From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 5462 invoked by alias); 11 Apr 2003 19:43:47 -0000 Mailing-List: contact libc-hacker-help@sources.redhat.com; run by ezmlm Precedence: bulk List-Subscribe: List-Archive: List-Post: List-Help: , Sender: libc-hacker-owner@sources.redhat.com Received: (qmail 5446 invoked from network); 11 Apr 2003 19:43:47 -0000 Received: from unknown (HELO e6.ny.us.ibm.com) (32.97.182.106) by sources.redhat.com with SMTP; 11 Apr 2003 19:43:47 -0000 Received: from northrelay01.pok.ibm.com (northrelay01.pok.ibm.com [9.56.224.149]) by e6.ny.us.ibm.com (8.12.9/8.12.2) with ESMTP id h3BJhk9d119414 for ; Fri, 11 Apr 2003 15:43:46 -0400 Received: from d27ml105.rchland.ibm.com (d01av03.pok.ibm.com [9.56.224.217]) by northrelay01.pok.ibm.com (8.12.8/NCO/VER6.5) with ESMTP id h3BJhgdu102894 for ; Fri, 11 Apr 2003 15:43:42 -0400 Subject: Re: [PATCH] Fix ppc64 test-fenv To: Jakub Jelinek Cc: Ulrich Drepper , GNU libc hacker , "Peter Bergner" Message-ID: From: "Steve Munroe" Date: Fri, 11 Apr 2003 19:43:00 -0000 MIME-Version: 1.0 Content-type: text/plain; charset=us-ascii X-SW-Source: 2003-04/txt/msg00034.txt.bz2 Jakub Jelinek writes > If the official kernel source contained a buggy prctl so that it is unsafe > to try prctl on kernels between 2.4.19 and 2.4.21, then linux/configure.in > needs to be changed for 2.4.21 the minimum required kernel version. > Really, having glibc built without --enable-kernel switch just not work > forever no matter what kernel it is running on is a bad idea. prctl is not buggy. It either supports the feature or not. Your patch is OK and should be integrated. It just does not correct the fundamental problem. The 2.4.20 kernel does not initialize FE0|1 correctly for new processes lwp's. This disables FPE raise, until/unless this state is explicitely changed later. The original fe_nomask.c hack (inherited from PPC32) to set FE0|1 was only partially reliable on uniprocessors and unreliable on SMPs. That is why we added the PR_SET_FPEXC feature. I feel that fe_nomask should either work correctly or return ENOSYS. Your patch prevents test-fenv from seeing a EINVAL. The fix (both correct initial state for FE0|1 and the PR_SET_FPEXC feature are in Marcelo's 2.4.21.pre tree and will be released with 2.4.21.