From mboxrd@z Thu Jan 1 00:00:00 1970 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: base64 Subject: usbip: vhci_hcd: Mark expected switch fall-through From: Greg Kroah-Hartman Message-Id: <20190430154444.GA4224@kroah.com> Date: Tue, 30 Apr 2019 17:44:44 +0200 To: "Gustavo A. R. Silva" Cc: David Laight , Valentina Manea , Shuah Khan , "linux-usb@vger.kernel.org" , "linux-kernel@vger.kernel.org" , Kees Cook List-ID: T24gTW9uLCBBcHIgMjksIDIwMTkgYXQgMTA6MDU6NTFBTSAtMDUwMCwgR3VzdGF2byBBLiBSLiBT aWx2YSB3cm90ZToKPiAKPiAKPiBPbiA0LzI5LzE5IDk6NDQgQU0sIERhdmlkIExhaWdodCB3cm90 ZToKPiA+IEZyb206IEd1c3Rhdm8gQS4gUi4gU2lsdmEKPiA+PiBTZW50OiAyOSBBcHJpbCAyMDE5 IDE1OjQwCj4gPj4gSW4gcHJlcGFyYXRpb24gdG8gZW5hYmxpbmcgLVdpbXBsaWNpdC1mYWxsdGhy b3VnaCwgbWFyayBzd2l0Y2gKPiA+PiBjYXNlcyB3aGVyZSB3ZSBhcmUgZXhwZWN0aW5nIHRvIGZh bGwgdGhyb3VnaC4KPiA+IC4uLgo+ID4+IGRpZmYgLS1naXQgYS9kcml2ZXJzL3VzYi91c2JpcC92 aGNpX2hjZC5jIGIvZHJpdmVycy91c2IvdXNiaXAvdmhjaV9oY2QuYwo+ID4+IGluZGV4IDY2N2Q5 YzBlYzkwNS4uMDAwYWI3MjI1NzE3IDEwMDY0NAo+ID4+IC0tLSBhL2RyaXZlcnMvdXNiL3VzYmlw L3ZoY2lfaGNkLmMKPiA+PiArKysgYi9kcml2ZXJzL3VzYi91c2JpcC92aGNpX2hjZC5jCj4gPj4g QEAgLTUwOCw2ICs1MDgsNyBAQCBzdGF0aWMgaW50IHZoY2lfaHViX2NvbnRyb2woc3RydWN0IHVz Yl9oY2QgKmhjZCwgdTE2IHR5cGVSZXEsIHUxNiB3VmFsdWUsCj4gPj4gIAkJY2FzZSBVU0JfUE9S VF9GRUFUX1UxX1RJTUVPVVQ6Cj4gPj4gIAkJCXVzYmlwX2RiZ192aGNpX3JoKAo+ID4+ICAJCQkJ IiBTZXRQb3J0RmVhdHVyZTogVVNCX1BPUlRfRkVBVF9VMV9USU1FT1VUXG4iKTsKPiA+PiArCQkJ LyogRmFsbCB0aHJvdWdoICovCj4gPj4gIAkJY2FzZSBVU0JfUE9SVF9GRUFUX1UyX1RJTUVPVVQ6 Cj4gPj4gIAkJCXVzYmlwX2RiZ192aGNpX3JoKAo+ID4+ICAJCQkJIiBTZXRQb3J0RmVhdHVyZTog VVNCX1BPUlRfRkVBVF9VMl9USU1FT1VUXG4iKTsKPiA+IAo+ID4gVGhhdCBkb2Vzbid0IGxvb2sg cmlnaHQsIGJvdGggZGVidWcgbWVzc2FnZXMgc2VlbSB0byBnZXQgcHJpbnRlZC4KPiA+IAo+IAo+ IEF0IGZpcnN0IHNpZ2h0LCBJIHRob3VnaHQgdGhlIHNhbWUgd2F5LCB0aGVuIEkgdG9vayBhIGxv b2sgaW50bwo+IGNvbW1pdDoKPiAKPiAxYzlkZTViZjQyODYxMjQ1ODQyNzk0M2I3MjRiZWE1MWFi ZGU1MjBhCj4gCj4gYW5kIG5vdGljZWQgdGhhdCB0aGUgb3JpZ2luYWwgZGV2ZWxvcGVyIHByb3Bl cmx5IGFkZGVkIGZhbGwtdGhyb3VnaAo+IGNvbW1lbnRzIGluIG90aGVyIHBsYWNlcyBpbiB0aGUg c2FtZSBzd2l0Y2goKSBjb2RlLCB0aGF0IGdhdmUgbWUgdGhlCj4gaW1wcmVzc2lvbiBoZSBrbmV3 IHdoYXQgaGUgd2FzIGRvaW5nOyB0aGVuIEkgbm90aWNlZCB0aGUgZm9sbG93aW5nCj4gZXJyb3Ig bWVzc2FnZSBpbiBjYXNlIFVTQl9QT1JUX0ZFQVRfVTJfVElNRU9VVDoKPiAKPiAJaWYgKGhjZC0+ c3BlZWQgIT0gSENEX1VTQjMpIHsKPiAJCXByX2VycigiVVNCX1BPUlRfRkVBVF9VMS8yX1RJTUVP VVQgcmVxIG5vdCAiCj4gCQkgICAgICAgInN1cHBvcnRlZCBmb3IgVVNCIDIuMCByb290aHViXG4i KTsKPiAJCWdvdG8gZXJyb3I7Cj4gCX0KPiAKPiB0aGlzIGVycm9yIG1lc3NhZ2UgaXMgd2hhdCBt YWtlcyBtZSB0aGluayB0aGUgZmFsbC10aHJvdWdoIGlzCj4gaW50ZW50aW9uYWw7IG90aGVyd2lz ZSBJIHRoaW5rIGl0IHdvdWxkIGxvb2sgbGlrZSB0aGlzIGluc3RlYWQ6Cj4gCj4gCWlmIChoY2Qt PnNwZWVkICE9IEhDRF9VU0IzKSB7Cj4gCQlwcl9lcnIoIlVTQl9QT1JUX0ZFQVRfVTJfVElNRU9V VCByZXEgbm90ICIKPiAJCSAgICAgICAic3VwcG9ydGVkIGZvciBVU0IgMi4wIHJvb3RodWJcbiIp Owo+IAkJZ290byBlcnJvcjsKPiAJfQoKSSB0aGluayB5b3UgYXJlIHJpZ2h0LCB0aGF0J3MgaG9y cmlkLCBidXQgY29ycmVjdCA6KAoKV2lsbCBnbyBxdWV1ZSB0aGlzIHVwLCB0aGFua3MuCgpncmVn IGstaAo= 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 X-Spam-Level: X-Spam-Status: No, score=-5.4 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_PASS, T_DKIMWL_WL_HIGH,USER_AGENT_MUTT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BFA71C43219 for ; Tue, 30 Apr 2019 15:44:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8EA292173E for ; Tue, 30 Apr 2019 15:44:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1556639088; bh=rrcsqZYKEnEJrIdXuKxxMtHlVHbhSKZ1Kz45Y55dS2U=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=wacgaUP7rJQTj7b6pwq/i7pv2uQKODJk9/CPajB13trc+/vx2Jqa0tvRwFXZnPT3Y wUYx+sMadLBer50k3u+yW+/9q7foh0hJv6pInQfJIr3rEfRahuJtFxoRuYqBOT6AKp 73A/7aIkQPgGqwdJJ6VX1efmZRIS192qZTQTolCk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725950AbfD3Pos (ORCPT ); Tue, 30 Apr 2019 11:44:48 -0400 Received: from mail.kernel.org ([198.145.29.99]:57898 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725906AbfD3Por (ORCPT ); Tue, 30 Apr 2019 11:44:47 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id CA30C21734; Tue, 30 Apr 2019 15:44:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1556639087; bh=rrcsqZYKEnEJrIdXuKxxMtHlVHbhSKZ1Kz45Y55dS2U=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=FirvzScPjS7RmCBuQQS2UfrvORNpS6ms7ZN8jkKNd/7jz8fuGSfnsarVTtu+qTtam kWtSTyY4vCTCPe1lNlvQzSiLcAPFcveskn0IRfmsrv3rKIixB8Mzp/gK+sGFIOXXFQ VWrcQBTR5q9vwahfuQp4KuIM0UZclWBjJVQ9Gnjo= Date: Tue, 30 Apr 2019 17:44:44 +0200 From: Greg Kroah-Hartman To: "Gustavo A. R. Silva" Cc: David Laight , Valentina Manea , Shuah Khan , "linux-usb@vger.kernel.org" , "linux-kernel@vger.kernel.org" , Kees Cook Subject: Re: [PATCH] usbip: vhci_hcd: Mark expected switch fall-through Message-ID: <20190430154444.GA4224@kroah.com> References: <20190429143957.GA6725@embeddedor> <1daec8c8929e4d18b2059ab1dfbfdf4a@AcuMS.aculab.com> <287c8504-eafa-ebbb-aa39-babb86fdeb94@embeddedor.com> MIME-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline In-Reply-To: <287c8504-eafa-ebbb-aa39-babb86fdeb94@embeddedor.com> User-Agent: Mutt/1.11.4 (2019-03-13) Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org Message-ID: <20190430154444.igHROpPtc6QcZmtgxbIQsOumXs9InKWuMsYwd2_wBQU@z> On Mon, Apr 29, 2019 at 10:05:51AM -0500, Gustavo A. R. Silva wrote: > > > On 4/29/19 9:44 AM, David Laight wrote: > > From: Gustavo A. R. Silva > >> Sent: 29 April 2019 15:40 > >> In preparation to enabling -Wimplicit-fallthrough, mark switch > >> cases where we are expecting to fall through. > > ... > >> diff --git a/drivers/usb/usbip/vhci_hcd.c b/drivers/usb/usbip/vhci_hcd.c > >> index 667d9c0ec905..000ab7225717 100644 > >> --- a/drivers/usb/usbip/vhci_hcd.c > >> +++ b/drivers/usb/usbip/vhci_hcd.c > >> @@ -508,6 +508,7 @@ static int vhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue, > >> case USB_PORT_FEAT_U1_TIMEOUT: > >> usbip_dbg_vhci_rh( > >> " SetPortFeature: USB_PORT_FEAT_U1_TIMEOUT\n"); > >> + /* Fall through */ > >> case USB_PORT_FEAT_U2_TIMEOUT: > >> usbip_dbg_vhci_rh( > >> " SetPortFeature: USB_PORT_FEAT_U2_TIMEOUT\n"); > > > > That doesn't look right, both debug messages seem to get printed. > > > > At first sight, I thought the same way, then I took a look into > commit: > > 1c9de5bf428612458427943b724bea51abde520a > > and noticed that the original developer properly added fall-through > comments in other places in the same switch() code, that gave me the > impression he knew what he was doing; then I noticed the following > error message in case USB_PORT_FEAT_U2_TIMEOUT: > > if (hcd->speed != HCD_USB3) { > pr_err("USB_PORT_FEAT_U1/2_TIMEOUT req not " > "supported for USB 2.0 roothub\n"); > goto error; > } > > this error message is what makes me think the fall-through is > intentional; otherwise I think it would look like this instead: > > if (hcd->speed != HCD_USB3) { > pr_err("USB_PORT_FEAT_U2_TIMEOUT req not " > "supported for USB 2.0 roothub\n"); > goto error; > } I think you are right, that's horrid, but correct :( Will go queue this up, thanks. greg k-h