1 files changed, 21 insertions, 13 deletions

diff --git a/kernel/events/core.c b/kernel/events/core.c
index 4c1ee7f2bebc..19efcf13375a 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -4461,18 +4461,14 @@ perf_output_sample_regs(struct perf_output_handle *handle,
 }
 
 static void perf_sample_regs_user(struct perf_regs *regs_user,
-                                  struct pt_regs *regs)
+                                  struct pt_regs *regs,
+                                  struct pt_regs *regs_user_copy)
 {
-        if (!user_mode(regs)) {
-                if (current->mm)
-                        regs = task_pt_regs(current);
-                else
-                        regs = NULL;
-        }
-
-        if (regs) {
-                regs_user->abi  = perf_reg_abi(current);
+        if (user_mode(regs)) {
+                regs_user->abi = perf_reg_abi(current);
                 regs_user->regs = regs;
+        } else if (current->mm) {
+                perf_get_regs_user(regs_user, regs, regs_user_copy);
         } else {
                 regs_user->abi = PERF_SAMPLE_REGS_ABI_NONE;
                 regs_user->regs = NULL;
@@ -4951,7 +4947,8 @@ void perf_prepare_sample(struct perf_event_header *header,
         }
 
         if (sample_type & (PERF_SAMPLE_REGS_USER | PERF_SAMPLE_STACK_USER))
-                perf_sample_regs_user(&data->regs_user, regs);
+                perf_sample_regs_user(&data->regs_user, regs,
+                                      &data->regs_user_copy);
 
         if (sample_type & PERF_SAMPLE_REGS_USER) {
                 /* regs dump ABI info */
@@ -6779,7 +6776,6 @@ skip_type:
                 __perf_event_init_context(&cpuctx->ctx);
                 lockdep_set_class(&cpuctx->ctx.mutex, &cpuctx_mutex);
                 lockdep_set_class(&cpuctx->ctx.lock, &cpuctx_lock);
-                cpuctx->ctx.type = cpu_context;
                 cpuctx->ctx.pmu = pmu;
 
                 __perf_cpu_hrtimer_init(cpuctx, cpu);
@@ -7423,7 +7419,19 @@ SYSCALL_DEFINE5(perf_event_open,
                  * task or CPU context:
                  */
                 if (move_group) {
-                        if (group_leader->ctx->type != ctx->type)
+                        /*
+                         * Make sure we're both on the same task, or both
+                         * per-cpu events.
+                         */
+                        if (group_leader->ctx->task != ctx->task)
+                                goto err_context;
+
+                        /*
+                         * Make sure we're both events for the same CPU;
+                         * grouping events for different CPUs is broken; since
+                         * you can never concurrently schedule them anyhow.
+                         */
+                        if (group_leader->cpu != event->cpu)
                                 goto err_context;
                 } else {
                         if (group_leader->ctx != ctx)