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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 41DB7C433EF for ; Fri, 15 Apr 2022 02:34:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1348707AbiDOChU (ORCPT ); Thu, 14 Apr 2022 22:37:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50604 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232664AbiDOChS (ORCPT ); Thu, 14 Apr 2022 22:37:18 -0400 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 565303B283; Thu, 14 Apr 2022 19:34:51 -0700 (PDT) Received: from dggpeml500025.china.huawei.com (unknown [172.30.72.57]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4KfgNV5DVczgYnH; Fri, 15 Apr 2022 10:32:58 +0800 (CST) Received: from [10.174.176.117] (10.174.176.117) by dggpeml500025.china.huawei.com (7.185.36.35) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Fri, 15 Apr 2022 10:34:48 +0800 Subject: Re: [PATCH bpf-next v2 4/6] bpf, arm64: Impelment bpf_arch_text_poke() for arm64 To: Xu Kuohai , , , , , CC: Catalin Marinas , Will Deacon , Steven Rostedt , Ingo Molnar , Daniel Borkmann , Alexei Starovoitov , Zi Shen Lim , Andrii Nakryiko , Martin KaFai Lau , Song Liu , Yonghong Song , John Fastabend , KP Singh , "David S . Miller" , Hideaki YOSHIFUJI , David Ahern , Thomas Gleixner , Borislav Petkov , Dave Hansen , , , Shuah Khan , Mark Rutland , Ard Biesheuvel , Pasha Tatashin , Peter Collingbourne , Daniel Kiss , Sudeep Holla , Steven Price , Marc Zyngier , Mark Brown , Kumar Kartikeya Dwivedi , Delyan Kratunov References: <20220414162220.1985095-1-xukuohai@huawei.com> <20220414162220.1985095-5-xukuohai@huawei.com> From: Hou Tao Message-ID: Date: Fri, 15 Apr 2022 10:34:47 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.6.0 MIME-Version: 1.0 In-Reply-To: <20220414162220.1985095-5-xukuohai@huawei.com> Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Content-Language: en-US X-Originating-IP: [10.174.176.117] X-ClientProxiedBy: dggems706-chm.china.huawei.com (10.3.19.183) To dggpeml500025.china.huawei.com (7.185.36.35) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, On 4/15/2022 12:22 AM, Xu Kuohai wrote: > Impelment bpf_arch_text_poke() for arm64, so bpf trampoline code can use > it to replace nop with jump, or replace jump with nop. > > Signed-off-by: Xu Kuohai > Acked-by: Song Liu > --- > arch/arm64/net/bpf_jit_comp.c | 52 +++++++++++++++++++++++++++++++++++ > 1 file changed, 52 insertions(+) > > diff --git a/arch/arm64/net/bpf_jit_comp.c b/arch/arm64/net/bpf_jit_comp.c > index 8ab4035dea27..1a1c3ea75ee2 100644 > --- a/arch/arm64/net/bpf_jit_comp.c > +++ b/arch/arm64/net/bpf_jit_comp.c > @@ -9,6 +9,7 @@ > > #include > #include > +#include > #include > #include > #include > @@ -18,6 +19,7 @@ > #include > #include > #include > +#include > #include > > #include "bpf_jit.h" > @@ -1529,3 +1531,53 @@ void bpf_jit_free_exec(void *addr) > { > return vfree(addr); > } > + > +static int gen_branch_or_nop(enum aarch64_insn_branch_type type, void *ip, > + void *addr, u32 *insn) > +{ > + if (!addr) > + *insn = aarch64_insn_gen_nop(); > + else > + *insn = aarch64_insn_gen_branch_imm((unsigned long)ip, > + (unsigned long)addr, > + type); > + > + return *insn != AARCH64_BREAK_FAULT ? 0 : -EFAULT; > +} > + > +int bpf_arch_text_poke(void *ip, enum bpf_text_poke_type poke_type, > + void *old_addr, void *new_addr) > +{ > + int ret; > + u32 old_insn; > + u32 new_insn; > + u32 replaced; > + enum aarch64_insn_branch_type branch_type; > + In bpf_arch_text_poke() of x86, it disables the poking of kernel module, can you explain why it is OK to do so in arm64 ? Because there is no test cases for fentry on linux kernel module, could you please add some tests for it ? > + if (poke_type == BPF_MOD_CALL) > + branch_type = AARCH64_INSN_BRANCH_LINK; > + else > + branch_type = AARCH64_INSN_BRANCH_NOLINK; > + > + if (gen_branch_or_nop(branch_type, ip, old_addr, &old_insn) < 0) > + return -EFAULT; > + > + if (gen_branch_or_nop(branch_type, ip, new_addr, &new_insn) < 0) > + return -EFAULT; > + > + mutex_lock(&text_mutex); > + if (aarch64_insn_read(ip, &replaced)) { > + ret = -EFAULT; > + goto out; > + } > + > + if (replaced != old_insn) { > + ret = -EFAULT; > + goto out; > + } > + > + ret = aarch64_insn_patch_text_nosync((void *)ip, new_insn); > +out: > + mutex_unlock(&text_mutex); > + return ret; > +} 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 8377FC433F5 for ; Fri, 15 Apr 2022 02:36:10 +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-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:Date: Message-ID:From:References:CC:To:Subject:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Owner; bh=HnxJywH5iDL7gIfPtpI6eAREGxPXtL5rYzXd1TSZDsk=; b=NieZ/pTDhEhPE3FkPEEb/EdZlO Ca94BhQKWZGW75BA9K9K8yrcs3+wb/KjnXRqPpiRCT2AejtZU/U8jxMr18r5UdQvvmfAvE2SwBtp2 0dwEb2QllfiqZ9AVBbm2bcqWEewRyffGZ2O+Pb7slW6yTaXN9p/R2z5xTsqWlmOwzETZFJVVcBQM4 Lhd7UuqwhC/cDxOl3CaY26CEgu7hUEYHIMJjNhlqQ2cRCHNVeeD8kOXmppibe8eCBYTOyzyQqgBNe sSiYI6XJ3D3JTg0UYbnIA4M/QtIQAfoAzWx9Q4Zsgrx6cceFpdmEIzM/3YKAIugkwyrf4CBdSiYbp +5NKHN9A==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nfBne-0089az-34; Fri, 15 Apr 2022 02:35:06 +0000 Received: from szxga01-in.huawei.com ([45.249.212.187]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1nfBnZ-0089Vw-Lp for linux-arm-kernel@lists.infradead.org; Fri, 15 Apr 2022 02:35:03 +0000 Received: from dggpeml500025.china.huawei.com (unknown [172.30.72.57]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4KfgNV5DVczgYnH; Fri, 15 Apr 2022 10:32:58 +0800 (CST) Received: from [10.174.176.117] (10.174.176.117) by dggpeml500025.china.huawei.com (7.185.36.35) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Fri, 15 Apr 2022 10:34:48 +0800 Subject: Re: [PATCH bpf-next v2 4/6] bpf, arm64: Impelment bpf_arch_text_poke() for arm64 To: Xu Kuohai , , , , , CC: Catalin Marinas , Will Deacon , Steven Rostedt , Ingo Molnar , Daniel Borkmann , Alexei Starovoitov , Zi Shen Lim , Andrii Nakryiko , Martin KaFai Lau , Song Liu , Yonghong Song , John Fastabend , KP Singh , "David S . Miller" , Hideaki YOSHIFUJI , David Ahern , Thomas Gleixner , Borislav Petkov , Dave Hansen , , , Shuah Khan , Mark Rutland , Ard Biesheuvel , Pasha Tatashin , Peter Collingbourne , Daniel Kiss , Sudeep Holla , Steven Price , Marc Zyngier , Mark Brown , Kumar Kartikeya Dwivedi , Delyan Kratunov References: <20220414162220.1985095-1-xukuohai@huawei.com> <20220414162220.1985095-5-xukuohai@huawei.com> From: Hou Tao Message-ID: Date: Fri, 15 Apr 2022 10:34:47 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.6.0 MIME-Version: 1.0 In-Reply-To: <20220414162220.1985095-5-xukuohai@huawei.com> Content-Language: en-US X-Originating-IP: [10.174.176.117] X-ClientProxiedBy: dggems706-chm.china.huawei.com (10.3.19.183) To dggpeml500025.china.huawei.com (7.185.36.35) X-CFilter-Loop: Reflected X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220414_193502_098602_8E4B60F8 X-CRM114-Status: GOOD ( 20.05 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hi, On 4/15/2022 12:22 AM, Xu Kuohai wrote: > Impelment bpf_arch_text_poke() for arm64, so bpf trampoline code can use > it to replace nop with jump, or replace jump with nop. > > Signed-off-by: Xu Kuohai > Acked-by: Song Liu > --- > arch/arm64/net/bpf_jit_comp.c | 52 +++++++++++++++++++++++++++++++++++ > 1 file changed, 52 insertions(+) > > diff --git a/arch/arm64/net/bpf_jit_comp.c b/arch/arm64/net/bpf_jit_comp.c > index 8ab4035dea27..1a1c3ea75ee2 100644 > --- a/arch/arm64/net/bpf_jit_comp.c > +++ b/arch/arm64/net/bpf_jit_comp.c > @@ -9,6 +9,7 @@ > > #include > #include > +#include > #include > #include > #include > @@ -18,6 +19,7 @@ > #include > #include > #include > +#include > #include > > #include "bpf_jit.h" > @@ -1529,3 +1531,53 @@ void bpf_jit_free_exec(void *addr) > { > return vfree(addr); > } > + > +static int gen_branch_or_nop(enum aarch64_insn_branch_type type, void *ip, > + void *addr, u32 *insn) > +{ > + if (!addr) > + *insn = aarch64_insn_gen_nop(); > + else > + *insn = aarch64_insn_gen_branch_imm((unsigned long)ip, > + (unsigned long)addr, > + type); > + > + return *insn != AARCH64_BREAK_FAULT ? 0 : -EFAULT; > +} > + > +int bpf_arch_text_poke(void *ip, enum bpf_text_poke_type poke_type, > + void *old_addr, void *new_addr) > +{ > + int ret; > + u32 old_insn; > + u32 new_insn; > + u32 replaced; > + enum aarch64_insn_branch_type branch_type; > + In bpf_arch_text_poke() of x86, it disables the poking of kernel module, can you explain why it is OK to do so in arm64 ? Because there is no test cases for fentry on linux kernel module, could you please add some tests for it ? > + if (poke_type == BPF_MOD_CALL) > + branch_type = AARCH64_INSN_BRANCH_LINK; > + else > + branch_type = AARCH64_INSN_BRANCH_NOLINK; > + > + if (gen_branch_or_nop(branch_type, ip, old_addr, &old_insn) < 0) > + return -EFAULT; > + > + if (gen_branch_or_nop(branch_type, ip, new_addr, &new_insn) < 0) > + return -EFAULT; > + > + mutex_lock(&text_mutex); > + if (aarch64_insn_read(ip, &replaced)) { > + ret = -EFAULT; > + goto out; > + } > + > + if (replaced != old_insn) { > + ret = -EFAULT; > + goto out; > + } > + > + ret = aarch64_insn_patch_text_nosync((void *)ip, new_insn); > +out: > + mutex_unlock(&text_mutex); > + return ret; > +} _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel