From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ot0-f200.google.com (mail-ot0-f200.google.com [74.125.82.200]) by kanga.kvack.org (Postfix) with ESMTP id 950806B025E for ; Mon, 30 Jan 2017 07:04:54 -0500 (EST) Received: by mail-ot0-f200.google.com with SMTP id g13so287367080otd.5 for ; Mon, 30 Jan 2017 04:04:54 -0800 (PST) Received: from EUR03-DB5-obe.outbound.protection.outlook.com (mail-eopbgr40109.outbound.protection.outlook.com. [40.107.4.109]) by mx.google.com with ESMTPS id r188si5335530oib.142.2017.01.30.04.04.53 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Mon, 30 Jan 2017 04:04:53 -0800 (PST) From: Dmitry Safonov Subject: [PATCHv4 1/5] x86/mm: split arch_mmap_rnd() on compat/native versions Date: Mon, 30 Jan 2017 15:04:28 +0300 Message-ID: <20170130120432.6716-2-dsafonov@virtuozzo.com> In-Reply-To: <20170130120432.6716-1-dsafonov@virtuozzo.com> References: <20170130120432.6716-1-dsafonov@virtuozzo.com> MIME-Version: 1.0 Content-Type: text/plain Sender: owner-linux-mm@kvack.org List-ID: To: linux-kernel@vger.kernel.org Cc: 0x7f454c46@gmail.com, Dmitry Safonov , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , Andy Lutomirski , Borislav Petkov , x86@kernel.org, linux-mm@kvack.org I need those arch_{native,compat}_rnd() to compute separately random factor for mmap() in compat syscalls for 64-bit binaries and vice-versa for native syscall in 32-bit compat binaries. They will be used in the following patches. Signed-off-by: Dmitry Safonov --- arch/x86/mm/mmap.c | 25 ++++++++++++++++--------- 1 file changed, 16 insertions(+), 9 deletions(-) diff --git a/arch/x86/mm/mmap.c b/arch/x86/mm/mmap.c index d2dc0438d654..42063e787717 100644 --- a/arch/x86/mm/mmap.c +++ b/arch/x86/mm/mmap.c @@ -65,20 +65,27 @@ static int mmap_is_legacy(void) return sysctl_legacy_va_layout; } -unsigned long arch_mmap_rnd(void) +#ifdef CONFIG_COMPAT +static unsigned long arch_compat_rnd(void) { - unsigned long rnd; + return (get_random_long() & ((1UL << mmap_rnd_compat_bits) - 1)) + << PAGE_SHIFT; +} +#endif - if (mmap_is_ia32()) +static unsigned long arch_native_rnd(void) +{ + return (get_random_long() & ((1UL << mmap_rnd_bits) - 1)) << PAGE_SHIFT; +} + +unsigned long arch_mmap_rnd(void) +{ #ifdef CONFIG_COMPAT - rnd = get_random_long() & ((1UL << mmap_rnd_compat_bits) - 1); -#else - rnd = get_random_long() & ((1UL << mmap_rnd_bits) - 1); + if (mmap_is_ia32()) + return arch_compat_rnd(); #endif - else - rnd = get_random_long() & ((1UL << mmap_rnd_bits) - 1); - return rnd << PAGE_SHIFT; + return arch_native_rnd(); } static unsigned long mmap_base(unsigned long rnd) -- 2.11.0 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org