From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-oi0-f70.google.com (mail-oi0-f70.google.com [209.85.218.70]) by kanga.kvack.org (Postfix) with ESMTP id C848E6B0033 for ; Mon, 6 Feb 2017 11:47:00 -0500 (EST) Received: by mail-oi0-f70.google.com with SMTP id w144so83498101oiw.0 for ; Mon, 06 Feb 2017 08:47:00 -0800 (PST) Received: from EUR01-DB5-obe.outbound.protection.outlook.com (mail-db5eur01on0122.outbound.protection.outlook.com. [104.47.2.122]) by mx.google.com with ESMTPS id 73si495766otu.116.2017.02.06.08.46.59 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Mon, 06 Feb 2017 08:46:59 -0800 (PST) Subject: Re: [PATCHv4 0/5] Fix compatible mmap() return pointer over 4Gb References: <20170130120432.6716-1-dsafonov@virtuozzo.com> From: Dmitry Safonov Message-ID: Date: Mon, 6 Feb 2017 19:46:55 +0300 MIME-Version: 1.0 In-Reply-To: <20170130120432.6716-1-dsafonov@virtuozzo.com> Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: linux-kernel@vger.kernel.org, Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , Andy Lutomirski , Borislav Petkov Cc: 0x7f454c46@gmail.com, x86@kernel.org, linux-mm@kvack.org, Shuah Khan , linux-kselftest@vger.kernel.org On 01/30/2017 03:04 PM, Dmitry Safonov wrote: > Changes since v3: > - fixed usage of 64-bit random mask for 32-bit mm->mmap_compat_base, > during introducing mmap_compat{_legacy,}_base > > Changes since v2: > - don't distinguish native and compat tasks by TIF_ADDR32, > introduced mmap_compat{_legacy,}_base which allows to treat them > the same > - fixed kbuild errors > > Changes since v1: > - Recalculate mmap_base instead of using max possible virtual address > for compat/native syscall. That will make policy for allocation the > same in 32-bit binaries and in 32-bit syscalls in 64-bit binaries. > I need this because sys_mmap() in restored 32-bit process shouldn't > hit the stack area. > - Fixed mmap() with MAP_32BIT flag in the same usecases > - used in_compat_syscall() helper rather TS_COMPAT check (Andy noticed) > - introduced find_top() helper as suggested by Andy to simplify code > - fixed test error-handeling: it checked the result of sys_mmap() with > MMAP_FAILED, which is not correct, as it calls raw syscall - now > checks return value to be aligned to PAGE_SIZE. > > Description from v1 [2]: > > A fix for bug in mmap() that I referenced in [1]. > Also selftest for it. Gentle ping. Any thought on this? > > [1]: https://marc.info/?l=linux-kernel&m=148311451525315 > [2]: https://marc.info/?l=linux-kernel&m=148415888707662 > > Cc: Thomas Gleixner > Cc: Ingo Molnar > Cc: "H. Peter Anvin" > Cc: Andy Lutomirski > Cc: Borislav Petkov > Cc: x86@kernel.org > Cc: linux-mm@kvack.org > > Dmitry Safonov (5): > x86/mm: split arch_mmap_rnd() on compat/native versions > x86/mm: introduce mmap{,_legacy}_base > x86/mm: fix 32-bit mmap() for 64-bit ELF > x86/mm: check in_compat_syscall() instead TIF_ADDR32 for > mmap(MAP_32BIT) > selftests/x86: add test to check compat mmap() return addr > > arch/Kconfig | 7 + > arch/x86/Kconfig | 1 + > arch/x86/include/asm/elf.h | 4 +- > arch/x86/include/asm/processor.h | 3 +- > arch/x86/kernel/sys_x86_64.c | 32 +++- > arch/x86/mm/mmap.c | 89 +++++++---- > include/linux/mm_types.h | 5 + > tools/testing/selftests/x86/Makefile | 2 +- > tools/testing/selftests/x86/test_compat_mmap.c | 208 +++++++++++++++++++++++++ > 9 files changed, 311 insertions(+), 40 deletions(-) > create mode 100644 tools/testing/selftests/x86/test_compat_mmap.c > -- Dmitry -- 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