From: Vladimir Zapolskiy <vladimir.zapolskiy@linaro.org>
To: Mike Rapoport <rppt@kernel.org>
Cc: lkml <linux-kernel@vger.kernel.org>,
linux-mm@kvack.org, Catalin Marinas <catalin.marinas@arm.com>
Subject: Re: Panic on kmemleak scan
Date: Tue, 12 Oct 2021 11:21:38 +0300 [thread overview]
Message-ID: <147cd17b-7cba-e015-ce94-ad4b9c3f07e6@linaro.org> (raw)
In-Reply-To: <YWUmaV7pDBX9zSOl@kernel.org>
Hi Mike,
On 10/12/21 9:08 AM, Mike Rapoport wrote:
> (added Catalin)
>
> On Mon, Oct 11, 2021 at 02:23:31PM +0300, Vladimir Zapolskiy wrote:
>> Hello Mike,
>>
>> commit a7259df767 ("memblock: make memblock_find_in_range method private") [1]
>> invokes a kernel panic while running kmemleak on OF platforms with nomaped
>> regions, basically it's similar to an issue reported and fixed earlier by [2]:
>>
>> Unable to handle kernel paging request at virtual address ffff000021e00000
>
> Does this virtual address correspond to a nomap area?
Yes, it does:
OF: reserved mem: allocated memory for 'rmtfs@86700000' node: base 0x00000000a1e00000, size 2 MiB
and 'rmtfs@86700000' device node has a 'no-map' property.
Also:
# echo dump=0xffff000021e00000 > /sys/kernel/debug/kmemleak
[ 35.679096] kmemleak: Object 0xffff000021e00000 (size 2097152):
[ 35.679172] kmemleak: comm "swapper", pid 0, jiffies 4294892296
[ 35.683860] kmemleak: min_count = 0
[ 35.690106] kmemleak: count = 0
[ 35.693752] kmemleak: flags = 0x1
[ 35.697050] kmemleak: checksum = 0
[ 35.700350] kmemleak: backtrace:
[ 35.704170] kmemleak_alloc_phys+0x2c/0x40
[ 35.707381] memblock_alloc_range_nid+0x150/0x170
[ 35.711810] memblock_phys_alloc_range+0xb8/0xc8
[ 35.716931] early_init_dt_alloc_reserved_memory_arch+0x40/0x94
[ 35.721968] __reserved_mem_alloc_size+0x200/0x308
[ 35.727955] fdt_init_reserved_mem+0x154/0x284
[ 35.733164] early_init_fdt_scan_reserved_mem+0x80/0xfc
[ 35.737939] arm64_memblock_init+0x23c/0x278
[ 35.743406] setup_arch+0x18c/0x228
[ 35.748266] start_kernel+0x94/0x610
[ 35.751825] __primary_switched+0xc0/0xc8
> Can you check if this patch helps:
>
> diff --git a/mm/memblock.c b/mm/memblock.c
> index 184dcd2e5d99..5c3503c98b2f 100644
> --- a/mm/memblock.c
> +++ b/mm/memblock.c
> @@ -936,7 +936,12 @@ int __init_memblock memblock_mark_mirror(phys_addr_t base, phys_addr_t size)
> */
> int __init_memblock memblock_mark_nomap(phys_addr_t base, phys_addr_t size)
> {
> - return memblock_setclr_flag(base, size, 1, MEMBLOCK_NOMAP);
> + int ret = memblock_setclr_flag(base, size, 1, MEMBLOCK_NOMAP);
> +
> + if (!ret)
> + kmemleak_free_part_phys(base, size);
> +
> + return ret;
> }
>
> /**
>
The change fixes the issue, thank you!
The object is also gone from being under kmemleak:
# echo dump=0xffff000021e00000 > /sys/kernel/debug/kmemleak
kmemleak: Unknown object at 0xffff000021e00000
Please feel free to add my
Tested-by: Vladimir Zapolskiy <vladimir.zapolskiy@linaro.org>
>> [...]
>> scan_block+0x64/0x170
>> scan_gray_list+0xe8/0x17c
>> kmemleak_scan+0x270/0x514
>> kmemleak_write+0x34c/0x4ac
>>
>> I believe it would be a trivial problem to correct for you, thank you in
>> advance!
>>
>> [1] https://lore.kernel.org/all/20210816122622.30279-1-rppt@kernel.org/T/#u
>> [2] https://lore.kernel.org/lkml/20190119132832.GA29881@MBP.local/t/#m032124f36c07
--
Best wishes,
Vladimir
prev parent reply other threads:[~2021-10-12 8:21 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-10-11 11:23 Panic on kmemleak scan Vladimir Zapolskiy
2021-10-12 6:08 ` Mike Rapoport
2021-10-12 8:21 ` Vladimir Zapolskiy [this message]
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