[PATCH] x86: Check invalid immediate for rdmsr and wrmsrns

[Jan Beulich]

On 08.04.2026 02:22, H.J. Lu wrote:
> Verify immediate operand before processing immediate for rdmsr and
> wrmsrns.
> 
> PR gas/34028
> * config/tc-i386.c (i386_assemble): Verify immediate operand
> before processing immediate for rdmsr and wrmsrns.
> * testsuite/gas/i386/msr_imm-inval.l: Updated.
> * testsuite/gas/i386/x86-64-msr_imm-inval.l: Likewise.
> * testsuite/gas/i386/msr_imm-inval.s: Add new rdmsr and wrmsrns
> tests.
> * testsuite/gas/i386/x86-64-msr_imm-inval.s: Likewise.

The new insn forms you add don't make clear what exactly you're after:
The %cs operands make them invalid no matter what immediate is used. I
don't mind you adding "bogus register" forms, but that's not related
to the purpose of the patch. $y, otoh, looks like an entirely valid
operand to me: y can be an absolute symbol defined elsewhere. So what
exactly is it that you're trying to (a) prevent and (b) test?

As an aside, adding further insn forms to the 32-bit testcase looks
pretty meaningless to me. The forms with operands aren't supported
outside of 64-bit mode anyway, no matter what exactly the operands
are.

Jan