This is a note to let you know that I've just added the patch titled
s390/sclp: Fix sclp_init() cleanup on failure
to the 5.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
s390-sclp-fix-sclp_init-cleanup-on-failure.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit b5aecc51f0af71fcf6accf51cc48cd2adff840cf
Author: Heiko Carstens <hca@xxxxxxxxxxxxx>
Date: Fri Jun 14 18:09:01 2024 +0200
s390/sclp: Fix sclp_init() cleanup on failure
[ Upstream commit 6434b33faaa063df500af355ee6c3942e0f8d982 ]
If sclp_init() fails it only partially cleans up: if there are multiple
failing calls to sclp_init() sclp_state_change_event will be added several
times to sclp_reg_list, which results in the following warning:
------------[ cut here ]------------
list_add double add: new=000003ffe1598c10, prev=000003ffe1598bf0, next=000003ffe1598c10.
WARNING: CPU: 0 PID: 1 at lib/list_debug.c:35 __list_add_valid_or_report+0xde/0xf8
CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.10.0-rc3
Krnl PSW : 0404c00180000000 000003ffe0d6076a (__list_add_valid_or_report+0xe2/0xf8)
R:0 T:1 IO:0 EX:0 Key:0 M:1 W:0 P:0 AS:3 CC:0 PM:0 RI:0 EA:3
...
Call Trace:
[<000003ffe0d6076a>] __list_add_valid_or_report+0xe2/0xf8
([<000003ffe0d60766>] __list_add_valid_or_report+0xde/0xf8)
[<000003ffe0a8d37e>] sclp_init+0x40e/0x450
[<000003ffe00009f2>] do_one_initcall+0x42/0x1e0
[<000003ffe15b77a6>] do_initcalls+0x126/0x150
[<000003ffe15b7a0a>] kernel_init_freeable+0x1ba/0x1f8
[<000003ffe0d6650e>] kernel_init+0x2e/0x180
[<000003ffe000301c>] __ret_from_fork+0x3c/0x60
[<000003ffe0d759ca>] ret_from_fork+0xa/0x30
Fix this by removing sclp_state_change_event from sclp_reg_list when
sclp_init() fails.
Reviewed-by: Peter Oberparleiter <oberpar@xxxxxxxxxxxxx>
Signed-off-by: Heiko Carstens <hca@xxxxxxxxxxxxx>
Signed-off-by: Alexander Gordeev <agordeev@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/s390/char/sclp.c b/drivers/s390/char/sclp.c
index d2ab3f07c008c..8296e6bc229ee 100644
--- a/drivers/s390/char/sclp.c
+++ b/drivers/s390/char/sclp.c
@@ -1208,6 +1208,7 @@ sclp_init(void)
fail_unregister_reboot_notifier:
unregister_reboot_notifier(&sclp_reboot_notifier);
fail_init_state_uninitialized:
+ list_del(&sclp_state_change_event.list);
sclp_init_state = sclp_init_state_uninitialized;
free_page((unsigned long) sclp_read_sccb);
free_page((unsigned long) sclp_init_sccb);
