INFO: [BISECTED] Regression: A Problem with /sys/kernel/debug/kmemleak output: backtrace not printed since 6.2.0-rc1

黄朝阳 (Zhaoyang Huang)
2023-01-17T02:04:55Z

>>>>> /sys/kernel/debug/kmemleak output: backtrace not printed since
>>>>> 6.2.0-rc1
>>>>>
>>>>>
>>>>>> On 12. 01. 2023. 20:50, Mirsad Todorovac wrote:
>>>>>>> Hi all,
>>>>>>>
>>>>>>> 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.
>>>>>>>
>>>>>>> The bisection gave this commit as the culprit for the severed stack
>>>>>>> backtrace print in /sys/kernel/debug/kmemleak:
>>>>>>>
>>>>>>> mtodorov@domac:~/linux/kernel/linux_torvalds$ git bisect good
>>>>>>> 56a61617dd2276cbc56a6c868599716386d70041 is the first bad commit
>>>>>>> commit 56a61617dd2276cbc56a6c868599716386d70041
>>>>>>> Author: Zhaoyang Huang <zhaoyang.huang@unisoc.com>
>>>>>>> Date: Thu Oct 27 17:50:24 2022 +0800
>>>>>>>
>>>>>>> mm: use stack_depot for recording kmemleak's backtrace
>>>>>>>
>>>>>>> Using stack_depot to record kmemleak's backtrace which has
>>> been
>>>>>>> implemented on slub for reducing redundant information.
>>>>>>>
>>>>>>> The complete bisect log is:
>>>>>>>
>>>>>>> mtodorov@domac:~/linux/kernel/linux_torvalds$ git bisect log git
>>>>>>> bisect start '--' 'mm'
>>>>>>> # good: [830b3c68c1fb1e9176028d02ef86f3cf76aa2476] Linux 6.1 git
>>>>>>> bisect good 830b3c68c1fb1e9176028d02ef86f3cf76aa2476
>>>>>>> # bad: [1b929c02afd37871d5afb9d498426f83432e71c2] Linux 6.2-rc1 git
>>>>>>> bisect bad 1b929c02afd37871d5afb9d498426f83432e71c2
>>>>>>> # good: [8b9ed79c2d587bec5f603d66801478a5af9af842] Merge tag
>>>>>>> 'x86_asm_for_v6.2' of
>>>>>>> git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
>>>>>>> git bisect good 8b9ed79c2d587bec5f603d66801478a5af9af842
>>>>>>> # good: [e83b39d6bbdb6d25bd6f5c258832774635d29b47] mm: make
>>>>>>> drop_caches keep reclaiming on all nodes git bisect good
>>>>>>> e83b39d6bbdb6d25bd6f5c258832774635d29b47
>>>>>>> # good: [9997bc017549acd6425e32300eff28424ffeeb6b] zsmalloc:
>>>>>> implement
>>>>>>> writeback mechanism for zsmalloc git bisect good
>>>>>>> 9997bc017549acd6425e32300eff28424ffeeb6b
>>>>>>> # good: [6287b7dae80944bfa37784a8f9d6861a4facaa6e] mm,thp,rmap:
>>> fix
>>>>>>> races between updates of subpages_mapcount git bisect good
>>>>>>> 6287b7dae80944bfa37784a8f9d6861a4facaa6e
>>>>>>> # good: [8fa590bf344816c925810331eea8387627bbeb40] Merge tag
>>>>>>> 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
>>>>>>> git bisect good 8fa590bf344816c925810331eea8387627bbeb40
>>>>>>> # good: [4f292c4de4f6fb83776c0ff22674121eb6ddfa2f] Merge tag
>>>>>>> 'x86_mm_for_6.2_v2' of
>>>>>>> git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
>>>>>>> git bisect good 4f292c4de4f6fb83776c0ff22674121eb6ddfa2f
>>>>>>> # bad: [1ea9d333ba475041efe43d9d9bc32e64aea2ea2b] Merge tag
>>>>>>> 'mm-stable-2022-12-17-2' of
>>>>>>> git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
>>>>>>> git bisect bad 1ea9d333ba475041efe43d9d9bc32e64aea2ea2b
>>>>>>> # bad: [56a61617dd2276cbc56a6c868599716386d70041] mm: use
>>>>>> stack_depot
>>>>>>> for recording kmemleak's backtrace git bisect bad
>>>>>>> 56a61617dd2276cbc56a6c868599716386d70041
>>>>>>> # good: [61b963b52f59524e27692bc1c14bfb2459e32eb3] mm/gup_test:
>>>>>> free
>>>>>>> memory allocated via kvcalloc() using kvfree() git bisect good
>>>>>>> 61b963b52f59524e27692bc1c14bfb2459e32eb3
>>>>>>> # first bad commit: [56a61617dd2276cbc56a6c868599716386d70041]
>>> mm:
>>>>>> use
>>>>>>> stack_depot for recording kmemleak's backtrace # good:
>>>>>>> [9102b78b6f6ae6af3557114c265c266b312c1319] maple_tree: update
>>>>>>> copyright dates for test code git bisect good
>>>>>>> 9102b78b6f6ae6af3557114c265c266b312c1319
>>>>>>> # first bad commit: [56a61617dd2276cbc56a6c868599716386d70041]
>>> mm:
>>>>>> use
>>>>>>> stack_depot for recording kmemleak's backtrace You have mail in
>>>>>>> /var/mail/mtodorov mtodorov@domac:~/linux/kernel/linux_torvalds$
>>>>>>>
>>>>>>> The platform is 10TX000VCR
>>>>>> (LENOVO_MT_10TX_BU_Lenovo_FM_V530S-07ICB)
>>>>>>> running AlmaLinux 8.7 (CentOS clone) and BIOS M22KT49A.
>>>>>>>
>>>>>>> GCC used was:
>>>>>>>
>>>>>>> mtodorov@domac:~/linux/kernel/linux_torvalds$ gcc --version gcc
>>>>>>> (Debian 8.3.0-6) 8.3.0 Copyright (C) 2018 Free Software Foundation,
>>>>>>> Inc.
>>>>>>> This is free software; see the source for copying conditions.
>>>>>>> There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A
>>>>>> PARTICULAR PURPOSE.
>>>>>>> mtodorov@domac:~/linux/kernel/linux_torvalds$
>>>>>>>
>>>>>>> Hope this helps.
>>>>>>>
>>>>>>> I lack the insight to pinpoint the exact fault in the patch.
>>>>>>
>>>>>> P.S.
>>>>>>
>>>>>> To further complicate things, on Ubuntu 22.10 Lenovo Ideapad 3
>>>>>> 15ITL6 laptop the kmemleak stack backtrace is printed correctly with
>>>>>> the same kernels (but .deb instead of .rpm for the same build):
>>>>>>
>>>>>> unreferenced object 0xffff94ca88e042d0 (size 80):
>>>>>> comm "thermald", pid 768, jiffies 4294893592 (age 78581.504s)
>>>>>> hex dump (first 32 bytes):
>>>>>> 00 00 00 00 00 00 00 00 0d 01 2d 00 00 00 00 00 ..........-.....
>>>>>> af 07 01 80 fd ac ff ff 00 00 00 00 00 00 00 00 ................
>>>>>> backtrace:
>>>>>> [<ffffffffa0dcb921>] slab_post_alloc_hook+0x91/0x320
>>>>>> [<ffffffffa0dcfb79>] kmem_cache_alloc+0x169/0x2f0
>>>>>> [<ffffffffa12b1def>] acpi_os_acquire_object+0x2c/0x32
>>>>>> [<ffffffffa12b1ea2>] acpi_ps_alloc_op+0x4a/0x99
>>>>>> [<ffffffffa12af5c8>] acpi_ps_get_next_arg+0x611/0x761
>>>>>> [<ffffffffa12afbbc>] acpi_ps_parse_loop+0x494/0x8d7
>>>>>> [<ffffffffa12b1434>] acpi_ps_parse_aml+0x1bb/0x561
>>>>>> [<ffffffffa12b24c8>] acpi_ps_execute_method+0x20f/0x2d5
>>>>>> [<ffffffffa12a7acf>] acpi_ns_evaluate+0x34d/0x4f3
>>>>>> [<ffffffffa12ad6a3>] acpi_evaluate_object+0x180/0x3ae
>>>>>> [<ffffffffa1269ca8>] acpi_run_osc+0x128/0x250
>>>>>> [<ffffffffc0bbb14f>] int3400_thermal_run_osc+0x6f/0xc0
>>>>>> [int3400_thermal]
>>>>>> [<ffffffffc0bbb293>] current_uuid_store+0xe3/0x120
>>> [int3400_thermal]
>>>>>> [<ffffffffa13b8ed4>] dev_attr_store+0x14/0x30
>>>>>> [<ffffffffa0ee0458>] sysfs_kf_write+0x38/0x50
>>>>>> [<ffffffffa0edf516>] kernfs_fop_write_iter+0x146/0x1d0 You have
>>>>>> new mail in /var/mail/root
>>>>>> root@marvin-IdeaPad-3-15ITL6:/home/marvin#
>>>>>>
>>>>>> Regards,
>>>>>> Mirsad
>>>>>
>>>>> thanks for head up. Could you please help to check If
>>>>> CONFIG_STACKTRACE and CONFIG_STACKDEPOT is enabled on the fault
>>> kernel?
>>>> Please try the patch below if the configs are right. I think it should
>>>> be caused by the late ready for kmemleak
>>>>
>>>> commit 556eb1927da99ab366e370d593fc32da946768c3
>>>> Author: Zhaoyang Huang <zhaoyang.huang@unisoc.com>
>>>> Date: Fri Jan 13 14:13:39 2023 +0800
>>>>
>>>> mm: instroduce a flag to indicate stack_depot's ready
>>>>
>>>> try to solve the kmemleak's late ready issue.
>>>>
>>>> diff --git a/mm/kmemleak.c b/mm/kmemleak.c index 762b91f..7eb24bc
>>>> 100644
>>>> --- a/mm/kmemleak.c
>>>> +++ b/mm/kmemleak.c
>>>> @@ -216,6 +216,7 @@ struct kmemleak_object {  static int
>>> kmemleak_warning;
>>>> /* set if a fatal kmemleak error has occurred */ static int
>>>> kmemleak_error;
>>>> +static int kmemleak_stadep_initialized;
>>>>
>>>> /* minimum and maximum address that may be valid pointers */ static
>>> unsigned long min_addr = ULONG_MAX; @@ -601,7 +602,7 @@ static noinline
>>> depot_stack_handle_t set_track_prepare(void)
>>>> unsigned long entries[MAX_TRACE];
>>>> unsigned int nr_entries;
>>>>
>>>> - if (!kmemleak_initialized)
>>>> + if (!kmemleak_stadep_initialized)
>>>> return 0;
>>>> nr_entries = stack_trace_save(entries, ARRAY_SIZE(entries), 3);
>>>> trace_handle = stack_depot_save(entries, nr_entries,
>>> GFP_NOWAIT); @@ -2110,6 +2111,7 @@ void __init kmemleak_init(void)
>>>> create_object((unsigned long)__start_ro_after_init,
>>>> __end_ro_after_init -
>>> __start_ro_after_init,
>>>> KMEMLEAK_GREY, GFP_ATOMIC);
>>>> + kmemleak_stadep_initialized = 1;
>>>> }
>>>
>>> Hi, Zhaoyang,
>>>
>>> Sorry, applied the patch and rebuilt, but it didn't work for me:
>>>
>>> [root@pc-mtodorov marvin]# uname -rms
>>> Linux 6.2.0-rc3-mglru-kmemlk-patch-zhaoyang1+ x86_64 [root@pc-mtodorov
>>> marvin]# cat /sys/kernel/debug/kmemleak [root@pc-mtodorov marvin]# echo
>>> scan | tee !$ echo scan | tee /sys/kernel/debug/kmemleak scan
>>> [root@pc-mtodorov marvin]# cat /sys/kernel/debug/kmemleak unreferenced
>>> object 0xffff98938fed1ee0 (size 16):
>>> comm "kworker/u12:2", pid 57, jiffies 4294894053 (age 66.616s)
>>> 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 marvin]#
>>>
>>> Still the stack backtrace list is severed.
>>> CONFIG_STACKDEPOT and CONFIG_STACKTRACE are both "=y":
>>>
>>> [root@pc-mtodorov marvin]# grep -E 'CONFIG_(STACKTRACE|STACKDEPOT)'
>>> /boot/config-6.2.0-rc3-mglru-kmemlk-patch-zhaoyang1+
>>> CONFIG_STACKTRACE_SUPPORT=y
>>> CONFIG_STACKDEPOT=y
>>> # CONFIG_STACKTRACE_BUILD_ID is not set
>>> CONFIG_STACKTRACE=y
>>> [root@pc-mtodorov marvin]#
>>>
>>> Your patch was successfully applied (after some tweaks):
>>>
>>> mtodorov@domac:~/linux/kernel/linux_torvalds$ git diff mm diff --git
>>> a/mm/kmemleak.c b/mm/kmemleak.c index 92f670edbf51..78fd3b89b057
>>> 100644
>>> --- a/mm/kmemleak.c
>>> +++ b/mm/kmemleak.c
>>> @@ -216,6 +216,7 @@ static int kmemleak_initialized;
>>> static int kmemleak_warning;
>>> /* set if a fatal kmemleak error has occurred */
>>> static int kmemleak_error;
>>> +static int kmemleak_stadep_initialized;
>>>
>>> /* minimum and maximum address that may be valid pointers */
>>> static unsigned long min_addr = ULONG_MAX; @@ -601,7 +602,7 @@ static
>>> noinline depot_stack_handle_t set_track_prepare(void)
>>> unsigned long entries[MAX_TRACE];
>>> unsigned int nr_entries;
>>>
>>> - if (!kmemleak_initialized)
>>> + if (!kmemleak_stadep_initialized)
>>> return 0;
>>> nr_entries = stack_trace_save(entries, ARRAY_SIZE(entries), 3);
>>> trace_handle = stack_depot_save(entries, nr_entries,
>>> GFP_NOWAIT); @@ -2110,6 +2111,7 @@ void __init kmemleak_init(void)
>>> create_object((unsigned long)__start_ro_after_init,
>>> __end_ro_after_init -
>>> __start_ro_after_init,
>>> KMEMLEAK_GREY, GFP_ATOMIC);
>>> + kmemleak_stadep_initialized = 1;
>>> }
>>>
>>> /*
>>> mtodorov@domac:~/linux/kernel/linux_torvalds$
>>>
>>> Please verify that the above is correct.
>> It is correct. Another reason could be the stack is less than 3 layers which could be surpassed by stack_trace_save. Could you please try to modify the code as bellow and try again.
>> static noinline depot_stack_handle_t set_track_prepare(void)
>> {
>> depot_stack_handle_t trace_handle;
>> unsigned long entries[MAX_TRACE];
>> unsigned int nr_entries;
>>
>> if (!kmemleak_initialized)
>> return 0;
>> - nr_entries = stack_trace_save(entries, ARRAY_SIZE(entries), 3);
>> + nr_entries = stack_trace_save(entries, ARRAY_SIZE(entries), 0);
>> trace_handle = stack_depot_save(entries, nr_entries, GFP_NOWAIT);
>>
>> return trace_handle;
>> }
>
> Tried that, rebuilt, still no luck:
>
> [root@pc-mtodorov marvin]# uname -rms
> Linux 6.2.0-rc3-mglru-kmemlk-patch-zhaoyang2+ x86_64
> [root@pc-mtodorov marvin]# cat /sys/kernel/debug/kmemleak
> unreferenced object 0xffff8e8c86483c00 (size 16):
> comm "kworker/u12:5", pid 364, jiffies 4294894029 (age 135.024s)
> hex dump (first 16 bytes):
> 6d 65 6d 73 74 69 63 6b 30 00 00 00 00 00 00 00 memstick0.......
> backtrace:
> unreferenced object 0xffff8e8c8edb3f70 (size 16):
> comm "kworker/u12:5", pid 364, jiffies 4294894033 (age 135.008s)
> 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 marvin]#
>
> What I have here is:
>
> static noinline depot_stack_handle_t set_track_prepare(void)
> {
> depot_stack_handle_t trace_handle;
> unsigned long entries[MAX_TRACE];
> unsigned int nr_entries;
>
> if (!kmemleak_stadep_initialized)
> return 0;
> nr_entries = stack_trace_save(entries, ARRAY_SIZE(entries), 0);
> trace_handle = stack_depot_save(entries, nr_entries, GFP_NOWAIT);
>
> return trace_handle;
> }
>
> Maybe this will help (dmesg says that Stack Depot is disabled due to errors?):
>
> [ 0.072031] Memory: 16152080K/16658536K available (18432K kernel code, 4118K rwdata, 7184K rodata, 4420K init, 7684K bss, 506196K reserved, 0K cma-reserved)
> [    0.072219] SLUB: HWalign=64, Order=0-3, MinObjects=0, CPUs=6, Nodes=1
> [    0.072222] Stack Depot allocating hash table of 1048576 entries with kvcalloc
> [    0.072226] swapper: vmalloc error: size 8388608, vm_struct allocation failed, mode:0xdc0(GFP_KERNEL|__GFP_ZERO), nodemask=(null),cpuset=(null),mems_allowed=0-1023
> [    0.072235] CPU: 0 PID: 0 Comm: swapper Not tainted 6.2.0-rc3-mglru-kmemlk-patch-zhaoyang2+ #23
> [    0.072237] Hardware name: LENOVO 10TX000VCR/3140, BIOS M22KT49A 11/10/2022
> [    0.072238] Call Trace:
> [    0.072240]  <TASK>
> [    0.072242]  dump_stack_lvl+0x49/0x63
> [    0.072248]  dump_stack+0x10/0x16
> [    0.072250]  warn_alloc.cold.161+0x75/0xe8
> [    0.072255]  ? __get_vm_area_node+0x14d/0x160
> [    0.072260]  __vmalloc_node_range+0x5e5/0x7d0
> [    0.072264]  ? stack_depot_init.cold.2+0x7e/0xb3
> [    0.072267]  ? __kmalloc_large_node+0xf8/0x150
> [    0.072270]  ? kvmalloc_node+0x4f/0xe0
> [    0.072274]  kvmalloc_node+0xb1/0xe0
> [    0.072276]  ? stack_depot_init.cold.2+0x7e/0xb3
> [    0.072278]  stack_depot_init.cold.2+0x7e/0xb3
> [    0.072280]  kmemleak_init+0x1b/0x114
> [    0.072284]  start_kernel+0x710/0x9dc
> [    0.072288]  x86_64_start_reservations+0x24/0x2a
> [    0.072290]  x86_64_start_kernel+0xf2/0xfd
> [    0.072292]  secondary_startup_64_no_verify+0xe5/0xeb
> [    0.072297]  </TASK>
> [    0.072298] Mem-Info:
> [    0.072299] active_anon:0 inactive_anon:0 isolated_anon:0
> active_file:0 inactive_file:0 isolated_file:0
> unevictable:0 dirty:0 writeback:0
> slab_reclaimable:0 slab_unreclaimable:26
> mapped:0 shmem:0 pagetables:0
> sec_pagetables:0 bounce:0
> kernel_misc_reclaimable:0
> free:4037994 free_pcp:0 free_cma:0
> [    0.072303] Node 0 active_anon:0kB inactive_anon:0kB active_file:0kB inactive_file:0kB unevictable:0kB isolated(anon):0kB isolated(file):0kB mapped:0kB dirty:0kB writeback:0kB shmem:0kB shmem_thp: 0kB shmem_pmdmapped: 0kB anon_thp: 0kB writeback_tmp:0kB kernel_stack:0kB pagetables:0kB sec_pagetables:0kB all_unreclaimable? no
> [    0.072307] Node 0 DMA free:14336kB boost:0kB min:0kB low:0kB high:0kB reserved_highatomic:0KB active_anon:0kB inactive_anon:0kB active_file:0kB inactive_file:0kB unevictable:0kB writepending:0kB present:15992kB managed:14336kB mlocked:0kB bounce:0kB free_pcp:0kB local_pcp:0kB free_cma:0kB
> [    0.072311] lowmem_reserve[]: 0 0 0 0 0
> [    0.072314] Node 0 DMA32 free:2085160kB boost:0kB min:0kB low:0kB high:0kB reserved_highatomic:0KB active_anon:0kB inactive_anon:0kB active_file:0kB inactive_file:0kB unevictable:0kB writepending:0kB present:2257392kB managed:2085160kB mlocked:0kB bounce:0kB free_pcp:0kB local_pcp:0kB free_cma:0kB
> [    0.072318] lowmem_reserve[]: 0 0 0 0 0
> [    0.072321] Node 0 Normal free:14052480kB boost:0kB min:0kB low:0kB high:0kB reserved_highatomic:0KB active_anon:0kB inactive_anon:0kB active_file:0kB inactive_file:0kB unevictable:0kB writepending:0kB present:14385152kB managed:14052844kB mlocked:0kB bounce:0kB free_pcp:0kB local_pcp:0kB free_cma:0kB
> [    0.072325] lowmem_reserve[]: 0 0 0 0 0
> [    0.072328] Node 0 DMA: 0*4kB 0*8kB 0*16kB 0*32kB 0*64kB 0*128kB 0*256kB 0*512kB 2*1024kB (UM) 2*2048kB (M) 2*4096kB (M) = 14336kB
> [    0.072338] Node 0 DMA32: 8*4kB (M) 9*8kB (M) 8*16kB (M) 8*32kB (M) 7*64kB (M) 7*128kB (M) 8*256kB (M) 7*512kB (M) 5*1024kB (M) 6*2048kB (M) 503*4096kB (M) = 2085160kB
> [    0.072352] Node 0 Normal: 8*4kB (UM) 8*8kB (M) 2*16kB (UM) 2*32kB (M) 1*64kB (M) 3*128kB (UM) 2*256kB (M) 4*512kB (UM) 2*1024kB (UM) 3*2048kB (UM) 3428*4096kB (M) = 14052480kB
> [    0.072366] 0 total pagecache pages
> [    0.072367] 0 pages in swap cache
> [    0.072367] Free swap = 0kB
> [    0.072368] Total swap = 0kB
> [    0.072369] 4164634 pages RAM
> [    0.072369] 0 pages HighMem/MovableOnly
> [    0.072370] 126549 pages reserved
> [    0.072371] 0 pages hwpoisoned
> [    0.072372] Stack Depot hash table allocation failed, disabling

Hi again,

I have an additional info:

Here we see Stack Depot trying to alocate 1024 * 1024 entires on a 16 GiB RAM
AlmaLinux 8.7 (CentOS clone):

[ 0.071875] Stack Depot allocating hash table of 1048576 entries with kvcalloc
[ 0.071879] swapper: vmalloc error: size 8388608, vm_struct allocation failed, mode:0xdc0(GFP_KERNEL|__GFP_ZERO), nodemask=(null),cpuset=(null),mems_allowed=0-1023
[ 0.071888] CPU: 0 PID: 0 Comm: swapper Not tainted 6.2.0-rc3-mglru-kmemlk-nokasan-fixed-rcu+ #2
[ 0.071891] Hardware name: LENOVO 10TX000VCR/3140, BIOS M22KT49A 11/10/2022

On another machine with just 8 GiB this mechanism is less demanding, requests
slightly more than 512 * 1024 entries and succeeds:

[ 0.037858] Stack Depot allocating hash table of 524288 entries with kvcalloc
[ 0.038225] ftrace: allocating 52222 entries in 204 pages

I am not that deep into kernel code to debug this :-(

As plain kvcalloc() fails, the only thing that comes to mind - maybe 0.072 s
since boot is still too early to request 8.3 MB? What are the probable causes
that kvcalloc and vmalloc should fail?

Thanks,
Mirsad

Please help to check if the patch bellow will help. thanks. stack_depot_early_init will get memory directly from memblock_alloc.

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

--
Mirsad Goran Todorovac
Sistem inženjer
Grafički fakultet | Akademija likovnih umjetnosti
Sveučilište u Zagrebu

System engineer
Faculty of Graphic Arts | Academy of Fine Arts
University of Zagreb, Republic of Croatia
The European Union