Re: [PATCH 5.15.y] Revert "mm: kmemleak: take a full lowmem check in kmemleak_*_phys()"

From: Greg KH
Date: Tue Sep 06 2022 - 08:09:05 EST


On Tue, Sep 06, 2022 at 03:03:06PM +0800, yee.lee@xxxxxxxxxxxx wrote:
> From: Yee Lee <yee.lee@xxxxxxxxxxxx>
>
> This reverts commit 23c2d497de21f25898fbea70aeb292ab8acc8c94.
>
> Commit 23c2d497de21 ("mm: kmemleak: take a full lowmem check in
> kmemleak_*_phys()") brought false leak alarms on some archs like arm64
> that does not init pfn boundary in early booting. The final solution
> lands on linux-6.0: commit 0c24e061196c ("mm: kmemleak: add rbtree and
> store physical address for objects allocated with PA").
>
> Revert this commit before linux-6.0. The original issue of invalid PA
> can be mitigated by additional check in devicetree.
>
> The false alarm report is as following: Kmemleak output: (Qemu/arm64)
> unreferenced object 0xffff0000c0170a00 (size 128):
> comm "swapper/0", pid 1, jiffies 4294892404 (age 126.208s)
> hex dump (first 32 bytes):
> 62 61 73 65 00 00 00 00 00 00 00 00 00 00 00 00 base............
> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
> backtrace:
> [<(____ptrval____)>] __kmalloc_track_caller+0x1b0/0x2e4
> [<(____ptrval____)>] kstrdup_const+0x8c/0xc4
> [<(____ptrval____)>] kvasprintf_const+0xbc/0xec
> [<(____ptrval____)>] kobject_set_name_vargs+0x58/0xe4
> [<(____ptrval____)>] kobject_add+0x84/0x100
> [<(____ptrval____)>] __of_attach_node_sysfs+0x78/0xec
> [<(____ptrval____)>] of_core_init+0x68/0x104
> [<(____ptrval____)>] driver_init+0x28/0x48
> [<(____ptrval____)>] do_basic_setup+0x14/0x28
> [<(____ptrval____)>] kernel_init_freeable+0x110/0x178
> [<(____ptrval____)>] kernel_init+0x20/0x1a0
> [<(____ptrval____)>] ret_from_fork+0x10/0x20
>
> This pacth is also applicable to linux-5.17.y/linux-5.18.y/linux-5.19.y
>
> Cc: <stable@xxxxxxxxxxxxxxx>
> Signed-off-by: Yee Lee <yee.lee@xxxxxxxxxxxx>
> ---
> mm/kmemleak.c | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)

What is the git commit id of this change in Linus's tree?

And what about older stable trees with this commit in it?

thanks,

greg k-h