Re: [PATCH] iommu/io-pgtable-arm-v7s: only kmemleak_ignore L2 tables

From: Greg KH
Date: Mon Jan 28 2019 - 05:15:46 EST


On Mon, Jan 28, 2019 at 05:43:01PM +0800, Nicolas Boichat wrote:
> L1 tables are allocated with __get_dma_pages, and therefore already
> ignored by kmemleak.
>
> Without this, the kernel would print this error message on boot,
> when the first L1 table is allocated:
>
> [ 2.810533] kmemleak: Trying to color unknown object at 0xffffffd652388000 as Black
> [ 2.818190] CPU: 5 PID: 39 Comm: kworker/5:0 Tainted: G S 4.19.16 #8
> [ 2.831227] Workqueue: events deferred_probe_work_func
> [ 2.836353] Call trace:
> ...
> [ 2.852532] paint_ptr+0xa0/0xa8
> [ 2.855750] kmemleak_ignore+0x38/0x6c
> [ 2.859490] __arm_v7s_alloc_table+0x168/0x1f4
> [ 2.863922] arm_v7s_alloc_pgtable+0x114/0x17c
> [ 2.868354] alloc_io_pgtable_ops+0x3c/0x78
> ...
>
> Fixes: e5fc9753b1a8314 ("iommu/io-pgtable: Add ARMv7 short descriptor support")
> Signed-off-by: Nicolas Boichat <drinkcat@xxxxxxxxxxxx>
> ---
>
> I only tested this on top of my other series
> (https://patchwork.kernel.org/patch/10720495/), but I think the same fix
> applies. I'm still a bit confused as to why this only shows up now, as IIUC,
> the kmemleak_ignore call was always wrong with L1 tables.
>
> drivers/iommu/io-pgtable-arm-v7s.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)

<formletter>

This is not the correct way to submit patches for inclusion in the
stable kernel tree. Please read:
https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html
for how to do this properly.

</formletter>