[Patch 1/4] Allow arch-specific cleanup before breakpoint unregistration

K.Prasad
2010-05-25T09:14:27Z

[-- Attachment #1: arch_unregister_hbp_02 --]
[-- Type: text/plain, Size: 1284 bytes --]

Certain architectures (such as PowerPC Book III S) have a need to cleanup
data-structures before the breakpoint is unregistered. This patch introduces
an arch-specific hook in release_bp_slot() along with a weak definition in
the form of a stub funciton.

Signed-off-by: K.Prasad <prasad@linux.vnet.ibm.com>
---
kernel/hw_breakpoint.c | 12 ++++++++++++
1 file changed, 12 insertions(+)

Index: linux-2.6.ppc64_test/kernel/hw_breakpoint.c
===================================================================
--- linux-2.6.ppc64_test.orig/kernel/hw_breakpoint.c
+++ linux-2.6.ppc64_test/kernel/hw_breakpoint.c
@@ -242,6 +242,17 @@ toggle_bp_slot(struct perf_event *bp, bo
}

/*
+ * Function to perform processor-specific cleanup during unregistration
+ */
+__weak void arch_unregister_hw_breakpoint(struct perf_event *bp)
+{
+ /*
+ * A weak stub function here for those archs that don't define
+ * it inside arch/.../kernel/hw_breakpoint.c
+ */
+}
+
+/*
* Contraints to check before allowing this new breakpoint counter:
*
* == Non-pinned counter == (Considered as pinned for now)
@@ -339,6 +350,7 @@ void release_bp_slot(struct perf_event *
{
mutex_lock(&nr_bp_mutex);

+ arch_unregister_hw_breakpoint(bp);
__release_bp_slot(bp);

mutex_unlock(&nr_bp_mutex);