From patchwork Wed Apr 13 05:49:57 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Xu Kuohai X-Patchwork-Id: 12811513 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 8947EC433F5 for ; Wed, 13 Apr 2022 05:39:05 +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:MIME-Version:References:In-Reply-To: Message-ID:Date:Subject:CC:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=SqKCYJX687zTKFr+vAEkpIVM8kQGMozcVWmzXgp3U/U=; b=EzjgnKwwyvQowp A3gEWLrunY/HadEW9nfYkbgyFmaE3OXsfZZSvGGBzpu/+H6jQuqVmvfKWSvAN8qNX+HUIvw/7Vhvi vY/oc/A8gIJblMn8qwW6uMI++RsReP5uVxoFGVzhjGMxnme8KqUNji2TiHERXi9agxIRZDRwym9Yc 1z/8YZo9++xUDnhG3cB6AREMnpPOkuetUgKkdiOBPwiprrowfdKgfxQId6wB1/NQE0QBtzDJWxxKq 9YKUexgo0KKuqhUqDq9o6UxhqxqLbDDeRBXQzZhAaLdvFG7izRk83fDX6MCExEil25SAnx8F0GpmM YJyvsi6jhImhe1UnLLxg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1neVhX-00GqWq-1n; Wed, 13 Apr 2022 05:37:59 +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 1neVhI-00GqPC-RJ for linux-arm-kernel@lists.infradead.org; Wed, 13 Apr 2022 05:37:47 +0000 Received: from kwepemi500013.china.huawei.com (unknown [172.30.72.57]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4KdWXJ41WkzgYk6; Wed, 13 Apr 2022 13:35:44 +0800 (CST) Received: from huawei.com (10.67.174.197) by kwepemi500013.china.huawei.com (7.221.188.120) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Wed, 13 Apr 2022 13:37:32 +0800 From: Xu Kuohai To: , , , , CC: Will Deacon , Steven Rostedt , Daniel Borkmann , Alexei Starovoitov , Zi Shen Lim , Andrii Nakryiko , Martin KaFai Lau , Song Liu , Yonghong Song , John Fastabend , KP Singh , , , 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 Subject: [PATCH bpf-next 3/5] bpf, arm64: Impelment bpf_arch_text_poke() for arm64 Date: Wed, 13 Apr 2022 01:49:57 -0400 Message-ID: <20220413054959.1053668-4-xukuohai@huawei.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220413054959.1053668-1-xukuohai@huawei.com> References: <20220413054959.1053668-1-xukuohai@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.67.174.197] X-ClientProxiedBy: dggems704-chm.china.huawei.com (10.3.19.181) To kwepemi500013.china.huawei.com (7.221.188.120) X-CFilter-Loop: Reflected X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220412_223745_249177_AA43A3E1 X-CRM114-Status: GOOD ( 11.26 ) 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: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org 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 --- 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; + + 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; +}