From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (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 B00314E73C7 for ; Thu, 17 Sep 2026 16:01:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789660886; cv=none; b=YE2Fz/Dym47BUCcDMz+gwA+zqN8N01wPLiWi6vISrra4+szH6xsTtWI5cGyZQYMwzvu62OT6vSWDNwq0PGeF3pEwzBIF3NxdzBlrWdRB3W4oI0TfBKgSzRFu3wAaWVglBfPJ/FE5F6FDAvTTB7G/4n0l5HlRfhLkM3efYBqNodk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789660886; c=relaxed/simple; bh=Zl7XEDEzyGFjQ8NnXy+A8Z96YlY800L0M+pR+Mfnr7c=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=m506AS/DQmt3cF8ymQb1ENJKzvtOzOTKuJEnzsJ1G8Wwn9pkljRlZyzgVcDgVsBWILJH70iKP4alJyqvU/OedMrWi/2MuCStSlz7ZRCUX+txOl/WCj1AvqNOBQ9pxPP00rEED4ql8zopmMI9xCbY0Ju0XlUSzqrLHSU5EUWiHOs= 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=b3SGjnQa; arc=none smtp.client-ip=170.10.133.124 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="b3SGjnQa" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1789660883; 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=AxqSSuC6j5VlzBVquLjSQshKehqZsLbhTW+tuSGZqqk=; b=b3SGjnQaE/eT97eSayHaCdn57dIs0bi8f+fvnNROGasIFDfQn6rRKaRnxp/jfl9Hcx1M/i 1Qw9/SJc/JScj6kZULdHHfn0qbSEBInIYZVwd3nVNJKWakAkaA8DHk7Yq2nWKM3vIoUCIC N36B44e8BJ/aDXZ16Gr4MkQty5wGihg= 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-186-rncYLlFTPy2Lq00Orktw_w-1; Thu, 17 Sep 2026 12:01:19 -0400 X-MC-Unique: rncYLlFTPy2Lq00Orktw_w-1 X-Mimecast-MFC-AGG-ID: rncYLlFTPy2Lq00Orktw_w_1789660878 Received: from mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.111]) (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 DD834193E8AD; Thu, 17 Sep 2026 16:01:17 +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-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 860F018004D2; Thu, 17 Sep 2026 16:01:15 +0000 (UTC) From: Florian Weimer To: Stian Halseth Cc: brauner@kernel.org, viro@zeniv.linux.org.uk, jack@suse.cz, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, sparclinux@vger.kernel.org, schwab@suse.de Subject: Re: [PATCH 0/2] fs: honor FOP_UNSIGNED_OFFSET in llseek and positional I/O In-Reply-To: <20260917151614.376867-1-stian@itx.no> (Stian Halseth's message of "Thu, 17 Sep 2026 17:16:12 +0200") References: <20260917151614.376867-1-stian@itx.no> Date: Thu, 17 Sep 2026 18:01:13 +0200 Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.111 * Stian Halseth: > Tested on an UltraSPARC T4: pread(), preadv(), pwrite(), pwritev() and > lseek() on /proc/PID/mem at positions above 2^63 return the correct data > and offset; a negative position on a regular file or a pipe still fails > with EINVAL and position 0 on a pipe with ESPIPE, as before; and the > stock pldd(1) works again. On other architectures the change is a no-op > for every file without FOP_UNSIGNED_OFFSET, and userspace addresses > never set the top bit, so the new paths are only reachable by passing > a bogus position to /proc/PID/mem or /dev/mem, which then fails in the > driver instead of the wrapper. For lseek, aren't some file offsets (the top 4095 bytes or so just before 2**64) ambiguous as error indicators? You would have to use _llseek when accessing /proc/PID/mem. Thanks, Florian