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 625C622FDFF for ; Mon, 19 Jan 2026 12:33:05 +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=1768825986; cv=none; b=qXoZWeYkAmPXdMpkX5bXSSUXFRwkKaBISfiveKjMu/KWy4tP+FRBsxLGvxUbzBvCwIZbmA3AvsntGWAYNWUr0mCULv0dJNJLje8jjPe1/Kos6wd5lwpC0mbcUGbVZ7W+XifsCqlF1fUbCMpVYOKBZZ03VPHdhwe6m7WnIBBvRs0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768825986; c=relaxed/simple; bh=i3hsGS0pUj7EGcq+Tc3/dOUXLo7FKE1blYiehdBzORI=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: In-Reply-To:Content-Type:Content-Disposition; b=Hb1cfIQ6lZFEwso4rbFZ+cY6VsItdRQKeFy7Y/vmXtWRxc/7POIkomhFcBJ5oWzk0zTwPxn6GkpC3I54hoY/Q0lIWdkkmCeYCW8TS8XH94GfWMwy1VmFCUjWK3F8wT6A4Kqr9+pEKYnH2G+O3ff1i3e2vMOFVeMdYBR2mQQwkE8= 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=IZhHp3xt; 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="IZhHp3xt" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1768825984; 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=4Sh/WGXdrqYgx/1SqZs5wNEd0zGF+41SfbuHpfPFZi0=; b=IZhHp3xtQhML3RWKGxVhygIiWnF3+Q6seNHUNQjGGN+xJAZolhZnsOuzDYLGihbxBPBRsH G0eJqfiO6xvzuNt3ycf71Neu9tcT29S+KvTUOvbkPLvdbS68iuwSwC2tadW4+kkrwKOHIl Vjsmanum850Bu4WiBunidZt3dNeToAc= 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-383-V1Es3rz6PPG-zOODFADzkw-1; Mon, 19 Jan 2026 07:33:01 -0500 X-MC-Unique: V1Es3rz6PPG-zOODFADzkw-1 X-Mimecast-MFC-AGG-ID: V1Es3rz6PPG-zOODFADzkw_1768825980 Received: from mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.4]) (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 3899B1956058; Mon, 19 Jan 2026 12:33:00 +0000 (UTC) Received: from fedora (unknown [10.44.33.237]) by mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with SMTP id 65C1430001A7; Mon, 19 Jan 2026 12:32:58 +0000 (UTC) Received: by fedora (nbSMTP-1.00) for uid 1000 oleg@redhat.com; Mon, 19 Jan 2026 13:32:59 +0100 (CET) Date: Mon, 19 Jan 2026 13:32:56 +0100 From: Oleg Nesterov To: Chris Li Cc: Luc Van Oostenryck , Alexey Gladkov , linux-sparse@vger.kernel.org Subject: Re: [PATCH] sparse/pre-process: introduce "dissect_mode" option to fix dissect/semind Message-ID: References: Precedence: bulk X-Mailing-List: linux-sparse@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 In-Reply-To: X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.4 X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: 2RxLObLCwTiIxr_rHDtmPPrzVZiNW5N8JvsqrP6Vw8Q_1768825980 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit On 01/18, Chris Li wrote: > > On Sat, Jan 17, 2026 at 8:32 AM Oleg Nesterov wrote: > > > > On a 2nd thought... > > > > Unlike other warnings, this one (sizeof-void.c:20:27) refers to the > > inner "sizeof *ptr", so I think that this patch fixes the reported > > position. So yes, I think we don't care even if the new column == 27 > > differs from other warnings. > > > > What do you think? > > I would just update the checker to have the new expected value > matching what new pos so validation can pass without errors. Yes, this is what I did. See [PATCH] sparse/pre-process: don't update next->pos in collect_arg() https://lore.kernel.org/all/aWz0V_zQ47afKFJy@redhat.com/ I was confused and tried to confuse you... let me explain. With this patch ./sparse -Wpointer-arith validation/sizeof-void.c outputs validation/sizeof-void.c:16:14: warning: expression using sizeof(void) validation/sizeof-void.c:17:14: warning: expression using sizeof(void) validation/sizeof-void.c:18:14: warning: expression using sizeof(void) validation/sizeof-void.c:19:14: warning: expression using sizeof(void) validation/sizeof-void.c:20:27: warning: expression using sizeof(void) // changed validation/sizeof-void.c:21:14: warning: expression using sizeof(void) validation/sizeof-void.c:22:14: warning: expression using sizeof(void) validation/sizeof-void.c:23:14: warning: expression using sizeof(void) and somehow I wrongly came to conlusion that my patch is incomplete or inconsistent because it only corrects the warning's position for the line 20. Now that I actually looked at validation/sizeof-void.c, I see that the code at line 20 s += is_constexpr(sizeof *ptr); differs in that it is the inner "sizeof *ptr" which triggers the warning, so I think the patch is fine. Thank you, Oleg.