From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-181.mta0.migadu.com (out-181.mta0.migadu.com [91.218.175.181]) (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 9196A335081 for ; Mon, 20 Apr 2026 14:19:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.181 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776694749; cv=none; b=I6eKBzrHpT+ZijFuzcQvGD0Kxswt3/UKVd00vdE5o7WzlXa5SG+sYmqvULOr9U8zfoykdRVXMLm+BKfqNl2euveVGjTQIU1wIvkKyn/aL2XEBHAXnuUkvGtD69B4A13rAiOileamLzHP4YMSjjWx9UuwXL/s2sMOo0oX1aA2cP8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776694749; c=relaxed/simple; bh=7GDfzP1SCF8OJlze5vbOCTiWLcdzuPkW6DGupCCtS5E=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=kSaIkTerxDLieyh5Py0ohapAkbldcVwUr9SM5GEOtnWBOAfUR8ulGUM9tyulBL7OvGWTMZCwyAOW5d5/Zn4LLpoEBNIuALsyGk9yJ9lGRXd8lgiNxfsRkWQlUALefDPE0wAn/TF25rmw77kx/rGjy3ycR+oT/+eDhT051qS9MpY= 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=VqU73nuY; arc=none smtp.client-ip=91.218.175.181 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="VqU73nuY" 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=1776694744; 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=GEeJufUFCM31pPFUommNebrX+FUSmW3KoKjheeJJK5g=; b=VqU73nuYgeerdcGQhWn5Okc4wjuI67GLlBMziCHN4Ln9yPzqt/ue6XIax0ZorJHKZTc0L8 qNu1DQKHYPWMZ5XO1JR4LVFvnoKPJhnZo5rFLt5Xf2gZNDiqPkjZyhHCo1JuPcwi68iiOk 3WsS9t9oBsF0Cn2GQYBLEun892+7PHg= From: Leon Hwang To: bpf@vger.kernel.org Cc: Alexei Starovoitov , Daniel Borkmann , John Fastabend , Andrii Nakryiko , Martin KaFai Lau , Eduard Zingerman , Song Liu , Yonghong Song , KP Singh , Stanislav Fomichev , Hao Luo , Jiri Olsa , Shuah Khan , Christian Brauner , Seth Forshee , Yuichiro Tsuji , Andrey Albershteyn , Leon Hwang , Willem de Bruijn , Jason Xing , Tao Chen , Mykyta Yatsenko , Kumar Kartikeya Dwivedi , Anton Protopopov , Amery Hung , Rong Tao , linux-kernel@vger.kernel.org, linux-api@vger.kernel.org, linux-kselftest@vger.kernel.org, kernel-patches-bot@fb.com Subject: [PATCH bpf-next v12 2/8] libbpf: Add support for extended BPF syscall Date: Mon, 20 Apr 2026 22:17:58 +0800 Message-ID: <20260420141804.27179-3-leon.hwang@linux.dev> In-Reply-To: <20260420141804.27179-1-leon.hwang@linux.dev> References: <20260420141804.27179-1-leon.hwang@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: 8bit X-Migadu-Flow: FLOW_OUT To support the extended BPF syscall introduced in the previous commit, introduce the following internal APIs: * 'sys_bpf_ext()' * 'sys_bpf_ext_fd()' They wrap the raw 'syscall()' interface to support passing extended attributes. * 'probe_sys_bpf_ext()' Check whether current kernel supports the BPF syscall common attributes. Acked-by: Andrii Nakryiko Signed-off-by: Leon Hwang --- tools/lib/bpf/bpf.c | 36 +++++++++++++++++++++++++++++++++ tools/lib/bpf/features.c | 8 ++++++++ tools/lib/bpf/libbpf_internal.h | 3 +++ 3 files changed, 47 insertions(+) diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c index 5846de364209..9d8740761b7a 100644 --- a/tools/lib/bpf/bpf.c +++ b/tools/lib/bpf/bpf.c @@ -69,6 +69,42 @@ static inline __u64 ptr_to_u64(const void *ptr) return (__u64) (unsigned long) ptr; } +static inline int sys_bpf_ext(enum bpf_cmd cmd, union bpf_attr *attr, + unsigned int size, + struct bpf_common_attr *attr_common, + unsigned int size_common) +{ + cmd = attr_common ? (cmd | BPF_COMMON_ATTRS) : (cmd & ~BPF_COMMON_ATTRS); + return syscall(__NR_bpf, cmd, attr, size, attr_common, size_common); +} + +static inline int sys_bpf_ext_fd(enum bpf_cmd cmd, union bpf_attr *attr, + unsigned int size, + struct bpf_common_attr *attr_common, + unsigned int size_common) +{ + int fd; + + fd = sys_bpf_ext(cmd, attr, size, attr_common, size_common); + return ensure_good_fd(fd); +} + +int probe_sys_bpf_ext(void) +{ + const size_t attr_sz = offsetofend(union bpf_attr, prog_token_fd); + union bpf_attr attr; + int fd; + + memset(&attr, 0, attr_sz); + fd = syscall(__NR_bpf, BPF_PROG_LOAD | BPF_COMMON_ATTRS, &attr, attr_sz, NULL, + sizeof(struct bpf_common_attr)); + if (fd >= 0) { + close(fd); + return -EINVAL; + } + return errno == EFAULT ? 1 : 0; +} + static inline int sys_bpf(enum bpf_cmd cmd, union bpf_attr *attr, unsigned int size) { diff --git a/tools/lib/bpf/features.c b/tools/lib/bpf/features.c index 4f19a0d79b0c..b7e388f99d0b 100644 --- a/tools/lib/bpf/features.c +++ b/tools/lib/bpf/features.c @@ -615,6 +615,11 @@ static int probe_kern_btf_layout(int token_fd) (char *)layout, token_fd)); } +static int probe_bpf_syscall_common_attrs(int token_fd) +{ + return probe_sys_bpf_ext(); +} + typedef int (*feature_probe_fn)(int /* token_fd */); static struct kern_feature_cache feature_cache; @@ -699,6 +704,9 @@ static struct kern_feature_desc { [FEAT_BTF_LAYOUT] = { "kernel supports BTF layout", probe_kern_btf_layout, }, + [FEAT_BPF_SYSCALL_COMMON_ATTRS] = { + "BPF syscall common attributes support", probe_bpf_syscall_common_attrs, + }, }; bool feat_supported(struct kern_feature_cache *cache, enum kern_feature_id feat_id) diff --git a/tools/lib/bpf/libbpf_internal.h b/tools/lib/bpf/libbpf_internal.h index cabdaef79098..21ccdf4d9284 100644 --- a/tools/lib/bpf/libbpf_internal.h +++ b/tools/lib/bpf/libbpf_internal.h @@ -398,6 +398,8 @@ enum kern_feature_id { FEAT_UPROBE_SYSCALL, /* Kernel supports BTF layout information */ FEAT_BTF_LAYOUT, + /* Kernel supports BPF syscall common attributes */ + FEAT_BPF_SYSCALL_COMMON_ATTRS, __FEAT_CNT, }; @@ -767,4 +769,5 @@ int probe_fd(int fd); #define SHA256_DWORD_SIZE SHA256_DIGEST_LENGTH / sizeof(__u64) void libbpf_sha256(const void *data, size_t len, __u8 out[SHA256_DIGEST_LENGTH]); +int probe_sys_bpf_ext(void); #endif /* __LIBBPF_LIBBPF_INTERNAL_H */ -- 2.53.0