Re: [PATCH] genwqe: Fix size check

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Wed, Dec 12, 2018 at 03:36:57PM +0100, Christian Borntraeger wrote:
> On 12.12.2018 15:18, haver wrote:
> > Hi Christian,
> > 
> > On 2018-12-12 14:45, Christian Borntraeger wrote:
> >> Calling the test program genwqe_cksum with the default buffer size of
> >> 2MB triggers the following kernel warning on s390:
> >>
> >> WARNING: CPU: 30 PID: 9311 at mm/page_alloc.c:3189
> >> __alloc_pages_nodemask+0x45c/0xbe0
> >> CPU: 30 PID: 9311 Comm: genwqe_cksum Kdump: loaded Not tainted
> >> 3.10.0-957.el7.s390x #1
> >> task: 00000005e5d13980 ti: 00000005e7c6c000 task.ti: 00000005e7c6c000
> >> Krnl PSW : 0704c00180000000 00000000002780ac
> >> (__alloc_pages_nodemask+0x45c/0xbe0)
> >>            R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 CC:0 PM:0 EA:3
> >> Krnl GPRS: 00000000002932b8 0000000000b73d7c 0000000000000010 0000000000000009
> >>            0000000000000041 00000005e7c6f9b8 0000000000000001 00000000000080d0
> >>            0000000000000000 0000000000b70500 0000000000000001 0000000000000000
> >>            0000000000b70528 00000000007682c0 0000000000277df2 00000005e7c6f9a0
> >> Krnl Code: 000000000027809e: de7195001000    ed    1280(114,%r9),0(%r1)
> >>        00000000002780a4: a774fead        brc    7,277dfe
> >>       #00000000002780a8: a7f40001        brc    15,2780aa
> >>       >00000000002780ac: 92011000        mvi    0(%r1),1
> >>        00000000002780b0: a7f4fea7        brc    15,277dfe
> >>        00000000002780b4: 9101c6b6        tm    1718(%r12),1
> >>        00000000002780b8: a784ff3a        brc    8,277f2c
> >>        00000000002780bc: a7f4fe2e        brc    15,277d18
> >> Call Trace:
> >> ([<0000000000277df2>] __alloc_pages_nodemask+0x1a2/0xbe0)
> >>  [<000000000013afae>] s390_dma_alloc+0xfe/0x310
> >>  [<000003ff8065f362>] __genwqe_alloc_consistent+0xfa/0x148 [genwqe_card]
> >>  [<000003ff80658f7a>] genwqe_mmap+0xca/0x248 [genwqe_card]
> >>  [<00000000002b2712>] mmap_region+0x4e2/0x778
> >>  [<00000000002b2c54>] do_mmap+0x2ac/0x3e0
> >>  [<0000000000292d7e>] vm_mmap_pgoff+0xd6/0x118
> >>  [<00000000002b081c>] SyS_mmap_pgoff+0xdc/0x268
> >>  [<00000000002b0a34>] SyS_old_mmap+0x8c/0xb0
> >>  [<000000000074e518>] sysc_tracego+0x14/0x1e
> >>  [<000003ffacf87dc6>] 0x3ffacf87dc6
> >>
> >> turns out the check in __genwqe_alloc_consistent uses "> MAX_ORDER"
> >> while the mm code uses ">= MAX_ORDER". Fix genwqe.
> >>
> >> Cc: stable@vger.kernel.org
> >> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
> >> ---
> >>  drivers/misc/genwqe/card_utils.c | 2 +-
> >>  1 file changed, 1 insertion(+), 1 deletion(-)
> >>
> >> diff --git a/drivers/misc/genwqe/card_utils.c b/drivers/misc/genwqe/card_utils.c
> >> index 3fcb9a2fe1c9..efe2fb72d54b 100644
> >> --- a/drivers/misc/genwqe/card_utils.c
> >> +++ b/drivers/misc/genwqe/card_utils.c
> >> @@ -215,7 +215,7 @@ u32 genwqe_crc32(u8 *buff, size_t len, u32 init)
> >>  void *__genwqe_alloc_consistent(struct genwqe_dev *cd, size_t size,
> >>                     dma_addr_t *dma_handle)
> >>  {
> >> -    if (get_order(size) > MAX_ORDER)
> >> +    if (get_order(size) >= MAX_ORDER)
> >>          return NULL;
> >>
> >>      return dma_zalloc_coherent(&cd->pci_dev->dev, size, dma_handle,
> > 
> > Thanks for sending a fix for this ugly message.
> > Regards
> > 
> > Frank
> > 
> > Signed-off-by: Frank Haverkamp <haver@linux.vnet.ibm.com>
> 
> This should have been an Acked-by, I guess.
> Will this go via Gregs misc driver tree?

Yes, I can take it, thanks.

greg k-h