Commit 993f57e0 authored by Zhaoyang Huang's avatar Zhaoyang Huang Committed by Andrew Morton
Browse files

mm: use stack_depot_early_init for kmemleak 

Mirsad report the below error which is caused by stack_depot_init()
failure 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.

[vbabka@suse.cz: remove stack_depot_init() call]
Link: https://lore.kernel.org/all/5272a819-ef74-65ff-be61-4d2d567337de@alu.unizg.hr/
Link: https://lkml.kernel.org/r/1674091345-14799-2-git-send-email-zhaoyang.huang@unisoc.com


Fixes: 56a61617 ("mm: use stack_depot for recording kmemleak's backtrace")
Reported-by: default avatarMirsad Todorovac <mirsad.todorovac@alu.unizg.hr>
Suggested-by: default avatarVlastimil Babka <vbabka@suse.cz>
Signed-off-by: default avatarZhaoyang Huang <zhaoyang.huang@unisoc.com>
Acked-by: default avatarMike Rapoport (IBM) <rppt@kernel.org>
Acked-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
Acked-by: default avatarVlastimil Babka <vbabka@suse.cz>
Tested-by: default avatarBorislav Petkov (AMD) <bp@alien8.de>
Cc: ke.wang <ke.wang@unisoc.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent f65c4bbb

lib/Kconfig.debug

+1 −0
Original line number Diff line number Diff line
@@ -754,6 +754,7 @@ config DEBUG_KMEMLEAK 
	select KALLSYMS

	select CRC32

	select STACKDEPOT

	select STACKDEPOT_ALWAYS_INIT if !DEBUG_KMEMLEAK_DEFAULT_OFF

	help

	  Say Y here if you want to enable the memory leak

	  detector. The memory allocation/freeing is traced in a way

mm/kmemleak.c

+3 −2
Original line number Diff line number Diff line
@@ -2070,8 +2070,10 @@ static int __init kmemleak_boot_config(char *str) 
		return -EINVAL;

	if (strcmp(str, "off") == 0)

		kmemleak_disable();

	else if (strcmp(str, "on") == 0)

	else if (strcmp(str, "on") == 0) {

		kmemleak_skip_disable = 1;

		stack_depot_want_early_init();

	}

	else

		return -EINVAL;

	return 0;
@@ -2093,7 +2095,6 @@ void __init kmemleak_init(void) 
	if (kmemleak_error)

		return;



	stack_depot_init();

	jiffies_min_age = msecs_to_jiffies(MSECS_MIN_AGE);

	jiffies_scan_wait = msecs_to_jiffies(SECS_SCAN_WAIT * 1000);