From patchwork Mon Jun 5 07:40:23 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Puranjay Mohan X-Patchwork-Id: 13267028 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 0D91BC7EE24 for ; Mon, 5 Jun 2023 07:40:53 +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=QxS6R2XqSlZwZAEJBS2FOYD/fNM0ddKLRMAJsSmufN8=; b=EicBTpVuuOp2Fs CBWj4Mrvl2IwCOF/9TzbvUPqFI83VxTw6MFoz+2lsgDb8IgiuF3Wx/eEbNq+97uzgT5krhMXIADMj IChnrF3FXPbUvGfK+aAVOsK0ElztNCtXpQ0tXizsZVO5YV6WvEm5pLuEf+urtU2iuZ6TQBr00DmeO jeH40YD8mjAf8UGtxjs9LzkhVBpCfgkyEWsK1/BFZHEZ5cZ8/d5BCSvk9tHXYcSCbDA7ltXYt0NdE esecmy39GdYZxFFady1aRqekUdiarxpq1DSXDhGr7b1ndilrYRv50xtnlggTO4n4u2DpEm8Z2ukG4 LBtk2dJrQrd9G/VCz1Xg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1q64pL-00Ea2D-2Z; Mon, 05 Jun 2023 07:40:31 +0000 Received: from mail-wm1-x334.google.com ([2a00:1450:4864:20::334]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1q64pJ-00Ea0a-03 for linux-arm-kernel@lists.infradead.org; Mon, 05 Jun 2023 07:40:30 +0000 Received: by mail-wm1-x334.google.com with SMTP id 5b1f17b1804b1-3f6e13940daso45841205e9.0 for ; Mon, 05 Jun 2023 00:40:28 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1685950827; x=1688542827; 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=IkzqYxL73s22EAwsna++GGXRkm1HvzsrQXeSnzKLJ6M=; b=ad1sTI8nqnhQ4S/1WnIPW6zm48etDauqxoNS4yAm8F/DkP+AJY3rZU6ft/MBECBmMb 8F29zfFuogHVFdyX+p0h627jFsihUhI+MZrV4E4xFEuBWhoo0iFHN7HEUNxT79PjePaz +OscpeOPWhNmq9mW15hMqAabb4Fm1MjCFVWwut+poRj6rFEvyyXhz9ey5BpE6FTxpnrR QHqIXTmpLEefs/M+wfYU967NOJITwOMCfXsOGa+tn8EA457L1tuFaRi6+MoeqHipcZmw IlKuB8RufCWHnEqiToTsqgaZzPE30xdn6xutUufEjbRcTpN07qItho2sPv/8hxbKlYxK Fipg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1685950827; x=1688542827; 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=IkzqYxL73s22EAwsna++GGXRkm1HvzsrQXeSnzKLJ6M=; b=fBdUIzZcKLVZsIcWgZveh4toz+KnbeqgTVdR1bR5OB/peS6HkDCNhCanIgXZ56iIvw B0zA3sMWjf6iGdEtUQwEApxeYf1EjX3xNmSK3ePvATFTMQhGsHn1ykh2eEjPtwpsIy8L 10vGZvQDOLZVsQDqYIvDGsEorOJdrnBXQWL2WetAUKGleLusR5uHSjlNs5k2cIzNdpAM nn1EwYQ3/I1uofW+2POYOl2DvKxmKcCgl2VBQTYRgg0dj5AtitWMl1cR9Ryg0hsjRzVK b4uZNN1AI46Cr4U3ozC62DS7mLWaoq7sCW9mXwizpIBIVIc8LJ/pIxlTXjnbYwRhDYHo H51Q== X-Gm-Message-State: AC+VfDxpAEhM/za+xq6/DGzbS3xtcnnr28vuDboHkfgXRV7Sf88rcEx7 VVJQmqNsgN0BboFYX1ohbkY= X-Google-Smtp-Source: ACHHUZ7Ls9cXd9bOy8NVrhksZPkskca3CwSJJZLtxIsyFgHq0GzJNJ2CJ6bYNnwlMBoG7rmQWQMQgg== X-Received: by 2002:a7b:ca46:0:b0:3f1:789d:ad32 with SMTP id m6-20020a7bca46000000b003f1789dad32mr8195807wml.11.1685950826769; Mon, 05 Jun 2023 00:40:26 -0700 (PDT) Received: from ip-172-31-22-112.eu-west-1.compute.internal (ec2-34-244-49-215.eu-west-1.compute.amazonaws.com. [34.244.49.215]) by smtp.gmail.com with ESMTPSA id c18-20020adfed92000000b0030ae499da59sm8882103wro.111.2023.06.05.00.40.26 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 05 Jun 2023 00:40:26 -0700 (PDT) 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 Cc: puranjay12@gmail.com Subject: [PATCH bpf-next 2/3] arm64: patching: Add aarch64_insn_copy() Date: Mon, 5 Jun 2023 07:40:23 +0000 Message-Id: <20230605074024.1055863-3-puranjay12@gmail.com> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230605074024.1055863-1-puranjay12@gmail.com> References: <20230605074024.1055863-1-puranjay12@gmail.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230605_004029_052566_A3F8152E X-CRM114-Status: GOOD ( 15.75 ) 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 This will be used by BPF JIT compiler to dump JITed binary to a RX huge page, and thus allow multiple BPF programs sharing the a huge (2MB) page. The bpf_prog_pack allocator that implements the above feature allocates a RX/RW buffer pair. The JITed code is written to the RW buffer and then this function will be used to copy the code from RW to RX buffer. Signed-off-by: Puranjay Mohan Acked-by: Song Liu --- arch/arm64/include/asm/patching.h | 1 + arch/arm64/kernel/patching.c | 39 +++++++++++++++++++++++++++++++ 2 files changed, 40 insertions(+) diff --git a/arch/arm64/include/asm/patching.h b/arch/arm64/include/asm/patching.h index 68908b82b168..dba9eb392bf1 100644 --- a/arch/arm64/include/asm/patching.h +++ b/arch/arm64/include/asm/patching.h @@ -8,6 +8,7 @@ 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_copy(void *addr, const void *opcode, 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..48c710f6a1ff 100644 --- a/arch/arm64/kernel/patching.c +++ b/arch/arm64/kernel/patching.c @@ -105,6 +105,45 @@ noinstr int aarch64_insn_write_literal_u64(void *addr, u64 val) return ret; } +/** + * aarch64_insn_copy - Copy instructions into (an unused part of) RX memory + * @addr: address to modify + * @opcode: 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 *addr, const void *opcode, size_t len) +{ + unsigned long flags; + size_t patched = 0; + size_t size; + void *waddr; + void *dst; + int ret; + + raw_spin_lock_irqsave(&patch_lock, flags); + + while (patched < len) { + dst = addr + patched; + size = min_t(size_t, PAGE_SIZE - offset_in_page(dst), + len - patched); + + waddr = patch_map(dst, FIX_TEXT_POKE0); + ret = copy_to_kernel_nofault(waddr, opcode + 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); + + return addr; +} + int __kprobes aarch64_insn_patch_text_nosync(void *addr, u32 insn) { u32 *tp = addr;