Re: x86-32: Early microcode loading stumbles over disabledDYNAMIC_FTRACE

[Steven Rostedt]

On Sat, 31 Aug 2013 07:07:37 +0200
Borislav Petkov <bp@xxxxxxxxx> wrote:

> On Fri, Aug 30, 2013 at 08:17:41PM -0400, Steven Rostedt wrote:
> > On Fri, 30 Aug 2013 13:48:55 -0700
> > "H. Peter Anvin" <hpa@xxxxxxxxx> wrote:
> > 
> > > >> You *could* bail out of the calling address is < PAGE_OFFSET.
> > > 
> > > Anyway... can we add this to the static tracing code?  It is two
> > > instructions and is only needed on x86-32.  For performance, use dynamic.
> > 
> > Sure, do you want to add it ?
> 
> Another, simpler option could be to make static tracing depend on
> !MICROCODE until the first has been removed.
> 

Might be trickier than you think. Static tracing is the default.
Dynamic tracing is the extension. By making static tracing depend
on !MICROCODE, you basically made function tracing depend on !MICROCODE.

I guess you could make MICROCODE select DYNAMIC_FTRACE, but that could
get messy.

-- Steve
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/