Re: [PATCH] scsi: lpfc: Use struct_group to isolate cast to larger object

From: "Martin K. Petersen" <martin.petersen@oracle.com>
To: James Smart <james.smart@broadcom.com>,
	Kees Cook <keescook@chromium.org>
Cc: "Martin K . Petersen" <martin.petersen@oracle.com>,
	linux-scsi@vger.kernel.org,
	"James E.J. Bottomley" <jejb@linux.ibm.com>,
	linux-kernel@vger.kernel.org,
	Dick Kennedy <dick.kennedy@broadcom.com>,
	linux-hardening@vger.kernel.org
Subject: Re: [PATCH] scsi: lpfc: Use struct_group to isolate cast to larger object
Date: Thu, 16 Dec 2021 23:04:43 -0500	[thread overview]
Message-ID: <163971367437.637.1523954588992475904.b4-ty@oracle.com> (raw)
In-Reply-To: <20211203223351.107323-1-keescook@chromium.org>

On Fri, 3 Dec 2021 14:33:51 -0800, Kees Cook wrote:

> When building under -Warray-bounds, a warning is generated when casting
> a u32 into MAILBOX_t (which is larger). This warning is conservative, but
> it's not an unreasonable change to make to improve future robustness. Use
> a tagged struct_group that can refer to either the specific fields or
> the first u32 separately, silencing this warning:
> 
> drivers/scsi/lpfc/lpfc_sli.c: In function 'lpfc_reset_barrier':
> drivers/scsi/lpfc/lpfc_sli.c:4787:29: error: array subscript 'MAILBOX_t[0]' is partly outside array bounds of 'volatile uint32_t[1]' {aka 'volatile unsigned int[1]'} [-Werror=array-bounds]
>  4787 |         ((MAILBOX_t *)&mbox)->mbxCommand = MBX_KILL_BOARD;
>       |                             ^~
> drivers/scsi/lpfc/lpfc_sli.c:4752:27: note: while referencing 'mbox'
>  4752 |         volatile uint32_t mbox;
>       |                           ^~~~
> 
> [...]

Applied to 5.17/scsi-queue, thanks!

[1/1] scsi: lpfc: Use struct_group to isolate cast to larger object
      https://git.kernel.org/mkp/scsi/c/c167dd0b2a7a

-- 
Martin K. Petersen	Oracle Linux Engineering