From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4906BC10DCE for ; Mon, 16 Mar 2020 02:37:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1CF2A20658 for ; Mon, 16 Mar 2020 02:37:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1584326278; bh=B7VCjfXUJJnPc9HcAd5IjQF9bDnM9fbTDTAhWgmBR34=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=LSamlfCR8ZuxquIEskLM0L2L91CFBK9/t6WzPunBaZFzFd/2rbeYEnWuXagZ/0VpT WpLINySpptQ9wSbJM73vvt72uv8i03XyUP9ohLFt0hruwnzXnVVzN3fkhnx6ioNzoE oCq+Bjrco+G6OPFDqE4qMem3xBo36lSA9p9a3vIw= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730392AbgCPChx (ORCPT ); Sun, 15 Mar 2020 22:37:53 -0400 Received: from mail.kernel.org ([198.145.29.99]:39354 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729631AbgCPCfL (ORCPT ); Sun, 15 Mar 2020 22:35:11 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 1B19B206EB; Mon, 16 Mar 2020 02:35:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1584326111; bh=B7VCjfXUJJnPc9HcAd5IjQF9bDnM9fbTDTAhWgmBR34=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Ogu0GllGWjbmAqEozETsKu62fX5wNH6x/Aoje9FjXXjbaF1CtyNy3SJWXMAtNBfyH +fytoFxuqHxlAOzVidQcjOhzk9hGED3wPSlZ1zWVtvJADCqas1AR7skDqf85NMURLD SnZjbzwxFbt8y43NY4xEHU2kii0YhyEAcBPrwbqs= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Vincent Chen , Alexandre Ghiti , Anup Patel , Carlos de Paula , Palmer Dabbelt , Sasha Levin , linux-riscv@lists.infradead.org Subject: [PATCH AUTOSEL 4.19 14/20] riscv: avoid the PIC offset of static percpu data in module beyond 2G limits Date: Sun, 15 Mar 2020 22:34:47 -0400 Message-Id: <20200316023453.1800-14-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200316023453.1800-1-sashal@kernel.org> References: <20200316023453.1800-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Vincent Chen [ Upstream commit 0cff8bff7af886af0923d5c91776cd51603e531f ] The compiler uses the PIC-relative method to access static variables instead of GOT when the code model is PIC. Therefore, the limitation of the access range from the instruction to the symbol address is +-2GB. Under this circumstance, the kernel cannot load a kernel module if this module has static per-CPU symbols declared by DEFINE_PER_CPU(). The reason is that kernel relocates the .data..percpu section of the kernel module to the end of kernel's .data..percpu. Hence, the distance between the per-CPU symbols and the instruction will exceed the 2GB limits. To solve this problem, the kernel should place the loaded module in the memory area [&_end-2G, VMALLOC_END]. Signed-off-by: Vincent Chen Suggested-by: Alexandre Ghiti Suggested-by: Anup Patel Tested-by: Alexandre Ghiti Tested-by: Carlos de Paula Signed-off-by: Palmer Dabbelt Signed-off-by: Sasha Levin --- arch/riscv/kernel/module.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/arch/riscv/kernel/module.c b/arch/riscv/kernel/module.c index 7dd308129b40f..7c012ad1d7ede 100644 --- a/arch/riscv/kernel/module.c +++ b/arch/riscv/kernel/module.c @@ -16,6 +16,10 @@ #include #include #include +#include +#include +#include +#include static int apply_r_riscv_32_rela(struct module *me, u32 *location, Elf_Addr v) { @@ -394,3 +398,15 @@ int apply_relocate_add(Elf_Shdr *sechdrs, const char *strtab, return 0; } + +#if defined(CONFIG_MMU) && defined(CONFIG_64BIT) +#define VMALLOC_MODULE_START \ + max(PFN_ALIGN((unsigned long)&_end - SZ_2G), VMALLOC_START) +void *module_alloc(unsigned long size) +{ + return __vmalloc_node_range(size, 1, VMALLOC_MODULE_START, + VMALLOC_END, GFP_KERNEL, + PAGE_KERNEL_EXEC, 0, NUMA_NO_NODE, + __builtin_return_address(0)); +} +#endif -- 2.20.1