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-rw-r--r--arch/Kconfig3
-rw-r--r--include/linux/jump_label.h28
-rw-r--r--kernel/jump_label.c22
3 files changed, 52 insertions, 1 deletions
diff --git a/arch/Kconfig b/arch/Kconfig
index 6801123932a5..9d329608913e 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -359,6 +359,9 @@ config HAVE_PERF_USER_STACK_DUMP
config HAVE_ARCH_JUMP_LABEL
bool
+config HAVE_ARCH_JUMP_LABEL_RELATIVE
+ bool
+
config HAVE_RCU_TABLE_FREE
bool
diff --git a/include/linux/jump_label.h b/include/linux/jump_label.h
index 2eadff9b3b90..2768a925bafa 100644
--- a/include/linux/jump_label.h
+++ b/include/linux/jump_label.h
@@ -121,6 +121,32 @@ struct static_key {
#include <asm/jump_label.h>
#ifndef __ASSEMBLY__
+#ifdef CONFIG_HAVE_ARCH_JUMP_LABEL_RELATIVE
+
+struct jump_entry {
+ s32 code;
+ s32 target;
+ long key; // key may be far away from the core kernel under KASLR
+};
+
+static inline unsigned long jump_entry_code(const struct jump_entry *entry)
+{
+ return (unsigned long)&entry->code + entry->code;
+}
+
+static inline unsigned long jump_entry_target(const struct jump_entry *entry)
+{
+ return (unsigned long)&entry->target + entry->target;
+}
+
+static inline struct static_key *jump_entry_key(const struct jump_entry *entry)
+{
+ long offset = entry->key & ~1L;
+
+ return (struct static_key *)((unsigned long)&entry->key + offset);
+}
+
+#else
static inline unsigned long jump_entry_code(const struct jump_entry *entry)
{
@@ -137,6 +163,8 @@ static inline struct static_key *jump_entry_key(const struct jump_entry *entry)
return (struct static_key *)((unsigned long)entry->key & ~1UL);
}
+#endif
+
static inline bool jump_entry_is_branch(const struct jump_entry *entry)
{
return (unsigned long)entry->key & 1UL;
diff --git a/kernel/jump_label.c b/kernel/jump_label.c
index 834e43de0daf..898a1d0c38dc 100644
--- a/kernel/jump_label.c
+++ b/kernel/jump_label.c
@@ -47,14 +47,34 @@ static int jump_label_cmp(const void *a, const void *b)
return 0;
}
+static void jump_label_swap(void *a, void *b, int size)
+{
+ long delta = (unsigned long)a - (unsigned long)b;
+ struct jump_entry *jea = a;
+ struct jump_entry *jeb = b;
+ struct jump_entry tmp = *jea;
+
+ jea->code = jeb->code - delta;
+ jea->target = jeb->target - delta;
+ jea->key = jeb->key - delta;
+
+ jeb->code = tmp.code + delta;
+ jeb->target = tmp.target + delta;
+ jeb->key = tmp.key + delta;
+}
+
static void
jump_label_sort_entries(struct jump_entry *start, struct jump_entry *stop)
{
unsigned long size;
+ void *swapfn = NULL;
+
+ if (IS_ENABLED(CONFIG_HAVE_ARCH_JUMP_LABEL_RELATIVE))
+ swapfn = jump_label_swap;
size = (((unsigned long)stop - (unsigned long)start)
/ sizeof(struct jump_entry));
- sort(start, size, sizeof(struct jump_entry), jump_label_cmp, NULL);
+ sort(start, size, sizeof(struct jump_entry), jump_label_cmp, swapfn);
}
static void jump_label_update(struct static_key *key);