From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pz2-f42.google.com (mail-pz2-f42.google.com [74.125.228.42]) (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 8336F519E16 for ; Thu, 17 Sep 2026 17:04:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=74.125.228.42 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789664666; cv=none; b=RBvKh5SBodp0GGBRi9U3h8AVGxmlnRSod6qRTvrI59Ptmf6KrpvYpyFIH7hqVg+KiQA9pZz61Ks6qvQ0oKT6J4AJajls24M9BSbaaH+lLlO7UOzOJ5vYvpbCPY0duMyusjlgaCFw8wM1SShbZLVHO34du4uoGVlwZQ2QFwuZeUM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789664666; c=relaxed/simple; bh=NQWcloj+nbFeZO8NPKTYbZfeCxkiVpCyiPlzalyQgH4=; h=Content-Type:Date:Message-Id:Cc:Subject:From:To:In-Reply-To: References:MIME-Version; b=TFAYhLUwG6q5CTWvBISpzywWhj/PADMuODyM7o5WIAJ1IQHFaTV8JpB3nh8vIsr0Smq0pILKio8D7OCw8R6s4ilryketCHv9mYriHC+vu/QJd6m5bsM2r7kO8iTdnuWIA799bXXZ/DZhyzuIdOeIPE7cDjLC/oeSmOue+6+9otk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=S7t21GgW; arc=none smtp.client-ip=74.125.228.42 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="S7t21GgW" Received: by mail-pz2-f42.google.com with SMTP id 41be03b00d2f7-cc1cea50dc1so723731a12.0 for ; Thu, 17 Sep 2026 10:04:24 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1789664664; x=1790269464; darn=vger.kernel.org; h=mime-version:content-transfer-encoding:references:in-reply-to:to :from:subject:cc:message-id:date:content-type:from:to:cc:subject :date:message-id:reply-to:content-type; bh=4JizY9SP2XHp6s2Wy9xHaS9gqEw+FcWondhVau1ra78=; b=S7t21GgWYr3E4HeM8TT94QjsKRA+DFCzcuMTMXirfzzXKaeoZC+QgIO3p4pJsUa6T5 bpkNN6J1PO95tC4JE/BIbEFnVQhNUn1WjFYGC6zY4mRh95q7Z68+6ITHO4roTBUMMECe zDmojS6ugE5gxd1gizaE++gg8qzQwXQZ9YoZzXV5OSi0UGZUwP2PwyDPPo0HLhsFJIJL 8F7nUmpknkn0AowSgLXerVlVBSqfEp5HtggWvX59K8gGxAYbiYoRU7fRBteT1hrZqG1H 1sj+a5f55aFv6KGzfphBexeNFFZzFWepp6GUiemz7UGzuHNhFkpVkj40k3jyR12QOlf2 3gRw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1789664664; x=1790269464; h=mime-version:content-transfer-encoding:references:in-reply-to:to :from:subject:cc:message-id:date:content-type:x-gm-gg :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to :content-type; bh=4JizY9SP2XHp6s2Wy9xHaS9gqEw+FcWondhVau1ra78=; b=JhqYxNZSWDm12FaAmkt4jh1wINljj4P9xbSubqy2cEn3CDoS+/URa/pgHtaV5HzjhB c6I8eAN+/2I+vX6CVOEltv/hk90pUxABoJWjzCCC5c2bV+PJLI5BF61bkt6gERsUjMJN WO6vbLoQGlz7WqWfw1HDsc4rUPL2fdnMM8EEwfkaP+Krwdp36K7ST6vNUWLHwAlTs44G YvbvgpRL3EugQ6ap5/StFJ3V4yhNnD+ySuvQUDqQUKqofa92zqRW8qiGLzaqrFWmZEc0 inKcWYPahcKpKBozLvCMapEA4a7iYuvhLSL7MwyXCKwMmqn1h3W1QvKdN0fCFAqNQfVP uWjg== X-Forwarded-Encrypted: i=1; AKwUvByLwbfg8qaGihAGN4uOcWr2XXMGAAt6sqIWUvIytZLXIj5JAdmjfTBZk84bpMi7iuTEyY4=@vger.kernel.org X-Gm-Message-State: AFuF++lZCpUT2EohfdY9tnFLcPvXll9yzH1AfyhbdaLzIEyE2CfyECS6 sGDXkTZteS10HzWUriG3NyszEheofus4NCDbrxk0G9LVlld9V/Qs5ldp X-Gm-Gg: AYBFou3OsU+7y5jXpO4OvSJS4gpFEsuFegEdiyH1u2TvcrpMqOMGMROcU/P7M5y5qCQ LPQKAFPKFPWyyhFbtYIh69Pzm2+Pj6PppglidAkF/FntbYGrdf520EN3GdaoYAenpZyU2Mud5Ng HRpPlqErqRrGOWMwTrlFCx/PEepyxKvFcZeVCJyhrh+3Ljoj2MKskRJGwVNd1yW9dCXPBA2Gd34 Br8NCRSlk7kXaP4pTMURwXXHm7pzyyzBJM3C42Th5tkwRbubmVno4jO+H+7IryP8kY05Vjy13SY VvxrAKK2ZrQzckywf/npglo9xdTBb3u6lJ67Cv6U0oP1swbAtsEl6+ZqTGZY2w50KATdFgz9rVC EYOoLLR4Zt2fTT+KNEkcqtUqyPs2AmCZshfTYPYi3xsUA5ng0z+wvDNyhTyZeYjbsSXpR3vCCvr KJa+SA6nXjPeLLgvAuRs96NQ1WpLV5D3xoBXeByLoRTajVGuRIAElKEZab8V2/ViWQ/kUOT/tdF xBA7vSVs4eChIgsJYYC/5MLnCQov9fNvdv3do9bW6Sex5SRvJ9nypf2648sUQ58uqlrQkQGB6CD oY2O X-Received: by 2002:a05:6a21:113:b0:3dd:55f2:9785 with SMTP id adf61e73a8af0-3dd5f7ada67mr18804336637.26.1789664663533; Thu, 17 Sep 2026 10:04:23 -0700 (PDT) Received: from localhost ([153.61.198.241]) by smtp.gmail.com with ESMTPSA id 41be03b00d2f7-cc50c24487bsm3294479a12.12.2026.09.17.10.04.22 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 17 Sep 2026 10:04:22 -0700 (PDT) Content-Type: text/plain; charset=UTF-8 Date: Thu, 17 Sep 2026 17:04:22 +0000 Message-Id: Cc: , , , , , , , , , , , , Subject: Re: [PATCH bpf-next 1/8] bpf: Add UHMUL and SHMUL instructions From: "Alexei Starovoitov" To: "Yazhou Tang" , , In-Reply-To: <20260917041712.1860722-2-tangyazhou@zju.edu.cn> References: <20260917041712.1860722-1-tangyazhou@zju.edu.cn> <20260917041712.1860722-2-tangyazhou@zju.edu.cn> X-Mailer: mkdraft (claude review draft; edit before sending) Content-Transfer-Encoding: 8bit Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 On Thu, Sep 17, 2026 at 12:17 PM Yazhou Tang wrote: > diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h > index 732b35cc08d1..845eee536198 100644 > --- a/include/uapi/linux/bpf.h > +++ b/include/uapi/linux/bpf.h > @@ -34,6 +34,16 @@ > #define BPF_FROM_LE BPF_TO_LE > #define BPF_FROM_BE BPF_TO_BE > > +/* > + * BPF_MUL variants selected by the off field. > + * UHMUL and SHMUL are only valid for BPF_ALU64. > + */ > +enum bpf_mul_variant { > + BPF_MUL_VARIANT_LO = 0, > + BPF_MUL_VARIANT_UHMUL = 1, > + BPF_MUL_VARIANT_SHMUL = 2, > +}; Slept on it and imo it's too verbose for uapi. Maybe just BPF_UHMUL = 1, BPF_SHMUL = 2 ? No need to name zero, sdiv doesn't. > diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c > index 4e208cc94752..4f746973481b 100644 > --- a/kernel/bpf/core.c > +++ b/kernel/bpf/core.c [...] > + ALU_MUL_X: > + if (OFF != BPF_MUL_VARIANT_LO) > + goto default_label; > + DST = (u32) DST * (u32) SRC; > + CONT; The verifier already rejected these. Interpreter doesn't need to re-validate. pw-bot: cr