[Date Prev][Date Next] [Thread Prev][Thread Next] [Date Index] [Thread Index]

Re: Request for help: unaligned trap



This one time, at band camp, Steve Langasek said:
> On Mon, Apr 11, 2005 at 10:43:59PM -0400, Stephen Gran wrote:
> > Hello all,
> 
> > Could somebody please take a look at
> > http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=289187 
> > ?
> 
> > The gist of the report is that the kernel is reporting unaligned trap
> > problem with clamd.  Beyond getting the idea that this is probably a
> > sizeof() problem or similar, I am not sure hw to proceed.
> 
> > It appears alpha specific, and I don't have any experience with alpha
> > issues at all.
> 
> Usually not; usually such bugs are reproducible on sparc and ia64 as well,
> and IIRC both of those architectures are easier to debug because the trap
> is exposed to userspace (i.e., SIGBUS), making it much simpler to get a
> backtrace.
This one time, at band camp, Falk Hueffner said:
> Just add this code to main:
> 
> #if defined(__alpha__) && defined(__linux__)
>     // Deliver SIGBUS on unaligned traps instead of fixing them up.
>     #include <unistd.h>
>     #include <asm/sysinfo.h>
>     #include <asm/unistd.h>
>     syscall(__NR_osf_setsysinfo, SSI_NVPAIRS,
> 	    (unsigned int[]) { SSIN_UACPROC, UAC_SIGBUS | UAC_NOPRINT },
> 	    1, 0, 0, 0);
> #endif

Thanks very much for this, folks.  It appears the various project alpha
machines are down, but if I can reproduce it on sparc or something as
well, it ought to be doable.

Thanks again,
-- 
 -----------------------------------------------------------------
|   ,''`.					     Stephen Gran |
|  : :' :					 sgran@debian.org |
|  `. `'			Debian user, admin, and developer |
|    `-					    http://www.debian.org |
 -----------------------------------------------------------------

Attachment: pgpwLgbWJMd4m.pgp
Description: PGP signature


Reply to: