cvs commit: src/sys/kern vfs_mount.c

Nate Lawson nate at
Wed Nov 9 08:07:12 GMT 2005

Poul-Henning Kamp wrote:
> In message <43716BD6.5050604 at>, Nate Lawson writes:
>>While I don't have ideas for a better general mechanism for this, I 
>>think it sets a bad precedent.  We can't have every complex syscall 
>>transporting its own error message strings back to the user program. 
>>And we can't expand errno to be the union of every single API-specific 
>>error either.
> That was one the main points of my ioctl talk at BSDcan.
> One way to solve it:
> Hang a sbuf pointer in each thread and APIs cound stuff their error
> message there.
> Add a new syscall to return the string to userland.
> Modify perror(3), err(3) and similar to pull out the "extended"
> error, if there is one.

This sounds better.  Not sure if it's fully baked, but definitely a 
better direction.


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