunc id:-1")) + goto cleanup; + + ret =3D libbpf_probe_bpf_kfunc(100000, kfunc_id, -1, NULL); + if (!ASSERT_ERR(ret, "invalid prog type:100000")) + goto cleanup; + + if (!env.has_testmod) + goto cleanup; + + module_btf =3D btf__load_module_btf("bpf_testmod", vmlinux_btf); + if (!ASSERT_OK_PTR(module_btf, "load module BTF")) + goto cleanup; + + kfunc_id =3D btf__find_by_name(module_btf, "bpf_kfunc_call_test1"); + if (!ASSERT_GT(kfunc_id, 0, "func not found")) + goto cleanup; + + fd =3D module_btf_fd("bpf_testmod"); + if (!ASSERT_GE(fd, 0, "module BTF fd")) + goto cleanup; + + /* prog BPF_PROG_TYPE_SYSCALL supports kfunc bpf_kfunc_call_test1 in bpf_= testmod */ + ret =3D libbpf_probe_bpf_kfunc(BPF_PROG_TYPE_SYSCALL, kfunc_id, fd, NULL); + if (!ASSERT_EQ(ret, 1, "kfunc in module BTF support")) + goto cleanup_fd; + + /* prog BPF_PROG_TYPE_KPROBE does not support kfunc bpf_kfunc_call_test1 + * in bpf_testmod + */ + ret =3D libbpf_probe_bpf_kfunc(BPF_PROG_TYPE_KPROBE, kfunc_id, fd, NULL); + if (!ASSERT_EQ(ret, 0, "kfunc in module BTF not support")) + goto cleanup_fd; + + ret =3D libbpf_probe_bpf_kfunc(BPF_PROG_TYPE_SYSCALL, -1, fd, NULL); + if (!ASSERT_EQ(ret, 0, "invalid kfunc id in module BTF")) + goto cleanup_fd; + + ret =3D libbpf_probe_bpf_kfunc(BPF_PROG_TYPE_SYSCALL, kfunc_id, 100, NULL= ); + ASSERT_EQ(ret, 0, "invalid BTF fd in module BTF"); + +cleanup_fd: + close(fd); +cleanup: + btf__free(vmlinux_btf); + btf__free(module_btf); +} + +static const struct { + const char *name; + int code; +} program_types[] =3D { +#define _T(n) { #n, BPF_PROG_TYPE_##n } + _T(KPROBE), + _T(XDP), + _T(SYSCALL), + _T(SCHED_CLS), + _T(SCHED_ACT), + _T(SK_SKB), + _T(SOCKET_FILTER), + _T(CGROUP_SKB), + _T(LWT_OUT), + _T(LWT_IN), + _T(LWT_XMIT), + _T(LWT_SEG6LOCAL), + _T(NETFILTER), + _T(CGROUP_SOCK_ADDR), + _T(SCHED_ACT) +#undef _T +}; + +void test_libbpf_probe_kfuncs_many(void) +{ + int i, kfunc_id, ret, id; + const struct btf_type *t; + struct btf *btf =3D NULL; + const char *kfunc; + const char *tag; + + btf =3D btf__parse("/sys/kernel/btf/vmlinux", NULL); + if (!ASSERT_OK_PTR(btf, "btf_parse")) + return; + for (id =3D 0; id < btf__type_cnt(btf); ++id) { + t =3D btf__type_by_id(btf, id); + if (!t) + continue; + if (!btf_is_decl_tag(t)) + continue; + tag =3D btf__name_by_offset(btf, t->name_off); + if (strcmp(tag, "bpf_kfunc") !=3D 0) + continue; + kfunc_id =3D t->type; + t =3D btf__type_by_id(btf, kfunc_id); + if (!btf_is_func(t)) + continue; + kfunc =3D btf__name_by_offset(btf, t->name_off); + for (i =3D 0; i < ARRAY_SIZE(program_types); ++i) { + ret =3D libbpf_probe_bpf_kfunc(program_types[i].code, + kfunc_id, -1, NULL); + if (ret < 0) { + ASSERT_FAIL("kfunc:%s use prog type:%d", + kfunc, program_types[i].code); + goto cleanup; + } + } + } +cleanup: + btf__free(btf); +} --=20 2.43.0