2021-12-17 15:44:30

by Thadeu Lima de Souza Cascardo

Subject: [PATCH 1/2] ipmi: bail out if init_srcu_struct fails

In case, init_srcu_struct fails (because of memory allocation failure), we
might proceed with the driver initialization despite srcu_struct not being
entirely initialized.

Fixes: 913a89f009d9 ("ipmi: Don't initialize anything in the core until something uses it")
Signed-off-by: Thadeu Lima de Souza Cascardo <[email protected]>
Cc: Corey Minyard <[email protected]>
Cc: [email protected]
---
drivers/char/ipmi/ipmi_msghandler.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/char/ipmi/ipmi_msghandler.c b/drivers/char/ipmi/ipmi_msghandler.c
index c837d5416e0e..84975b21fff2 100644
--- a/drivers/char/ipmi/ipmi_msghandler.c
+++ b/drivers/char/ipmi/ipmi_msghandler.c
@@ -5392,7 +5392,9 @@ static int ipmi_init_msghandler(void)
if (initialized)
goto out;

- init_srcu_struct(&ipmi_interfaces_srcu);
+ rv = init_srcu_struct(&ipmi_interfaces_srcu);
+ if (rv)
+ goto out;

timer_setup(&ipmi_timer, ipmi_timeout, 0);
mod_timer(&ipmi_timer, jiffies + IPMI_TIMEOUT_JIFFIES);
--
2.32.0

2021-12-17 15:44:38

by Thadeu Lima de Souza Cascardo

Subject: [PATCH 2/2] ipmi: fix initialization when workqueue allocation fails

If the workqueue allocation fails, the driver is marked as not initialized,
and timer and panic_notifier will be left registered.

Instead of removing those when workqueue allocation fails, do the workqueue
initialization before doing it, and cleanup srcu_struct if it fails.

Fixes: 1d49eb91e86e ("ipmi: Move remove_work to dedicated workqueue")
Signed-off-by: Thadeu Lima de Souza Cascardo <[email protected]>
Cc: Corey Minyard <[email protected]>
Cc: Ioanna Alifieraki <[email protected]>
Cc: [email protected]
---
drivers/char/ipmi/ipmi_msghandler.c | 15 +++++++++------
1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/drivers/char/ipmi/ipmi_msghandler.c b/drivers/char/ipmi/ipmi_msghandler.c
index 84975b21fff2..266c7bc58dda 100644
--- a/drivers/char/ipmi/ipmi_msghandler.c
+++ b/drivers/char/ipmi/ipmi_msghandler.c
@@ -5396,20 +5396,23 @@ static int ipmi_init_msghandler(void)
if (rv)
goto out;

- timer_setup(&ipmi_timer, ipmi_timeout, 0);
- mod_timer(&ipmi_timer, jiffies + IPMI_TIMEOUT_JIFFIES);
-
- atomic_notifier_chain_register(&panic_notifier_list, &panic_block);
-
remove_work_wq = create_singlethread_workqueue("ipmi-msghandler-remove-wq");
if (!remove_work_wq) {
pr_err("unable to create ipmi-msghandler-remove-wq workqueue");
rv = -ENOMEM;
- goto out;
+ goto out_wq;
}

+ timer_setup(&ipmi_timer, ipmi_timeout, 0);
+ mod_timer(&ipmi_timer, jiffies + IPMI_TIMEOUT_JIFFIES);
+
+ atomic_notifier_chain_register(&panic_notifier_list, &panic_block);
+
initialized = true;

+out_wq:
+ if (rv)
+ cleanup_srcu_struct(&ipmi_interfaces_srcu);
out:
mutex_unlock(&ipmi_interfaces_mutex);
return rv;
--
2.32.0

2021-12-17 20:42:16

by Corey Minyard

Subject: Re: [PATCH 2/2] ipmi: fix initialization when workqueue allocation fails

Thanks for this, I need to be more careful about looking at code and not
just looking at patches. Both in my queue, I'll try to get them in to
5.16.

-corey

On Fri, Dec 17, 2021 at 12:44:10PM -0300, Thadeu Lima de Souza Cascardo wrote:
> If the workqueue allocation fails, the driver is marked as not initialized,
> and timer and panic_notifier will be left registered.
>
> Instead of removing those when workqueue allocation fails, do the workqueue
> initialization before doing it, and cleanup srcu_struct if it fails.
>
> Fixes: 1d49eb91e86e ("ipmi: Move remove_work to dedicated workqueue")
> Signed-off-by: Thadeu Lima de Souza Cascardo <[email protected]>
> Cc: Corey Minyard <[email protected]>
> Cc: Ioanna Alifieraki <[email protected]>
> Cc: [email protected]
> ---
> drivers/char/ipmi/ipmi_msghandler.c | 15 +++++++++------
> 1 file changed, 9 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/char/ipmi/ipmi_msghandler.c b/drivers/char/ipmi/ipmi_msghandler.c
> index 84975b21fff2..266c7bc58dda 100644
> --- a/drivers/char/ipmi/ipmi_msghandler.c
> +++ b/drivers/char/ipmi/ipmi_msghandler.c
> @@ -5396,20 +5396,23 @@ static int ipmi_init_msghandler(void)
> if (rv)
> goto out;
>
> - timer_setup(&ipmi_timer, ipmi_timeout, 0);
> - mod_timer(&ipmi_timer, jiffies + IPMI_TIMEOUT_JIFFIES);
> -
> - atomic_notifier_chain_register(&panic_notifier_list, &panic_block);
> -
> remove_work_wq = create_singlethread_workqueue("ipmi-msghandler-remove-wq");
> if (!remove_work_wq) {
> pr_err("unable to create ipmi-msghandler-remove-wq workqueue");
> rv = -ENOMEM;
> - goto out;
> + goto out_wq;
> }
>
> + timer_setup(&ipmi_timer, ipmi_timeout, 0);
> + mod_timer(&ipmi_timer, jiffies + IPMI_TIMEOUT_JIFFIES);
> +
> + atomic_notifier_chain_register(&panic_notifier_list, &panic_block);
> +
> initialized = true;
>
> +out_wq:
> + if (rv)
> + cleanup_srcu_struct(&ipmi_interfaces_srcu);
> out:
> mutex_unlock(&ipmi_interfaces_mutex);
> return rv;
> --
> 2.32.0
>