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 03BE81AB53A for ; Wed, 28 Aug 2024 19:15:03 +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=1724872506; cv=none; b=CWstiq/gwyCU1RfzLnpudZmnnC7RocBPHjqpnyRNu9cphdvT4Z6brFwIBkegqDxc1NCzGktrcfqBE5iOe0P4wzUz9ewSC5zX0KclkWKsYAj5bcstK9WD3A7HCriJyRj9+Dk9w67o4ATBTLXIHwSuphxu7Up0rOjE9xwxWsVZYs8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724872506; c=relaxed/simple; bh=LbQZQ/vVDRJDmBbeVufxWeOTUlxLOSsNWpUr0EkBfCg=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=ow7YSblPE7AkXubbkTXVdNca+WDwE9Ufitk7P5bcLWTXbE83KfxB96fQAQeS2tFg50isnMU73eyonygeeuJULgUM8Gd0u/+W3I3hNOedu+/D6fsEWXnQksD6OgYRY5uTtnGjFsjJaBmC5mDSGcg1Jw92PZoPMzQSqi+izseY4Uk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none 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=VV2l2Z5Y; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none 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="VV2l2Z5Y" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1724872503; 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=u1UnXvwzw9mLNwzHOV1gSoNN+qWpQMXD0QiKEQ3cstw=; b=VV2l2Z5YjKAhvzNoYmqOIlIb0frXKjPa3STsYVjcIUjskwD1lpU484iiUrGEcc7iKMXcjQ slwfds/1LPsLA0mmXzMULFf1MYIz5XbjLGwJSFE8aJzp6X48W/zPX5EM49KD3z3GV+KYwu TzxCmyISAlwJWonB127bAjd2ax8XY+U= Received: from mx-prod-mc-02.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-358-XThQpjJ8PEibi0dnCnwzZg-1; Wed, 28 Aug 2024 15:14:59 -0400 X-MC-Unique: XThQpjJ8PEibi0dnCnwzZg-1 Received: from mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.12]) (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-02.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 59D6A1955D58; Wed, 28 Aug 2024 19:14:57 +0000 (UTC) Received: from dhcp-27-174.brq.redhat.com (unknown [10.45.224.93]) by mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with SMTP id 449AE1955BF1; Wed, 28 Aug 2024 19:14:53 +0000 (UTC) Received: by dhcp-27-174.brq.redhat.com (nbSMTP-1.00) for uid 1000 oleg@redhat.com; Wed, 28 Aug 2024 21:14:49 +0200 (CEST) Date: Wed, 28 Aug 2024 21:14:45 +0200 From: Oleg Nesterov To: Alexey Gladkov Cc: linux-kernel@vger.kernel.org, bpf@vger.kernel.org, linux-kbuild@vger.kernel.org, Masahiro Yamada , Alexei Starovoitov , Andrii Nakryiko , Daniel Borkmann Subject: Re: [PATCH v3] bpf: Remove custom build rule Message-ID: <20240828191444.GA3806@redhat.com> References: <20240828181028.4166334-1-legion@kernel.org> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240828181028.4166334-1-legion@kernel.org> User-Agent: Mutt/1.5.24 (2015-08-30) X-Scanned-By: MIMEDefang 3.0 on 10.30.177.12 I know nothing about Kbuild, I can only confirm that this patch fixes the problem I encountered in practice. On 08/28, Alexey Gladkov wrote: > > $ touch kernel/bpf/core.c > $ make C=2 CHECK=true kernel/bpf/core.o > > Outputs: > > CHECK scripts/mod/empty.c > CALL scripts/checksyscalls.sh > DESCEND objtool > INSTALL libsubcmd_headers > CC kernel/bpf/core.o > > As can be seen the compilation is done, but CHECK is not executed. And after that $ make C=2 CHECK=true kernel/bpf/core.o CHECK scripts/mod/empty.c CALL scripts/checksyscalls.sh DESCEND objtool INSTALL libsubcmd_headers CHECK is also not executed. compare with, for example, $ touch kernel/trace/trace.c $ make C=2 CHECK=true kernel/trace/trace.o CHECK scripts/mod/empty.c CALL scripts/checksyscalls.sh DESCEND objtool INSTALL libsubcmd_headers CC kernel/trace/trace.o CHECK kernel/trace/trace.c $ make C=2 CHECK=true kernel/trace/trace.o CHECK scripts/mod/empty.c CALL scripts/checksyscalls.sh DESCEND objtool INSTALL libsubcmd_headers CHECK kernel/trace/trace.c Tested-by: Oleg Nesterov