WARNING - OLD ARCHIVES

This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
   
 
 
Xen 
 
Home Products Support Community News
 
   
 

xen-devel

[Xen-devel] [PATCH RFC V2 3/5] jump_label: if a key has already been ini

To: Steven Rostedt <rostedt@xxxxxxxxxxx>
Subject: [Xen-devel] [PATCH RFC V2 3/5] jump_label: if a key has already been initialized, don't nop it out
From: Jeremy Fitzhardinge <jeremy@xxxxxxxx>
Date: Sat, 1 Oct 2011 14:55:35 -0700
Cc: Xen Devel <xen-devel@xxxxxxxxxxxxxxxxxxx>, Jan Glauber <jang@xxxxxxxxxxxxxxxxxx>, Jason Baron <jbaron@xxxxxxxxxx>, the arch/x86 maintainers <x86@xxxxxxxxxx>, David Daney <david.daney@xxxxxxxxxx>, Linux Kernel Mailing List <linux-kernel@xxxxxxxxxxxxxxx>, Michael Ellerman <michael@xxxxxxxxxxxxxx>, Jeremy Fitzhardinge <jeremy.fitzhardinge@xxxxxxxxxx>, "David S. Miller" <davem@xxxxxxxxxxxxx>
Delivery-date: Sat, 01 Oct 2011 15:06:22 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
In-reply-to: <cover.1317506051.git.jeremy.fitzhardinge@xxxxxxxxxx>
In-reply-to: <cover.1317506051.git.jeremy.fitzhardinge@xxxxxxxxxx>
List-help: <mailto:xen-devel-request@lists.xensource.com?subject=help>
List-id: Xen developer discussion <xen-devel.lists.xensource.com>
List-post: <mailto:xen-devel@lists.xensource.com>
List-subscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe>
References: <cover.1317506051.git.jeremy.fitzhardinge@xxxxxxxxxx>
References: <cover.1317506051.git.jeremy.fitzhardinge@xxxxxxxxxx>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
From: Jeremy Fitzhardinge <jeremy.fitzhardinge@xxxxxxxxxx>

If a key has been enabled before jump_label_init() is called, don't
nop it out.

This removes arch_jump_label_text_poke_early() (which can only nop
out a site) and uses arch_jump_label_transform() instead.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@xxxxxxxxxx>
---
 include/linux/jump_label.h |    3 ++-
 kernel/jump_label.c        |   20 ++++++++------------
 2 files changed, 10 insertions(+), 13 deletions(-)

diff --git a/include/linux/jump_label.h b/include/linux/jump_label.h
index 1213e9d..c8fb1b3 100644
--- a/include/linux/jump_label.h
+++ b/include/linux/jump_label.h
@@ -45,7 +45,8 @@ extern void jump_label_lock(void);
 extern void jump_label_unlock(void);
 extern void arch_jump_label_transform(struct jump_entry *entry,
                                 enum jump_label_type type);
-extern void arch_jump_label_text_poke_early(jump_label_t addr);
+extern void arch_jump_label_transform_early(struct jump_entry *entry,
+                                enum jump_label_type type);
 extern int jump_label_text_reserved(void *start, void *end);
 extern void jump_label_inc(struct jump_label_key *key);
 extern void jump_label_dec(struct jump_label_key *key);
diff --git a/kernel/jump_label.c b/kernel/jump_label.c
index a8ce450..059202d5 100644
--- a/kernel/jump_label.c
+++ b/kernel/jump_label.c
@@ -121,13 +121,6 @@ static void __jump_label_update(struct jump_label_key *key,
        }
 }
 
-/*
- * Not all archs need this.
- */
-void __weak arch_jump_label_text_poke_early(jump_label_t addr)
-{
-}
-
 static __init int jump_label_init(void)
 {
        struct jump_entry *iter_start = __start___jump_table;
@@ -139,12 +132,15 @@ static __init int jump_label_init(void)
        jump_label_sort_entries(iter_start, iter_stop);
 
        for (iter = iter_start; iter < iter_stop; iter++) {
-               arch_jump_label_text_poke_early(iter->code);
-               if (iter->key == (jump_label_t)(unsigned long)key)
+               struct jump_label_key *iterk;
+
+               iterk = (struct jump_label_key *)(unsigned long)iter->key;
+               arch_jump_label_transform(iter, jump_label_enabled(iterk) ?
+                                         JUMP_LABEL_ENABLE : 
JUMP_LABEL_DISABLE);
+               if (iterk == key)
                        continue;
 
-               key = (struct jump_label_key *)(unsigned long)iter->key;
-               atomic_set(&key->enabled, 0);
+               key = iterk;
                key->entries = iter;
 #ifdef CONFIG_MODULES
                key->next = NULL;
@@ -212,7 +208,7 @@ void jump_label_apply_nops(struct module *mod)
                return;
 
        for (iter = iter_start; iter < iter_stop; iter++)
-               arch_jump_label_text_poke_early(iter->code);
+               arch_jump_label_transform(iter, JUMP_LABEL_DISABLE);
 }
 
 static int jump_label_add_module(struct module *mod)
-- 
1.7.6.2


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel

<Prev in Thread] Current Thread [Next in Thread>