Re: [PATCH] Make EWOULDBLOCK be equal to EAGAIN on parisc.

[John David Anglin <dave.anglin@bell.net>]

On 1/16/2014 3:02 PM, Carlos O'Donell wrote:
> On Thu, Jan 16, 2014 at 11:17 AM, Guy Martin <gmsoft@tuxicoman.be> wrote:
>> On Linux, only parisc uses a different value for EWOULDBLOCK which
>> causes a lot of troubles for applications not checking for both values.
>> Since the hpux compat is long dead, make EWOULDBLOCK behave the same as
>> all other architectures.
>>
>> Signed-off-by: Guy Martin  <gmsoft@tuxicoman.be>
>> ---
>>   arch/parisc/include/uapi/asm/errno.h | 2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/arch/parisc/include/uapi/asm/errno.h
>> b/arch/parisc/include/uapi/asm/errno.h
>> index f3a8aa5..c0ae625 100644
>> --- a/arch/parisc/include/uapi/asm/errno.h
>> +++ b/arch/parisc/include/uapi/asm/errno.h
>> @@ -106,7 +106,7 @@
>>
>>   #define        EALREADY        244     /* Operation already in progress */
>>   #define        EINPROGRESS     245     /* Operation now in progress */
>> -#define        EWOULDBLOCK     246     /* Operation would block (Linux
>> returns EAGAIN) */
>> +#define        EWOULDBLOCK     EAGAIN  /* Operation would block (Not HPUX
>> compliant) */
>>   #define        ENOTEMPTY       247     /* Directory not empty */
>>   #define        ENAMETOOLONG    248     /* File name too long */
>>   #define        ELOOP           249     /* Too many symbolic links
>> encountered */
> This is an ABI break.
>
> You can't do this without rebuilding userspace.
>
> You need debian an gentoo onboard to do this ABI break.
This would take about a month on Debian, so I'm against.  Various bits 
of kernel code traditionally
return EWOULDBLOCK, so any application code that just checks EWOULDBLOCK 
would fail.

Dave

-- 
John David Anglin    dave.anglin@bell.net