2020-04-03 09:12:06

by Wen Yang

[permalink] [raw]
Subject: [PATCH] ipmi: fix hung processes in __get_guid()

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 <[email protected]>
Cc: Corey Minyard <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: [email protected]
Cc: [email protected]
---
drivers/char/ipmi/ipmi_msghandler.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/char/ipmi/ipmi_msghandler.c b/drivers/char/ipmi/ipmi_msghandler.c
index 64ba16dcb681..c48d8f086382 100644
--- a/drivers/char/ipmi/ipmi_msghandler.c
+++ b/drivers/char/ipmi/ipmi_msghandler.c
@@ -3193,8 +3193,8 @@ static void __get_guid(struct ipmi_smi *intf)
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();
--
2.23.0


2020-04-03 13:06:45

by Corey Minyard

[permalink] [raw]
Subject: Re: [PATCH] ipmi: fix hung processes in __get_guid()

On Fri, Apr 03, 2020 at 05:04:08PM +0800, Wen Yang wrote:
> 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:

Oops, yeah, that's a problem. Thanks for the patch, I've put it into my
next tree.

I've requested a stable backport.

-corey

>
> [ 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 <[email protected]>
> Cc: Corey Minyard <[email protected]>
> Cc: Arnd Bergmann <[email protected]>
> Cc: Greg Kroah-Hartman <[email protected]>
> Cc: [email protected]
> Cc: [email protected]
> ---
> drivers/char/ipmi/ipmi_msghandler.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/char/ipmi/ipmi_msghandler.c b/drivers/char/ipmi/ipmi_msghandler.c
> index 64ba16dcb681..c48d8f086382 100644
> --- a/drivers/char/ipmi/ipmi_msghandler.c
> +++ b/drivers/char/ipmi/ipmi_msghandler.c
> @@ -3193,8 +3193,8 @@ static void __get_guid(struct ipmi_smi *intf)
> 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();
> --
> 2.23.0
>