From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from 66-220-155-179.mail-mxout.facebook.com (66-220-155-179.mail-mxout.facebook.com [66.220.155.179]) (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 561272FD7BC for ; Tue, 21 Apr 2026 17:20:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=66.220.155.179 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776792023; cv=none; b=RpfjJcR259BHurWiciVg9WZCDltxSzFeEMq5IJWBm54kAuZzlwpBczrm5xRvjkIhK9Wl7p6ndlPS0Gal3aBFRnNHxgTfuAEy56j6nEkf/MnckbtFLKDps0+LsrN0QU3wth6JQzQeW8rmWxia+J9SI1+U3OUnuCJlys/u7nUxjiE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776792023; c=relaxed/simple; bh=fMeAI7T7wu0W+P7X6IcEBujh4ipY8ou4xcTlEesf8G4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=gD189D3gfccvNlq5exiJ2AV9iSSTYq5ofSuqhFZGG7CHiMcfSrtNC0FWJWXjkVg9v3cf7XDU4XfzgATahvBfG2VOF+nIrQg71Ueor3DvBxGcLfF3pafc6RwhGaFITV+aZcs73nR5Pf0ygCGib3Kz5HNLxiAC/gTicckoboNlPX4= 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=66.220.155.179 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 1764344B27A39; Tue, 21 Apr 2026 10:20:13 -0700 (PDT) From: Yonghong Song To: bpf@vger.kernel.org Cc: Alexei Starovoitov , Andrii Nakryiko , Daniel Borkmann , "Jose E . Marchesi" , kernel-team@fb.com, Martin KaFai Lau , Puranjay Mohan Subject: [PATCH bpf-next 9/9] bpf: Reuse MAX_BPF_FUNC_ARGS for maximum number of arguments Date: Tue, 21 Apr 2026 10:20:13 -0700 Message-ID: <20260421172013.3512808-1-yonghong.song@linux.dev> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20260421171927.3507554-1-yonghong.song@linux.dev> References: <20260421171927.3507554-1-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 Currently, MAX_BPF_FUNC_ARGS is used for tracepoint related progs where the number of parameters cannot exceed MAX_BPF_FUNC_ARGS. Here, MAX_BPF_FUNC_ARGS is reused to set a limit of the number of argumen= ts for bpf functions and kfunc's. The current value for MAX_BPF_FUNC_ARGS is 12 which should be sufficient for majority of bpf functions and kfunc's. Acked-by: Puranjay Mohan Signed-off-by: Yonghong Song --- include/linux/bpf.h | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 3cb6b9e70080..c8e387b0ce46 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -1151,6 +1151,11 @@ struct bpf_prog_offload { =20 /* The longest tracepoint has 12 args. * See include/trace/bpf_probe.h + * + * Also reuse this macro for maximum number of arguments a BPF function + * or a kfunc can have. Args 1-5 are passed in registers, args 6-12 via + * stack arg slots. The JIT may map some stack arg slots to registers ba= sed + * on the native calling convention (e.g., arg 6 to R9 on x86-64). */ #define MAX_BPF_FUNC_ARGS 12 =20 --=20 2.52.0