Re: [PATCH v3 3/6] ptrace: Order and comment PT_flags

Will Deacon
2021-10-14T09:31:29Z

On Sat, Oct 09, 2021 at 12:07:57PM +0200, Peter Zijlstra wrote:
> Add a comment to the PT_flags to indicate their actual value, this
> makes it easier to see what bits are used and where there might be a
> possible hole to use.
>
> Notable PT_SEIZED was placed wrong, also PT_EVENT_FLAG() space seems
> ill defined, as written is seems to be meant to cover the entire
> PTRACE_O_ range offset by 3 bits, which would then be 3+[0..21],
> however PT_SEIZED is in the middle of that.

Why do you think PT_EVENT_FLAG() should cover all the PTRACE_O_* options?
Just going by the name and current callers, I'd only expect it to cover
the PTRACE_EVENT_* flags, no?

But in any case, having the comments is helpful, so:

Acked-by: Will Deacon <will@kernel.org>

Will