[PATCH] mm: use stack_depot_early_init for kmemleak

From: zhaoyang.huang
Date: Tue Jan 17 2023 - 01:01:21 EST


From: Zhaoyang Huang <zhaoyang.huang@xxxxxxxxxx>

Mirsad report bellow error which caused by stack_depot_init failed in kvcalloc.
Solve this by having stackdepot use stack_depot_early_init.

On 1/4/23 17:08, Mirsad Goran Todorovac wrote:
I hate to bring bad news again, but there seems to be a problem with the output of /sys/kernel/debug/kmemleak:

[root@pc-mtodorov ~]# cat /sys/kernel/debug/kmemleak
unreferenced object 0xffff951c118568b0 (size 16):
comm "kworker/u12:2", pid 56, jiffies 4294893952 (age 4356.548s)
hex dump (first 16 bytes):
6d 65 6d 73 74 69 63 6b 30 00 00 00 00 00 00 00 memstick0.......
backtrace:
[root@pc-mtodorov ~]#
Apparently, backtrace of called functions on the stack is no longer printed with the list of memory leaks.
This appeared on Lenovo desktop 10TX000VCR, with AlmaLinux 8.7 and BIOS version M22KT49A (11/10/2022)
and 6.2-rc1 and 6.2-rc2 builds.
This worked on 6.1 with the same CONFIG_KMEMLEAK=y and MGLRU enabled on a vanilla mainstream kernel
from Mr. Torvalds' tree. I don't know if this is deliberate feature for some reason or a bug.
Please find attached the config, lshw and kmemleak output.

reported-by: Mirsad Todorovac <mirsad.todorovac@xxxxxxxxxxxx>
Signed-off-by: Zhaoyang Huang <zhaoyang.huang@xxxxxxxxxx>
---
lib/Kconfig.debug | 1 +
1 file changed, 1 insertion(+)

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 401ad4b..50cc9f5 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -727,6 +727,7 @@ config DEBUG_KMEMLEAK
select KALLSYMS
select CRC32
select STACKDEPOT
+ select STACKDEPOT_ALWAYS_INIT
help
Say Y here if you want to enable the memory leak
detector. The memory allocation/freeing is traced in a way
--
1.9.1