4.19-stable review patch. If anyone has any objections, please let me know.
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From: Heiko Carstens hca@linux.ibm.com
[ 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@linux.ibm.com Signed-off-by: Heiko Carstens hca@linux.ibm.com Signed-off-by: Alexander Gordeev agordeev@linux.ibm.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/s390/char/sclp.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/drivers/s390/char/sclp.c b/drivers/s390/char/sclp.c index e9aa71cdfc44e..74df353d2244c 100644 --- a/drivers/s390/char/sclp.c +++ b/drivers/s390/char/sclp.c @@ -1206,6 +1206,7 @@ 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; fail_unlock: spin_unlock_irqrestore(&sclp_lock, flags);