Re: PATCH - x86-64 signed-compare bug, was Re: select() setting ERESTARTNOHAND (514).

[Andi Kleen <ak@suse.de>]

On Thursday 11 January 2007 01:37, Neil Brown wrote:
> On Wednesday January 10, jafo@tummy.com wrote:
> > 
> > In looking at the Linux code for ERESTARTNOHAND, I see that
> > include/linux/errno.h says this errno should never make it to the user.
> > However, in this instance we ARE seeing it.  Looking around on google shows
> > others are seeing it as well, though hits are few.
> ..
> > 
> > Thoughts?
> 
> Just a 'me too' at this point. 
> The X server on my shiny new notebook (Core 2 Duo) occasionally dies
> with 'select' repeatedly returning ERESTARTNOHAND.  It is most
> annoying!

Normally it should be only visible in strace. Did you see it without
strace?

> 
> You don't mention in the Email which kernel version you use but I see
> from the web page you reference it is 2.6.19.1.  I'm using
> 2.6.18.something.
> 
> I thought I'd have a quick look at the code, comparing i386 to x86-64
> and guess what I found.....
> 
> On x86-64, regs->rax is "unsigned long", so the following is
> needed....

regs->rax is unsigned long.
I don't think your patch will make any difference. What do you think
it will change?

-Andi