hw-breakpoints: Use struct perf_event_attr to define user breakpoints

In-kernel user 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
archictectures 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: <1259294154-5197-1-git-send-regression-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 16 insertions, 20 deletions

diff --git a/include/linux/hw_breakpoint.h b/include/linux/hw_breakpoint.h
index c9f7f7c7b0e0..5da472e434b7 100644
--- a/include/linux/hw_breakpoint.h
+++ b/include/linux/hw_breakpoint.h
@@ -20,6 +20,14 @@ enum {
 
 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 
+/* As it's for in-kernel or ptrace use, we want it to be pinned */
+#define DEFINE_BREAKPOINT_ATTR(name)	\
+struct perf_event_attr name = {		\
+	.type = PERF_TYPE_BREAKPOINT,	\
+	.size = sizeof(name),		\
+	.pinned = 1,			\
+};
+
 static inline unsigned long hw_breakpoint_addr(struct perf_event *bp)
 {
 	return bp->attr.bp_addr;
@@ -36,22 +44,16 @@ static inline int hw_breakpoint_len(struct perf_event *bp)
 }
 
 extern struct perf_event *
-register_user_hw_breakpoint(unsigned long addr,
-			    int len,
-			    int type,
+register_user_hw_breakpoint(struct perf_event_attr *attr,
 			    perf_callback_t triggered,
-			    struct task_struct *tsk,
-			    bool active);
+			    struct task_struct *tsk);
 
 /* FIXME: only change from the attr, and don't unregister */
 extern struct perf_event *
 modify_user_hw_breakpoint(struct perf_event *bp,
-			  unsigned long addr,
-			  int len,
-			  int type,
+			  struct perf_event_attr *attr,
 			  perf_callback_t triggered,
-			  struct task_struct *tsk,
-			  bool active);
+			  struct task_struct *tsk);
 
 /*
  * Kernel breakpoints are not associated with any particular thread.
@@ -89,20 +91,14 @@ static inline struct arch_hw_breakpoint *counter_arch_bp(struct perf_event *bp)
 #else /* !CONFIG_HAVE_HW_BREAKPOINT */
 
 static inline struct perf_event *
-register_user_hw_breakpoint(unsigned long addr,
-			    int len,
-			    int type,
+register_user_hw_breakpoint(struct perf_event_attr *attr,
 			    perf_callback_t triggered,
-			    struct task_struct *tsk,
-			    bool active)		{ return NULL; }
+			    struct task_struct *tsk)	{ return NULL; }
 static inline struct perf_event *
 modify_user_hw_breakpoint(struct perf_event *bp,
-			  unsigned long addr,
-			  int len,
-			  int type,
+			  struct perf_event_attr *attr,
 			  perf_callback_t triggered,
-			  struct task_struct *tsk,
-			  bool active)			{ return NULL; }
+			  struct task_struct *tsk)	{ return NULL; }
 static inline struct perf_event *
 register_wide_hw_breakpoint_cpu(unsigned long addr,
 				int len,