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.
Yes, I managed to reproduce this on top of -rc4 (see below). I suspect you
/are/ the intersection of people using v7s w/ kmemleak, so this has just
lingered and never been hit until now.
For the patch (assuming this is going via Joerg):
Acked-by: Will Deacon <will.deacon@xxxxxxx>
Will
--->8
[ 0.124473] kmemleak: Trying to color unknown object at 0xffff8000042d8000 as Black
[ 0.125312] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.0.0-rc4-00012-g40b114779944 #1
[ 0.126181] Hardware name: linux,dummy-virt (DT)
[ 0.126680] Call trace:
[ 0.126950] dump_backtrace+0x0/0x140
[ 0.127346] show_stack+0x14/0x20
[ 0.127706] dump_stack+0x90/0xb4
[ 0.128066] paint_ptr+0x94/0xa8
[ 0.128417] kmemleak_ignore+0x54/0x60
[ 0.128991] __arm_v7s_alloc_table+0x6c/0x240
[ 0.129661] arm_v7s_alloc_pgtable+0x10c/0x188
[ 0.130359] alloc_io_pgtable_ops+0x44/0xb0
[ 0.131006] arm_v7s_do_selftests+0x84/0x4bc
[ 0.131663] do_one_initcall+0x74/0x178
[ 0.132253] kernel_init_freeable+0x188/0x220
[ 0.132923] kernel_init+0x10/0x100
[ 0.133460] ret_from_fork+0x10/0x18
[ 0.142102] arm-v7s io-pgtable: self test ok
