Re: [PATCH 02/05] Linux Kernel Markers, architecture independant code.

Mathieu Desnoyers
2007-02-15T19:12:25Z

* Andrew Morton (akpm@linux-foundation.org) wrote:
> On Sun, 11 Feb 2007 15:03:24 -0500 Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> wrote:
>
> > Linux Kernel Markers, architecture independant code.
> >
> > Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
> >
> > ...
> >
> > +
> > +#ifndef MARK
> > +#define MARK GEN_MARK
> > +#define MARK_ENABLE_TYPE GEN_MARK_ENABLE_TYPE
> > +#define MARK_ENABLE_IMMEDIATE_OFFSET GEN_MARK_ENABLE_IMMEDIATE_OFFSET
> > +#endif
>
> Also perhaps this nastiness can go away once each architecture has
> asm/marker.h?
>
Yes, absolutely.

> > +#ifdef MARK_POLYMORPHIC
>
> What's this? Is it commented somewhere? (It should be...)
>

No, but should be : it is defined by the architecture's marker.h when
the marker flavor has to do code motification when the marker state is
modified.

> > +static int marker_set_ins_enable(void *address, char enable)
> > +{
> > +#ifdef CONFIG_X86_32
> > + return arch_marker_set_ins_enable(address, enable);
> > +#else
> > + char newi[MARK_ENABLE_IMMEDIATE_OFFSET+1];
> > + int size = MARK_ENABLE_IMMEDIATE_OFFSET+sizeof(MARK_ENABLE_TYPE);
> > +
> > + memcpy(newi, address, size);
> > + MARK_ENABLE(&newi[0]) = enable;
> > + memcpy(address, newi, size);
> > + flush_icache_range((unsigned long)address, size);
> > + return 0;
> > +#endif //CONFIG_X86_32
> > +}
>
> eww. Can we put a suitable arch_marker_set_ins_enable() into each arch's
> marker.h?
>

Or maybe put that in asm-generic so we do not duplicate code.

> > +#else
> > +static int marker_set_ins_enable(void *address, char enable)
> > +{
> > + return -EPERM;
> > +}
> > +#endif //MARK_POLYMORPHIC
> > +
> >
> > ...
> >
>

--
Mathieu Desnoyers
Computer Engineering Ph.D. Candidate, École Polytechnique de Montréal
OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68