* [PATCH] hdlcdrv: replace assertion with recovery code
@ 2019-12-15 17:58 Aditya Pakki
2019-12-15 18:50 ` Markus Elfring
2019-12-15 19:20 ` Stephen Hemminger
0 siblings, 2 replies; 3+ messages in thread
From: Aditya Pakki @ 2019-12-15 17:58 UTC (permalink / raw)
To: pakki001
Cc: kjlu, David S. Miller, Greg Kroah-Hartman, Markus Elfring,
Richard Fontana, Thomas Gleixner, netdev, linux-kernel
In hdlcdrv_register, failure to register the driver causes a crash.
However, by returning the error to the caller in case ops is NULL
can avoid the crash. The patch fixes this issue.
Signed-off-by: Aditya Pakki <pakki001@umn.edu>
---
drivers/net/hamradio/hdlcdrv.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/net/hamradio/hdlcdrv.c b/drivers/net/hamradio/hdlcdrv.c
index df495b5595f5..38e5d1e54800 100644
--- a/drivers/net/hamradio/hdlcdrv.c
+++ b/drivers/net/hamradio/hdlcdrv.c
@@ -687,7 +687,8 @@ struct net_device *hdlcdrv_register(const struct hdlcdrv_ops *ops,
struct hdlcdrv_state *s;
int err;
- BUG_ON(ops == NULL);
+ if (!ops)
+ return ERR_PTR(-EINVAL);
if (privsize < sizeof(struct hdlcdrv_state))
privsize = sizeof(struct hdlcdrv_state);
--
2.20.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] hdlcdrv: replace assertion with recovery code
2019-12-15 17:58 [PATCH] hdlcdrv: replace assertion with recovery code Aditya Pakki
@ 2019-12-15 18:50 ` Markus Elfring
2019-12-15 19:20 ` Stephen Hemminger
1 sibling, 0 replies; 3+ messages in thread
From: Markus Elfring @ 2019-12-15 18:50 UTC (permalink / raw)
To: Aditya Pakki, netdev
Cc: Kangjie Lu, David S. Miller, Greg Kroah-Hartman, Richard Fontana,
Thomas Gleixner, linux-kernel
> However, by returning the error to the caller in case ops is NULL
> can avoid the crash.
I suggest to improve this change description by choosing also
a more imperative wording.
> The patch fixes this issue.
Please replace this sentence by the tag “Fixes”.
Regards,
Markus
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] hdlcdrv: replace assertion with recovery code
2019-12-15 17:58 [PATCH] hdlcdrv: replace assertion with recovery code Aditya Pakki
2019-12-15 18:50 ` Markus Elfring
@ 2019-12-15 19:20 ` Stephen Hemminger
1 sibling, 0 replies; 3+ messages in thread
From: Stephen Hemminger @ 2019-12-15 19:20 UTC (permalink / raw)
To: Aditya Pakki
Cc: kjlu, David S. Miller, Greg Kroah-Hartman, Markus Elfring,
Richard Fontana, Thomas Gleixner, netdev, linux-kernel
On Sun, 15 Dec 2019 11:58:41 -0600
Aditya Pakki <pakki001@umn.edu> wrote:
> In hdlcdrv_register, failure to register the driver causes a crash.
> However, by returning the error to the caller in case ops is NULL
> can avoid the crash. The patch fixes this issue.
>
> Signed-off-by: Aditya Pakki <pakki001@umn.edu>
> ---
> drivers/net/hamradio/hdlcdrv.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/net/hamradio/hdlcdrv.c b/drivers/net/hamradio/hdlcdrv.c
> index df495b5595f5..38e5d1e54800 100644
> --- a/drivers/net/hamradio/hdlcdrv.c
> +++ b/drivers/net/hamradio/hdlcdrv.c
> @@ -687,7 +687,8 @@ struct net_device *hdlcdrv_register(const struct hdlcdrv_ops *ops,
> struct hdlcdrv_state *s;h
> int err;
>
> - BUG_ON(ops == NULL);
> + if (!ops)
> + return ERR_PTR(-EINVAL);
>
> if (privsize < sizeof(struct hdlcdrv_state))
> privsize = sizeof(struct hdlcdrv_state);
It is good to remove BUG_ON's but this is not a good way to fix it.
The original code was being over paranoid. There are only 3 places
this function is called in the current kernel and all pass a valid
pointer. Better just remove the BUG_ON all together; it is not
worth carrying bug checks for "some day somebody might add broken code".
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2019-12-15 19:20 UTC | newest]
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2019-12-15 17:58 [PATCH] hdlcdrv: replace assertion with recovery code Aditya Pakki
2019-12-15 18:50 ` Markus Elfring
2019-12-15 19:20 ` Stephen Hemminger
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