Re: kern/16284 running function in stoped gdb ...

[David Holland <dholland-bugs%netbsd.org@localhost>]

The following reply was made to PR kern/16284; it has been noted by GNATS.

From: David Holland <dholland-bugs%netbsd.org@localhost>
To: gnats-bugs%NetBSD.org@localhost
Cc: kern-bug-people%netbsd.org@localhost, gnats-admin%netbsd.org@localhost,
        netbsd-bugs%netbsd.org@localhost, lha%stacken.kth.se@localhost
Subject: Re: kern/16284 running function in stoped gdb ...
Date: Sun, 3 Jan 2010 21:19:36 +0000

 On Sun, Jan 03, 2010 at 09:10:06PM +0000, David Laight wrote:
  >  This still happens, errno is unchanged and the 'ret' value
  >  from select() seems to be undefined.
 
 My first guess would be that something in gdb that thinks %eax doesn't
 have to be saved and restored (because it's caller-save) is trashing
 the return value (which is held in %eax).
 
  >  Sometimes, but not always, I also see almost 2 seconds delay before
  >  the output from the called function - not sure where that delay comes from.
 
 maybe another trip into select?
 
  >  (A 2nd ^C gives a "Corrupt Obj_Entry pointer in GOT" error.)
 
 That's weird.
 
  >  Anyone know the ptrace interface well enough to know what gdb is
  >  trying to do ?
 
 Not without reading gdb code.
 
 -- 
 David A. Holland
 dholland%netbsd.org@localhost