From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f199.google.com (mail-pf0-f199.google.com [209.85.192.199]) by kanga.kvack.org (Postfix) with ESMTP id 5F8FD6B0260 for ; Mon, 16 Jan 2017 07:36:39 -0500 (EST) Received: by mail-pf0-f199.google.com with SMTP id y143so248275266pfb.6 for ; Mon, 16 Jan 2017 04:36:39 -0800 (PST) Received: from EUR02-AM5-obe.outbound.protection.outlook.com (mail-eopbgr00106.outbound.protection.outlook.com. [40.107.0.106]) by mx.google.com with ESMTPS id i8si1695660pll.65.2017.01.16.04.36.38 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Mon, 16 Jan 2017 04:36:38 -0800 (PST) From: Dmitry Safonov Subject: [PATCHv2 1/5] x86/mm: split arch_mmap_rnd() on compat/native versions Date: Mon, 16 Jan 2017 15:33:06 +0300 Message-ID: <20170116123310.22697-2-dsafonov@virtuozzo.com> In-Reply-To: <20170116123310.22697-1-dsafonov@virtuozzo.com> References: <20170116123310.22697-1-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/include/asm/elf.h | 5 +++++ arch/x86/mm/mmap.c | 25 ++++++++++++++++--------- 2 files changed, 21 insertions(+), 9 deletions(-) diff --git a/arch/x86/include/asm/elf.h b/arch/x86/include/asm/elf.h index e7f155c3045e..ee1a87782b2c 100644 --- a/arch/x86/include/asm/elf.h +++ b/arch/x86/include/asm/elf.h @@ -349,6 +349,11 @@ static inline int mmap_is_ia32(void) test_thread_flag(TIF_ADDR32)); } +#ifdef CONFIG_COMPAT +extern unsigned long arch_compat_rnd(void); +#endif +extern unsigned long arch_native_rnd(void); + /* Do not change the values. See get_align_mask() */ enum align_flags { ALIGN_VA_32 = BIT(0), diff --git a/arch/x86/mm/mmap.c b/arch/x86/mm/mmap.c index d2dc0438d654..0b2007b08194 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 +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()) +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