From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 143223955EA for ; Fri, 25 Sep 2026 19:55:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790366108; cv=none; b=j4Pr5AIvryGDINgID+wX4bn/Wlpx6mgfdBKnWYsMHBLsVFWU5xS7mva948bOBg8IslLTevchcak1FchvJjGL3hcd59EzE5deQypr7tZS+/9XSzBwfX1eqWIuRdxDW1D3QochrBZaI4CwveFu4OLqu5s4okDT8UrdpmexWTwLW7Q= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790366108; c=relaxed/simple; bh=VAYx2Qzp30BDLeHyjHKkGaMW63Lk2SDdL/cg4JsHDTc=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=oQCwdafsc3cQkztnoWAwjTwiUCoQbn2JK7tu0SK0iDqhK1zLEC427Lt/k/Z8xfOh658y8uvMgOXXI6Y+ziH0xwDINus1NnFWPepvhvxd3aJfOleITh9V85eJwWw07sYmYS0tLcJYsSnzHft/kzFNqOkL7Q9xxR+uS3eRV1pyXIw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=F7AJTCd1; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="F7AJTCd1" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1790366105; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=7R8g2g5io5Mc6RO3UGBOrZqqRoN8DE1RnEMk++o65BA=; b=F7AJTCd1Vl0dGN2GCSnlegoObUmgUQ4FsLZoG9JgaXRU9mo6II1N4VImJWR2L5fXLrtNvN XASgNsZognq3QhVLfXOnLzTbhXKBolmhY64HehbN0cEkTwugkI52sQ7hOzjcoine/GLybo 3SAOBznN+puzSVlKWaZ5CHJC633ddjA= Received: from mx-prod-mc-03.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-163-o8NgNQbtMVmEIv14y3B1kA-1; Fri, 25 Sep 2026 15:55:00 -0400 X-MC-Unique: o8NgNQbtMVmEIv14y3B1kA-1 X-Mimecast-MFC-AGG-ID: o8NgNQbtMVmEIv14y3B1kA_1790366099 Received: from mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.17]) (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-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id CE060195BDF1; Fri, 25 Sep 2026 19:54:58 +0000 (UTC) Received: from fweimer-oldenburg.csb.redhat.com (headnet05.pony-001.prod.iad2.dc.redhat.com [10.2.32.117]) by mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id D1F06195604D; Fri, 25 Sep 2026 19:54:56 +0000 (UTC) From: Florian Weimer To: Rich Felker Cc: Trevor Gross , Alejandro Colomar , linux-man@vger.kernel.org, libc-alpha@sourceware.org, musl@lists.openwall.com Subject: Re: [musl] [PATCH 2/2] man/man2/fork.2: Document glibc and musl relaxed fork->exec AS requirements In-Reply-To: <20260923234714.GB23438@brightrain.aerifal.cx> (Rich Felker's message of "Wed, 23 Sep 2026 19:47:14 -0400") References: <44aca4d502f6891df1587ed1c4c9b6a1@trevorgross.com> <20260923233818.25289-3-tg@trevorgross.com> <20260923234714.GB23438@brightrain.aerifal.cx> Date: Fri, 25 Sep 2026 21:54:54 +0200 Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Precedence: bulk X-Mailing-List: linux-man@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain X-Scanned-By: MIMEDefang 3.0 on 10.30.177.17 * Rich Felker: >> +On glibc and musl libc, this is relaxed; >> +it is safe to call non-async-signal-safe functions in the time between >> +.BR fork () >> +and >> +.BR exec () >> +\&. > While glibc has taken measures to make this mostly work, especially > malloc-after-fork, I don't think glibc has an intentional model for > ensuring that arbitrary libc functions work right in the child of a > multithreaded fork. Before accepting such a man page patch, we should > at least get an official position from glibc on whether they claim > this property or at least aim for it. Far from everything in glibc is fork-protected, so the statement is not true today as far as glibc is concerned. We try to maintain compatibility with existing application requirements, but the precise goals have not been written down. Thanks, Florian