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=-15.4 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=unavailable 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 A107BC433E6 for ; Tue, 2 Feb 2021 05:56:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6461364ED3 for ; Tue, 2 Feb 2021 05:56:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231898AbhBBF4X (ORCPT ); Tue, 2 Feb 2021 00:56:23 -0500 Received: from mail.loongson.cn ([114.242.206.163]:53328 "EHLO loongson.cn" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S231683AbhBBF4U (ORCPT ); Tue, 2 Feb 2021 00:56:20 -0500 Received: from [10.130.0.55] (unknown [113.200.148.30]) by mail.loongson.cn (Coremail) with SMTP id AQAAf9AxmdRN6RhgBbkBAA--.1938S3; Tue, 02 Feb 2021 13:55:26 +0800 (CST) Subject: Re: [PATCH] MIPS: relocatable: Provide kaslr_offset() to get the kernel offset To: Thomas Bogendoerfer References: <1611720745-8256-1-git-send-email-hejinyang@loongson.cn> <20210201125028.GA8621@alpha.franken.de> Cc: Huacai Chen , Jiaxun Yang , linux-mips@vger.kernel.org, linux-kernel@vger.kernel.org From: Jinyang He Message-ID: Date: Tue, 2 Feb 2021 13:55:25 +0800 User-Agent: Mozilla/5.0 (X11; Linux mips64; rv:45.0) Gecko/20100101 Thunderbird/45.4.0 MIME-Version: 1.0 In-Reply-To: <20210201125028.GA8621@alpha.franken.de> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit X-CM-TRANSID: AQAAf9AxmdRN6RhgBbkBAA--.1938S3 X-Coremail-Antispam: 1UD129KBjvJXoWxZF45tF43ZFy5GFyxWw1rZwb_yoWrGryxpa nrA3WkGrZ0gryUAFZ5ZFykur13Gws8Wr4a9FsrK3y8Z3ZFqF1UJ3Z7Wrs8urWjqFy0gF1I va4YqF12vw4vv3JanT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUv2b7Iv0xC_Kw4lb4IE77IF4wAFF20E14v26r1j6r4UM7CY07I2 0VC2zVCF04k26cxKx2IYs7xG6rWj6s0DM7CIcVAFz4kK6r1j6r18M28lY4IEw2IIxxk0rw A2F7IY1VAKz4vEj48ve4kI8wA2z4x0Y4vE2Ix0cI8IcVAFwI0_Gr0_Xr1l84ACjcxK6xII jxv20xvEc7CjxVAFwI0_Gr0_Cr1l84ACjcxK6I8E87Iv67AKxVWxJr0_GcWl84ACjcxK6I 8E87Iv6xkF7I0E14v26rxl6s0DM2AIxVAIcxkEcVAq07x20xvEncxIr21l5I8CrVACY4xI 64kE6c02F40Ex7xfMcIj6xIIjxv20xvE14v26r1j6r18McIj6I8E87Iv67AKxVW8JVWxJw Am72CE4IkC6x0Yz7v_Jr0_Gr1lF7xvr2IY64vIr41lc7I2V7IY0VAS07AlzVAYIcxG8wCY 02Avz4vE14v_GrWl42xK82IYc2Ij64vIr41l4I8I3I0E4IkC6x0Yz7v_Jr0_Gr1lx2IqxV Aqx4xG67AKxVWUJVWUGwC20s026x8GjcxK67AKxVWUGVWUWwC2zVAF1VAY17CE14v26r12 6r1DMIIYrxkI7VAKI48JMIIF0xvE2Ix0cI8IcVAFwI0_Jr0_JF4lIxAIcVC0I7IYx2IY6x kF7I0E14v26r1j6r4UMIIF0xvE42xK8VAvwI8IcIk0rVWrZr1j6s0DMIIF0xvEx4A2jsIE 14v26r1j6r4UMIIF0xvEx4A2jsIEc7CjxVAFwI0_Jr0_GrUvcSsGvfC2KfnxnUUI43ZEXa 7IU5tku3UUUUU== X-CM-SenderInfo: pkhmx0p1dqwqxorr0wxvrqhubq/ Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 02/01/2021 08:50 PM, Thomas Bogendoerfer wrote: > On Wed, Jan 27, 2021 at 12:12:25PM +0800, Jinyang He wrote: >> Use kimage_vaddr to indicate kernel start address. Provide kaslr_offset() >> to get the kernel offset when KASLR is enabled. Error may occur before >> update_kimage_vaddr(), so put it at the end of the offset branch. >> >> Fixes: a307a4ce9ecd ("MIPS: Loongson64: Add KASLR support") >> Reported-by: kernel test robot >> Signed-off-by: Jinyang He >> --- >> arch/mips/include/asm/page.h | 6 ++++++ >> arch/mips/kernel/relocate.c | 12 ++++++++++++ >> arch/mips/kernel/setup.c | 3 +++ >> 3 files changed, 21 insertions(+) >> >> diff --git a/arch/mips/include/asm/page.h b/arch/mips/include/asm/page.h >> index 6a77bc4..9429520 100644 >> --- a/arch/mips/include/asm/page.h >> +++ b/arch/mips/include/asm/page.h >> @@ -255,6 +255,12 @@ extern bool __virt_addr_valid(const volatile void *kaddr); >> >> #define VM_DATA_DEFAULT_FLAGS VM_DATA_FLAGS_TSK_EXEC >> >> +extern unsigned long kimage_vaddr; >> +static inline unsigned long kaslr_offset(void) >> +{ >> + return kimage_vaddr - VMLINUX_LOAD_ADDRESS; >> +} > this breaks for 32bit kernels: > > :0:22: error: large integer implicitly truncated to unsigned type [-Werror=overflow] > /local/tbogendoerfer/korg/linux/arch/mips/kernel/setup.c:87:41: note: in expansion of macro ‘VMLINUX_LOAD_ADDRESS’ > unsigned long kimage_vaddr __initdata = VMLINUX_LOAD_ADDRESS; > ^~~~~~~~~~~~~~~~~~~~ > cc1: all warnings being treated as errors > Sorry for not considering the 32bits kernel. Maybe a variable is enough. Like this, diff --git a/arch/mips/include/asm/page.h b/arch/mips/include/asm/page.h index 6a77bc4a6eec..74082e35d57c 100644 --- a/arch/mips/include/asm/page.h +++ b/arch/mips/include/asm/page.h @@ -255,6 +255,12 @@ extern bool __virt_addr_valid(const volatile void *kaddr); #define VM_DATA_DEFAULT_FLAGS VM_DATA_FLAGS_TSK_EXEC +extern unsigned long __kaslr_offset; +static inline unsigned long kaslr_offset(void) +{ + return __kaslr_offset; +} + #include #include diff --git a/arch/mips/kernel/relocate.c b/arch/mips/kernel/relocate.c index c643c816cbe0..95abb9c82f00 100644 --- a/arch/mips/kernel/relocate.c +++ b/arch/mips/kernel/relocate.c @@ -300,6 +300,13 @@ static inline int __init relocation_addr_valid(void *loc_new) return 1; } +static inline void __init update_kaslr_offset(unsigned long *addr, long offset) +{ + unsigned long *new_addr = (unsigned long *)RELOCATED(addr); + + *new_addr = (unsigned long)offset; +} + #if defined(CONFIG_USE_OF) void __weak *plat_get_fdt(void) { @@ -410,6 +417,9 @@ void *__init relocate_kernel(void) /* Return the new kernel's entry point */ kernel_entry = RELOCATED(start_kernel); + + /* Error may occur before, so keep it at last */ + update_kaslr_offset(&__kaslr_offset, offset); } out: return kernel_entry; diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c index 7e1f8e277437..cde234326738 100644 --- a/arch/mips/kernel/setup.c +++ b/arch/mips/kernel/setup.c @@ -84,6 +84,9 @@ static struct resource code_resource = { .name = "Kernel code", }; static struct resource data_resource = { .name = "Kernel data", }; static struct resource bss_resource = { .name = "Kernel bss", }; +unsigned long __kaslr_offset __initdata = 0; +EXPORT_SYMBOL(__kaslr_offset); + static void *detect_magic __initdata = detect_memory_region; #ifdef CONFIG_MIPS_AUTO_PFN_OFFSET I'll send v2 later if no other comment. Thanks, Jinyang