From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5D140C54F32 for ; Wed, 28 Aug 2024 12:26:29 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id C91586B0089; Wed, 28 Aug 2024 08:26:28 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id C40C46B008A; Wed, 28 Aug 2024 08:26:28 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id AE1106B008C; Wed, 28 Aug 2024 08:26:28 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id 8F88C6B0089 for ; Wed, 28 Aug 2024 08:26:28 -0400 (EDT) Received: from smtpin17.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id 17C64160CC9 for ; Wed, 28 Aug 2024 12:26:28 +0000 (UTC) X-FDA: 82501577256.17.4CFED68 Received: from nyc.source.kernel.org (nyc.source.kernel.org [147.75.193.91]) by imf20.hostedemail.com (Postfix) with ESMTP id EAB331C0016 for ; Wed, 28 Aug 2024 12:26:25 +0000 (UTC) Authentication-Results: imf20.hostedemail.com; dkim=pass header.d=zx2c4.com header.s=20210105 header.b=pZhFFwvf; dmarc=pass (policy=quarantine) header.from=zx2c4.com; spf=pass (imf20.hostedemail.com: domain of "SRS0=8W/7=P3=zx2c4.com=Jason@kernel.org" designates 147.75.193.91 as permitted sender) smtp.mailfrom="SRS0=8W/7=P3=zx2c4.com=Jason@kernel.org" ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1724847921; a=rsa-sha256; cv=none; b=GxV1WzmfOD12rbP6KgLvksrln1BvEKN4Rd9C0r97e3aqv1V4fNkwoHpV6e1AXcGxogTkQu L36Ff+0Q+68yZs6O5Tp9hwEanMz/8HTOdde/QlImB9AHae4uP1gTRZFkylV8KvzgDTnJJQ /FZCG3RsutjNK9WUP4L/ToALZF8rC3A= ARC-Authentication-Results: i=1; imf20.hostedemail.com; dkim=pass header.d=zx2c4.com header.s=20210105 header.b=pZhFFwvf; dmarc=pass (policy=quarantine) header.from=zx2c4.com; spf=pass (imf20.hostedemail.com: domain of "SRS0=8W/7=P3=zx2c4.com=Jason@kernel.org" designates 147.75.193.91 as permitted sender) smtp.mailfrom="SRS0=8W/7=P3=zx2c4.com=Jason@kernel.org" ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1724847921; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=uEFEGqQJQMz8Ub4wy+aep50eWmgdp8pcSL8AmUjJ5J8=; b=pn0XRrs1e3uia2UorxQSRRTeoMZde+JkElolyCyw71R9dvqaU2HPhJqepV0svN4CUaYdI+ +RS9Q7PeaGd+PfUGOVUc697z8KVlLIM4lZRF2t4LyjrbaxzSL85AjOyEt1icFDjoaJuVnl KoC/z07QyhifY+01XZadI0zVnoYgAV8= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by nyc.source.kernel.org (Postfix) with ESMTP id 335B6A401EB for ; Wed, 28 Aug 2024 12:26:18 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6A99AC98EDB for ; Wed, 28 Aug 2024 12:26:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zx2c4.com; s=20210105; t=1724847983; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=uEFEGqQJQMz8Ub4wy+aep50eWmgdp8pcSL8AmUjJ5J8=; b=pZhFFwvf2+rUCk0mnu74yzuq8D0OlV5RRX3O/pUcL2EJirk1lWLjJ7T+VmJhAB+Nwuqruo 5w43+j7738kAhUtF/Op+T7PkY55MvhYmMEm2AulNbOZOm5YzBQVDPiZl6Xd1e0lo4jpoA9 0Tg6/x3YqzwUs/XLZ+j/psnPUsH+3wQ= Received: by mail.zx2c4.com (ZX2C4 Mail Server) with ESMTPSA id d52a4da1 (TLSv1.3:TLS_AES_256_GCM_SHA384:256:NO) for ; Wed, 28 Aug 2024 12:26:22 +0000 (UTC) Received: by mail-oa1-f50.google.com with SMTP id 586e51a60fabf-27018df4ff3so4910520fac.1 for ; Wed, 28 Aug 2024 05:26:21 -0700 (PDT) X-Forwarded-Encrypted: i=1; AJvYcCWVBjqNRquQBXIERcLTS1nXUuRDC2MCJTYzwXuzISXvj/Xzsob0OlA4yZCk4gllXIoq6aR3AEUu8w==@kvack.org X-Gm-Message-State: AOJu0YwAPS4eePjXCGi5a4MZv2/yrpoIc39AMF7KSRwbkMU2qym8yLqI J9Jz6wCkDHQ9M2NZMlnAi6SjyaYj5M5qDKy8SOMKVLTW36B1BGqK/wJhBtF2LdoyPxAcCSWGdKk h89tFgjMFIOlx907Ox84mKw0wy9I= X-Google-Smtp-Source: AGHT+IHXO1KZEIb1pBgGn7dKx8LC6G7ifrWZYsusE/oKQVZmO1hrOeMVz7hy7j/rnnH9GmqVmjbXApoOhTEeHD761oc= X-Received: by 2002:a05:6870:1713:b0:25e:bd9d:b1cb with SMTP id 586e51a60fabf-273e667ed95mr19307401fac.40.1724847980462; Wed, 28 Aug 2024 05:26:20 -0700 (PDT) MIME-Version: 1.0 References: <5deb67090b214f0e6eae96b7c406546d1a16f89b.1724309198.git.christophe.leroy@csgroup.eu> <20240827180819.GB2049@sol.localdomain> <20240827225330.GC29862@gate.crashing.org> In-Reply-To: From: "Jason A. Donenfeld" Date: Wed, 28 Aug 2024 14:26:08 +0200 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH v2 05/17] vdso: Avoid call to memset() by getrandom To: Arnd Bergmann Cc: Segher Boessenkool , Eric Biggers , Christophe Leroy , Michael Ellerman , Nicholas Piggin , Naveen N Rao , Andy Lutomirski , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , "Theodore Ts'o" , Andrew Morton , Steven Rostedt , Masami Hiramatsu , Mathieu Desnoyers , Vincenzo Frascino , shuah , linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, Linux-Arch , linux-mm@kvack.org, linux-trace-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Rspamd-Queue-Id: EAB331C0016 X-Rspam-User: X-Rspamd-Server: rspam05 X-Stat-Signature: bqtygeihtfstnisithk71soho73nfa9d X-HE-Tag: 1724847985-500108 X-HE-Meta: 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 Pjc5ijRR BRnT1mHSUwYV/KnaLq07yxvxn4BbQGE5N0JkPnElEjTBkNqZnbOD51E1dONFOC7EzxKVnf2Ez6z1c4OMjITtMPqsRgqm8ur5vxyNIGzzl2MIadesD50B+nVyuDt7cL3blBmbYQzplFdXAZQEMJewBkaqeUc4BQavB7fH4vJ+8b43qi33E0gb/ty/Zmc4EKYQ89TxMVPmpq4ErcYRl+PlCZp5KFNxzH+P3hlm0GPjY3tFtcjpt3xIJlhVeMY/hQhh+T4t33dFhHzXJ8JtTPXULHsneYuUsdw9KWzCi4NJEd598BaLkD2L3kzUWlZtIZZFGtkN9CmSBsn3E17j+qgye5A/y8RkzTBwE+QxEagzgeAczHwO8dZz3VlwUMAOGuXTLNUhQz5t8yqS43Xbv6t2Mir7cdBdomANE0zmWMYqQaxCDpGLHCYWt9FYNSYn987SWG9s5gJt7dbzFo9edQEwnZJyrtWdRNJooLr0EDSD6GI6vj9g= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Wed, Aug 28, 2024 at 2:24=E2=80=AFPM Arnd Bergmann wrote= : > > On Wed, Aug 28, 2024, at 11:18, Jason A. Donenfeld wrote: > > On Tue, Aug 27, 2024 at 05:53:30PM -0500, Segher Boessenkool wrote: > >> On Tue, Aug 27, 2024 at 11:08:19AM -0700, Eric Biggers wrote: > >> > > >> > Is there a compiler flag that could be used to disable the generatio= n of calls > >> > to memset? > >> > >> -fno-tree-loop-distribute-patterns . But, as always, read up on it, s= ee > >> what it actually does (and how it avoids your problem, and mostly: lea= rn > >> what the actual problem *was*!) > > > > This might help with various loops, but it doesn't help with the matter > > that this patch fixes, which is struct initialization. I just tried it > > with the arm64 patch to no avail. > > Maybe -ffreestanding can help here? That should cause the vdso to be buil= t > with the assumption that there is no libc, so it would neither add nor > remove standard library calls. Not sure if that causes other problems, > e.g. if the calling conventions are different. >From https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D90701: | You need -ffreestanding but that is documented to emit memset and memcpy still.