hw-breakpoints: Tag ptrace breakpoint as exclude_kernel

Tag ptrace breakpoints with the exclude_kernel attribute set. This
will make it easier to set generic policies on breakpoints, when it
comes to ensure nobody unpriviliged try to breakpoint on the kernel.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Cc: K. Prasad <prasad@linux.vnet.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ingo Molnar <mingo@elte.hu>

1 files changed, 6 insertions, 0 deletions

diff --git a/include/linux/hw_breakpoint.h b/include/linux/hw_breakpoint.h
index c70d27af03f9..a0aa5a9cfb0e 100644
--- a/include/linux/hw_breakpoint.h
+++ b/include/linux/hw_breakpoint.h
@@ -34,6 +34,12 @@ static inline void hw_breakpoint_init(struct perf_event_attr *attr)
         attr->sample_period = 1;
 }
 
+static inline void ptrace_breakpoint_init(struct perf_event_attr *attr)
+{
+        hw_breakpoint_init(attr);
+        attr->exclude_kernel = 1;
+}
+
 static inline unsigned long hw_breakpoint_addr(struct perf_event *bp)
 {
         return bp->attr.bp_addr;