David, Mike,
thanks for reminding me; did we get a chance to go through that summary
set of patches for x86 and x86-64 from the frysk project (
http://sourceware.org/frysk ) that were posted. See:
http://lists.gnu.org/archive/html/libunwind-devel/2006-11/msg00003.html
It would be good to see these merged
Andrew
David Mosberger-Tang wrote:
Corey,
The HP-PA port of libunwind isn't terribly stable or even complete.
Looking at x86, x86-64, or ia64 ports is probably a better idea.
--david
On 1/9/07, Corey Ashford <[EMAIL PROTECTED]> wrote:
Hello,
I'm currently working on a port of libunwind to the PowerPC and am
having trouble understanding some parts of the code in libunwind.
In particular, I'm not sure of the right place to put the code to update
c->dwarf.loc[UNW_TDEP_IP] during a call to unw_step(). The return
address register is getting updated correctly, but the IP address is a
pseudo-dwarf register, and so the dwarf unwinding isn't doing that part
of the logic.
Where would be the best place to put the code that updates this
pseudo-register?
On a related subject:
In trying to figure this out, I was looking at the HPPA implementation
and I see the following code in tdep_access_reg:
switch (reg)
{
case UNW_HPPA_IP:
if (write)
c->dwarf.ip = *valp; /* update the IP cache */
if (c->dwarf.pi_valid && (*valp < c->dwarf.pi.start_ip ||
*valp >= c->dwarf.pi.end_ip))
c->dwarf.pi_valid = 0; /* new IP outside of current proc */
break;
...
}
if ((unsigned) (reg - UNW_HPPA_GR) >= 32) /**** SEE BELOW ****/
return -UNW_EBADREG;
loc = c->dwarf.loc[reg];
if (write)
return dwarf_put (&c->dwarf, loc, *valp);
else
return dwarf_get (&c->dwarf, loc, valp);
}
Here's a problem, as I see it. (UNW_TDEP_IP - UNW_HPPA_GR) == 64 which
is >= 32 and therefore an attempt to read the UNW_TDEP_IP register will
result in returning -UNW_EBADREG.
Is that right or am I missing something there?
Thanks for your consideration,
- Corey
--
Corey Ashford
Software Engineer
IBM Linux Technology Center, Linux Toolchain
Beaverton, OR
503-578-3507
[EMAIL PROTECTED]
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