On 08/28/2017 06:14 PM, Alexander Kanavin wrote:
On 08/28/2017 05:43 PM, Richard Purdie wrote:
The bitfield operation that says "can I read this fd?" probably
overflows into the next data item in the structure (I haven't checked
exactly how it fails). It may be "set", certainly the case I debugged
had to have thought it was and the code thinks "fd 1025 is ready for
reading" when in fact it may not be. The code then calls read() on it
and if it wasn't ready for reading, it would block.
Right; what I am getting at is that we might have a bug here
(specifically the absence of check against FD_SETSIZE), rather than
something that needs to be solved by switching to poll().
Does the code use that constant anywhere?
Actually, wait: "Executing FD_CLR() or FD_SET() with a value of fd that
is negative or is equal to or larger than FD_SETSIZE will result in
undefined behavior." (man select)
This means that select() cannot be used with fd >= FD_SETSIZE at all?
Alex
--
_______________________________________________
Openembedded-core mailing list
Openembedded-core@lists.openembedded.org
http://lists.openembedded.org/mailman/listinfo/openembedded-core
