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 45E37346771 for ; Sat, 4 Jul 2026 11:18:02 +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=1783163884; cv=none; b=bgZ9VHTdgYEfbWx1Uao7E0pK3XThygJ6Zs2DfyS/vHCZ7ay9q1bPn9+4tHY4pkpPyyNlhopMGESokd9lbUL+q5/0B3FAiWz2DWA6LviIG5DdGi9xytzL0FO5ozAfhZQDlaerAkskR4gVsI528bUCosFYi98OKJzTjoy/YUZZ69Y= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783163884; c=relaxed/simple; bh=F2NpG5CMHj6bG2FVoWKyHsWI+YaA/R8O0fwd1a47Wtw=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=DaWvZrzK7lKugLHHgknKZqL7utJwk/9eRtrliVkhpaQjXxeUNsbh8vHHrhLAPysBk6weSwH8C4zONllKXGFn4DjxGDeFyoDDI5cVMO+LWRBLWZlYkT488KNYiP0c9KW4/WD78v+ow3lXZqcfF/FqEXTwApPrFVfdFAm6MvEUzo0= 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=Lw2+iO20; 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="Lw2+iO20" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1783163882; 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=4N0SgbSPp6lDXmBX+y7Fr4Pnr9YnDdQicG29eLuDjv4=; b=Lw2+iO20h/yUizMcQn+LGAPl1d+G0dDfMvDUk0wQMhdDLQCfOtqllHAJtL8EleVfoINuWO Vwf26N0K5bbdnWykgbRhtZDbRmeE82j1jbXXXmG8KRpluXQzNBHyX8dSbbjzQQbRDyO6hC qp6NP5LXDT8AdN/oCSjsWiO3ffZuiFc= Received: from mx-prod-mc-05.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-455-5AJTf4ssPbOBSV61AQ_VpA-1; Sat, 04 Jul 2026 07:17:55 -0400 X-MC-Unique: 5AJTf4ssPbOBSV61AQ_VpA-1 X-Mimecast-MFC-AGG-ID: 5AJTf4ssPbOBSV61AQ_VpA_1783163874 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-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id A08AB1953977; Sat, 4 Jul 2026 11:17:53 +0000 (UTC) Received: from fedora (unknown [10.44.32.112]) by mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with SMTP id 353561800840; Sat, 4 Jul 2026 11:17:49 +0000 (UTC) Received: by fedora (nbSMTP-1.00) for uid 1000 oleg@redhat.com; Sat, 4 Jul 2026 13:17:53 +0200 (CEST) Date: Sat, 4 Jul 2026 13:17:48 +0200 From: Oleg Nesterov To: Renzo Davoli Cc: linux-kernel@vger.kernel.org, Andrew Morton , Shuah Khan , Alexey Gladkov , Eugene Syromyatnikov , Davide Berardi , strace-devel@lists.strace.io, "Dmitry V . Levin" Subject: Re: [PATCH 1/2] ptrace: PTRACE_SET_SYSCALL_INFO syscall skipping support Message-ID: References: <20260704083359.632410-1-renzo@cs.unibo.it> <20260704083359.632410-2-renzo@cs.unibo.it> Precedence: bulk X-Mailing-List: linux-kernel@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: <20260704083359.632410-2-renzo@cs.unibo.it> X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.111 On 07/04, Renzo Davoli wrote: > > - /* Changing the type of the system call stop is not supported yet. */ > - if (ptrace_get_syscall_info_op(child) != info.op) > - return -EINVAL; > + /* > + * Changing the type of the system call stop is not allowed, with the > + * following exception: > + * PTRACE_SYSCALL_INFO_SECCOMP or PTRACE_SYSCALL_INFO_ENTRY can be changed > + * to PTRACE_SYSCALL_INFO_EXIT to skip the system call > + */ > + > + if (ptrace_get_syscall_info_op(child) != info.op) { > + if (info.op != PTRACE_SYSCALL_INFO_EXIT) > + return -EINVAL; > + skip_syscall = true; > + } Ah... I forgot that ptrace_get_syscall_info_op() can return _NONE. We should not allow _NONE -> _EXIT transition. Oleg.