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To:     Adaptec OEM Raid Solutions <aacraid@microsemi.com>,
        "James E.J. Bottomley" <jejb@linux.vnet.ibm.com>,
        "Martin K. Petersen" <martin.petersen@oracle.com>,
        SCSI development list <linux-scsi@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
From:   Hans de Goede <hdegoede@redhat.com>
Subject: aacraid code passes GFP_DMA32 to kmalloc this will not work
Message-ID: <258be5fa-f930-bc5e-d8a0-3d6b5bee0a8b@redhat.com>
Date:   Thu, 29 Mar 2018 16:51:28 +0200
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Hi All,

Since I made the same mistake myself I've done a quick grep for
GFP_DMA32 in the kernel and drivers/scsi/aacraid/commctrl.c
came up as a result of this grep, it does:

                                 p = kmalloc(sg_count[i], GFP_KERNEL|GFP_DMA32);

But kmalloc always returns memory from the normal memory-zone,
if you need memory from a specific memory-zone like the
DMA32 zone, you must use the dma allocation functions (which
from a quick glance at the code seems appropriate here) or
directly call alloc_page or __get_free_page.

Regards,

Hans