[PATCH 08/13] jump_label: Free jump_entry::key bit1 for build use

From: Peter Zijlstra
Date: Thu May 06 2021 - 15:44:08 EST


Have jump_label_init() set jump_entry::key bit1 to either 0 ot 1
unconditionally. This makes it available for build-time games.

Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
---
include/linux/jump_label.h | 7 +++++--
kernel/jump_label.c | 10 ++++++----
2 files changed, 11 insertions(+), 6 deletions(-)

--- a/include/linux/jump_label.h
+++ b/include/linux/jump_label.h
@@ -171,9 +171,12 @@ static inline bool jump_entry_is_init(co
return (unsigned long)entry->key & 2UL;
}

-static inline void jump_entry_set_init(struct jump_entry *entry)
+static inline void jump_entry_set_init(struct jump_entry *entry, bool set)
{
- entry->key |= 2;
+ if (set)
+ entry->key |= 2;
+ else
+ entry->key &= ~2;
}

static inline int jump_entry_size(struct jump_entry *entry)
--- a/kernel/jump_label.c
+++ b/kernel/jump_label.c
@@ -475,13 +475,14 @@ void __init jump_label_init(void)

for (iter = iter_start; iter < iter_stop; iter++) {
struct static_key *iterk;
+ bool in_init;

/* rewrite NOPs */
if (jump_label_type(iter) == JUMP_LABEL_NOP)
arch_jump_label_transform_static(iter, JUMP_LABEL_NOP);

- if (init_section_contains((void *)jump_entry_code(iter), 1))
- jump_entry_set_init(iter);
+ in_init = init_section_contains((void *)jump_entry_code(iter), 1);
+ jump_entry_set_init(iter, in_init);

iterk = jump_entry_key(iter);
if (iterk == key)
@@ -626,9 +627,10 @@ static int jump_label_add_module(struct

for (iter = iter_start; iter < iter_stop; iter++) {
struct static_key *iterk;
+ bool in_init;

- if (within_module_init(jump_entry_code(iter), mod))
- jump_entry_set_init(iter);
+ in_init = within_module_init(jump_entry_code(iter), mod);
+ jump_entry_set_init(iter, in_init);

iterk = jump_entry_key(iter);
if (iterk == key)