[dpdk-dev] [PATCH v2] ethdev: add sanity checks in control APIs

[Stephen Hemminger]

On Thu, 29 Apr 2021 10:48:34 -0700
Tyler Retzlaff <roretzla at linux.microsoft.com> wrote:

> On Tue, Apr 13, 2021 at 11:22:14AM +0800, Min Hu (Connor) wrote:
> > This patch adds more sanity checks in control path APIs.
> > 
> > Fixes: 214ed1acd125 ("ethdev: add iterator to match devargs input")
> > Fixes: 3d98f921fbe9 ("ethdev: unify prefix for static functions and variables")
> > Fixes: 0366137722a0 ("ethdev: check for invalid device name")
> > Fixes: d948f596fee2 ("ethdev: fix port data mismatched in multiple process model")
> > Fixes: 5b7ba31148a8 ("ethdev: add port ownership")
> > Fixes: f8244c6399d9 ("ethdev: increase port id range")
> > Cc: stable at dpdk.org
> > 
> > Signed-off-by: Min Hu (Connor) <humin29 at huawei.com>
> > ---  
> 
> this whole patch breaks abi since it returns new errno that were not
> previously documented or returned. even if it is accepted it probably
> should not be backported to stable.
> 
> it is entirely conceivable that you can have code that was calling these
> functions and checking for specific return values where the new return
> values will not be handled at all or improperly handled.
> 
> you can't just start emitting brand new errors or different errors for
> the same input parameters.

In practice, checking for passing a NULL doesn't add a lot of value.
No program should ever do that, and if it did the crash that happens
when it dereferenced is as good as an assert() or an error return.