[PATCH RFC V4 08/10] x86/jump_label: add arch_jump_label_transform_static()

Jeremy Fitzhardinge
2011-10-13T00:09:46Z

From: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>

This allows jump-label entries to be cheaply updated on code which is
not yet live.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Acked-by: Jason Baron <jbaron@redhat.com>
---
arch/x86/kernel/jump_label.c | 20 +++++++++++++++++---
1 files changed, 17 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kernel/jump_label.c b/arch/x86/kernel/jump_label.c
index 2ad0298..ea9d5f2f 100644
--- a/arch/x86/kernel/jump_label.c
+++ b/arch/x86/kernel/jump_label.c
@@ -24,8 +24,9 @@ union jump_code_union {
} __attribute__((packed));
};

-void arch_jump_label_transform(struct jump_entry *entry,
- enum jump_label_type type)
+static void __jump_label_transform(struct jump_entry *entry,
+ enum jump_label_type type,
+ void *(*poker)(void *, const void *, size_t))
{
union jump_code_union code;

@@ -35,11 +36,24 @@ void arch_jump_label_transform(struct jump_entry *entry,
(entry->code + JUMP_LABEL_NOP_SIZE);
} else
memcpy(&code, ideal_nops[NOP_ATOMIC5], JUMP_LABEL_NOP_SIZE);
+
+ (*poker)((void *)entry->code, &code, JUMP_LABEL_NOP_SIZE);
+}
+
+void arch_jump_label_transform(struct jump_entry *entry,
+ enum jump_label_type type)
+{
get_online_cpus();
mutex_lock(&text_mutex);
- text_poke_smp((void *)entry->code, &code, JUMP_LABEL_NOP_SIZE);
+ __jump_label_transform(entry, type, text_poke_smp);
mutex_unlock(&text_mutex);
put_online_cpus();
}

+void arch_jump_label_transform_static(struct jump_entry *entry,
+ enum jump_label_type type)
+{
+ __jump_label_transform(entry, type, text_poke_early);
+}
+
#endif
--
1.7.6.4