Re: [PATCH net v2] xdp: xdp_mem_allocator can be NULL in trace_mem_connect().

Sebastian Andrzej Siewior [off-list ref] writes:

Since the commit mentioned below __xdp_reg_mem_model() can return a NULL
pointer. This pointer is dereferenced in trace_mem_connect() which leads
to segfault.

The trace points (mem_connect + mem_disconnect) were put in place to
pair connect/disconnect using the IDs. The ID is only assigned if
__xdp_reg_mem_model() does not return NULL. That connect trace point is
of no use if there is no ID.

Skip that connect trace point if xdp_alloc is NULL.

[ Toke Høiland-Jørgensen delivered the reasoning for skipping the trace
  point ]

Fixes: 4a48ef70b93b8 ("xdp: Allow registering memory model without rxq reference")
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>

With Steven's fix:

Acked-by: Toke Høiland-Jørgensen <redacted>