mm: use stack_depot_early_init for kmemleak
authorZhaoyang Huang <zhaoyang.huang@unisoc.com>
Thu, 19 Jan 2023 01:22:25 +0000 (09:22 +0800)
committerAndrew Morton <akpm@linux-foundation.org>
Wed, 1 Feb 2023 00:44:10 +0000 (16:44 -0800)
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: 56a61617dd22 ("mm: use stack_depot for recording kmemleak's backtrace")
Reported-by: Mirsad Todorovac <mirsad.todorovac@alu.unizg.hr>
Suggested-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Zhaoyang Huang <zhaoyang.huang@unisoc.com>
Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Tested-by: Borislav 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: Andrew Morton <akpm@linux-foundation.org>
lib/Kconfig.debug
mm/kmemleak.c

index 881c3f8..80c69d0 100644 (file)
@@ -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
index 92f670e..55dc8b8 100644 (file)
@@ -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);