[rfc] For mips, sign-extended ecoff offsets
Ian Lance Taylor
Mon Jun 19 20:39:00 GMT 2000
Date: Tue, 20 Jun 2000 11:50:26 +1000 (EST)
From: Alan Modra <email@example.com>
> > I'm worried about what happens if things like PDR.adr get changed from
> > 0xa0000000 to 0xffffffffa0000000.
> Thats why I'm asking :-) Remember though, on the MIPS platform, if
> ``PDR.adr'' is an address then, the canonical form of the value
> ``0xa0000000'' obtained from an elf32 binary is 0xffffffffa00000000.
> GDB and BFD have, for too many years, been bribed and cajoled into
> perpetuated the lie that MIPS doesn't sign extend addresses. GDB's now
> decided to come clean on this matter (and purge an amazing amount of
> bogus code :-).
> I guess the question for BFD people is, is this the correct approach to
> fixing this bug?
I'd like to hear Ian's comments on this before you check it in.
This is all due to a long-ago decision to ship support for a 64-bit
MIPS chip using a 32-bit MIPS target. I think that sign extending
pdr.ADR is probably right, since that is how 32 bit addresses are
treated by the relocation routines. But the real fix is to use a
64-bit MIPS target.
More information about the Gdb-patches