Bug 216922

Summary: bpf(4): opening already opened device returns EBUSY; not documented as supported error in open(2) and not documented in bpf manpages
Product: Documentation Reporter: Enji Cooper <ngie>
Component: Manual PagesAssignee: freebsd-doc (Nobody) <doc>
Status: New ---    
Severity: Affects Some People CC: doc
Priority: ---    
Version: Latest   
Hardware: Any   
OS: Any   

Description Enji Cooper freebsd_committer freebsd_triage 2017-02-08 18:13:38 UTC 
We have some code at $work that opens bpf(4) devices. It has to handle EBUSY because of this line of code: https://svnweb.freebsd.org/base/head/sys/net/bpf.c?annotate=303382#l869

It seems like there are 2 bugs, potentially:
- open(2) should note that behavior for character devices may vary from the ERRORS section.
- bpf(4) returning EBUSY when the device is in use should be documented, somewhere (maybe in bpf(9)?).