Re: [PATCH RFC 00/33] Compile-time thread-safety checking

[Bart Van Assche]

On 2/7/25 1:08 AM, Peter Zijlstra wrote:
> On Fri, Feb 07, 2025 at 10:05:47AM +0100, Marco Elver wrote:
> > Yes, you can add multiple guarded_by. But it's just going to enforce
> > that you need to hold both locks before you access the member. If you
> > want the rules to be more complex, the best way to express that is with
> > some helpers. E.g. something like this (tested on top my series)
>
> Oh gawd, this is going to be a pain, isn't it :/

The Clang thread-safety annotations are used widely so behavior of
existing attributes must be preserved. I propose to introduce new
thread-safety attributes when useful to annotate kernel code. As an
example, the Clang try_acquire_capability function attribute does not
support functions that return pointers although this is a common pattern
in the Linux kernel. I think that introducing a new function attribute
to support functions that return pointers is a better solution than
trying to annotate such functions with any of the existing Clang
thread-safety attributes.

Thanks,

Bart.