Re: [PATCH] net: Change the layout of structure trace_event_raw_fib_table_lookup

From: David Miller
Date: Mon Aug 13 2018 - 12:37:06 EST


From: Zong Li <zong@xxxxxxxxxxxxx>
Date: Mon, 13 Aug 2018 10:26:52 +0800

> There is an unalignment access about the structure
> 'trace_event_raw_fib_table_lookup'.
>
> In include/trace/events/fib.h, there is a memory operation which casting
> the 'src' data member to a pointer, and then store a value to this
> pointer point to.
>
> p32 = (__be32 *) __entry->src;
> *p32 = flp->saddr;
>
> The offset of 'src' in structure trace_event_raw_fib_table_lookup is not
> four bytes alignment. On some architectures, they don't permit the
> unalignment access, it need to pay the price to handle this situation in
> exception handler.
>
> Adjust the layout of structure to avoid this case.
>
> Signed-off-by: Zong Li <zong@xxxxxxxxxxxxx>

Applied, with Fixes tag from David added.