workqueue: skip the node_nr_active update for non-unbound workqueuesgrafted

apply_wqattrs_commit() updates node_nr_active->max unconditionally.
wq->node_nr_active[] is only allocated for unbound workqueues, so guard
the call before per-cpu workqueues start using this path.

No functional change: only unbound workqueues reach apply_wqattrs_*()
today.

Signed-off-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Tejun Heo <tj@kernel.org>

1 files changed, 44 insertions, 0 deletions

diff --git a/tools/include/vdso/unaligned.h b/tools/include/vdso/unaligned.h
new file mode 100644
index 000000000..9076483c9
--- /dev/null
+++ b/tools/include/vdso/unaligned.h
@@ -0,0 +1,44 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __VDSO_UNALIGNED_H
+#define __VDSO_UNALIGNED_H
+
+#include <linux/compiler_types.h>
+
+/**
+ * __get_unaligned_t - read an unaligned value from memory.
+ * @type:	the type to load from the pointer.
+ * @ptr:	the pointer to load from.
+ *
+ * Use memcpy to affect an unaligned type sized load avoiding undefined behavior
+ * from approaches like type punning that require -fno-strict-aliasing in order
+ * to be correct. As type may be const, use __unqual_scalar_typeof to map to a
+ * non-const type - you can't memcpy into a const type. The
+ * __get_unaligned_ctrl_type gives __unqual_scalar_typeof its required
+ * expression rather than type, a pointer is used to avoid warnings about mixing
+ * the use of 0 and NULL. The void* cast silences ubsan warnings.
+ */
+#define __get_unaligned_t(type, ptr) ({					\
+	type *__get_unaligned_ctrl_type __always_unused = NULL;		\
+	__unqual_scalar_typeof(*__get_unaligned_ctrl_type) __get_unaligned_val; \
+	__builtin_memcpy(&__get_unaligned_val, (void *)(ptr),		\
+			 sizeof(__get_unaligned_val));			\
+	__get_unaligned_val;						\
+})
+
+/**
+ * __put_unaligned_t - write an unaligned value to memory.
+ * @type:	the type of the value to store.
+ * @val:	the value to store.
+ * @ptr:	the pointer to store to.
+ *
+ * Use memcpy to affect an unaligned type sized store avoiding undefined
+ * behavior from approaches like type punning that require -fno-strict-aliasing
+ * in order to be correct. The void* cast silences ubsan warnings.
+ */
+#define __put_unaligned_t(type, val, ptr) do {				\
+	type __put_unaligned_val = (val);				\
+	__builtin_memcpy((void *)(ptr), &__put_unaligned_val,		\
+			 sizeof(__put_unaligned_val));			\
+} while (0)
+
+#endif /* __VDSO_UNALIGNED_H */