From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Sun, 11 Nov 2018 23:27:04 +0100 (CET) Received: from mail.kernel.org ([198.145.29.99]:46856 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by eddie.linux-mips.org with ESMTP id S23992066AbeKKW1A1qhLL (ORCPT ); Sun, 11 Nov 2018 23:27:00 +0100 Received: from localhost (unknown [206.108.79.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id CCE9C2175B; Sun, 11 Nov 2018 22:26:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1541975218; bh=Rx3BK9wNQ7WRAINZj8JQsEa0Nf7iAX5LUk5+nLvsV2Q=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=k4E8kkqxzMhiyVwSU4uXp/4Ifen24sbTPQ1ZhP3eXuUm99c0ADcSP9ih+YD8N2w47 fx3bz3kPWnPHRRug3FMGOtZUEd+1tIgqsyKweaG6Q+4Z3elHVnfaaKcwu/nDK9c83G 8qRoheWiB6IsqcIxB4xoVApxqMy3XXYmmT/PpZFQ= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Huacai Chen , Paul Burton , Ralf Baechle , James Hogan , linux-mips@linux-mips.org, Fuxin Zhang , Zhangjin Wu , Huacai Chen , Sasha Levin Subject: [PATCH 4.19 002/361] MIPS: VDSO: Reduce VDSO_RANDOMIZE_SIZE to 64MB for 64bit Date: Sun, 11 Nov 2018 14:15:49 -0800 Message-Id: <20181111221620.507857847@linuxfoundation.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20181111221619.915519183@linuxfoundation.org> References: <20181111221619.915519183@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Return-Path: X-Envelope-To: <"|/home/ecartis/ecartis -s linux-mips"> (uid 0) X-Orcpt: rfc822;linux-mips@linux-mips.org Original-Recipient: rfc822;linux-mips@linux-mips.org X-archive-position: 67239 X-ecartis-version: Ecartis v1.0.0 Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org X-original-sender: gregkh@linuxfoundation.org Precedence: bulk List-help: List-unsubscribe: List-software: Ecartis version 1.0.0 List-Id: linux-mips X-List-ID: linux-mips List-subscribe: List-owner: List-post: List-archive: X-list: linux-mips 4.19-stable review patch. If anyone has any objections, please let me know. ------------------ [ Upstream commit c61c7def1fa0a722610d89790e0255b74f3c07dd ] Commit ea7e0480a4b6 ("MIPS: VDSO: Always map near top of user memory") set VDSO_RANDOMIZE_SIZE to 256MB for 64bit kernel. But take a look at arch/mips/mm/mmap.c we can see that MIN_GAP is 128MB, which means the mmap_base may be at (user_address_top - 128MB). This make the stack be surrounded by mmaped areas, then stack expanding fails and causes a segmentation fault. Therefore, VDSO_RANDOMIZE_SIZE should be less than MIN_GAP and this patch reduce it to 64MB. Signed-off-by: Huacai Chen Signed-off-by: Paul Burton Fixes: ea7e0480a4b6 ("MIPS: VDSO: Always map near top of user memory") Patchwork: https://patchwork.linux-mips.org/patch/20910/ Cc: Ralf Baechle Cc: James Hogan Cc: linux-mips@linux-mips.org Cc: Fuxin Zhang Cc: Zhangjin Wu Cc: Huacai Chen Cc: stable@vger.kernel.org # 4.19 Signed-off-by: Sasha Levin --- arch/mips/include/asm/processor.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/mips/include/asm/processor.h b/arch/mips/include/asm/processor.h index 49d6046ca1d0..c373eb605040 100644 --- a/arch/mips/include/asm/processor.h +++ b/arch/mips/include/asm/processor.h @@ -81,7 +81,7 @@ extern unsigned int vced_count, vcei_count; #endif -#define VDSO_RANDOMIZE_SIZE (TASK_IS_32BIT_ADDR ? SZ_1M : SZ_256M) +#define VDSO_RANDOMIZE_SIZE (TASK_IS_32BIT_ADDR ? SZ_1M : SZ_64M) extern unsigned long mips_stack_top(void); #define STACK_TOP mips_stack_top() -- 2.17.1