Re: [PATCH v3 02/13] mm: introduce execmem_text_alloc() and execmem_free()

[Mike Rapoport <rppt@kernel.org>]

On Thu, Sep 21, 2023 at 03:14:54PM -0700, Song Liu wrote:
> On Mon, Sep 18, 2023 at 12:30 AM Mike Rapoport <rppt@kernel.org> wrote:
> >
> [...]
> > +
> > +/**
> > + * enum execmem_type - types of executable memory ranges
> > + *
> > + * There are several subsystems that allocate executable memory.
> > + * Architectures define different restrictions on placement,
> > + * permissions, alignment and other parameters for memory that can be used
> > + * by these subsystems.
> > + * Types in this enum identify subsystems that allocate executable memory
> > + * and let architectures define parameters for ranges suitable for
> > + * allocations by each subsystem.
> > + *
> > + * @EXECMEM_DEFAULT: default parameters that would be used for types that
> > + * are not explcitly defined.
> > + * @EXECMEM_MODULE_TEXT: parameters for module text sections
> > + * @EXECMEM_KPROBES: parameters for kprobes
> > + * @EXECMEM_FTRACE: parameters for ftrace
> > + * @EXECMEM_BPF: parameters for BPF
> > + * @EXECMEM_TYPE_MAX:
> > + */
> > +enum execmem_type {
> > +       EXECMEM_DEFAULT,
> 
> I found EXECMEM_DEFAULT more confusing than helpful.

I hesitated a lot about that, but in the end decided to have
EXECMEM_DEFAULT and alias EXECMEM_MODULE_TEXT to it because this is what we
essentially have now for the most architectures.

If you'll take a look at arch-specific patches, in many cases there is only
EXECMEM_DEFAULT that an architecture defines and that default is used by
all the subsystems.
 
> Song
> 
> > +       EXECMEM_MODULE_TEXT = EXECMEM_DEFAULT,
> > +       EXECMEM_KPROBES,
> > +       EXECMEM_FTRACE,
> > +       EXECMEM_BPF,
> > +       EXECMEM_TYPE_MAX,
> > +};
> > +
> [...]

-- 
Sincerely yours,
Mike.