From patchwork Thu Feb 20 01:20:41 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Peilin Ye X-Patchwork-Id: 13983166 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 33773C021AA for ; Thu, 20 Feb 2025 01:24:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Type:Cc:To:From: Subject:Message-ID:References:Mime-Version:In-Reply-To:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=AVw9FAeQI7lCZwFZLEeeKDcfx7NZFxNIup/gnaKUq1Q=; b=j+QMQwt0Mt/34pd1uN1USRgEYp j+c1OuD0WG4ztMhp3W3/qMaQncZEbb4XNnxOBISjTDLeriJqeGwmElUR6erp8RtO2UegDdxv9ZvY7 PVBe/GXuBRKUNerlFjs0PiHvJmXWxo9uNJh8FOo6UvOeQYvAMwiLoRb/mKZssLsAdG/DMWyOTEGCh eP4MWPeuz80T/1iI9FzVMEO3UWzGkJpLeY6PaeeKZ/7q1rXK4DGKFqxWTAIyjqxCB615dGZWI1lLZ a2ciH+g0O5OoaoT9CyZHYPCHaGl3JVBdfiEDyZB5aHD3u2aRvrc5n0DWKlxZIHvUl7V59WaWXETQC o/oLsU0Q==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tkvIU-0000000G5vm-2oOr; Thu, 20 Feb 2025 01:24:14 +0000 Received: from mail-pl1-x64a.google.com ([2607:f8b0:4864:20::64a]) by bombadil.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1tkvFE-0000000G4t6-0svj for linux-arm-kernel@lists.infradead.org; Thu, 20 Feb 2025 01:20:53 +0000 Received: by mail-pl1-x64a.google.com with SMTP id d9443c01a7336-2210121ac27so7301735ad.1 for ; Wed, 19 Feb 2025 17:20:51 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1740014451; x=1740619251; darn=lists.infradead.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=AVw9FAeQI7lCZwFZLEeeKDcfx7NZFxNIup/gnaKUq1Q=; b=nY41MOv1zGfsgkLEsUAfThtQIsHfsa8aVfkNmX+ru0xzOjYGVnM2O+v17C55t4NhTc R/Ie2pB2072MWZCT86TpYhLj80KyXy47AgHr1B9kuZyzpjF4hxjgS2Uo85wELr3XIn+L eslt2ASJj1daLYZc0bJaR0m4OpcGwBEnQ9SzMhuJa28HBblgW7uyvpimML4ibgFUjjga IvbVTeTN/Rt+NTlnkUvRiHnHFTA1AJ4fD1zQYq85R9Ngs+8rw7c544/HaRw8AhMPE7np Fssip4N9tK4tlrEPnv4yRtkxqvwPQRTy+dhdJWn6sySwfMybRt2uqaRp80qvqEUJce/5 YvCw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1740014451; x=1740619251; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=AVw9FAeQI7lCZwFZLEeeKDcfx7NZFxNIup/gnaKUq1Q=; b=kBGZ6GknoQlyfxtS/q0xgmGRpB2h8cBtmDi9aAahqPr/z75ecPDi+rX3D/lnkqERMw 6lw5uNOXHWgZyltc0PI3l5xY+Apbe2OjgnIuWqK2qasicGbF7WIkgoCzxTasJE1MSKLz md1bT5D+Rz0DXa8pRD5kkKBHHmKFRI9SZD4gFFV6t6ttHqeogFUOGddioDxCTdRATi+U yNsUEGzXtO/kQVHUBsdzShnIgRYzqCjXeqkglNrKQwLMkJhA7l+3poby8fbXvkG0F2HR 5x8bDAlOmzQssQ8ievej5BZK5IOPllK6/gjapMYnSpVK2GvJSGAGSHlUSUZkzZhvTl53 VEHw== X-Forwarded-Encrypted: i=1; AJvYcCWZvRQHSAF/R08w+SlqpC4Ob5yeGM7jUW1nYbzfi4KeipXuz3r8KIoEA7HdG87hbyPOxNN4pPPFf8BfchSKzzsV@lists.infradead.org X-Gm-Message-State: AOJu0Ywu5zxqgOe0Ms7LTYugMfTT6xn/AjM5+8QaVS2yBnMJO9zN4HHW /NWkZ4/7KXsb/pFc5LVlzEHGblSxeL0j7/MdKIL2z0wA0xKEZ5A8JUj4zRlSie9Sw2OyO/GadZg yW/Nkb4Y5Wg== X-Google-Smtp-Source: AGHT+IELkZhp3dnu1j1hrZyZSNzylf6/SsN58EX3cCnB9zawb1C1aTd09ns9uhXgPWFn3IcwfNEV46XMOLhkTw== X-Received: from plbbj7.prod.google.com ([2002:a17:902:8507:b0:221:7c80:aeff]) (user=yepeilin job=prod-delivery.src-stubby-dispatcher) by 2002:a17:903:41c3:b0:220:ef79:aca9 with SMTP id d9443c01a7336-221711c8dd8mr102260065ad.53.1740014451316; Wed, 19 Feb 2025 17:20:51 -0800 (PST) Date: Thu, 20 Feb 2025 01:20:41 +0000 In-Reply-To: Mime-Version: 1.0 References: X-Mailer: git-send-email 2.48.1.601.g30ceb7b040-goog Message-ID: <91e99076cf23e75e4831c75b38f8cfa84d7da34b.1740009184.git.yepeilin@google.com> Subject: [PATCH bpf-next v3 2/9] bpf/verifier: Factor out check_atomic_rmw() From: Peilin Ye To: bpf@vger.kernel.org, linux-arm-kernel@lists.infradead.org Cc: Peilin Ye , bpf@ietf.org, Xu Kuohai , Eduard Zingerman , David Vernet , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Martin KaFai Lau , Song Liu , Yonghong Song , John Fastabend , KP Singh , Stanislav Fomichev , Hao Luo , Jiri Olsa , Jonathan Corbet , "Paul E. McKenney" , Puranjay Mohan , Ilya Leoshkevich , Heiko Carstens , Vasily Gorbik , Catalin Marinas , Will Deacon , Quentin Monnet , Mykola Lysenko , Shuah Khan , Ihor Solodrai , Yingchi Long , Josh Don , Barret Rhoden , Neel Natu , Benjamin Segall , linux-kernel@vger.kernel.org X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250219_172052_252946_96B6FE0C X-CRM114-Status: GOOD ( 15.99 ) 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 Currently, check_atomic() only handles atomic read-modify-write (RMW) instructions. Since we are planning to introduce other types of atomic instructions (i.e., atomic load/store), extract the existing RMW handling logic into its own function named check_atomic_rmw(). Remove the @insn_idx parameter as it is not really necessary. Use 'env->insn_idx' instead, as in other places in verifier.c. Signed-off-by: Peilin Ye --- kernel/bpf/verifier.c | 53 +++++++++++++++++++++++-------------------- 1 file changed, 29 insertions(+), 24 deletions(-) diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 21658bd5e6d8..63d810bbc26e 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -7615,28 +7615,12 @@ static int check_mem_access(struct bpf_verifier_env *env, int insn_idx, u32 regn static int save_aux_ptr_type(struct bpf_verifier_env *env, enum bpf_reg_type type, bool allow_trust_mismatch); -static int check_atomic(struct bpf_verifier_env *env, int insn_idx, struct bpf_insn *insn) +static int check_atomic_rmw(struct bpf_verifier_env *env, + struct bpf_insn *insn) { int load_reg; int err; - switch (insn->imm) { - case BPF_ADD: - case BPF_ADD | BPF_FETCH: - case BPF_AND: - case BPF_AND | BPF_FETCH: - case BPF_OR: - case BPF_OR | BPF_FETCH: - case BPF_XOR: - case BPF_XOR | BPF_FETCH: - case BPF_XCHG: - case BPF_CMPXCHG: - break; - default: - verbose(env, "BPF_ATOMIC uses invalid atomic opcode %02x\n", insn->imm); - return -EINVAL; - } - if (BPF_SIZE(insn->code) != BPF_W && BPF_SIZE(insn->code) != BPF_DW) { verbose(env, "invalid atomic operand size\n"); return -EINVAL; @@ -7698,12 +7682,12 @@ static int check_atomic(struct bpf_verifier_env *env, int insn_idx, struct bpf_i /* Check whether we can read the memory, with second call for fetch * case to simulate the register fill. */ - err = check_mem_access(env, insn_idx, insn->dst_reg, insn->off, + err = check_mem_access(env, env->insn_idx, insn->dst_reg, insn->off, BPF_SIZE(insn->code), BPF_READ, -1, true, false); if (!err && load_reg >= 0) - err = check_mem_access(env, insn_idx, insn->dst_reg, insn->off, - BPF_SIZE(insn->code), BPF_READ, load_reg, - true, false); + err = check_mem_access(env, env->insn_idx, insn->dst_reg, + insn->off, BPF_SIZE(insn->code), + BPF_READ, load_reg, true, false); if (err) return err; @@ -7713,13 +7697,34 @@ static int check_atomic(struct bpf_verifier_env *env, int insn_idx, struct bpf_i return err; } /* Check whether we can write into the same memory. */ - err = check_mem_access(env, insn_idx, insn->dst_reg, insn->off, + err = check_mem_access(env, env->insn_idx, insn->dst_reg, insn->off, BPF_SIZE(insn->code), BPF_WRITE, -1, true, false); if (err) return err; return 0; } +static int check_atomic(struct bpf_verifier_env *env, struct bpf_insn *insn) +{ + switch (insn->imm) { + case BPF_ADD: + case BPF_ADD | BPF_FETCH: + case BPF_AND: + case BPF_AND | BPF_FETCH: + case BPF_OR: + case BPF_OR | BPF_FETCH: + case BPF_XOR: + case BPF_XOR | BPF_FETCH: + case BPF_XCHG: + case BPF_CMPXCHG: + return check_atomic_rmw(env, insn); + default: + verbose(env, "BPF_ATOMIC uses invalid atomic opcode %02x\n", + insn->imm); + return -EINVAL; + } +} + /* When register 'regno' is used to read the stack (either directly or through * a helper function) make sure that it's within stack boundary and, depending * on the access type and privileges, that all elements of the stack are @@ -19187,7 +19192,7 @@ static int do_check(struct bpf_verifier_env *env) enum bpf_reg_type dst_reg_type; if (BPF_MODE(insn->code) == BPF_ATOMIC) { - err = check_atomic(env, env->insn_idx, insn); + err = check_atomic(env, insn); if (err) return err; env->insn_idx++;