On Fri, 11 Jul 2014 20:09:26 +0200 Ard Biesheuvel <[email protected]> wrote:
> On 11 July 2014 17:40, Ard Biesheuvel <[email protected]> wrote: > > On 11 July 2014 17:30, Steven Rostedt <[email protected]> wrote: > >> On Fri, 11 Jul 2014 08:12:40 -0700 > >> "Paul E. McKenney" <[email protected]> wrote: > >> > >>> On Fri, Jul 11, 2014 at 01:38:12PM +0200, Ard Biesheuvel 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 <[email protected]> > >>> > Cc: [email protected] > >>> > Cc: [email protected] > >>> > Cc: [email protected] > >>> > >>> If you get a Reviewed-by from Steven Rostedt, I will be happy to queue > >>> this one. > >> > >> I'm fine with it, but it should add a comment. > >> > >> > >>> > >>> Thanx, Paul > >>> > >>> > --- > >>> > kernel/rcu/tree.c | 9 ++++++++- > >>> > 1 file changed, 8 insertions(+), 1 deletion(-) > >>> > > >>> > diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c > >>> > index f1ba77363fbb..ac1984149eb5 100644 > >>> > --- a/kernel/rcu/tree.c > >>> > +++ b/kernel/rcu/tree.c > >>> > @@ -79,9 +79,16 @@ 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. > >>> > */ > >>> > +#ifdef CONFIG_TRACING > >> > >> /* > >> * When tracing is enabled, DEFINE_TPS() will export the string to > >> * userspace via the tracing debugfs directory. This allows userspace > >> * tools to read the binary tracepoints that reference the pointer > >> * to the string and not the string itself. > >> */ > >> > >> > > Ehm, actually, a comment to that effect is already right there in the file. > Would you still like me to add this additional comment? Heh, I surprised myself with my own documentation :-) No, I think the existing comment is good enough. Just rename the macro then. Thanks! -- Steve > > >>> > +#define DEFINE_TPS(sname) \ > >>> > +static const char *tp_##sname##_varname __used __tracepoint_string = > >>> > sname##_varname; > >>> > +#else > >>> > +#define DEFINE_TPS(sname) > >>> > +#endif > >> > >> Also, perhaps we should call it: > >> > >> DEFINE_RCU_TPS() > >> > >> Other than that, I'm fine with the patch. > >> > >> I'll review v2 ;-) > >> > > > > Thanks gents, v2 coming up. > > > > -- > > Ard. > > > > > >>> > + > >>> > #define RCU_STATE_INITIALIZER(sname, sabbr, cr) \ > >>> > static char sname##_varname[] = #sname; \ > >>> > -static const char *tp_##sname##_varname __used __tracepoint_string = > >>> > sname##_varname; \ > >>> > +DEFINE_TPS(sname) \ > >>> > struct rcu_state sname##_state = { \ > >>> > .level = { &sname##_state.node[0] }, \ > >>> > .call = cr, \ > >>> > -- > >>> > 1.8.3.2 > >>> > > >> -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
