Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751493AbdI3GWE (ORCPT ); Sat, 30 Sep 2017 02:22:04 -0400 Received: from mail3-relais-sop.national.inria.fr ([192.134.164.104]:63511 "EHLO mail3-relais-sop.national.inria.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750944AbdI3GWD (ORCPT ); Sat, 30 Sep 2017 02:22:03 -0400 X-IronPort-AV: E=Sophos;i="5.42,456,1500933600"; d="scan'208";a="239213300" Date: Sat, 30 Sep 2017 08:21:56 +0200 (CEST) From: Julia Lawall X-X-Sender: jll@hadrien To: Srishti Sharma cc: Greg KH , devel@driverdev.osuosl.org, Linux kernel mailing list , outreachy-kernel Subject: Re: [Outreachy kernel] [PATCH] Staging: rtl8188eu: core: Use list_entry instead of container_of In-Reply-To: Message-ID: References: <1506734581-10932-1-git-send-email-srishtishar@gmail.com> User-Agent: Alpine 2.20 (DEB 67 2015-01-07) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 7083 Lines: 185 On Sat, 30 Sep 2017, Srishti Sharma wrote: > On Sat, Sep 30, 2017 at 11:36 AM, Julia Lawall wrote: > > > > > > On Sat, 30 Sep 2017, Srishti Sharma wrote: > > > >> On Sat, Sep 30, 2017 at 10:35 AM, Julia Lawall wrote: > >> > > >> > > >> > On Sat, 30 Sep 2017, Srishti Sharma wrote: > >> > > >> >> For variables of the type struct list_head* use list_entry to access > >> >> the current list element instead of using container_of. > >> >> Done using the following semantic patch by coccinelle. > >> >> > >> >> @r@ > >> >> identifier e; > >> >> struct list_head* l; > >> >> @@ > >> >> > >> >> <... when != l == NULL > >> >> l; > >> >> ...> > >> > I don't see what is the goal of the above code. The list_head variable is > >> > not going to be in a statement by itself. There is also no need to check > >> > for l being NULL. If it is NULL, the original code is incorrect too. > >> > >> Since only those container_of are to replaced with list_entry which > >> have a variable of type list_head* , I wanted to check if it occurs > >> anywhere before > >> container_of , > > > > Why? If it is a list, then it seems appropriate to access it using > > list_head. > > > >> which it only does in it's declaration , because it > >> can't be in any > >> statement by itself . I think it will be better to write . > >> > >> @r@ > >> identifier e; > >> struct list_head* l; > >> @@ > >> > >> <... > >> container_of(l,...); > >> ...> > > > > This doesn't ensure that there is a preceding container_of, if that is > > what you are trying to do. The problem is that <... P ...> finds 0 or > > more occurrences of pattern P, not 1 or more occurrences. 1 or more > > occurrences is <+... P ...+>. But it would be simpler if you want an > > occurrence of container_of before the thing you are transforming to put > > > > container_of(l,...); > > ... > > e = ... > > > > But this doesn't make sense either, partly because the preceding > > container_of is just not needed, and also because a container_of would not > > be in a statement by itself. In Coccinelle, when you put a ; after > > something is means that the thing is a complete statement, not just the > > end half of a statement. > > So , I guess we can simply write. > > e = > -container_of > +list_entry > (l,...) Yes. You don't even need the e =. As long as there is a call to container_of on a list_head * value, you can change it. julia > > Regards, > Srishti > > > > > julia > > > >> e = > >> -container_of > >> +list_entry > >> ( > >> ....) > >> > >> >> ( > >> >> e = > >> >> -container_of > >> >> +list_entry > >> >> ( > >> >> ...) > >> >> ) > >> > > >> > Here you don't need the outer ( ). This makes a disjunction with only > >> > one choice. Since there is only one choice, you don't need the > >> > disjunction. > >> > >> Thanks a lot , for pointing out the errors . > >> > >> Regards, > >> Srishti > >> > julia > >> > > >> >> Signed-off-by: Srishti Sharma > >> >> --- > >> >> drivers/staging/rtl8188eu/core/rtw_sta_mgt.c | 12 ++++++------ > >> >> 1 file changed, 6 insertions(+), 6 deletions(-) > >> >> > >> >> diff --git a/drivers/staging/rtl8188eu/core/rtw_sta_mgt.c b/drivers/staging/rtl8188eu/core/rtw_sta_mgt.c > >> >> index 22cf362..f9df4ac 100644 > >> >> --- a/drivers/staging/rtl8188eu/core/rtw_sta_mgt.c > >> >> +++ b/drivers/staging/rtl8188eu/core/rtw_sta_mgt.c > >> >> @@ -152,8 +152,8 @@ u32 _rtw_free_sta_priv(struct sta_priv *pstapriv) > >> >> while (phead != plist) { > >> >> int i; > >> >> > >> >> - psta = container_of(plist, struct sta_info, > >> >> - hash_list); > >> >> + psta = list_entry(plist, struct sta_info, > >> >> + hash_list); > >> >> plist = plist->next; > >> >> > >> >> for (i = 0; i < 16; i++) { > >> >> @@ -323,7 +323,7 @@ u32 rtw_free_stainfo(struct adapter *padapter, struct sta_info *psta) > >> >> plist = phead->next; > >> >> > >> >> while (!list_empty(phead)) { > >> >> - prframe = container_of(plist, struct recv_frame, list); > >> >> + prframe = list_entry(plist, struct recv_frame, list); > >> >> > >> >> plist = plist->next; > >> >> > >> >> @@ -399,7 +399,7 @@ void rtw_free_all_stainfo(struct adapter *padapter) > >> >> plist = phead->next; > >> >> > >> >> while (phead != plist) { > >> >> - psta = container_of(plist, struct sta_info, hash_list); > >> >> + psta = list_entry(plist, struct sta_info, hash_list); > >> >> > >> >> plist = plist->next; > >> >> > >> >> @@ -435,7 +435,7 @@ struct sta_info *rtw_get_stainfo(struct sta_priv *pstapriv, u8 *hwaddr) > >> >> plist = phead->next; > >> >> > >> >> while (phead != plist) { > >> >> - psta = container_of(plist, struct sta_info, hash_list); > >> >> + psta = list_entry(plist, struct sta_info, hash_list); > >> >> > >> >> if ((!memcmp(psta->hwaddr, addr, ETH_ALEN)) == true) { > >> >> /* if found the matched address */ > >> >> @@ -493,7 +493,7 @@ u8 rtw_access_ctrl(struct adapter *padapter, u8 *mac_addr) > >> >> phead = get_list_head(pacl_node_q); > >> >> plist = phead->next; > >> >> while (phead != plist) { > >> >> - paclnode = container_of(plist, struct rtw_wlan_acl_node, list); > >> >> + paclnode = list_entry(plist, struct rtw_wlan_acl_node, list); > >> >> plist = plist->next; > >> >> > >> >> if (!memcmp(paclnode->addr, mac_addr, ETH_ALEN)) { > >> >> -- > >> >> 2.7.4 > >> >> > >> >> -- > >> >> You received this message because you are subscribed to the Google Groups "outreachy-kernel" group. > >> >> To unsubscribe from this group and stop receiving emails from it, send an email to outreachy-kernel+unsubscribe@googlegroups.com. > >> >> To post to this group, send email to outreachy-kernel@googlegroups.com. > >> >> To view this discussion on the web visit https://groups.google.com/d/msgid/outreachy-kernel/1506734581-10932-1-git-send-email-srishtishar%40gmail.com. > >> >> For more options, visit https://groups.google.com/d/optout. > >> >> > >> > > -- > You received this message because you are subscribed to the Google Groups "outreachy-kernel" group. > To unsubscribe from this group and stop receiving emails from it, send an email to outreachy-kernel+unsubscribe@googlegroups.com. > To post to this group, send email to outreachy-kernel@googlegroups.com. > To view this discussion on the web visit https://groups.google.com/d/msgid/outreachy-kernel/CAB3L5ox9u0pj04pjkiC8MRgx%3DMZqwh%3Dg%3D2VE0-ZG8NYvrUrDBg%40mail.gmail.com. > For more options, visit https://groups.google.com/d/optout. >