From patchwork Wed Nov 25 10:07:18 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jinyang He X-Patchwork-Id: 11930989 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 4D32FC5519F for ; Wed, 25 Nov 2020 10:07:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F3DB520857 for ; Wed, 25 Nov 2020 10:07:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728833AbgKYKHW (ORCPT ); Wed, 25 Nov 2020 05:07:22 -0500 Received: from mail.loongson.cn ([114.242.206.163]:38556 "EHLO loongson.cn" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726197AbgKYKHW (ORCPT ); Wed, 25 Nov 2020 05:07:22 -0500 Received: from bogon.localdomain (unknown [113.200.148.30]) by mail.loongson.cn (Coremail) with SMTP id AQAAf9DxL9PWLL5fkH8WAA--.45482S2; Wed, 25 Nov 2020 18:07:18 +0800 (CST) From: Jinyang He To: Thomas Bogendoerfer Cc: linux-mips@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 1/2] MIPS: KASLR: Correcte valid bits in apply_r_mips_26_rel() Date: Wed, 25 Nov 2020 18:07:18 +0800 Message-Id: <1606298838-7006-1-git-send-email-hejinyang@loongson.cn> X-Mailer: git-send-email 2.1.0 X-CM-TRANSID: AQAAf9DxL9PWLL5fkH8WAA--.45482S2 X-Coremail-Antispam: 1UD129KBjvJXoW7tw4UGF13tw18Gw1fWw17Wrg_yoW8WF13pr nrG34xKrW7JrWjkrWDXFyUJr1UJw4DZa47XFn7Kw1xuw15uryDGF18Gw1xta4UGry0kF47 Xa4Dtr1Utr4UAw7anT9S1TB71UUUUUDqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUkYb7Iv0xC_Kw4lb4IE77IF4wAFF20E14v26r1j6r4UM7CY07I2 0VC2zVCF04k26cxKx2IYs7xG6rWj6s0DM7CIcVAFz4kK6r1j6r18M28lY4IEw2IIxxk0rw A2F7IY1VAKz4vEj48ve4kI8wA2z4x0Y4vE2Ix0cI8IcVAFwI0_Ar0_tr1l84ACjcxK6xII jxv20xvEc7CjxVAFwI0_Cr0_Gr1UM28EF7xvwVC2z280aVAFwI0_GcCE3s1l84ACjcxK6I 8E87Iv6xkF7I0E14v26rxl6s0DM2AIxVAIcxkEcVAq07x20xvEncxIr21l5I8CrVACY4xI 64kE6c02F40Ex7xfMcIj6xIIjxv20xvE14v26r1Y6r17McIj6I8E87Iv67AKxVW8JVWxJw Am72CE4IkC6x0Yz7v_Jr0_Gr1lF7xvr2IYc2Ij64vIr41lc2xSY4AK67AK6r4DMxAIw28I cxkI7VAKI48JMxC20s026xCaFVCjc4AY6r1j6r4UMI8I3I0E5I8CrVAFwI0_Jr0_Jr4lx2 IqxVCjr7xvwVAFwI0_JrI_JrWlx4CE17CEb7AF67AKxVWUXVWUAwCIc40Y0x0EwIxGrwCI 42IY6xIIjxv20xvE14v26r1j6r1xMIIF0xvE2Ix0cI8IcVCY1x0267AKxVWUJVW8JwCI42 IY6xAIw20EY4v20xvaj40_Gr0_Zr1lIxAIcVC2z280aVAFwI0_Jr0_Gr1lIxAIcVC2z280 aVCY1x0267AKxVW8JVW8JrUvcSsGvfC2KfnxnUUI43ZEXa7IU5GhF3UUUUU== X-CM-SenderInfo: pkhmx0p1dqwqxorr0wxvrqhubq/ Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org Apply_r_mips_26_rel() relocates instructions like j, jal and etc. These instructions consist of 6bits function field and 26bits address field. The value of target_addr as follows, ================================================================= | high 4bits | low 28bits | ================================================================= |the high 4bits of this PC | the low 26bits of instructions << 2| ================================================================= Thus, loc_orig and log_new both need high 4bits rather than high 6bits. Signed-off-by: Jinyang He --- v2: Replace ~0x0fffffff with 0xf0000000 arch/mips/kernel/relocate.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/mips/kernel/relocate.c b/arch/mips/kernel/relocate.c index 3d80a51..8561c7a 100644 --- a/arch/mips/kernel/relocate.c +++ b/arch/mips/kernel/relocate.c @@ -95,7 +95,7 @@ static int __init apply_r_mips_26_rel(u32 *loc_orig, u32 *loc_new, long offset) /* Original target address */ target_addr <<= 2; - target_addr += (unsigned long)loc_orig & ~0x03ffffff; + target_addr += (unsigned long)loc_orig & 0xf0000000; /* Get the new target address */ target_addr += offset; @@ -105,7 +105,7 @@ static int __init apply_r_mips_26_rel(u32 *loc_orig, u32 *loc_new, long offset) return -ENOEXEC; } - target_addr -= (unsigned long)loc_new & ~0x03ffffff; + target_addr -= (unsigned long)loc_new & 0xf0000000; target_addr >>= 2; *loc_new = (*loc_new & ~0x03ffffff) | (target_addr & 0x03ffffff);