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authorNick Kossifidis <mickflemm@gmail.com>2012-12-16 22:18:11 -0500
committerTheodore Ts'o <tytso@mit.edu>2012-12-16 22:18:11 -0500
commit6133705494bb02953e1e2cc3018a4373981b3c97 (patch)
tree4c46ef0c3b1c6a3b07a7f98fda0873c4f201934c /kernel
parentec8f02da9ea500474417d1d31fa3d46a562ab366 (diff)
random: Mix cputime from each thread that exits to the pool
When a thread exits mix it's cputime (userspace + kernelspace) to the entropy pool. We don't know how "random" this is, so we use add_device_randomness that doesn't mess with entropy count. Signed-off-by: Nick Kossifidis <mickflemm@gmail.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/posix-cpu-timers.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c
index 125cb67daa2..f07827a4e28 100644
--- a/kernel/posix-cpu-timers.c
+++ b/kernel/posix-cpu-timers.c
@@ -9,6 +9,7 @@
#include <asm/uaccess.h>
#include <linux/kernel_stat.h>
#include <trace/events/timer.h>
+#include <linux/random.h>
/*
* Called after updating RLIMIT_CPU to run cpu timer and update
@@ -494,6 +495,8 @@ static void cleanup_timers(struct list_head *head,
*/
void posix_cpu_timers_exit(struct task_struct *tsk)
{
+ add_device_randomness((const void*) &tsk->se.sum_exec_runtime,
+ sizeof(unsigned long long));
cleanup_timers(tsk->cpu_timers,
tsk->utime, tsk->stime, tsk->se.sum_exec_runtime);