hw-breakpoints: Use struct perf_event_attr to define kernel breakpoints

Kernel breakpoints are created using functions in which we pass
breakpoint parameters as individual variables: address, length
and type.

Although it fits well for x86, this just does not scale across
architectures that may support this api later as these may have
more or different needs. Pass in a perf_event_attr structure
instead because it is meant to evolve as much as possible into
a generic hardware breakpoint parameter structure.

Reported-by: K.Prasad <prasad@linux.vnet.ibm.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <1259294154-5197-2-git-send-regression-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 4 insertions, 31 deletions

diff --git a/kernel/hw_breakpoint.c b/kernel/hw_breakpoint.c
index 2a47514..cf5ee16 100644
--- a/kernel/hw_breakpoint.c
+++ b/kernel/hw_breakpoint.c
@@ -339,42 +339,16 @@ void unregister_hw_breakpoint(struct perf_event *bp)
 }
 EXPORT_SYMBOL_GPL(unregister_hw_breakpoint);
 
-static struct perf_event *
-register_kernel_hw_breakpoint_cpu(unsigned long addr,
-				  int len,
-				  int type,
-				  perf_callback_t triggered,
-				  int cpu,
-				  bool active)
-{
-	DEFINE_BREAKPOINT_ATTR(attr);
-
-	attr.bp_addr = addr;
-	attr.bp_len = len;
-	attr.bp_type = type;
-
-	if (!active)
-		attr.disabled = 1;
-
-	return perf_event_create_kernel_counter(&attr, cpu, -1, triggered);
-}
-
 /**
  * register_wide_hw_breakpoint - register a wide breakpoint in the kernel
- * @addr: is the memory address that triggers the breakpoint
- * @len: the length of the access to the memory (1 byte, 2 bytes etc...)
- * @type: the type of the access to the memory (read/write/exec)
+ * @attr: breakpoint attributes
  * @triggered: callback to trigger when we hit the breakpoint
- * @active: should we activate it while registering it
  *
  * @return a set of per_cpu pointers to perf events
  */
 struct perf_event **
-register_wide_hw_breakpoint(unsigned long addr,
-			    int len,
-			    int type,
-			    perf_callback_t triggered,
-			    bool active)
+register_wide_hw_breakpoint(struct perf_event_attr *attr,
+			    perf_callback_t triggered)
 {
 	struct perf_event **cpu_events, **pevent, *bp;
 	long err;
@@ -386,8 +360,7 @@ register_wide_hw_breakpoint(unsigned long addr,
 
 	for_each_possible_cpu(cpu) {
 		pevent = per_cpu_ptr(cpu_events, cpu);
-		bp = register_kernel_hw_breakpoint_cpu(addr, len, type,
-					triggered, cpu, active);
+		bp = perf_event_create_kernel_counter(attr, cpu, -1, triggered);
 
 		*pevent = bp;