From patchwork Thu Jan 25 13:31:58 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Puranjay Mohan X-Patchwork-Id: 192080 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a05:7300:2553:b0:103:945f:af90 with SMTP id p19csp1640492dyi; Thu, 25 Jan 2024 05:33:06 -0800 (PST) X-Google-Smtp-Source: AGHT+IHrWe8obf4OqPbod2Ocua3NH7JE4YT1gu4+UqShy8d6zsHl2RYnISQoUKehvaPTlA1qCxCQ X-Received: by 2002:a05:6402:351:b0:55c:826b:70c3 with SMTP id r17-20020a056402035100b0055c826b70c3mr359273edw.39.1706189586807; Thu, 25 Jan 2024 05:33:06 -0800 (PST) ARC-Seal: i=2; a=rsa-sha256; t=1706189586; cv=pass; d=google.com; s=arc-20160816; b=y+tNDCw3mKilZSs3PEnt4GO8RlKRTI1t4U+/N/dmU71zEYbaXRIhAGwNSM0vjdKWTD bqryRan1IWIQSv0ncaXS/PHeMVUuM/XoAjGT9yptP4i3ZRFfBlGzv0HNhwypR0iQQToc wpWnnehOd96Fvtj89sfE8ZYDN/OAZK9j+MSMX5Dab6aDX/X8VRTmAW7O/M94LKpqgnYP /ibWNqJLEAK+xagnn6GgeK/xuKrkFSqMsC5jCejzQv2No7EsBTcVuy+IIJyuUhQUiEUU geUkLWOk1A2adB6ve18NXTiw3u6v9GPW7XybvgBkcf6g0TRT3QC/rXFt04HtEls/G5fS Y3IA== ARC-Message-Signature: i=2; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=content-transfer-encoding:mime-version:list-unsubscribe :list-subscribe:list-id:precedence:references:in-reply-to:message-id :date:subject:cc:to:from:dkim-signature; bh=FI4++Tri0XwJHgi/SwI3tIuIhoPqQHm+YqaSOpS3kwM=; fh=6T+NIsJaADDva4Mhm0u6AQLyVhrdmhpxfc6z2znUEcY=; b=Gdc6gPLMEml8jZmd1u0obf2AS/f5azqtLn2d09jkiXrP7FYlJtuTiJXaqSVyC9t6XR 9XAmG1tCsmk4CD5ro+ObpvYE3LQxOKeVSfUpcdHkl1nVGVvMnqllsPZL5M9wfs4LNTW6 ca/3ebgATpQk2GsosET6oJd6IZy+BNQ1eSSQKx3pA6SUvNjPpsyfyufeG6j7ghzWbtzH SZBgClKwqzcdgRet3TXfOwYo/S9PA6GrRadetC2GA10Tw9QUWIPboX0yycRJH7JptqL5 Krqp8YXiYaP3X5ckG+QVKcrnO1Wue5Y0BjRKKK55QnyWZ6YAGj6ZAVg1QKv1orjcoR7/ isIA== ARC-Authentication-Results: i=2; mx.google.com; dkim=pass header.i=@gmail.com header.s=20230601 header.b=T6zXWlq0; arc=pass (i=1 spf=pass spfdomain=gmail.com dkim=pass dkdomain=gmail.com dmarc=pass fromdomain=gmail.com); spf=pass (google.com: domain of linux-kernel+bounces-38652-ouuuleilei=gmail.com@vger.kernel.org designates 147.75.80.249 as permitted sender) smtp.mailfrom="linux-kernel+bounces-38652-ouuuleilei=gmail.com@vger.kernel.org"; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=gmail.com Received: from am.mirrors.kernel.org (am.mirrors.kernel.org. [147.75.80.249]) by mx.google.com with ESMTPS id o28-20020a509b1c000000b0055c35c96ca9si4389234edi.247.2024.01.25.05.33.06 for (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 25 Jan 2024 05:33:06 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel+bounces-38652-ouuuleilei=gmail.com@vger.kernel.org designates 147.75.80.249 as permitted sender) client-ip=147.75.80.249; Authentication-Results: mx.google.com; dkim=pass header.i=@gmail.com header.s=20230601 header.b=T6zXWlq0; arc=pass (i=1 spf=pass spfdomain=gmail.com dkim=pass dkdomain=gmail.com dmarc=pass fromdomain=gmail.com); spf=pass (google.com: domain of linux-kernel+bounces-38652-ouuuleilei=gmail.com@vger.kernel.org designates 147.75.80.249 as permitted sender) smtp.mailfrom="linux-kernel+bounces-38652-ouuuleilei=gmail.com@vger.kernel.org"; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=gmail.com Received: from smtp.subspace.kernel.org (wormhole.subspace.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by am.mirrors.kernel.org (Postfix) with ESMTPS id 3B75A1F2693B for ; Thu, 25 Jan 2024 13:33:06 +0000 (UTC) Received: from localhost.localdomain (localhost.localdomain [127.0.0.1]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 128705787E; Thu, 25 Jan 2024 13:32:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="T6zXWlq0" Received: from mail-wr1-f42.google.com (mail-wr1-f42.google.com [209.85.221.42]) (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 7A63C55C3E; Thu, 25 Jan 2024 13:32:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.221.42 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706189550; cv=none; b=m7DFSWYv1LX1JwCmnixtZjLXXLBrSENU0jFMH79vo4/U8/gPtAt80VAnr2vKve39O1jivGyV5+mOtFfcwNd4PpsHv+fEf9VQMdkqe7g8Me0XuYxHHui9wjAaIFLC9MKnaoSFbek7CAdcpzUBS+i80kTLatgo/g4X+JcLoMie6lQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706189550; c=relaxed/simple; bh=jZDJv0ysjPvVF3fqpYH9nGSFDwIoB/LyXOKFUfIztt8=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=icGm947kEG/UL2yqZRVykrS+07nCIPmifSq5vtrG1at5jo2LZiCY7SsYJ3ypVP9eaB0TSxRHOoqSMxJjJKVRvVstshWNcXKj09XhmRcffUgzyaFM4D6Nk2n5kPMIccPkALxdMy7S9NPTDEgxAwM5/Taw+xNfRARs67/RDUHgTe8= 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=T6zXWlq0; arc=none smtp.client-ip=209.85.221.42 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 Received: by mail-wr1-f42.google.com with SMTP id ffacd0b85a97d-337b8da1f49so5945778f8f.0; Thu, 25 Jan 2024 05:32:28 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1706189546; x=1706794346; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=FI4++Tri0XwJHgi/SwI3tIuIhoPqQHm+YqaSOpS3kwM=; b=T6zXWlq0SLlVgNqn1F1rStqkWh3Xly7sO2GhXk8tZFU9S91gr3oEdRvUWOWm40VDvk xBQw5XkDWWq84Okr0Es7oW3w+rQz4Gji9PaDwbiBWnLP9j3oc0f/kVfh4VSlaUPP9fKH H39a3QFe75nteJ/FKreOKykYBW5IpbotWA/e4Tw3knHF6BY7Z9WuQZrgFU9UbkOz6f58 S6qYHYZ7aKttnrSNdmseyXcqqoN8syYmznGW3c+N6717b0wv37g1CPqLdCA7Vaus9C/t 5zkpYeClig3IwMxCyu9vZ04rW0SiHXDCWU1OSvo2OTO9Ux2Y8dU+BBbMqAIEVawv1EGX 5bBQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1706189546; x=1706794346; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=FI4++Tri0XwJHgi/SwI3tIuIhoPqQHm+YqaSOpS3kwM=; b=Drm2dPEnVuKvLROeUJnK8y7vQ+Mci+Bupf6DTfGl3JvTfP12Ns5895fgIPrGxnzmXl EBTHR9p0dq8uo1zkSgHiKlmmRIPVsewUlNssHjpBDk/o8Pk6VRzDWSPvUMYWVrUWPJ8T Ql/bsosBLloN1mJrdh1J22NUQR2fsj4WDOMFsc7uSkTEY1PtO0kcGUcl+0lWxP2tJJS0 Z7KbxcNIuIWHw+9covBplv8X3K2t/3hO46QCnCtl++f42yNtd+aF+lSp+Zx69qmN6ETB 4RQa97IkTu4Ay1DBkLLggVHp5Z8O/Ez9K2rDWVy4OZQo1HRj9TZproh5dyLBVHV7m8aP 532g== X-Gm-Message-State: AOJu0YyVJcbjqZWjYS9h6OGpRgfR98jX3b6RzXqDqw2nYEZ7NJ7GqBMT TxIA0lULtNgmEXT3pnMN+lzHmRyi1P5R/iaic27k/XcxqJtpBLZIZwMhvBhoLtooQA== X-Received: by 2002:a05:6000:1757:b0:336:6920:d766 with SMTP id m23-20020a056000175700b003366920d766mr339879wrf.93.1706189546543; Thu, 25 Jan 2024 05:32:26 -0800 (PST) Received: from localhost (54-240-197-231.amazon.com. [54.240.197.231]) by smtp.gmail.com with ESMTPSA id t4-20020a5d42c4000000b003392c3141absm12418488wrr.1.2024.01.25.05.32.26 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Thu, 25 Jan 2024 05:32:26 -0800 (PST) From: Puranjay Mohan To: ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, martin.lau@linux.dev, song@kernel.org, catalin.marinas@arm.com, mark.rutland@arm.com, bpf@vger.kernel.org, kpsingh@kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, xukuohai@huaweicloud.com Cc: puranjay12@gmail.com Subject: [PATCH bpf-next v7 1/2] arm64: patching: implement text_poke API Date: Thu, 25 Jan 2024 13:31:58 +0000 Message-Id: <20240125133159.85086-2-puranjay12@gmail.com> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20240125133159.85086-1-puranjay12@gmail.com> References: <20240125133159.85086-1-puranjay12@gmail.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: 1789069451878226004 X-GMAIL-MSGID: 1789069451878226004 The text_poke API is used to implement functions like memcpy() and memset() for instruction memory (RO+X). The implementation is similar to the x86 version. This will be used by the BPF JIT to write and modify BPF programs. There could be more users of this in the future. Signed-off-by: Puranjay Mohan --- arch/arm64/include/asm/patching.h | 2 + arch/arm64/kernel/patching.c | 80 +++++++++++++++++++++++++++++++ 2 files changed, 82 insertions(+) diff --git a/arch/arm64/include/asm/patching.h b/arch/arm64/include/asm/patching.h index 68908b82b168..587bdb91ab7a 100644 --- a/arch/arm64/include/asm/patching.h +++ b/arch/arm64/include/asm/patching.h @@ -8,6 +8,8 @@ int aarch64_insn_read(void *addr, u32 *insnp); int aarch64_insn_write(void *addr, u32 insn); int aarch64_insn_write_literal_u64(void *addr, u64 val); +void *aarch64_insn_set(void *dst, u32 insn, size_t len); +void *aarch64_insn_copy(void *dst, void *src, size_t len); int aarch64_insn_patch_text_nosync(void *addr, u32 insn); int aarch64_insn_patch_text(void *addrs[], u32 insns[], int cnt); diff --git a/arch/arm64/kernel/patching.c b/arch/arm64/kernel/patching.c index b4835f6d594b..5c2d34d890cf 100644 --- a/arch/arm64/kernel/patching.c +++ b/arch/arm64/kernel/patching.c @@ -105,6 +105,86 @@ noinstr int aarch64_insn_write_literal_u64(void *addr, u64 val) return ret; } +typedef void text_poke_f(void *dst, void *src, size_t patched, size_t len); + +static void *__text_poke(text_poke_f func, void *addr, void *src, size_t len) +{ + unsigned long flags; + size_t patched = 0; + size_t size; + void *waddr; + void *ptr; + int ret; + + raw_spin_lock_irqsave(&patch_lock, flags); + + while (patched < len) { + ptr = addr + patched; + size = min_t(size_t, PAGE_SIZE - offset_in_page(ptr), + len - patched); + + waddr = patch_map(ptr, FIX_TEXT_POKE0); + func(waddr, src, patched, size); + patch_unmap(FIX_TEXT_POKE0); + + if (ret < 0) { + raw_spin_unlock_irqrestore(&patch_lock, flags); + return NULL; + } + patched += size; + } + raw_spin_unlock_irqrestore(&patch_lock, flags); + + flush_icache_range((uintptr_t)addr, (uintptr_t)addr + len); + + return addr; +} + +static void text_poke_memcpy(void *dst, void *src, size_t patched, size_t len) +{ + copy_to_kernel_nofault(dst, src + patched, len); +} + +static void text_poke_memset(void *dst, void *src, size_t patched, size_t len) +{ + u32 c = *(u32 *)src; + + memset32(dst, c, len / 4); +} + +/** + * aarch64_insn_copy - Copy instructions into (an unused part of) RX memory + * @dst: address to modify + * @src: source of the copy + * @len: length to copy + * + * Useful for JITs to dump new code blocks into unused regions of RX memory. + */ +noinstr void *aarch64_insn_copy(void *dst, void *src, size_t len) +{ + /* A64 instructions must be word aligned */ + if ((uintptr_t)dst & 0x3) + return NULL; + + return __text_poke(text_poke_memcpy, dst, src, len); +} + +/** + * aarch64_insn_set - memset for RX memory regions. + * @dst: address to modify + * @insn: value to set + * @len: length of memory region. + * + * Useful for JITs to fill regions of RX memory with illegal instructions. + */ +noinstr void *aarch64_insn_set(void *dst, u32 insn, size_t len) +{ + if ((uintptr_t)dst & 0x3) + return NULL; + + return __text_poke(text_poke_memset, dst, &insn, len); +} + int __kprobes aarch64_insn_patch_text_nosync(void *addr, u32 insn) { u32 *tp = addr; From patchwork Thu Jan 25 13:31:59 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Puranjay Mohan X-Patchwork-Id: 192081 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a05:7300:2553:b0:103:945f:af90 with SMTP id p19csp1640700dyi; Thu, 25 Jan 2024 05:33:27 -0800 (PST) X-Google-Smtp-Source: AGHT+IGJDdWwuuG4qtTBgQj2/6X06keyr5x1Ytpd2FrBDoe696sxeWdzZL3sdfUnrw6JhpJyq7f5 X-Received: by 2002:a05:6214:2685:b0:686:abea:623e with SMTP id gm5-20020a056214268500b00686abea623emr1041441qvb.38.1706189607618; Thu, 25 Jan 2024 05:33:27 -0800 (PST) ARC-Seal: i=2; a=rsa-sha256; t=1706189607; cv=pass; d=google.com; s=arc-20160816; b=ohmLDzgkYXM4Vw477WtoEShALs7Iqo5GRZU+fcyLloxZ6INaIFXDhZEwZmpGcnGcAI iGp3qnU1c2s44byutkr0P8HZQErFQjSoKqGgNldk8xLaPJdZqHfnyH9YuTJPAyVeF4FP bBUvHvXBH/jXCPNDusQWLYJEi5PrOqvVDzJH16m0A91qkhiUUfH2KHpvHKwLxHdk2kaM SgXOa9jMcdWQsE3tI51fziYYNRAwZKYvkxsS3q1ja0n/5/DE/cQ1vrNihqff84evG1le Idx0kpqWph2fTlRLe6R1wpUXlgODgHCQ6VpYJQjlRzr/YqWL4nvCSC/SYoS37qxyIUrX Vxpw== ARC-Message-Signature: i=2; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=content-transfer-encoding:mime-version:list-unsubscribe :list-subscribe:list-id:precedence:references:in-reply-to:message-id :date:subject:cc:to:from:dkim-signature; bh=JF/SHXxgK2ZiZmUy3urtep32hgaGvw6CLP99kn1BZtg=; fh=6T+NIsJaADDva4Mhm0u6AQLyVhrdmhpxfc6z2znUEcY=; b=cBSVwakAdZl9gjvzG155GALrOFjybCN0I9mA/heaE1jkZ+QZ4Ho+5uztPKakslRFSE DvIJc6eMiiG6C0haNh8rBpO5zXdpIJ+EfTHOC5iHgYCNmPvwiM9FYb+KqFfbn5TVNBE5 IhDllj7bqvHhvHhiQKSjA2sYJWmmn8bovKrwkD1qvmx5t1YWHpCub2lE1aqAzwJNU6EV ExJQcHIESvXcFdGCdDDmyXCT7BS76jWDh4PDW/o3PvuOyF44mG6HdgAuaiHVlo3rwiII Y/igtTqhMMvhwyZPFWs4yROb5H0QUTebWfra/rvD7ztz+sqg6lB63M63qpjaLcFO+Dr5 NC6Q== ARC-Authentication-Results: i=2; mx.google.com; dkim=pass header.i=@gmail.com header.s=20230601 header.b=Js89LdnW; arc=pass (i=1 spf=pass spfdomain=gmail.com dkim=pass dkdomain=gmail.com dmarc=pass fromdomain=gmail.com); spf=pass (google.com: domain of linux-kernel+bounces-38653-ouuuleilei=gmail.com@vger.kernel.org designates 2604:1380:45d1:ec00::1 as permitted sender) smtp.mailfrom="linux-kernel+bounces-38653-ouuuleilei=gmail.com@vger.kernel.org"; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=gmail.com Received: from ny.mirrors.kernel.org (ny.mirrors.kernel.org. [2604:1380:45d1:ec00::1]) by mx.google.com with ESMTPS id p6-20020a0cf546000000b0068173ad3ceesi12715146qvm.4.2024.01.25.05.33.27 for (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 25 Jan 2024 05:33:27 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel+bounces-38653-ouuuleilei=gmail.com@vger.kernel.org designates 2604:1380:45d1:ec00::1 as permitted sender) client-ip=2604:1380:45d1:ec00::1; Authentication-Results: mx.google.com; dkim=pass header.i=@gmail.com header.s=20230601 header.b=Js89LdnW; arc=pass (i=1 spf=pass spfdomain=gmail.com dkim=pass dkdomain=gmail.com dmarc=pass fromdomain=gmail.com); spf=pass (google.com: domain of linux-kernel+bounces-38653-ouuuleilei=gmail.com@vger.kernel.org designates 2604:1380:45d1:ec00::1 as permitted sender) smtp.mailfrom="linux-kernel+bounces-38653-ouuuleilei=gmail.com@vger.kernel.org"; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=gmail.com Received: from smtp.subspace.kernel.org (wormhole.subspace.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ny.mirrors.kernel.org (Postfix) with ESMTPS id 5A99C1C227FB for ; Thu, 25 Jan 2024 13:33:27 +0000 (UTC) Received: from localhost.localdomain (localhost.localdomain [127.0.0.1]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 36D7C58238; Thu, 25 Jan 2024 13:32:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="Js89LdnW" Received: from mail-wm1-f41.google.com (mail-wm1-f41.google.com [209.85.128.41]) (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 4F61457317; Thu, 25 Jan 2024 13:32:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.41 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706189553; cv=none; b=kWKG7Z4Qsy8x6qhG2UrFhG1Fg/YeE0I6J8+dCJfWen6m3LOneCn8TkZwsHrffsGOsjwBtiwgEtsHxJ2ce4vgZLC10WW8SNYsRmt1Rgc1JdaKBCclMbRd0PMsfv0w89HqOv12hAWusLFOGtSkWFk8tPTgnEXn0lVjnR6+oNVIblQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706189553; c=relaxed/simple; bh=O4GSXcbyEF1gKko/iFzgVckMygcE6RZ27ive23FoIhs=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=L1CsL1WqCVeYnF1dtjRVNd7BfwMYE+JcfkfXjBi5aS5K0HzPB8iyMJKwTH+7Bdzr7o3HOmHTycm45hvZm5F6ede+/XOPHxjRmYZnY2DMy+HRg58kBp6cxB/L9phqO3fVhpBNs6lvoeM0ZudW9YkRp4Nu5qp+Vqj357tI/eWhkkw= 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=Js89LdnW; arc=none smtp.client-ip=209.85.128.41 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 Received: by mail-wm1-f41.google.com with SMTP id 5b1f17b1804b1-40e60e137aaso73643865e9.0; Thu, 25 Jan 2024 05:32:30 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1706189549; x=1706794349; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=JF/SHXxgK2ZiZmUy3urtep32hgaGvw6CLP99kn1BZtg=; b=Js89LdnWa7WJ72GiBZjrAAjr/WZVB3f4RJd1l2tDcD1tZiUbtUlV8l6OCqV/JO4+qU QPrUmaxaNUi2/DQ7d+QAcNdb6J83AcnoHhHTFxTfEE0pQ6O5+IhUrKUt3fo35HCn+UNk KWbIjafSKMCaIS5if0aBvx2iHmq0W5TUNAKcDV6AyQ4qmP/HLZ/VDsUDDJ3Qs4NFeHtI lluWUGtZuLDe7WFp4tZiSMK4yppmJ0w54EVtip/Chamx7IaDVX1wGNNMbQq+0Is35IJy DgV8rgKx71x81rGsW+C3NaorYnPk4vcMZe6OPID6QVNCgyQXP1dOCq3Dp+AvmJljR7er rqcA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1706189549; x=1706794349; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=JF/SHXxgK2ZiZmUy3urtep32hgaGvw6CLP99kn1BZtg=; b=kY1b+e4bnsZ5T2AWImxl8d2210mYyElMNIoS3QLHwRaQ/KKQy84kkTxTBAC88EDTiP +2214TEgk33nm6L/7NInLI7FIcTygB5zqHKQ0pTaY5esujqabkIEB7VcyfHfLHw0zvRU DisqFM1qY8U60BdB+Cnzk6gk0PeGLyljcMyczE+hrQgCxoaeRE/J25rM5IFy6y5EdKeX 3HLSKRO+tL/08yR70xOIsl/lnxoCx2YjysYapMcDrQuIyl6WmUQa4kvnOr6OMja4RviP 53w1DYmj6SvbutnYGmKE91+h26sAkqPqhSKEbko1i+lufNf+au/p6WyvZ2kohg7FNMzh xcvw== X-Gm-Message-State: AOJu0YyKq5BUu+teiJuCdBzuPI2l6QKy6A0/bxwrnLmcQFbsVWEKxLF5 XmjlWVC1wmtzAH+ARLdoRoK3PTdrdLMusOJOi2cmzOTrEYJkWw56 X-Received: by 2002:a05:600c:1f90:b0:40e:c64b:9129 with SMTP id je16-20020a05600c1f9000b0040ec64b9129mr363558wmb.11.1706189549029; Thu, 25 Jan 2024 05:32:29 -0800 (PST) Received: from localhost (54-240-197-231.amazon.com. [54.240.197.231]) by smtp.gmail.com with ESMTPSA id t15-20020a05600c198f00b0040e395cd20bsm2651657wmq.7.2024.01.25.05.32.28 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Thu, 25 Jan 2024 05:32:28 -0800 (PST) From: Puranjay Mohan To: ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, martin.lau@linux.dev, song@kernel.org, catalin.marinas@arm.com, mark.rutland@arm.com, bpf@vger.kernel.org, kpsingh@kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, xukuohai@huaweicloud.com Cc: puranjay12@gmail.com Subject: [PATCH bpf-next v7 2/2] bpf, arm64: use bpf_prog_pack for memory management Date: Thu, 25 Jan 2024 13:31:59 +0000 Message-Id: <20240125133159.85086-3-puranjay12@gmail.com> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20240125133159.85086-1-puranjay12@gmail.com> References: <20240125133159.85086-1-puranjay12@gmail.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: 1789069473869075475 X-GMAIL-MSGID: 1789069473869075475 Use bpf_jit_binary_pack_alloc for memory management of JIT binaries in ARM64 BPF JIT. The bpf_jit_binary_pack_alloc creates a pair of RW and RX buffers. The JIT writes the program into the RW buffer. When the JIT is done, the program is copied to the final RX buffer with bpf_jit_binary_pack_finalize. Implement bpf_arch_text_copy() and bpf_arch_text_invalidate() for ARM64 JIT as these functions are required by bpf_jit_binary_pack allocator. Signed-off-by: Puranjay Mohan Acked-by: Song Liu --- arch/arm64/net/bpf_jit_comp.c | 139 ++++++++++++++++++++++++++++------ 1 file changed, 115 insertions(+), 24 deletions(-) diff --git a/arch/arm64/net/bpf_jit_comp.c b/arch/arm64/net/bpf_jit_comp.c index cfd5434de483..58e54a1929c9 100644 --- a/arch/arm64/net/bpf_jit_comp.c +++ b/arch/arm64/net/bpf_jit_comp.c @@ -76,6 +76,7 @@ struct jit_ctx { int *offset; int exentry_idx; __le32 *image; + __le32 *ro_image; u32 stack_size; int fpb_offset; }; @@ -205,6 +206,14 @@ static void jit_fill_hole(void *area, unsigned int size) *ptr++ = cpu_to_le32(AARCH64_BREAK_FAULT); } +int bpf_arch_text_invalidate(void *dst, size_t len) +{ + if (!aarch64_insn_set(dst, AARCH64_BREAK_FAULT, len)) + return -EINVAL; + + return 0; +} + static inline int epilogue_offset(const struct jit_ctx *ctx) { int to = ctx->epilogue_offset; @@ -707,7 +716,8 @@ static int add_exception_handler(const struct bpf_insn *insn, struct jit_ctx *ctx, int dst_reg) { - off_t offset; + off_t ins_offset; + off_t fixup_offset; unsigned long pc; struct exception_table_entry *ex; @@ -724,12 +734,17 @@ static int add_exception_handler(const struct bpf_insn *insn, return -EINVAL; ex = &ctx->prog->aux->extable[ctx->exentry_idx]; - pc = (unsigned long)&ctx->image[ctx->idx - 1]; + pc = (unsigned long)&ctx->ro_image[ctx->idx - 1]; - offset = pc - (long)&ex->insn; - if (WARN_ON_ONCE(offset >= 0 || offset < INT_MIN)) + /* + * This is the relative offset of the instruction that may fault from + * the exception table itself. This will be written to the exception + * table and if this instruction faults, the destination register will + * be set to '0' and the execution will jump to the next instruction. + */ + ins_offset = pc - (long)&ex->insn; + if (WARN_ON_ONCE(ins_offset >= 0 || ins_offset < INT_MIN)) return -ERANGE; - ex->insn = offset; /* * Since the extable follows the program, the fixup offset is always @@ -738,12 +753,25 @@ static int add_exception_handler(const struct bpf_insn *insn, * bits. We don't need to worry about buildtime or runtime sort * modifying the upper bits because the table is already sorted, and * isn't part of the main exception table. + * + * The fixup_offset is set to the next instruction from the instruction + * that may fault. The execution will jump to this after handling the + * fault. */ - offset = (long)&ex->fixup - (pc + AARCH64_INSN_SIZE); - if (!FIELD_FIT(BPF_FIXUP_OFFSET_MASK, offset)) + fixup_offset = (long)&ex->fixup - (pc + AARCH64_INSN_SIZE); + if (!FIELD_FIT(BPF_FIXUP_OFFSET_MASK, fixup_offset)) return -ERANGE; - ex->fixup = FIELD_PREP(BPF_FIXUP_OFFSET_MASK, offset) | + /* + * The offsets above have been calculated using the RO buffer but we + * need to use the R/W buffer for writes. + * switch ex to rw buffer for writing. + */ + ex = (void *)ctx->image + ((void *)ex - (void *)ctx->ro_image); + + ex->insn = ins_offset; + + ex->fixup = FIELD_PREP(BPF_FIXUP_OFFSET_MASK, fixup_offset) | FIELD_PREP(BPF_FIXUP_REG_MASK, dst_reg); ex->type = EX_TYPE_BPF; @@ -1511,7 +1539,8 @@ static inline void bpf_flush_icache(void *start, void *end) struct arm64_jit_data { struct bpf_binary_header *header; - u8 *image; + u8 *ro_image; + struct bpf_binary_header *ro_header; struct jit_ctx ctx; }; @@ -1520,12 +1549,14 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog) int image_size, prog_size, extable_size, extable_align, extable_offset; struct bpf_prog *tmp, *orig_prog = prog; struct bpf_binary_header *header; + struct bpf_binary_header *ro_header; struct arm64_jit_data *jit_data; bool was_classic = bpf_prog_was_classic(prog); bool tmp_blinded = false; bool extra_pass = false; struct jit_ctx ctx; u8 *image_ptr; + u8 *ro_image_ptr; if (!prog->jit_requested) return orig_prog; @@ -1552,8 +1583,11 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog) } if (jit_data->ctx.offset) { ctx = jit_data->ctx; - image_ptr = jit_data->image; + ro_image_ptr = jit_data->ro_image; + ro_header = jit_data->ro_header; header = jit_data->header; + image_ptr = (void *)header + ((void *)ro_image_ptr + - (void *)ro_header); extra_pass = true; prog_size = sizeof(u32) * ctx.idx; goto skip_init_ctx; @@ -1598,18 +1632,27 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog) /* also allocate space for plt target */ extable_offset = round_up(prog_size + PLT_TARGET_SIZE, extable_align); image_size = extable_offset + extable_size; - header = bpf_jit_binary_alloc(image_size, &image_ptr, - sizeof(u32), jit_fill_hole); - if (header == NULL) { + ro_header = bpf_jit_binary_pack_alloc(image_size, &ro_image_ptr, + sizeof(u32), &header, &image_ptr, + jit_fill_hole); + if (!ro_header) { prog = orig_prog; goto out_off; } /* 2. Now, the actual pass. */ + /* + * Use the image(RW) for writing the JITed instructions. But also save + * the ro_image(RX) for calculating the offsets in the image. The RW + * image will be later copied to the RX image from where the program + * will run. The bpf_jit_binary_pack_finalize() will do this copy in the + * final step. + */ ctx.image = (__le32 *)image_ptr; + ctx.ro_image = (__le32 *)ro_image_ptr; if (extable_size) - prog->aux->extable = (void *)image_ptr + extable_offset; + prog->aux->extable = (void *)ro_image_ptr + extable_offset; skip_init_ctx: ctx.idx = 0; ctx.exentry_idx = 0; @@ -1617,9 +1660,8 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog) build_prologue(&ctx, was_classic); if (build_body(&ctx, extra_pass)) { - bpf_jit_binary_free(header); prog = orig_prog; - goto out_off; + goto out_free_hdr; } build_epilogue(&ctx); @@ -1627,34 +1669,44 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog) /* 3. Extra pass to validate JITed code. */ if (validate_ctx(&ctx)) { - bpf_jit_binary_free(header); prog = orig_prog; - goto out_off; + goto out_free_hdr; } /* And we're done. */ if (bpf_jit_enable > 1) bpf_jit_dump(prog->len, prog_size, 2, ctx.image); - bpf_flush_icache(header, ctx.image + ctx.idx); - if (!prog->is_func || extra_pass) { if (extra_pass && ctx.idx != jit_data->ctx.idx) { pr_err_once("multi-func JIT bug %d != %d\n", ctx.idx, jit_data->ctx.idx); - bpf_jit_binary_free(header); prog->bpf_func = NULL; prog->jited = 0; prog->jited_len = 0; + goto out_free_hdr; + } + if (WARN_ON(bpf_jit_binary_pack_finalize(prog, ro_header, + header))) { + /* ro_header has been freed */ + ro_header = NULL; + prog = orig_prog; goto out_off; } - bpf_jit_binary_lock_ro(header); + /* + * The instructions have now been copied to the ROX region from + * where they will execute. Now the data cache has to be cleaned to + * the PoU and the I-cache has to be invalidated for the VAs. + */ + bpf_flush_icache(ro_header, ctx.ro_image + ctx.idx); } else { jit_data->ctx = ctx; - jit_data->image = image_ptr; + jit_data->ro_image = ro_image_ptr; jit_data->header = header; + jit_data->ro_header = ro_header; } - prog->bpf_func = (void *)ctx.image; + + prog->bpf_func = (void *)ctx.ro_image; prog->jited = 1; prog->jited_len = prog_size; @@ -1675,6 +1727,14 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog) bpf_jit_prog_release_other(prog, prog == orig_prog ? tmp : orig_prog); return prog; + +out_free_hdr: + if (header) { + bpf_arch_text_copy(&ro_header->size, &header->size, + sizeof(header->size)); + bpf_jit_binary_pack_free(ro_header, header); + } + goto out_off; } bool bpf_jit_supports_kfunc_call(void) @@ -1682,6 +1742,13 @@ bool bpf_jit_supports_kfunc_call(void) return true; } +void *bpf_arch_text_copy(void *dst, void *src, size_t len) +{ + if (!aarch64_insn_copy(dst, src, len)) + return ERR_PTR(-EINVAL); + return dst; +} + u64 bpf_jit_alloc_exec_limit(void) { return VMALLOC_END - VMALLOC_START; @@ -2310,3 +2377,27 @@ bool bpf_jit_supports_ptr_xchg(void) { return true; } + +void bpf_jit_free(struct bpf_prog *prog) +{ + if (prog->jited) { + struct arm64_jit_data *jit_data = prog->aux->jit_data; + struct bpf_binary_header *hdr; + + /* + * If we fail the final pass of JIT (from jit_subprogs), + * the program may not be finalized yet. Call finalize here + * before freeing it. + */ + if (jit_data) { + bpf_arch_text_copy(&jit_data->ro_header->size, &jit_data->header->size, + sizeof(jit_data->header->size)); + kfree(jit_data); + } + hdr = bpf_jit_binary_pack_hdr(prog); + bpf_jit_binary_pack_free(hdr, NULL); + WARN_ON_ONCE(!bpf_prog_kallsyms_verify_off(prog)); + } + + bpf_prog_unlock_free(prog); +}