trace: disable preemption before taking raw spinlocks

[linux-block.git] / kernel / trace / trace.c

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 02d32baa23ac9463bbadcce4a8ee75a04eb3b823..a3a8a87d7e91220190a0f15ac2ae47dea4674568 100644 (file)
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -808,6 +808,7 @@ void trace_find_cmdline(int pid, char comm[])
                return;
        }
 
+       preempt_disable();
        __raw_spin_lock(&trace_cmdline_lock);
        map = map_pid_to_cmdline[pid];
        if (map != NO_CMDLINE_MAP)
@@ -816,6 +817,7 @@ void trace_find_cmdline(int pid, char comm[])
                strcpy(comm, "<...>");
 
        __raw_spin_unlock(&trace_cmdline_lock);
+       preempt_enable();
 }
 
 void tracing_record_cmdline(struct task_struct *tsk)