linux-kernel - Re: [PATCH 3/7] V2 add syscall tracepoints

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <20090625044722.GA6071@nowhere>
Date:	Thu, 25 Jun 2009 06:47:23 +0200
From:	Frederic Weisbecker <fweisbec@...il.com>
To:	Li Zefan <lizf@...fujitsu.com>
Cc:	Jason Baron <jbaron@...hat.com>, linux-kernel@...r.kernel.org,
	mingo@...e.hu, laijs@...fujitsu.com, rostedt@...dmis.org,
	peterz@...radead.org, mathieu.desnoyers@...ymtl.ca,
	jiayingz@...gle.com, mbligh@...gle.com, roland@...hat.com,
	fche@...hat.com
Subject: Re: [PATCH 3/7] V2 add syscall tracepoints

On Thu, Jun 25, 2009 at 10:20:41AM +0800, Li Zefan wrote:
> > -#define DECLARE_TRACE(name, proto, args)				\
> > +#define DECLARE_TRACE_WITH_CALLBACK(name, proto, args, reg, unreg)	\
> >  	extern struct tracepoint __tracepoint_##name;			\
> >  	static inline void trace_##name(proto)				\
> >  	{								\
> > @@ -71,13 +73,29 @@ struct tracepoint {
> >  	}								\
> >  	static inline int register_trace_##name(void (*probe)(proto))	\
> >  	{								\
> > -		return tracepoint_probe_register(#name, (void *)probe);	\
> > +		int ret;						\
> > +		void (*func)(void) = (void (*)(void))reg;		\
> 
> The explicit cast seems unnecessary.


It seems even dangerous.
That might hide unmatching callback types passed in macro
arguments.

Frederic.


 
> > +									\
> > +		ret = tracepoint_probe_register(#name, (void *)probe);	\
> > +		if (func && !ret)					\
> > +			func();						\
> > +		return ret;						\
> >  	}								\
> >  	static inline int unregister_trace_##name(void (*probe)(proto))	\
> >  	{								\
> > -		return tracepoint_probe_unregister(#name, (void *)probe);\
> > +		int ret;						\
> > +		void (*func)(void) = (void (*)(void))unreg;		\
> > +									\
> > +		ret = tracepoint_probe_unregister(#name, (void *)probe);\
> > +		if (func && !ret)					\
> > +			func();						\
> > +		return ret;						\
> >  	}
> >  
> > +
> > +#define DECLARE_TRACE(name, proto, args)		\
> > +	DECLARE_TRACE_WITH_CALLBACK(name, TP_PROTO(proto), TP_ARGS(args), 0, 0);
> 
> I think DECLARE_TRACE_WITH_CALLBACK(..., NULL, NULL) is better.
> 
> > +
> >  #define DEFINE_TRACE(name)						\
> >  	static const char __tpstrtab_##name[]				\
> >  	__attribute__((section("__tracepoints_strings"))) = #name;	\
> > @@ -94,7 +112,7 @@ extern void tracepoint_update_probe_range(struct tracepoint *begin,
> >  	struct tracepoint *end);
> >  
> >  #else /* !CONFIG_TRACEPOINTS */
> > -#define DECLARE_TRACE(name, proto, args)				\
> > +#define DECLARE_TRACE_WITH_CALLBACK(name, proto, args, reg, unreg)	\
> >  	static inline void _do_trace_##name(struct tracepoint *tp, proto) \
> >  	{ }								\
> >  	static inline void trace_##name(proto)				\
> > @@ -108,6 +126,9 @@ extern void tracepoint_update_probe_range(struct tracepoint *begin,
> >  		return -ENOSYS;						\
> >  	}
> >  
> > +#define DECLARE_TRACE(name, proto, args)                \
> > +	DECLARE_TRACE_WITH_CALLBACK(name, TP_PROTO(proto), TP_ARGS(args), 0, 0);
> 
> ditto
> 
> > +
> >  #define DEFINE_TRACE(name)
> >  #define EXPORT_TRACEPOINT_SYMBOL_GPL(name)
> >  #define EXPORT_TRACEPOINT_SYMBOL(name)
> 
> 

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