* [PATCH v3] rcu: define tracepoint strings only if CONFIG_TRACING is set
@ 2014-07-12 17:01 Ard Biesheuvel
2014-07-14 17:03 ` Steven Rostedt
0 siblings, 1 reply; 3+ messages in thread
From: Ard Biesheuvel @ 2014-07-12 17:01 UTC (permalink / raw)
To: linux-kernel; +Cc: Ard Biesheuvel, rostedt, paulmck
Commit f7f7bac9cb1c ("rcu: Have the RCU tracepoints use the tracepoint_string
infrastructure") unconditionally populates the __tracepoint_str input section,
but this section is not assigned an output section if CONFIG_TRACING is not set.
This results in the __tracepoint_str turning up in unexpected places, i.e.,
after _edata.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: rostedt@goodmis.org
Cc: paulmck@linux.vnet.ibm.com
---
v3:
- make definition of <var>_varname conditional as well
v2:
- s/DEFINE_TPS/DEFINE_RCU_TPS/
kernel/rcu/tree.c | 15 ++++++++++++---
1 file changed, 12 insertions(+), 3 deletions(-)
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index f1ba77363fbb..0756a4696007 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -79,9 +79,18 @@ static struct lock_class_key rcu_fqs_class[RCU_NUM_LVLS];
* the tracing userspace tools to be able to decipher the string
* address to the matching string.
*/
-#define RCU_STATE_INITIALIZER(sname, sabbr, cr) \
+#ifdef CONFIG_TRACING
+# define DEFINE_RCU_TPS(sname) \
static char sname##_varname[] = #sname; \
-static const char *tp_##sname##_varname __used __tracepoint_string = sname##_varname; \
+static const char *tp_##sname##_varname __used __tracepoint_string = sname##_varname;
+# define RCU_STATE_NAME(sname) sname##_varname
+#else
+# define DEFINE_RCU_TPS(sname)
+# define RCU_STATE_NAME(sname) __stringify(sname)
+#endif
+
+#define RCU_STATE_INITIALIZER(sname, sabbr, cr) \
+DEFINE_RCU_TPS(sname) \
struct rcu_state sname##_state = { \
.level = { &sname##_state.node[0] }, \
.call = cr, \
@@ -93,7 +102,7 @@ struct rcu_state sname##_state = { \
.orphan_donetail = &sname##_state.orphan_donelist, \
.barrier_mutex = __MUTEX_INITIALIZER(sname##_state.barrier_mutex), \
.onoff_mutex = __MUTEX_INITIALIZER(sname##_state.onoff_mutex), \
- .name = sname##_varname, \
+ .name = RCU_STATE_NAME(sname), \
.abbr = sabbr, \
}; \
DEFINE_PER_CPU(struct rcu_data, sname##_data)
--
1.8.3.2
^ permalink raw reply related [flat|nested] 3+ messages in thread* Re: [PATCH v3] rcu: define tracepoint strings only if CONFIG_TRACING is set
2014-07-12 17:01 [PATCH v3] rcu: define tracepoint strings only if CONFIG_TRACING is set Ard Biesheuvel
@ 2014-07-14 17:03 ` Steven Rostedt
2014-07-16 11:55 ` Paul E. McKenney
0 siblings, 1 reply; 3+ messages in thread
From: Steven Rostedt @ 2014-07-14 17:03 UTC (permalink / raw)
To: Ard Biesheuvel; +Cc: linux-kernel, paulmck
On Sat, 12 Jul 2014 19:01:49 +0200
Ard Biesheuvel <ard.biesheuvel@linaro.org> wrote:
> Commit f7f7bac9cb1c ("rcu: Have the RCU tracepoints use the tracepoint_string
> infrastructure") unconditionally populates the __tracepoint_str input section,
> but this section is not assigned an output section if CONFIG_TRACING is not set.
> This results in the __tracepoint_str turning up in unexpected places, i.e.,
> after _edata.
>
> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
> Cc: rostedt@goodmis.org
> Cc: paulmck@linux.vnet.ibm.com
> ---
> v3:
> - make definition of <var>_varname conditional as well
> v2:
> - s/DEFINE_TPS/DEFINE_RCU_TPS/
>
> kernel/rcu/tree.c | 15 ++++++++++++---
> 1 file changed, 12 insertions(+), 3 deletions(-)
>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
-- Steve
> diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
> index f1ba77363fbb..0756a4696007 100644
> --- a/kernel/rcu/tree.c
> +++ b/kernel/rcu/tree.c
> @@ -79,9 +79,18 @@ static struct lock_class_key rcu_fqs_class[RCU_NUM_LVLS];
> * the tracing userspace tools to be able to decipher the string
> * address to the matching string.
> */
> -#define RCU_STATE_INITIALIZER(sname, sabbr, cr) \
> +#ifdef CONFIG_TRACING
> +# define DEFINE_RCU_TPS(sname) \
> static char sname##_varname[] = #sname; \
> -static const char *tp_##sname##_varname __used __tracepoint_string = sname##_varname; \
> +static const char *tp_##sname##_varname __used __tracepoint_string = sname##_varname;
> +# define RCU_STATE_NAME(sname) sname##_varname
> +#else
> +# define DEFINE_RCU_TPS(sname)
> +# define RCU_STATE_NAME(sname) __stringify(sname)
> +#endif
> +
> +#define RCU_STATE_INITIALIZER(sname, sabbr, cr) \
> +DEFINE_RCU_TPS(sname) \
> struct rcu_state sname##_state = { \
> .level = { &sname##_state.node[0] }, \
> .call = cr, \
> @@ -93,7 +102,7 @@ struct rcu_state sname##_state = { \
> .orphan_donetail = &sname##_state.orphan_donelist, \
> .barrier_mutex = __MUTEX_INITIALIZER(sname##_state.barrier_mutex), \
> .onoff_mutex = __MUTEX_INITIALIZER(sname##_state.onoff_mutex), \
> - .name = sname##_varname, \
> + .name = RCU_STATE_NAME(sname), \
> .abbr = sabbr, \
> }; \
> DEFINE_PER_CPU(struct rcu_data, sname##_data)
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [PATCH v3] rcu: define tracepoint strings only if CONFIG_TRACING is set
2014-07-14 17:03 ` Steven Rostedt
@ 2014-07-16 11:55 ` Paul E. McKenney
0 siblings, 0 replies; 3+ messages in thread
From: Paul E. McKenney @ 2014-07-16 11:55 UTC (permalink / raw)
To: Steven Rostedt; +Cc: Ard Biesheuvel, linux-kernel
On Mon, Jul 14, 2014 at 01:03:02PM -0400, Steven Rostedt wrote:
> On Sat, 12 Jul 2014 19:01:49 +0200
> Ard Biesheuvel <ard.biesheuvel@linaro.org> wrote:
>
> > Commit f7f7bac9cb1c ("rcu: Have the RCU tracepoints use the tracepoint_string
> > infrastructure") unconditionally populates the __tracepoint_str input section,
> > but this section is not assigned an output section if CONFIG_TRACING is not set.
> > This results in the __tracepoint_str turning up in unexpected places, i.e.,
> > after _edata.
> >
> > Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
> > Cc: rostedt@goodmis.org
> > Cc: paulmck@linux.vnet.ibm.com
> > ---
> > v3:
> > - make definition of <var>_varname conditional as well
> > v2:
> > - s/DEFINE_TPS/DEFINE_RCU_TPS/
> >
> > kernel/rcu/tree.c | 15 ++++++++++++---
> > 1 file changed, 12 insertions(+), 3 deletions(-)
> >
>
> Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Queued for 3.18, thank you both!
Thanx, Paul
> -- Steve
>
> > diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
> > index f1ba77363fbb..0756a4696007 100644
> > --- a/kernel/rcu/tree.c
> > +++ b/kernel/rcu/tree.c
> > @@ -79,9 +79,18 @@ static struct lock_class_key rcu_fqs_class[RCU_NUM_LVLS];
> > * the tracing userspace tools to be able to decipher the string
> > * address to the matching string.
> > */
> > -#define RCU_STATE_INITIALIZER(sname, sabbr, cr) \
> > +#ifdef CONFIG_TRACING
> > +# define DEFINE_RCU_TPS(sname) \
> > static char sname##_varname[] = #sname; \
> > -static const char *tp_##sname##_varname __used __tracepoint_string = sname##_varname; \
> > +static const char *tp_##sname##_varname __used __tracepoint_string = sname##_varname;
> > +# define RCU_STATE_NAME(sname) sname##_varname
> > +#else
> > +# define DEFINE_RCU_TPS(sname)
> > +# define RCU_STATE_NAME(sname) __stringify(sname)
> > +#endif
> > +
> > +#define RCU_STATE_INITIALIZER(sname, sabbr, cr) \
> > +DEFINE_RCU_TPS(sname) \
> > struct rcu_state sname##_state = { \
> > .level = { &sname##_state.node[0] }, \
> > .call = cr, \
> > @@ -93,7 +102,7 @@ struct rcu_state sname##_state = { \
> > .orphan_donetail = &sname##_state.orphan_donelist, \
> > .barrier_mutex = __MUTEX_INITIALIZER(sname##_state.barrier_mutex), \
> > .onoff_mutex = __MUTEX_INITIALIZER(sname##_state.onoff_mutex), \
> > - .name = sname##_varname, \
> > + .name = RCU_STATE_NAME(sname), \
> > .abbr = sabbr, \
> > }; \
> > DEFINE_PER_CPU(struct rcu_data, sname##_data)
>
^ permalink raw reply [flat|nested] 3+ messages in thread
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2014-07-12 17:01 [PATCH v3] rcu: define tracepoint strings only if CONFIG_TRACING is set Ard Biesheuvel
2014-07-14 17:03 ` Steven Rostedt
2014-07-16 11:55 ` Paul E. McKenney
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