| Message ID | 20140422142419.GD21121@dreric01-Precision-T1600 |
|---|---|
| State | New |
| Headers | show |
On Tue, Apr 22, 2014 at 07:24:20AM -0700, Drew Richardson wrote: > After commit de7b2973903c6cc50b31ee5682a69b2219b9919d ("tracepoint: > Use struct pointer instead of name hash for reg/unreg tracepoints"), > any tracepoints used in a kernel module must be exported. How does this matter given that there aren't any modular users? -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
On Tue, Apr 22, 2014 at 03:26:13PM +0100, Christoph Hellwig wrote: > On Tue, Apr 22, 2014 at 07:24:20AM -0700, Drew Richardson wrote: > > After commit de7b2973903c6cc50b31ee5682a69b2219b9919d ("tracepoint: > > Use struct pointer instead of name hash for reg/unreg tracepoints"), > > any tracepoints used in a kernel module must be exported. > > How does this matter given that there aren't any modular users? Gator (http://git.linaro.org/arm/ds5/gator.git), an out of tree kernel module, uses irq_handler_exit and softirq_exit. I thought it would be helpful to export the other tracepoints from trace/events/irq.h in case other users encountered a similar issue. Drew -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
On Tue, Apr 22, 2014 at 10:26 AM, Christoph Hellwig <hch@infradead.org> wrote: > On Tue, Apr 22, 2014 at 07:24:20AM -0700, Drew Richardson wrote: >> After commit de7b2973903c6cc50b31ee5682a69b2219b9919d ("tracepoint: >> Use struct pointer instead of name hash for reg/unreg tracepoints"), >> any tracepoints used in a kernel module must be exported. > > How does this matter given that there aren't any modular users? We had a bug report about this breaking systemtap type usage[1]. In there, Matthieu suggested that the new for_each_kernel_tracepoint interface be used. Drew, it would have been proper to CC the author of the change you're referencing on all of your patches to export these symbols. josh [1] https://bugzilla.redhat.com/show_bug.cgi?id=1087623 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
On Tue, Apr 22, 2014 at 08:00:31AM -0700, Drew Richardson wrote: > Gator (http://git.linaro.org/arm/ds5/gator.git), an out of tree kernel > module, uses irq_handler_exit and softirq_exit. I thought it would be > helpful to export the other tracepoints from trace/events/irq.h in > case other users encountered a similar issue. None of them should be exported unless we have in-tree modular users. And I don't think adding modular users for either of them is a good idea to start with. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
On Tue, Apr 22, 2014 at 04:01:03PM +0100, Josh Boyer wrote: > On Tue, Apr 22, 2014 at 10:26 AM, Christoph Hellwig <hch@infradead.org> wrote: > > On Tue, Apr 22, 2014 at 07:24:20AM -0700, Drew Richardson wrote: > >> After commit de7b2973903c6cc50b31ee5682a69b2219b9919d ("tracepoint: > >> Use struct pointer instead of name hash for reg/unreg tracepoints"), > >> any tracepoints used in a kernel module must be exported. > > > > How does this matter given that there aren't any modular users? > > We had a bug report about this breaking systemtap type usage[1]. In > there, Matthieu suggested that the new for_each_kernel_tracepoint > interface be used. > > Drew, it would have been proper to CC the author of the change you're > referencing on all of your patches to export these symbols. > > josh > > [1] https://bugzilla.redhat.com/show_bug.cgi?id=1087623 > Thanks Josh for pointing out that I should CC Mathieu and register_tracepoint_module_notifier, which will work for me. Drew -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
diff --git a/kernel/softirq.c b/kernel/softirq.c index b50990a5bea0..3a21a6c29406 100644 --- a/kernel/softirq.c +++ b/kernel/softirq.c @@ -30,6 +30,12 @@ #define CREATE_TRACE_POINTS #include <trace/events/irq.h> +EXPORT_TRACEPOINT_SYMBOL_GPL(irq_handler_entry); +EXPORT_TRACEPOINT_SYMBOL_GPL(irq_handler_exit); +EXPORT_TRACEPOINT_SYMBOL_GPL(softirq_entry); +EXPORT_TRACEPOINT_SYMBOL_GPL(softirq_exit); +EXPORT_TRACEPOINT_SYMBOL_GPL(softirq_raise); + /* - No shared variables, all the data are CPU local. - If a softirq needs serialization, let it serialize itself
After commit de7b2973903c6cc50b31ee5682a69b2219b9919d ("tracepoint: Use struct pointer instead of name hash for reg/unreg tracepoints"), any tracepoints used in a kernel module must be exported. Signed-off-by: Drew Richardson <drew.richardson@arm.com> Acked-by: Pawel Moll <pawel.moll@arm.com> --- kernel/softirq.c | 6 ++++++ 1 file changed, 6 insertions(+)