Re: [PATCH v7 bpf-next 06/10] tracepoint: compute num_args at build time

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Wed, 28 Mar 2018 10:10:34 -0700
Alexei Starovoitov <ast@xxxxxx> wrote:


> > and have:
> >
> > 	u64 tp_offset = (u64)tp - (u64)_sdata;
> >
> > 	if (WARN_ON(tp_offset > UINT_MAX)
> > 		return -EINVAL;
> >
> > 	 btp->tp_offset = (u32)tp_offset;  
> 
> above math has to be build time constant, so warn_on likely
> won't work.

Right, it would require a BUILD_BUG_ON.

> imo the whole thing is too fragile and obscure.
> I suggest to compress this 8 bytes * num_of_tracepoints later.
> Especially would be good to do it in one way for
> bpf_raw_event_map, ftrace and other places.

Fair enough. We can defer this shrinkage to another time. I only
suggested it here over your concern for the added bloat.

-- Steve
--
To unsubscribe from this list: send the line "unsubscribe linux-api" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html



[Index of Archives]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]

  Powered by Linux