I'd like to fix binutils ASAP. Here is a patch.
On Thu, Jul 25, 2002 at 03:29:12PM +0200, Carsten Langgaard wrote:
> "Maciej W. Rozycki" wrote:
> > On Wed, 24 Jul 2002, Carsten Langgaard wrote:
> > > We at MIPS are in the process of making an ABI spec for all this, which
> > > is the intention that should be used by the tool-vendors. So please
> > > don't change the ELF header defines.
> > It'd be better the spec matched the real world...
> Shouldn't it be the other way around, the real world should follow the spec
> The whole ELF header definition is just one big mess, because we are lacking
> a proper ABI spec.
> That's what has motivated us, to begin making this ABI spec.
> We have defined the e_flags this way:
> /* ELF header e_flags defines. MIPS architecture level. */
> #define EF_MIPS_ARCH_1 0x00000000 /* -mips1 code. */
> #define EF_MIPS_ARCH_2 0x10000000 /* -mips2 code. */
> #define EF_MIPS_ARCH_3 0x20000000 /* -mips3 code. */
> #define EF_MIPS_ARCH_4 0x30000000 /* -mips4 code. */
> #define EF_MIPS_ARCH_5 0x40000000 /* -mips5 code. */
> #define EF_MIPS_ARCH_32 0x60000000 /* MIPS32 code. */
> #define EF_MIPS_ARCH_64 0x70000000 /* MIPS64 code. */
> #define EF_MIPS_ARCH_32R2 0x80000000 /* MIPS32 code. */
> #define EF_MIPS_ARCH_64R2 0x90000000 /* MIPS64 code. */
> The missing value 0x50000000, is because IRIX has defined a EF_MIPS_ARCH_6
> and Algorithmics has a E_MIPS_ARCH_ALGOR_32, which has this value.
> If you look at the elf.h file in glibc, the you will see, it has the same
> values as the kernel.
> So I would prefer we fix that in binutils, I guess it not a problem as long
> as you don't have a toolchain that can generate MIPS32 or MIPS64 code.
> > > I don't see that is wrong with checking the ISA level, I rather have an
> > > error telling me that I can't execute a certain ISA level than
> > > eventually getting a reserved instruction or something worse like
> > > something unpredictable.
> > Well, -ENOEXEC in not any more useful than SIGILL -- with the latter you
> > have at least an idea what happened. The ISA check is not implemented for
> > any Linux port, so there no suitable hook in binfmt_*.c files. You might
> > propose an implementation if that's particularly important for you.
> I would like a message telling me that I can't run this ISA level on the
> Imagined what would happen, if you execute mips3 code and execute ld/sd
> instructions on a mips32 kernel (but on a 64-bit processor), the kernel only
> save half the register and then everything could happen.
> > > You are obviously right about the elf_check_arch in the 64-bit part of
> > > the kernel is broken. It's probably just be copied from the 32-bit part
> > > without changes, like a lot of the code in the 64-bit kernel is.
> > Possibly, but it still makes me wonder why it wasn't adjusted at the time
> > binfmt_elf32.c was created...
> > Maciej
> > --
> > + Maciej W. Rozycki, Technical University of Gdansk, Poland +
> > +--------------------------------------------------------------+
> > + e-mail: firstname.lastname@example.org, PGP key available +
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