Merge branch 'perf/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/random-tracing into perf/urgent

4 files changed, 15 insertions, 2 deletions

diff --git a/arch/x86/kernel/hw_breakpoint.c b/arch/x86/kernel/hw_breakpoint.c
index ff15c9dcc25d..42c594254507 100644
--- a/arch/x86/kernel/hw_breakpoint.c
+++ b/arch/x86/kernel/hw_breakpoint.c
@@ -433,6 +433,10 @@ static int __kprobes hw_breakpoint_handler(struct die_args *args)
         dr6_p = (unsigned long *)ERR_PTR(args->err);
         dr6 = *dr6_p;
 
+        /* If it's a single step, TRAP bits are random */
+        if (dr6 & DR_STEP)
+                return NOTIFY_DONE;
+
         /* Do an early return if no trap bits are set in DR6 */
         if ((dr6 & DR_TRAP_BITS) == 0)
                 return NOTIFY_DONE;
diff --git a/include/linux/hw_breakpoint.h b/include/linux/hw_breakpoint.h
index a2d6ea49ec56..d1e55fed2c7d 100644
--- a/include/linux/hw_breakpoint.h
+++ b/include/linux/hw_breakpoint.h
@@ -33,6 +33,8 @@ enum bp_type_idx {
 
 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 
+extern int __init init_hw_breakpoint(void);
+
 static inline void hw_breakpoint_init(struct perf_event_attr *attr)
 {
         memset(attr, 0, sizeof(*attr));
@@ -108,6 +110,8 @@ static inline struct arch_hw_breakpoint *counter_arch_bp(struct perf_event *bp)
 
 #else /* !CONFIG_HAVE_HW_BREAKPOINT */
 
+static inline int __init init_hw_breakpoint(void) { return 0; }
+
 static inline struct perf_event *
 register_user_hw_breakpoint(struct perf_event_attr *attr,
                             perf_overflow_handler_t triggered,
diff --git a/kernel/hw_breakpoint.c b/kernel/hw_breakpoint.c
index 2c9120f0afca..e5325825aeb6 100644
--- a/kernel/hw_breakpoint.c
+++ b/kernel/hw_breakpoint.c
@@ -620,7 +620,7 @@ static struct pmu perf_breakpoint = {
         .read           = hw_breakpoint_pmu_read,
 };
 
-static int __init init_hw_breakpoint(void)
+int __init init_hw_breakpoint(void)
 {
         unsigned int **task_bp_pinned;
         int cpu, err_cpu;
@@ -655,6 +655,5 @@ static int __init init_hw_breakpoint(void)
 
         return -ENOMEM;
 }
-core_initcall(init_hw_breakpoint);
 
 
diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index cb6c0d2af68f..f818d9d2dc93 100644
--- a/kernel/perf_event.c
+++ b/kernel/perf_event.c
@@ -31,6 +31,7 @@
 #include <linux/kernel_stat.h>
 #include <linux/perf_event.h>
 #include <linux/ftrace_event.h>
+#include <linux/hw_breakpoint.h>
 
 #include <asm/irq_regs.h>
 
@@ -6321,6 +6322,8 @@ perf_cpu_notify(struct notifier_block *self, unsigned long action, void *hcpu)
 
 void __init perf_event_init(void)
 {
+        int ret;
+
         perf_event_init_all_cpus();
         init_srcu_struct(&pmus_srcu);
         perf_pmu_register(&perf_swevent);
@@ -6328,4 +6331,7 @@ void __init perf_event_init(void)
         perf_pmu_register(&perf_task_clock);
         perf_tp_register();
         perf_cpu_notifier(perf_cpu_notify);
+
+        ret = init_hw_breakpoint();
+        WARN(ret, "hw_breakpoint initialization failed with: %d", ret);
 }