summaryrefslogtreecommitdiff
path: root/lib
diff options
context:
space:
mode:
Diffstat (limited to 'lib')
-rw-r--r--lib/Kconfig.debug20
-rw-r--r--lib/random32.c13
2 files changed, 32 insertions, 1 deletions
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index a48abeac753f..dd7f8858188a 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -980,6 +980,21 @@ config DEBUG_LOCKING_API_SELFTESTS
The following locking APIs are covered: spinlocks, rwlocks,
mutexes and rwsems.
+config LOCK_TORTURE_TEST
+ tristate "torture tests for locking"
+ depends on DEBUG_KERNEL
+ select TORTURE_TEST
+ default n
+ help
+ This option provides a kernel module that runs torture tests
+ on kernel locking primitives. The kernel module may be built
+ after the fact on the running kernel to be tested, if desired.
+
+ Say Y here if you want kernel locking-primitive torture tests
+ to be built into the kernel.
+ Say M if you want these torture tests to build as a module.
+ Say N if you are unsure.
+
endmenu # lock debugging
config TRACE_IRQFLAGS
@@ -1141,9 +1156,14 @@ config SPARSE_RCU_POINTER
Say N if you are unsure.
+config TORTURE_TEST
+ tristate
+ default n
+
config RCU_TORTURE_TEST
tristate "torture tests for RCU"
depends on DEBUG_KERNEL
+ select TORTURE_TEST
default n
help
This option provides a kernel module that runs torture tests
diff --git a/lib/random32.c b/lib/random32.c
index 1e5b2df44291..614896778700 100644
--- a/lib/random32.c
+++ b/lib/random32.c
@@ -244,8 +244,19 @@ static void __prandom_reseed(bool late)
static bool latch = false;
static DEFINE_SPINLOCK(lock);
+ /* Asking for random bytes might result in bytes getting
+ * moved into the nonblocking pool and thus marking it
+ * as initialized. In this case we would double back into
+ * this function and attempt to do a late reseed.
+ * Ignore the pointless attempt to reseed again if we're
+ * already waiting for bytes when the nonblocking pool
+ * got initialized.
+ */
+
/* only allow initial seeding (late == false) once */
- spin_lock_irqsave(&lock, flags);
+ if (!spin_trylock_irqsave(&lock, flags))
+ return;
+
if (latch && !late)
goto out;
latch = true;