[lttng-dev] [lttng-module PATCH] Fix last modifications to string_from_user operations

[Mathieu Desnoyers]

Yannick, I'm curious: does this fix the problem you experienced with
LTTng on -rt kernels recently (that was listed in my staging TODO) ?

Thanks,

Mathieu

* Mathieu Desnoyers (mathieu.desnoyers at efficios.com) wrote:
> * Yannick Brosseau (yannick.brosseau at gmail.com) wrote:
> > Signed-off-by: Yannick Brosseau <yannick.brosseau at gmail.com>
> 
> Merged into lttng-modules. I'll prepare a patch for staging too. Very,
> very nice catch!
> 
> Thanks,
> 
> Mathieu
> 
> > ---
> >  probes/lttng-events.h |    4 ++--
> >  1 files changed, 2 insertions(+), 2 deletions(-)
> > 
> > diff --git a/probes/lttng-events.h b/probes/lttng-events.h
> > index ff6273f..d486994 100644
> > --- a/probes/lttng-events.h
> > +++ b/probes/lttng-events.h
> > @@ -347,7 +347,7 @@ static __used struct lttng_probe_desc TP_ID(__probe_desc___, TRACE_SYSTEM) = {
> >  #undef __string_from_user
> >  #define __string_from_user(_item, _src)					       \
> >  	__event_len += __dynamic_len[__dynamic_len_idx++] =		       \
> > -		min_t(size_t, strlen_user(_src), 1);
> > +		max_t(size_t, strlen_user(_src), 1);
> >  
> >  #undef TP_PROTO
> >  #define TP_PROTO(args...) args
> > @@ -557,7 +557,7 @@ __assign_##dest##_2:							\
> >  			(void) __typemap.dest;				\
> >  		lib_ring_buffer_align_ctx(&__ctx, ltt_alignof(__typemap.dest));\
> >  		__ustrlen = __get_dynamic_array_len(dest);		\
> > -		if (likely(__ustrlen) > 1) {				\
> > +		if (likely(__ustrlen > 1)) {				\
> >  			__chan->ops->event_write_from_user(&__ctx, src,	\
> >  				__ustrlen - 1);				\
> >  		}							\
> > -- 
> > 1.7.7.3
> > 
> 
> -- 
> Mathieu Desnoyers
> Operating System Efficiency R&D Consultant
> EfficiOS Inc.
> http://www.efficios.com
> 
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> 

-- 
Mathieu Desnoyers
Operating System Efficiency R&D Consultant
EfficiOS Inc.
http://www.efficios.com