Re: Kernel oops in read()

[Larry Sendlosky <larry scrugs lkg dec com>]

> It seems that the standard RH kernel builds (certainly 6.0, 6.1) generate
> kernels under which
> the got table size is >64k. This breaks the exception table handling in the

  I build my own kernel and the .got section is < 64KB. I checked
  the RH 2.2.13-0.9 kernel and the .got is >64KB. 

> kernel.
> So when system calls do protected reads from user space they are not actually
> protected
> and generate oops if the user supplies bad addresses.
> 
> Anyway the fix/workaround is to uncomment the -relax option in the
> arch/alpha/Makefile.
> This (in most cases) reduces the got table to be <64k and so avoids the problem.

  Actually, if it is "legal" to build a kernel with a .got > 64KB,
  then the kernel exception handler needs to be fixed.
 

  larry

______________________________________________________________________
 Larry Sendlosky			 	            ATS
 larry@scrugs.lkg.dec.com (978) 506-6640                    Compaq
----------------------------------------------------------------------