From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752798AbbJOMol (ORCPT ); Thu, 15 Oct 2015 08:44:41 -0400 Received: from mout.kundenserver.de ([212.227.126.187]:59066 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751514AbbJOMoj (ORCPT ); Thu, 15 Oct 2015 08:44:39 -0400 From: Arnd Bergmann To: Szabolcs Nagy Cc: Will Deacon , Manjeet Pawar , catalin.marinas@arm.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, linux-api@vger.kernel.org, pankaj.m@samsung.com, Akhilesh Kumar , Rohit Thapliyal Subject: Re: [PATCHv3] ARM64:Fix MINSIGSTKSZ and SIGSTKSZ Date: Thu, 15 Oct 2015 14:44:05 +0200 Message-ID: <6205380.pxTZSIhjca@wuerfel> User-Agent: KMail/4.11.5 (Linux/3.16.0-10-generic; KDE/4.11.5; x86_64; ; ) In-Reply-To: <20151015121241.GA26080@port70.net> References: <1444386580-10917-1-git-send-email-manjeet.p@samsung.com> <20151009103352.GK26278@arm.com> <20151015121241.GA26080@port70.net> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" X-Provags-ID: V03:K0:ZP7ph8/7xxVATItWaRpXn2OQCgx+w8wdbd8vPjwnVdQFDGuhLLz obkiXNBvy5l8lvXltzgyB27IEizzvIB3vA659icrHrivzo7yW4kI0lhTZs+equDQpeR0cYg t6teI+YUsQFuR+lkhOnm9aS9RA8a0i4PKMtygU3UtVJy25+tbHWmK6u3LdX8Ntwd/3uIi5I qYMVNISMRmUOfz4TqhQwQ== X-UI-Out-Filterresults: notjunk:1;V01:K0:+yH7fWwiisM=:7NKX7GENa6CSOpLsLFWcYq 5IWHejIfbExSsZdjqlhYt1VTUsZ4ImtexnWpRs5bvOCwoBAAmaogE7AEFpXsTcTj9NtS82UlL o1MTR8qDAd5vZlkMTDz3ESttW2w/rEksKT37bOhRqyaQuDAx9DmxR3yY9T1a0oUXHt73ZgI36 KwABwknaoOWVVeaq9q08gOAXydlRilpaUdsq5bJ/k93jMAL9A9fSO8xEFiqeDxyG2DuldG2p9 7dq0hys/lJ5s0KlQQm6dCOSlz8lSqWFfjXEm0spX5ezSS+oWbkAkb5thRgQcLyCs170J3LEkS KxvprOySX+hLEQVunypGw8PUIF7FlIkE4ovdftFnzjrO7mOpVLpiCbS2pnUStBdjZ/9Iw29Xp h1672BOikxX9uARw9Sp+CedIDknHT8VK6RfZu5dPUX8ZevlIjUSKy4+tgZkEwQyVynDhukWbG Mr+4HLYcnzDRkPSjRH5Qw+KBtiImTJWKRmokBowG3gKirQjueUfgLxBHytFy2GalESRAn8BWy FY2jVD+k3HWwRdTdDEcrjzzIQKc+8RZPvSCbVomOt+W7E3VfNkm3Mzym/res4cLACcDgUvzsd mi11W6mxrBolk2xmBvBi6bijEUn7GkrxAo1BPPkyBX4jSCoM6Sz40laZkfNCp5mnRJOFUJ0y0 NJR9KRJ4yNwptpC4o+rhU0fFcbjJuYlTVtXVRQrqETV3FzgvQyLh3PTcQBSwJgVXxNCPms/ru LzUqMUojLDdQVn9H Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thursday 15 October 2015 14:12:41 Szabolcs Nagy wrote: > * Will Deacon [2015-10-09 11:33:52 +0100]: > > > On Fri, Oct 09, 2015 at 03:59:40PM +0530, Manjeet Pawar wrote: > > > MINSIGSTKSZ and SIGSTKSZ for ARM64 are not correctly set in latest kernel. > > > This patch fixes this issue. > > > > > > This issue is reported in LTP (testcase: sigaltstack02.c). > > > Testcase failed when sigaltstack() called with stack size "MINSIGSTKSZ - 1" > > > Since in Glibc-2.22, MINSIGSTKSZ is set to 5120 but in kernel > > > it is set to 2048 so testcase gets failed. > > > > > > Testcase Output: > > > sigaltstack02 1 TPASS : stgaltstack() fails, Invalid Flag value,errno:22 > > > sigaltstack02 2 TFAIL : sigaltstack() returned 0, expected -1,errno:12 > > > > I'm still unable to reproduce this failure. Is this with defconfig? > > > > > Reported Issue in Glibc Bugzilla: > > > Bugfix in Glibc-2.22: [Bug 16850] > > > https://sourceware.org/bugzilla/show_bug.cgi?id=16850 > > > > > > Signed-off-by: Akhilesh Kumar > > > Signed-off-by: Manjeet Pawar > > > Signed-off-by: Rohit Thapliyal > > > --- > > > v1 -> Changes in uapi overall header > > > v2 -> Changes done in arm64 headers > > > v3 -> Changes done in both uapi & arm64 headers > > > > > > arch/arm64/include/uapi/asm/signal.h | 3 +++ > > > include/uapi/asm-generic/signal.h | 2 ++ > > > 2 files changed, 5 insertions(+) > > > > Acked-by: Will Deacon > > > > Arnd: are you planning to take this via asm-generic, or shall I queue it > > on the arm64 fixes branch? > > > > i just noticed this and wanted to note that an old > glibc can fail on a new kernel with this patch if > an application uses MINSIGSTKSZ altstack. Well worth noting, but I think we should consider this intentional: If an application built against an old glibc uses MINSIGSTKSZ, it current gets random data corruption of a segmentation fault that are both hard to track down, while a new kernel would result in more sensible error code that is easier to debug. Arnd