On 13.1.2023. 11:14, 黄朝阳 (Zhaoyang Huang) wrote:
On 13.1.2023. 7:20, 黄朝阳 (Zhaoyang Huang) wrote:
/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@xxxxxxxxxx>
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@xxxxxxxxxx>
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
I have rebooted in the kernel 6.1.0-9102b78b6f6a build on
"git checkout 9102b78b6f6ae6af3557114c265c266b312c1319", and this dmesg Stack Depot error
disappeared. :-/
There is nothing in between of commit 9102b78b6f6ae6af3557114c265c266b312c1319
and your commit 56a61617dd2276cbc56a6c868599716386d70041:
commit 56a61617dd2276cbc56a6c868599716386d70041 (refs/bisect/bad)
Author: Zhaoyang Huang <zhaoyang.huang@xxxxxxxxxx>
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.
[akpm@xxxxxxxxxxxxxxxxxxxx: fix build - remove now-unused __save_stack_trace()]
[zhaoyang.huang@xxxxxxxxxx: v3]
Link: https://lkml.kernel.org/r/1667101354-4669-1-git-send-email-zhaoyang.huang@xxxxxxxxxx
[akpm@xxxxxxxxxxxxxxxxxxxx: fix v3 layout oddities]
[akpm@xxxxxxxxxxxxxxxxxxxx: coding-style cleanups]
Link: https://lkml.kernel.org/r/1666864224-27541-1-git-send-email-zhaoyang.huang@xxxxxxxxxx
Signed-off-by: Zhaoyang Huang <zhaoyang.huang@xxxxxxxxxx>
Acked-by: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: ke.wang <ke.wang@xxxxxxxxxx>
Cc: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Cc: Zhaoyang Huang <huangzhaoyang@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
commit 9102b78b6f6ae6af3557114c265c266b312c1319 (refs/bisect/good-9102b78b6f6ae6af3557114c265c266b312c1319)
Author: Liam Howlett <liam.howlett@xxxxxxxxxx>
Date: Tue Oct 25 17:37:23 2022 +0000
maple_tree: update copyright dates for test code
Add the span to the year of the development.
Link: https://lkml.kernel.org/r/20221025173709.2718725-1-Liam.Howlett@xxxxxxxxxx
Signed-off-by: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: Joe Perches <joe@xxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Maybe I'm doing something wrong? I have used the same .config for all builds, just
changed CONFIG_LOCALVERSION.
Regards,
Mirsad
--
Mirsad Todorovac
System engineer
Faculty of Graphic Arts | Academy of Fine Arts
University of Zagreb
Republic of Croatia, the European Union
--
Sistem inženjer
Grafički fakultet | Akademija likovnih umjetnosti
Sveučilište u Zagrebu
