Re: [PATCH] [1/2] kernel error reporting (revised)

[Andrew Morton <akpm@xxxxxxxx>]

Jim Keniston <jkenisto@xxxxxxxxxx> wrote:
>
> +int kernel_error_event_iov(const struct iovec *iov, unsigned int nseg,
> +     u32 groups)
> +{
> ...
> +
> +     return netlink_broadcast(kerror_nl, skb, 0, ~0, GFP_ATOMIC);

This appears to be deadlocky when called from interrupt handlers.

netlink_broadcast() does read_lock(&nl_table_lock).  But nl_table_lock is
not an irq-safe lock.

Possibly netlink_broadcast() can be made callable from hardirq context, but
it looks to be non trivial.  The various error and delivery handlers need
to be reviewed, the kfree_skb() calls should be thought about, etc.