Re: [PATCH] KVM: x86: fix cocci warnings

From: Paolo Bonzini
Date: Tue Nov 16 2021 - 04:51:37 EST

On 11/15/21 10:59, Vitaly Kuznetsov wrote:
One minor remark: 'kvm_set_pte_rmapp()' handler is passed to
'kvm_handle_gfn_range()' which does

bool ret = false;

ret |= handler(...);

and I find '|=' to not be very natural with booleans. I'm not sure it's
worth changing though.

Changing that would be "harder" than it seems because "ret = ret || handler(...)" is wrong, and "|" is even more unnatural than "|=" (so much that clang warns about it).

In fact I wonder if "|=" with a bool might end up warning with clang, which we should check before applying this patch. It doesn't seem to be in the original commit[1], but better safe than sorry: Nick, does clang intend to warn also about "ret |= fn()" and "ret &= fn()"? Technically, it is a bitwise operation with side-effects in the RHS.