- do {
- char raw_data[size];
- struct trace_entry *ent;
- /*
- * Zero dead bytes from alignment to avoid stack leak
- * to userspace
- */
- *(u64 *)(&raw_data[size - sizeof(u64)]) = 0ULL;
- entry = (struct kprobe_trace_entry *)raw_data;
- ent = &entry->ent;
-
- tracing_generic_entry_update(ent, irq_flags, pc);
- ent->type = call->id;
- entry->nargs = tp->nr_args;
- entry->ip = (unsigned long)kp->addr;
- for (i = 0; i < tp->nr_args; i++)
- entry->args[i] = call_fetch(&tp->args[i].fetch, regs);
- perf_tp_event(call->id, entry->ip, 1, entry, size);
- } while (0);
+ /*
+ * Protect the non nmi buffer
+ * This also protects the rcu read side
+ */
+ local_irq_save(irq_flags);
+ __cpu = smp_processor_id();
+
+ if (in_nmi())
+ raw_data = rcu_dereference(trace_profile_buf_nmi);
+ else
+ raw_data = rcu_dereference(trace_profile_buf);
+
+ if (!raw_data)
+ goto end;
+
+ raw_data = per_cpu_ptr(raw_data, __cpu);
+ /* Zero dead bytes from alignment to avoid buffer leak to userspace */
+ *(u64 *)(&raw_data[size - sizeof(u64)]) = 0ULL;
+ entry = (struct kprobe_trace_entry *)raw_data;
+ ent = &entry->ent;
+
+ tracing_generic_entry_update(ent, irq_flags, pc);
+ ent->type = call->id;
+ entry->nargs = tp->nr_args;
+ entry->ip = (unsigned long)kp->addr;
+ for (i = 0; i < tp->nr_args; i++)
+ entry->args[i] = call_fetch(&tp->args[i].fetch, regs);
+ perf_tp_event(call->id, entry->ip, 1, entry, size);
+end:
+ local_irq_restore(irq_flags);