[PATCH 5.5 233/257] ipmi: fix hung processes in __get_guid()

From: Greg Kroah-Hartman
Date: Thu Apr 16 2020 - 11:33:37 EST


From: Wen Yang <wenyang@xxxxxxxxxxxxxxxxx>

commit 32830a0534700f86366f371b150b17f0f0d140d7 upstream.

The wait_event() function is used to detect command completion.
When send_guid_cmd() returns an error, smi_send() has not been
called to send data. Therefore, wait_event() should not be used
on the error path, otherwise it will cause the following warning:

[ 1361.588808] systemd-udevd D 0 1501 1436 0x00000004
[ 1361.588813] ffff883f4b1298c0 0000000000000000 ffff883f4b188000 ffff887f7e3d9f40
[ 1361.677952] ffff887f64bd4280 ffffc90037297a68 ffffffff8173ca3b ffffc90000000010
[ 1361.767077] 00ffc90037297ad0 ffff887f7e3d9f40 0000000000000286 ffff883f4b188000
[ 1361.856199] Call Trace:
[ 1361.885578] [<ffffffff8173ca3b>] ? __schedule+0x23b/0x780
[ 1361.951406] [<ffffffff8173cfb6>] schedule+0x36/0x80
[ 1362.010979] [<ffffffffa071f178>] get_guid+0x118/0x150 [ipmi_msghandler]
[ 1362.091281] [<ffffffff810d5350>] ? prepare_to_wait_event+0x100/0x100
[ 1362.168533] [<ffffffffa071f755>] ipmi_register_smi+0x405/0x940 [ipmi_msghandler]
[ 1362.258337] [<ffffffffa0230ae9>] try_smi_init+0x529/0x950 [ipmi_si]
[ 1362.334521] [<ffffffffa022f350>] ? std_irq_setup+0xd0/0xd0 [ipmi_si]
[ 1362.411701] [<ffffffffa0232bd2>] init_ipmi_si+0x492/0x9e0 [ipmi_si]
[ 1362.487917] [<ffffffffa0232740>] ? ipmi_pci_probe+0x280/0x280 [ipmi_si]
[ 1362.568219] [<ffffffff810021a0>] do_one_initcall+0x50/0x180
[ 1362.636109] [<ffffffff812231b2>] ? kmem_cache_alloc_trace+0x142/0x190
[ 1362.714330] [<ffffffff811b2ae1>] do_init_module+0x5f/0x200
[ 1362.781208] [<ffffffff81123ca8>] load_module+0x1898/0x1de0
[ 1362.848069] [<ffffffff811202e0>] ? __symbol_put+0x60/0x60
[ 1362.913886] [<ffffffff8130696b>] ? security_kernel_post_read_file+0x6b/0x80
[ 1362.998514] [<ffffffff81124465>] SYSC_finit_module+0xe5/0x120
[ 1363.068463] [<ffffffff81124465>] ? SYSC_finit_module+0xe5/0x120
[ 1363.140513] [<ffffffff811244be>] SyS_finit_module+0xe/0x10
[ 1363.207364] [<ffffffff81003c04>] do_syscall_64+0x74/0x180

Fixes: 50c812b2b951 ("[PATCH] ipmi: add full sysfs support")
Signed-off-by: Wen Yang <wenyang@xxxxxxxxxxxxxxxxx>
Cc: Corey Minyard <minyard@xxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: openipmi-developer@xxxxxxxxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Cc: stable@xxxxxxxxxxxxxxx # 2.6.17-
Message-Id: <20200403090408.58745-1-wenyang@xxxxxxxxxxxxxxxxx>
Signed-off-by: Corey Minyard <cminyard@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/char/ipmi/ipmi_msghandler.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/char/ipmi/ipmi_msghandler.c
+++ b/drivers/char/ipmi/ipmi_msghandler.c
@@ -3188,8 +3188,8 @@ static void __get_guid(struct ipmi_smi *
if (rv)
/* Send failed, no GUID available. */
bmc->dyn_guid_set = 0;
-
- wait_event(intf->waitq, bmc->dyn_guid_set != 2);
+ else
+ wait_event(intf->waitq, bmc->dyn_guid_set != 2);

/* dyn_guid_set makes the guid data available. */
smp_rmb();