From patchwork Mon Jun 26 08:58:10 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Puranjay Mohan X-Patchwork-Id: 13292531 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 E0859EB64D7 for ; Mon, 26 Jun 2023 08:58:55 +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=w+2HburSXH4A5AkulX3uLMxv26wZiI+bU0XLNgRdh5s=; b=1sDFFKcnF9XAGI aYHgFYXDVnVXqo/vpFkVNa+3bfiYn6zi63p595i5uSdEnSXpnJLsakZbmtbkM93P29C2pAXCixEiJ +clqOIdSspiDmMNaGUXUPXtfWDFbWEvWbLR2vGLUwlXIvuDmULUkP/JlDW8vO3tkm+Bfd9wfT1UuP NAtxme5xjM9CuFr8dTBtgF03ZX/CKoF7RvQlVpuoxLUa6l4+0yW7F6zb7qgcnwi/r4C9qXMGqRpio S5zjp8IZqpV0IY/WXGDrLmFJgndGO2VzZNfPhYx0poR10Lq7+Pd+u0Slyhc90fMicoDnwZQgrAeyX yD2F2FSOvSj3YHfgxoKA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qDi3M-009gS3-2k; Mon, 26 Jun 2023 08:58:32 +0000 Received: from mail-wr1-x42b.google.com ([2a00:1450:4864:20::42b]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1qDi36-009gOT-2B for linux-arm-kernel@lists.infradead.org; Mon, 26 Jun 2023 08:58:18 +0000 Received: by mail-wr1-x42b.google.com with SMTP id ffacd0b85a97d-313e12db357so3225041f8f.0 for ; Mon, 26 Jun 2023 01:58:15 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1687769894; x=1690361894; 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=g89tOe+fXjd3eCewwiEMcP/rgT7hBlO+AcyleoZQ3c4=; b=KY0lFmAyiGPNFi5tejVkCcdML67r0m78mXYhfhaNGCExzjzcs4nhYQIlel/8BYJRpz lfJONMAVjcHCJoBzkI699nWEtuBaxhq4kUnUzVfCp05RtNkxj/MNfRMmkwqF2dGcptlp K7WCs3Dpzq03D6B5J1Y+pYbq7jphYR0ctaBFILc+EgjFpGk/2jYY0JVpw6Mojp+pnkHF oXn0DUAwYrCVOM+Sv4+yZGrcQ6/BdpbMGLHoG/hTWFRe9VdFj+XLKbB9kG5C0ozms0N4 L68Qd5rzZyyhPK6dC5WoUSjRvBj0BM37fSNgn8FGG5KJ0b6VIQDBl++oMAAX7fhemqfZ 7+mQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1687769894; x=1690361894; 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=g89tOe+fXjd3eCewwiEMcP/rgT7hBlO+AcyleoZQ3c4=; b=I/5mkUa1LqRH+g/fwAN8Mf1rpw02svvnOxwa26/RqdpebvMph9eZUrEFYzvE57+Ew7 iixmahu8t5zojo/58F4faF5Z2ZCMjQMA/RRjUd1QYmwayj88YXTleZnlphdYWBO/u5Dg ph9K0mq5MuGnsghiNUoGlliyMh8xPIt7/J89c8P3+gH1KlK68Wwzq8+Wo4AdyAqjIY3S uuNExSwEkAGzq6SAl/BQ+MSLofnR0bSAAqm9bL4Qv/FpCV1tQjvLohNYCkWxnwL0io1s RBEwka1UG1NseiMEXI6GthGpy9hqKVasEThAjTuDBmJgrKOUFxOulV95ETD4Pof7xQwH nJ6g== X-Gm-Message-State: AC+VfDxLwBH6K5QlJ5qRvBVLPsjtsMdWc/rNZRgybVD01z9kYPHLsC/8 JxFRjDU0GbBieFS78cmcOcc= X-Google-Smtp-Source: ACHHUZ4m62deog5lFK8+0lA0KYE/r/VTwsXj5L2YGdFLyxwDG7jb6AmJwJCCJu5KOCig62//DhK1dw== X-Received: by 2002:a05:6000:1004:b0:30a:dd26:63cd with SMTP id a4-20020a056000100400b0030add2663cdmr33892488wrx.5.1687769894028; Mon, 26 Jun 2023 01:58:14 -0700 (PDT) Received: from ip-172-31-22-112.eu-west-1.compute.internal (ec2-34-242-96-229.eu-west-1.compute.amazonaws.com. [34.242.96.229]) by smtp.gmail.com with ESMTPSA id h10-20020a5d504a000000b00313e8dc7facsm4883533wrt.116.2023.06.26.01.58.13 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 26 Jun 2023 01:58:13 -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 v4 2/3] arm64: patching: Add aarch64_insn_copy() Date: Mon, 26 Jun 2023 08:58:10 +0000 Message-Id: <20230626085811.3192402-3-puranjay12@gmail.com> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230626085811.3192402-1-puranjay12@gmail.com> References: <20230626085811.3192402-1-puranjay12@gmail.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230626_015816_711542_0F996545 X-CRM114-Status: GOOD ( 16.01 ) 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 --- Changes in v3 => v4 - No changes Changes in v2 => v3 - No changes Changes in v1 => v2: - Renamed addr/opcode to dst/src. - Added 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..f78a0409cbdb 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 *dst, const 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..419a9428402e 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 + * @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, const 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 = dst + patched; + size = min_t(size_t, PAGE_SIZE - offset_in_page(ptr), + len - patched); + + waddr = patch_map(ptr, FIX_TEXT_POKE0); + ret = copy_to_kernel_nofault(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); + + return dst; +} + int __kprobes aarch64_insn_patch_text_nosync(void *addr, u32 insn) { u32 *tp = addr;