Re: [PATCH v2 bpf-next 1/3] perf: enable branch record for software events

[Peter Zijlstra]

On Mon, Aug 30, 2021 at 05:41:46PM +0000, Song Liu wrote:
> DECLARE_STATIC_CALL(perf_snapshot_branch_stack,
>                    int (*)(struct perf_branch_snapshot *));

> Something like 
> 
> typedef int (perf_snapshot_branch_stack_t)(struct perf_branch_snapshot *);
> DECLARE_STATIC_CALL(perf_snapshot_branch_stack, perf_snapshot_branch_stack_t);
> 
> seems to work fine. 

Oh urg, indeed. It wants a function type, not a function pointer type.
I've been bitten by that before. Go with the typedef, that's the sanest.