From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 537E8C3ABBC for ; Tue, 6 May 2025 17:44:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:Content-Type: Content-Transfer-Encoding:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:From:References:CC:To:Subject: MIME-Version:Date:Message-ID:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=PtdhGVELE+Mq3AzSgQtNEiToffZkBg/hvyOJwk8RKu0=; b=Vtq0oVyC8hGadV hyu+4qUsnWRRWYdYfGecXTV3Q5okjs/MdfirXBFfWND7oQjGQQ3E6NvuXjeEkTuLy/iroKQxPJaeY cHkwsci/5HPGL2gAYWfX6hhNLzKR7XaQoqzeUDOMYlBpZlXXOL95A5HTJ3uZqyL0RkGTvXN2l1myH lEiML6VkTNETn/Rb2CmoFku34TiW19gBPVwjLyWY492OGSQojr6/Ra8sq5LykfZ1RwhcwRJewv24J /RTyUKK9leeWGky2jMnnWRPsYrcmyGtGlVaaifqAWHSrFV2TNfgH5X0+YPu/NsIjL5ZPSb3tm85FP O8aO0N1M49LUA6UZmglA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1uCMLO-0000000Ct8O-0Fpu; Tue, 06 May 2025 17:44:38 +0000 Received: from szxga04-in.huawei.com ([45.249.212.190]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1uCIu3-0000000CFAO-3xhw for linux-riscv@lists.infradead.org; Tue, 06 May 2025 14:04:13 +0000 Received: from mail.maildlp.com (unknown [172.19.162.112]) by szxga04-in.huawei.com (SkyGuard) with ESMTP id 4ZsKqh0LNYz2TS2d; Tue, 6 May 2025 22:03:28 +0800 (CST) Received: from kwepemf100007.china.huawei.com (unknown [7.202.181.221]) by mail.maildlp.com (Postfix) with ESMTPS id 6F554140203; Tue, 6 May 2025 22:04:01 +0800 (CST) Received: from [10.67.109.184] (10.67.109.184) by kwepemf100007.china.huawei.com (7.202.181.221) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.11; Tue, 6 May 2025 22:03:59 +0800 Message-ID: <83698e73-3b47-4cdc-af50-c4f3ca479b7a@huawei.com> Date: Tue, 6 May 2025 22:03:59 +0800 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH bpf-next 1/8] bpf/verifier: Handle BPF_LOAD_ACQ instructions in insn_def_regno() Content-Language: en-US To: Peilin Ye , CC: , Andrea Parri , =?UTF-8?B?QmrDtnJuIFTDtnBlbA==?= , Puranjay Mohan , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Martin KaFai Lau , Eduard Zingerman , "Paul E. McKenney" , Song Liu , Yonghong Song , John Fastabend , KP Singh , Stanislav Fomichev , Hao Luo , Jiri Olsa , Luke Nelson , Xi Wang , Paul Walmsley , Palmer Dabbelt , Albert Ou , Alexandre Ghiti , Mykola Lysenko , Shuah Khan , Josh Don , Barret Rhoden , Neel Natu , Benjamin Segall References: <2c1ec0e60974f8438730dc5126f9ed986b32a3f6.1745970908.git.yepeilin@google.com> From: Pu Lehui In-Reply-To: <2c1ec0e60974f8438730dc5126f9ed986b32a3f6.1745970908.git.yepeilin@google.com> X-Originating-IP: [10.67.109.184] X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) To kwepemf100007.china.huawei.com (7.202.181.221) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250506_070412_304868_9E336FFE X-CRM114-Status: GOOD ( 12.85 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org On 2025/4/30 8:50, Peilin Ye wrote: > In preparation for supporting BPF load-acquire and store-release > instructions for architectures where bpf_jit_needs_zext() returns true > (e.g. riscv64), make insn_def_regno() handle load-acquires properly. > > Signed-off-by: Peilin Ye > --- > kernel/bpf/verifier.c | 11 +++++++---- > 1 file changed, 7 insertions(+), 4 deletions(-) > > diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c > index 54c6953a8b84..6435ea23fee4 100644 > --- a/kernel/bpf/verifier.c > +++ b/kernel/bpf/verifier.c > @@ -3649,13 +3649,16 @@ static int insn_def_regno(const struct bpf_insn *insn) > case BPF_ST: > return -1; > case BPF_STX: > - if ((BPF_MODE(insn->code) == BPF_ATOMIC || > - BPF_MODE(insn->code) == BPF_PROBE_ATOMIC) && > - (insn->imm & BPF_FETCH)) { > + if (BPF_MODE(insn->code) == BPF_ATOMIC || > + BPF_MODE(insn->code) == BPF_PROBE_ATOMIC) { > if (insn->imm == BPF_CMPXCHG) > return BPF_REG_0; > - else > + else if (insn->imm == BPF_LOAD_ACQ) > + return insn->dst_reg; > + else if (insn->imm & BPF_FETCH) > return insn->src_reg; > + else > + return -1; > } else { > return -1; > } How about simplify like this: ``` static int insn_def_regno(const struct bpf_insn *insn) { switch (BPF_CLASS(insn->code)) { case BPF_JMP: case BPF_JMP32: case BPF_ST: return -1; case BPF_STX: if (BPF_MODE(insn->code) == BPF_ATOMIC || BPF_MODE(insn->code) == BPF_PROBE_ATOMIC) { if (insn->imm == BPF_CMPXCHG) return BPF_REG_0; else if (insn->imm == BPF_LOAD_ACQ) return insn->dst_reg; else if (insn->imm & BPF_FETCH) return insn->src_reg; } return -1; default: return insn->dst_reg; } } ``` _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv