__LINUX_ERRNO_EXTENSIONS__ and RTEMS

[Joel Sherrill]

Jeff Johnston wrote:
> On 16/10/09 12:58 PM, Joel Sherrill wrote:
>   
>> Hi,
>>
>> Ralf Corsepius didn't like my patch to turn on
>> __LINUX_ERRNO_EXTENSIONS__ for RTEMS. So in fairness,
>> I did some analysis from an RTEMS perspective
>> and here are the results.
>> RTEMS includes a port of the FreeBSD TCP/IP stack
>> and a few other BSD network services. I grep'ed
>> the RTEMS source for every errno marked as a
>> Linux extension by newlib. Here is the result:
>>
>> ======== EBADR
>> cpukit/libnetworking/lib/ftpfs.c
>> ========= EBADRQC
>> cpukit/libnetworking/lib/ftpfs.c
>> ========= EPFNOSUPPORT
>> cpukit/librpc/src/rpc/bindresvport.c
>> cpukit/librpc/src/rpc/clnt_generic.c
>> ========= EHOSTDOWN
>> cpukit/libnetworking/netinet/ip_input.c
>> cpukit/libnetworking/netinet/tcp_subr.c
>> cpukit/libnetworking/nfs/bootp_subr.c
>> cpukit/libnetworking/net/if_ethersubr.c
>> ========= ETOOMANYREFS
>> cpukit/libnetworking/netinet/ip_output.c
>> ========= EPROCLIM
>> cpukit/httpd/sock.c
>>
>> What are the above files from?
>> + libnetworking is the TCP/IP stack and some services.
>> + libnetworking/ftpfs is RTEMS specific but tests for an error
>> returned by the stack.
>> + librpc is Sun RPC/XDR.
>> + httpd is the GoAhead webserver.
>>
>> Are there any relevant standards?
>>
>> + EHOSTDOWN is from
>> http://www.opengroup.org/onlinepubs/009695399/functions/xsh_chap02_10.html
>> so it is probably really not Linux specific anyway.
>>
>> + Every errno in this list appears in the Open Group test suite.
>>
>> http://tetworks.opengroup.org/tet//sample_binaries/3.3/tet3.3-bin-linux2-dist.cpio.Z
>>
>> I was unable to uncompress this so don't know what that means.
>> I didn't see any obvious references to them at opengroup.org in
>> a standards page in my search.
>>
>> It would be interesting to see if other errnos marked
>> Linux extensions are also used by *BSD but the set above
>> are the problems for RTEMS. We cannot build RTEMS with
>> newlib cvs without those defined.
>>
>> What is the best solution?
>>
>>     
>
> I believe it was RTEMS originally that had the problem with all the 
> errnos being exposed so I am totally ok with you creating a new flag: 
> __OPEN_GROUP_ERRNO_EXTENSIONS__ and using this flag or'd with the 
> __LINUX_ERRNO_EXTENSIONS__ flag for the errnos above.
>
>   
Ralf.. is this OK with you?
> Another alternative would be to override sys/errno.h for RTEMS.
>
>   
I would rather not do that.
> -- Jeff J.
>   


-- 
Joel Sherrill, Ph.D.             Director of Research & Development
joel.sherrill@OARcorp.com        On-Line Applications Research
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