From patchwork Fri Jan 17 22:44:34 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: DJ Delorie X-Patchwork-Id: 105036 Return-Path: X-Original-To: patchwork@sourceware.org Delivered-To: patchwork@sourceware.org Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id A4FED383EC60 for ; Fri, 17 Jan 2025 22:45:40 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org A4FED383EC60 Authentication-Results: sourceware.org; dkim=pass (1024-bit key, unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=hj0htaRZ X-Original-To: libc-alpha@sourceware.org Delivered-To: libc-alpha@sourceware.org Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by sourceware.org (Postfix) with ESMTP id 136DE383EC46 for ; Fri, 17 Jan 2025 22:44:45 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 136DE383EC46 Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=redhat.com ARC-Filter: OpenARC Filter v1.0.0 sourceware.org 136DE383EC46 Authentication-Results: server2.sourceware.org; arc=none smtp.remote-ip=170.10.133.124 ARC-Seal: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1737153885; cv=none; b=iNz2MUVuyEAgOiohTMWLO4LSkpzOo58uCr6Ryw8163x1Frfr5JMqZ+bACuSQVLLU+hyf3feHzp5E5y1ViAxYynT5JFl8fY6F8xajr894kW5Ou/Xf3avccI7btPv29fuGQ40yVUg6M7oVaGiGKeXph9SJM/jfVG/XImzvJ8IyYtc= ARC-Message-Signature: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1737153885; c=relaxed/simple; bh=UIiOunOPcVSBgRChCg+YYqJTwOZpgWe5NoPN93gxFlw=; h=DKIM-Signature:Date:Message-Id:From:To:Subject; b=Vg0b9afI1LTWO3C2KNp5VDPHRCvf+GOPLBPla5Pb5XUA+ba9U6T2aGXlYtUnsbqr53KiIMwnKccUuBgmx9O2mCjpaY2jfOWwIBW/UF5sV/63wiWSsXZDiEpxuFjoxRNtcKA14aFkaXnLl8WLq4xt0jfQu/UjZW5JkUmXFRAzl0k= ARC-Authentication-Results: i=1; server2.sourceware.org DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 136DE383EC46 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1737153884; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:content-type:content-type; bh=mMntrUdaGiT72fH0S7iFHNgTlS2ecFy64Fb3bEel1J4=; b=hj0htaRZgh1s0GdOmd0ZKiFMZTPMMmgyllnokOLnhmbcxSzmgQ/a2+SBr4vj4lsfv6Q+vq HQgfYz4mLuhkK7o/I43NtyCcmNQCFGRT3/ES5bHwsZRhIkDHvdDFlQ/ACiuNHClBV2IZsj 2RFmI22NGMvydcYDGgpSc48FRTUPTDo= Received: from mx-prod-mc-04.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-428-juD3g18VMrqjIsuA4sA4BQ-1; Fri, 17 Jan 2025 17:44:43 -0500 X-MC-Unique: juD3g18VMrqjIsuA4sA4BQ-1 X-Mimecast-MFC-AGG-ID: juD3g18VMrqjIsuA4sA4BQ Received: from mx-prod-int-02.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-02.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.15]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-04.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id DC13F1955DCC for ; Fri, 17 Jan 2025 22:44:41 +0000 (UTC) Received: from greed.delorie.com (unknown [10.22.88.18]) by mx-prod-int-02.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 877C3195608A for ; Fri, 17 Jan 2025 22:44:41 +0000 (UTC) Received: from greed.delorie.com.redhat.com (localhost [127.0.0.1]) by greed.delorie.com (8.16.1/8.16.1) with ESMTP id 50HMiYXD759241 for ; Fri, 17 Jan 2025 17:44:34 -0500 Date: Fri, 17 Jan 2025 17:44:34 -0500 Message-Id: From: DJ Delorie To: libc-alpha@sourceware.org Subject: manual: Update signal descriptions X-Scanned-By: MIMEDefang 3.0 on 10.30.177.15 X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: NoYJi53MxseDA0KSm1W1uxYOg5v2K2gxDItW6gW26-M_1737153882 X-Mimecast-Originator: redhat.com content-type: text/plain; charset="US-ASCII"; x-default=true X-Spam-Status: No, score=-11.6 required=5.0 tests=BAYES_00, DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, GIT_PATCH_0, RCVD_IN_DNSWL_NONE, RCVD_IN_MSPIKE_H2, SPF_HELO_NONE, SPF_NONE, TXREP autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org X-BeenThere: libc-alpha@sourceware.org X-Mailman-Version: 2.1.30 Precedence: list List-Id: Libc-alpha mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: libc-alpha-bounces~patchwork=sourceware.org@sourceware.org Based on auditing all the signals and source trees for Hurd and Linux... SIGSYS - This is not used for a bad system call (ENOSYS is used for that). This is used by SECCOMP and some cases where an invalid sub-function was requested. SIGSTKFLT - Note it used to be a coprocessor stack fault but is now obsolete and available for general user use. SIGLOST - Hurd only now; note that its original purpose as an NFS lock lost signal is obsolete. SIGPWR - Note this is for power lost *and* power restored, and is more a user-mode signal than a kernel-generated signal. diff --git a/manual/signal.texi b/manual/signal.texi index 2012980efe..9d7f8667e5 100644 --- a/manual/signal.texi +++ b/manual/signal.texi @@ -427,11 +427,21 @@ failure to properly emulate them. @deftypevr Macro int SIGSYS @standards{Unix, signal.h} -Bad system call; that is to say, the instruction to trap to the -operating system was executed, but the code number for the system call -to perform was invalid. +System call event. This signal may be generated by a valid system +call which requested an invalid sub-function, and also by the SECCOMP +filter when it filters a system call. + +If the system call itself is invalid or unsupported by the kernel, the +call will not raise this signal, but will return ENOSYS. +@end deftypevr + +@deftypevr Macro int SIGSTKFLT +Coprocessor stack fault. Obsolete, no longer generated. This signal +may be used by applications in much the way @code{SIGUSR1} and +@code{SIGUSR2} are. @end deftypevr + @node Termination Signals @subsection Termination Signals @cindex program termination signals @@ -752,12 +762,11 @@ that isn't connected. @xref{Sending Data}. @deftypevr Macro int SIGLOST @standards{GNU, signal.h} @cindex lost resource signal -Resource lost. This signal is generated when you have an advisory lock -on an NFS file, and the NFS server reboots and forgets about your lock. - -On @gnuhurdsystems{}, @code{SIGLOST} is generated when any server program -dies unexpectedly. It is usually fine to ignore the signal; whatever -call was made to the server that died just returns an error. +Resource lost. On @gnuhurdsystems{}, @code{SIGLOST} is generated when +any server program dies unexpectedly. It is usually fine to ignore +the signal; whatever call was made to the server that died just +returns an error. This signal's original purpose of signalling a lost +NFS lock is obsolete. @end deftypevr @deftypevr Macro int SIGXCPU @@ -817,6 +826,17 @@ to print some status information about the system and what the process is doing. Otherwise the default is to do nothing. @end deftypevr +@deftypevr Macro int SIGPWR +@cindex power event signal +Power lost or restored. On s390x Linux systems, this signal is +generated when a machine check warning is issued, and is sent to the +process designated to receive ctrl-alt-del notificiations. Otherwise, +it is up to userspace applications to generate this signal and manage +notifications as to the type of power event that happened. + +The default action is to terminate the process. +@end deftypevr + @node Signal Messages @subsection Signal Messages @cindex signal messages