From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751947AbeDMSXl (ORCPT ); Fri, 13 Apr 2018 14:23:41 -0400 Received: from mail-io0-f179.google.com ([209.85.223.179]:40397 "EHLO mail-io0-f179.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750955AbeDMSXj (ORCPT ); Fri, 13 Apr 2018 14:23:39 -0400 X-Google-Smtp-Source: AIpwx4/W29BA/hNzWkycExEBdZwgxordytKy5A2aZsOBkFg7bf8dnc3dUfu4AiwlpF80WT0k34MQ+9aWAeeh/lmlCtc= MIME-Version: 1.0 In-Reply-To: <20180413175407.GO16141@n2100.armlinux.org.uk> References: <20180412110314.GA28070@altlinux.org> <20180412121949.GD16141@n2100.armlinux.org.uk> <20180412124928.GA29458@altlinux.org> <20180412131404.GE16141@n2100.armlinux.org.uk> <20180412172051.GK16141@n2100.armlinux.org.uk> <20180413094211.GN16141@n2100.armlinux.org.uk> <20180413170827.GB16308@e103592.cambridge.arm.com> <20180413175407.GO16141@n2100.armlinux.org.uk> From: Linus Torvalds Date: Fri, 13 Apr 2018 11:23:36 -0700 X-Google-Sender-Auth: Ndjbw9Q8If2_uijRw1ulxJZXVN8 Message-ID: Subject: Re: sparc/ppc/arm compat siginfo ABI regressions: sending SIGFPE via kill() returns wrong values in si_pid and si_uid To: Russell King - ARM Linux Cc: Dave Martin , Linux Kernel Mailing List , "Dmitry V. Levin" , "Eric W. Biederman" , sparclinux , ppc-dev , linux-arm-kernel Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Apr 13, 2018 at 10:54 AM, Russell King - ARM Linux wrote: > > FPE_FLTINV means "floating point invalid operation". Does it really > cover the case where hardware has failed, or is it intended to cover > the case where userspace did something wrong and asked for an invalid > operation from the FP hardware? Note that the number of people who actually look at the si_code is approximately zero. But the ones that _do_ check the si_code are certainly not going to check it against a new code that they don't know about. I suspect that if you start searching for FLT_xyz occurrences in code, approximately 100% of them are from the kernel code that generates them, not from any actual users. So I'd be very surprised if you can find *anybody* who cares about that exact value (with the possible exceptions of test-suites). Sadly, google code-search is no more. It was useful for things like that. Linus From mboxrd@z Thu Jan 1 00:00:00 1970 From: Linus Torvalds Date: Fri, 13 Apr 2018 18:23:36 +0000 Subject: Re: sparc/ppc/arm compat siginfo ABI regressions: sending SIGFPE via kill() returns wrong values in Message-Id: List-Id: References: <20180412110314.GA28070@altlinux.org> <20180412121949.GD16141@n2100.armlinux.org.uk> <20180412124928.GA29458@altlinux.org> <20180412131404.GE16141@n2100.armlinux.org.uk> <20180412172051.GK16141@n2100.armlinux.org.uk> <20180413094211.GN16141@n2100.armlinux.org.uk> <20180413170827.GB16308@e103592.cambridge.arm.com> <20180413175407.GO16141@n2100.armlinux.org.uk> In-Reply-To: <20180413175407.GO16141@n2100.armlinux.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-arm-kernel@lists.infradead.org On Fri, Apr 13, 2018 at 10:54 AM, Russell King - ARM Linux wrote: > > FPE_FLTINV means "floating point invalid operation". Does it really > cover the case where hardware has failed, or is it intended to cover > the case where userspace did something wrong and asked for an invalid > operation from the FP hardware? Note that the number of people who actually look at the si_code is approximately zero. But the ones that _do_ check the si_code are certainly not going to check it against a new code that they don't know about. I suspect that if you start searching for FLT_xyz occurrences in code, approximately 100% of them are from the kernel code that generates them, not from any actual users. So I'd be very surprised if you can find *anybody* who cares about that exact value (with the possible exceptions of test-suites). Sadly, google code-search is no more. It was useful for things like that. Linus From mboxrd@z Thu Jan 1 00:00:00 1970 From: torvalds@linux-foundation.org (Linus Torvalds) Date: Fri, 13 Apr 2018 11:23:36 -0700 Subject: sparc/ppc/arm compat siginfo ABI regressions: sending SIGFPE via kill() returns wrong values in si_pid and si_uid In-Reply-To: <20180413175407.GO16141@n2100.armlinux.org.uk> References: <20180412110314.GA28070@altlinux.org> <20180412121949.GD16141@n2100.armlinux.org.uk> <20180412124928.GA29458@altlinux.org> <20180412131404.GE16141@n2100.armlinux.org.uk> <20180412172051.GK16141@n2100.armlinux.org.uk> <20180413094211.GN16141@n2100.armlinux.org.uk> <20180413170827.GB16308@e103592.cambridge.arm.com> <20180413175407.GO16141@n2100.armlinux.org.uk> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Fri, Apr 13, 2018 at 10:54 AM, Russell King - ARM Linux wrote: > > FPE_FLTINV means "floating point invalid operation". Does it really > cover the case where hardware has failed, or is it intended to cover > the case where userspace did something wrong and asked for an invalid > operation from the FP hardware? Note that the number of people who actually look at the si_code is approximately zero. But the ones that _do_ check the si_code are certainly not going to check it against a new code that they don't know about. I suspect that if you start searching for FLT_xyz occurrences in code, approximately 100% of them are from the kernel code that generates them, not from any actual users. So I'd be very surprised if you can find *anybody* who cares about that exact value (with the possible exceptions of test-suites). Sadly, google code-search is no more. It was useful for things like that. Linus