From: "Gustavo A. R. Silva" <gustavo@embeddedor.com>
To: Cliff Whickman <cpw@sgi.com>, Robin Holt <robinmholt@gmail.com>,
Arnd Bergmann <arnd@arndb.de>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-kernel@vger.kernel.org, Kees Cook <keescook@chromium.org>
Subject: Re: [sgi-xp] Missing break or false positive?
Date: Wed, 20 Mar 2019 09:37:33 -0500 [thread overview]
Message-ID: <480940a4-1b7c-564e-2921-37c5b7e0a5b9@embeddedor.com> (raw)
In-Reply-To: <20190227042454.GA29535@embeddedor>
Hi all,
Friendly ping:
Who can provide some feedback on this?
Thanks
--
Gustavo
On 2/26/19 10:24 PM, Gustavo A. R. Silva wrote:
> Hi all,
>
> I'm taking a look into the following piece of code in drivers/misc/sgi-xp/xpc_uv.c:
>
> 561 case XPC_ACTIVATE_MQ_MSG_CHCTL_OPENCOMPLETE_UV: {
> 562 struct xpc_activate_mq_msg_chctl_opencomplete_uv *msg;
> 563
> 564 if (!part_setup)
> 565 break;
> 566
> 567 msg = container_of(msg_hdr, struct
> 568 xpc_activate_mq_msg_chctl_opencomplete_uv, hdr);
> 569 spin_lock_irqsave(&part->chctl_lock, irq_flags);
> 570 part->chctl.flags[msg->ch_number] |= XPC_CHCTL_OPENCOMPLETE;
> 571 spin_unlock_irqrestore(&part->chctl_lock, irq_flags);
> 572
> 573 xpc_wakeup_channel_mgr(part);
> 574 }
>
> and I'm trying to figure out if the following warning is due to a missing break
> at the end of the case, or if this is just a false positive and a /* fall through */
> annotation should be added:
>
> drivers/misc/sgi-xp/xpc_uv.c: In function ‘xpc_handle_activate_mq_msg_uv’:
> drivers/misc/sgi-xp/xpc_uv.c:573:3: warning: this statement may fall through [-Wimplicit-fallthrough=]
> xpc_wakeup_channel_mgr(part);
> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
> drivers/misc/sgi-xp/xpc_uv.c:575:2: note: here
> case XPC_ACTIVATE_MQ_MSG_MARK_ENGAGED_UV:
> ^~~~
>
> The piece of code above was introduced by the following commit in 2009:
>
> efdd06ed181a88a11e612238c1ac04668e665395
>
> The cases are pretty similar, and the fact that this code was introduced
> in the middle of the switch statement and not at the end or the beginning,
> leads me to believe that this is a false positive. On the other hand,
> all the other cases end with a break or a return but this one. So, I
> better ask your opinions about this.
>
> Thanks
> --
> Gustavo
>
next prev parent reply other threads:[~2019-03-20 14:37 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-27 4:24 [sgi-xp] Missing break or false positive? Gustavo A. R. Silva
2019-03-20 14:37 ` Gustavo A. R. Silva [this message]
2019-03-20 15:23 ` Robin Holt
2019-03-20 15:36 ` Gustavo A. R. Silva
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