Re: 32-bit gcore on amd64

[Daniel Jacobowitz <drow@false.org>]

On Thu, Feb 19, 2004 at 07:17:03PM -0500, Andrew Cagney wrote:
> >On Thu, Feb 19, 2004 at 06:12:22PM -0500, Andrew Cagney wrote:
> >
> >>>This is more questions than answers.  I'm trying to figure out how GDB 
> >>>should generate 32-bit core files on amd64 (i.e., get gmake check 
> >>>'RUNTESTFLAGS=--target_board=unix/-m32 gcore.exp' to pass).  The problem 
> >>>is, everything I look at feels wrong.
> >>>
> >>>Here's the first backtrace:
> >>>
> >>>#0  amd64_collect_native_gregset (regcache=0x808410, gregs=0x7fbfffead0,
> >>>    regnum=-1) at /home/cygnus/cagney/GDB/src/gdb/amd64-nat.c:124
> >>>#1  0x0000000000450e16 in fill_gregset (gregsetp=0x808410, 
> >>>regnum=-1073747248)
> >>>    at /home/cygnus/cagney/GDB/src/gdb/x86-64-linux-nat.c:126
> >>>#2  0x000000000045803d in linux_do_thread_registers (obfd=0x87fc90, ptid=
> >>>      {pid = 10494, lwp = 10494, tid = 0}, note_data=0x8b0960 "\005",
> >>>    note_size=0x7fbfffed8c) at 
> >>>/home/cygnus/cagney/GDB/src/gdb/linux-proc.c:180
> >>>
> >>>This function is asking fill_gregset to populate an amd64 gregset_t.  I 
> >>>think it should be asking for the 32-bit gregset_t to be filled in.
> >
> >
> >Does the same thing apply to mips64-linux/-mabi=32?  Normally we make a
> >point of only dealing with the registers' "real" size.
> 
> "Possibly", can you clarify this a little?
> 
> GDB debugging a 32-bit i386 program should always "gcore" a 32-bit i386 
> core file.

I was just referring to the same thing Mark mentioned: what the kernel
actually dumps.  I'm pretty sure a MIPS64 Linux kernel dumps 64-bit
core files for all programs.  On the other hand, it looks like the
latest 2.6 kernels don't do that any more; how fast I am outdated...

-- 
Daniel Jacobowitz
MontaVista Software                         Debian GNU/Linux Developer