Re: [PATCH 07/27] score: create head files elf.h emergency-restart.h errno.h

[Arnd Bergmann]

On Saturday 13 June 2009, liqin.chen@xxxxxxxxxxxxx wrote:
> > 
> > EMAXERRNO is mips specific right now. Do you actually need it somewhere?
> > 
> 
> Yes, I used it in entry.S, maybe I could remove this define latter.
> 

Ok. Note that the maximum error number that is supposed to get sent back
to user space is 511. Most architectures check the return value of the
system call to be between -4095 and zero upon entering user space.
Checking it in the kernel gives you the chance to override the
error status from a system call with force_successful_syscall_return().

If that is your intention, you should probably leave the definition in there.
Powerpc uses _LAST_ERRNO for the same purpose, which is somewhat inconsistent
with mips and also uses a different value to compare against.

	Arnd <><
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/