James Carlson wrote:
> Nils Goroll writes:
>> I am crossposting to networking-discuss and tools-compilers because I am not
>> sure if this is a compiler issue or a bug in the rpc module:
>
> It's a bug in the "rpc" module. Tunables must never be declared
> 'static' or the compiler can and will optimize them away (as you've
> discovered). This is a fairly old but recurring issue -- see CRs
> 4354490 and 6734437.
The ELF symbols are different for global vs static symbols. If you have a
list of known tunables, you should be able to audit this automatically by
having the build scan the symbols after you compile.
--chris
>
> It's something that code reviewers should catch.
>
>> Any pointers are highly appreciated. If this is not a compiler bug, I'd open
>> a
>> bug and prepare a webrev with the fix. If this issue is fixed with current
>> compilers, I apologize for the noise.
>
> Not a compiler bug, in my opinion. The compiler is doing exactly what
> we told it to do ("assume nobody outside of this module can modify
> this value unless someone here takes its address") ... just not what
> we wanted.
>
