rcutorture: Check nfakewriters parameter
Currently, a negative value for rcutorture.nfakewriters= can cause
rcutorture to pass a negative size to the memory allocator, which
is not really a particularly good thing to do. This commit therefore
adds bounds checking to this parameter, so that values that are less
than or equal to zero disable fake writing.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
index 7e29a32..2cbe569 100644
--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -1786,12 +1786,15 @@
writer_task);
if (firsterr)
goto unwind;
- fakewriter_tasks = kzalloc(nfakewriters * sizeof(fakewriter_tasks[0]),
- GFP_KERNEL);
- if (fakewriter_tasks == NULL) {
- VERBOSE_TOROUT_ERRSTRING("out of memory");
- firsterr = -ENOMEM;
- goto unwind;
+ if (nfakewriters > 0) {
+ fakewriter_tasks = kzalloc(nfakewriters *
+ sizeof(fakewriter_tasks[0]),
+ GFP_KERNEL);
+ if (fakewriter_tasks == NULL) {
+ VERBOSE_TOROUT_ERRSTRING("out of memory");
+ firsterr = -ENOMEM;
+ goto unwind;
+ }
}
for (i = 0; i < nfakewriters; i++) {
firsterr = torture_create_kthread(rcu_torture_fakewriter,