From: Nathan Chancellor <natechancellor@gmail.com>
To: Don.Brace@microchip.com
Cc: axboe@kernel.dk, aacraid@microsemi.com, jejb@linux.ibm.com,
martin.petersen@oracle.com, manoj@linux.ibm.com,
mrochs@linux.ibm.com, ukrishn@linux.ibm.com,
linuxdrivers@attotech.com, don.brace@microsemi.com,
brking@us.ibm.com, linux-ide@vger.kernel.org,
linux-kernel@vger.kernel.org, linux-scsi@vger.kernel.org,
esc.storagedev@microsemi.com, ndesaulniers@google.com,
bvanassche@acm.org
Subject: Re: [PATCH v4] scsi/ata: Use unsigned int for cmd's type in ioctls in scsi_host_template
Date: Mon, 28 Jan 2019 09:17:37 -0700 [thread overview]
Message-ID: <20190128161737.GA23636@archlinux-ryzen> (raw)
In-Reply-To: <SN6PR11MB2767DF2A2BEF95EE07C15172E1960@SN6PR11MB2767.namprd11.prod.outlook.com>
On Mon, Jan 28, 2019 at 04:16:34PM +0000, Don.Brace@microchip.com wrote:
>
> Clang warns several times in the scsi subsystem (trimmed for brevity):
>
> drivers/scsi/hpsa.c:6209:7: warning: overflow converting case value to switch condition type (2147762695 to 18446744071562347015) [-Wswitch]
> case CCISS_GETBUSTYPES:
> ^
> drivers/scsi/hpsa.c:6208:7: warning: overflow converting case value to switch condition type (2147762694 to 18446744071562347014) [-Wswitch]
> case CCISS_GETHEARTBEAT:
> ^
>
> The root cause is that the _IOC macro can generate really large numbers, which don't find into type 'int', which is used for the cmd paremeter in the ioctls in scsi_host_template. My research into how GCC and Clang are handling this at a low level didn't prove fruitful. However, looking at the rest of the kernel tree, all ioctls use an 'unsigned int' for the cmd parameter, which will fit all of the _IOC values in the scsi/ata subsystems.
>
> Make that change because none of the ioctls expect to take a negative value, it brings the ioctls inline with the reset of the kernel, and it removes ambiguity, which is never good when dealing with compilers.
>
> Link: https://github.com/ClangBuiltLinux/linux/issues/85
> Link: https://github.com/ClangBuiltLinux/linux/issues/154
> Link: https://github.com/ClangBuiltLinux/linux/issues/157
> Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
> Reviewed-by: Bart Van Assche <bvanassche@acm.org>
>
> static void __exit esas2r_exit(void)
> diff --git a/drivers/scsi/hpsa.c b/drivers/scsi/hpsa.c index ff67ef5d5347..28cfd3d01c5a 100644
> --- a/drivers/scsi/hpsa.c
> +++ b/drivers/scsi/hpsa.c
> @@ -251,10 +251,11 @@ static int number_of_controllers;
>
> Acked-by: Don Brace <don.brace@microsemi.com>
>
>
> diff --git a/drivers/scsi/smartpqi/smartpqi_init.c b/drivers/scsi/smartpqi/smartpqi_init.c
> index f564af8949e8..5d9ccbab7581 100644
> --- a/drivers/scsi/smartpqi/smartpqi_init.c
> +++ b/drivers/scsi/smartpqi/smartpqi_init.c
> @@ -6043,7 +6043,8 @@ static int pqi_passthru_ioctl(struct pqi_ctrl_info *ctrl_info, void __user *arg)
> return rc;
> }
>
> Acked-by: Don Brace <don.brace@microsemi.com>
>
>
Thank you for the reply and the review, I really appreciate it :)
Nathan
next prev parent reply other threads:[~2019-01-28 16:55 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-10-19 17:57 [PATCH] scsi/ata: Use unsigned int for cmd's type in ioctls in scsi_host_template Nathan Chancellor
2018-10-19 19:38 ` Bart Van Assche
2018-10-20 4:52 ` kbuild test robot
2018-10-20 5:01 ` [PATCH v2] " Nathan Chancellor
2018-12-17 17:31 ` Nathan Chancellor
2019-01-14 4:42 ` [PATCH v3] " Nathan Chancellor
2019-01-14 4:54 ` Bart Van Assche
2019-01-14 4:57 ` Nathan Chancellor
2019-01-26 7:52 ` [PATCH v4] " Nathan Chancellor
2019-01-26 9:19 ` Nick Desaulniers
2019-01-28 16:16 ` Don.Brace
2019-01-28 16:17 ` Nathan Chancellor [this message]
2019-02-05 18:42 ` Grove, Bradley
2019-02-07 10:52 ` Marc Gonzalez
2019-02-07 16:07 ` [PATCH v5] " Nathan Chancellor
2019-02-07 19:17 ` Nick Desaulniers
2019-02-08 8:05 ` Christoph Hellwig
2019-02-08 16:00 ` Nathan Chancellor
2019-02-08 22:33 ` Martin K. Petersen
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20190128161737.GA23636@archlinux-ryzen \
--to=natechancellor@gmail.com \
--cc=Don.Brace@microchip.com \
--cc=aacraid@microsemi.com \
--cc=axboe@kernel.dk \
--cc=brking@us.ibm.com \
--cc=bvanassche@acm.org \
--cc=don.brace@microsemi.com \
--cc=esc.storagedev@microsemi.com \
--cc=jejb@linux.ibm.com \
--cc=linux-ide@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-scsi@vger.kernel.org \
--cc=linuxdrivers@attotech.com \
--cc=manoj@linux.ibm.com \
--cc=martin.petersen@oracle.com \
--cc=mrochs@linux.ibm.com \
--cc=ndesaulniers@google.com \
--cc=ukrishn@linux.ibm.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).