[PATCH v1 2/2] powerpc/debug: hook to user return notifier infrastructure

[Luming Yu]

Wed, Aug 28, 2024 at 09:27:23AM +0200, Christophe Leroy wrote:
> 
> 
> Le 28/08/2024 à 08:50, Luming Yu a écrit :
> > On Wed, Aug 28, 2024 at 07:46:52AM +0200, Christophe Leroy wrote:
> > > Hi,
> > > 
> > > Le 28/08/2024 à 05:17, 虞陆铭 a écrit :
> > > > Hi,
> > > > 
> > > > it appears the little feature might require a little bit more work to find its value of the patch.
> > > > 
> > > > Using the following debug module ,  some debugging shows the TIF_USER_RETURN_NOTIFY
> > > > bit is propagated in __switch_to among tasks , but USER_RETURN_NOTIFY call back seems to
> > > > be dropped somewhere on somone who carries the bit return to user space.
> > > > side notes:
> > > > there is an issue that the module symbols is not appended to /sys/kernel/debug/tracing/available_filter_functions
this is not a problem as I just noticed that lib/Makefile carries this magic
ccflags-remove-$(CONFIG_FUNCTION_TRACER) += $(CC_FLAGS_FTRACE)