path: root/lib
diff options
authorEmese Revfy <>2016-06-20 20:42:34 +0200
committerKees Cook <>2016-10-10 14:51:45 -0700
commit0766f788eb727e2e330d55d30545db65bcf2623f (patch)
tree0436ae3b005558a4fb827459fe5c602037fe764a /lib
parent38addce8b600ca335dc86fa3d48c890f1c6fa1f4 (diff)
latent_entropy: Mark functions with __latent_entropy
The __latent_entropy gcc attribute can be used only on functions and variables. If it is on a function then the plugin will instrument it for gathering control-flow entropy. If the attribute is on a variable then the plugin will initialize it with random contents. The variable must be an integer, an integer array type or a structure with integer fields. These specific functions have been selected because they are init functions (to help gather boot-time entropy), are called at unpredictable times, or they have variable loops, each of which provide some level of latent entropy. Signed-off-by: Emese Revfy <> [kees: expanded commit message] Signed-off-by: Kees Cook <>
Diffstat (limited to 'lib')
2 files changed, 2 insertions, 2 deletions
diff --git a/lib/irq_poll.c b/lib/irq_poll.c
index 836f7db4e548..63be7495dbb2 100644
--- a/lib/irq_poll.c
+++ b/lib/irq_poll.c
@@ -74,7 +74,7 @@ void irq_poll_complete(struct irq_poll *iop)
-static void irq_poll_softirq(struct softirq_action *h)
+static void __latent_entropy irq_poll_softirq(struct softirq_action *h)
struct list_head *list = this_cpu_ptr(&blk_cpu_iopoll);
int rearm = 0, budget = irq_poll_budget;
diff --git a/lib/random32.c b/lib/random32.c
index 69ed593aab07..a30923573676 100644
--- a/lib/random32.c
+++ b/lib/random32.c
@@ -47,7 +47,7 @@ static inline void prandom_state_selftest(void)
-static DEFINE_PER_CPU(struct rnd_state, net_rand_state);
+static DEFINE_PER_CPU(struct rnd_state, net_rand_state) __latent_entropy;
* prandom_u32_state - seeded pseudo-random number generator.