Re: [PATCH] io_uring: propagate array_index_nospec opcode into req->opcode

[Keith Busch]

On Fri, May 15, 2026 at 10:58:11AM -0400, Michael Bommarito wrote:
> The compiled change is one instruction (a single mov of the clamped
> byte to req->opcode); the cmp/sbb/and clamp triplet is unchanged.
> No functional change: array_index_nospec() is a no-op for opcodes in
> [0, IORING_OP_LAST), and out-of-range opcodes are still rejected at
> the bounds check above this assignment.  

Since the bounds check above already catches an invalid opcode, why does
it need to be re-initialized to the clamped value? Surely it's already
the same value if we've taken this path, no?