perfcounters: flush on setuid exec

Pavel Machek pointed out that performance counters should be flushed
when crossing protection domains on setuid execution.

Reported-by: Pavel Machek <pavel@suse.cz>
Acked-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 8 insertions, 0 deletions

diff --git a/fs/exec.c b/fs/exec.c
index ec5df9a38313..d5165d899a49 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -33,6 +33,7 @@
 #include <linux/string.h>
 #include <linux/init.h>
 #include <linux/pagemap.h>
+#include <linux/perf_counter.h>
 #include <linux/highmem.h>
 #include <linux/spinlock.h>
 #include <linux/key.h>
@@ -1017,6 +1018,13 @@ int flush_old_exec(struct linux_binprm * bprm)
                 set_dumpable(current->mm, suid_dumpable);
         }
 
+        /*
+         * Flush performance counters when crossing a
+         * security domain:
+         */
+        if (!get_dumpable(current->mm))
+                perf_counter_exit_task(current);
+
         /* An exec changes our domain. We are no longer part of the thread
            group */