On 2/5/19 10:13 PM, Borislav Petkov wrote:
> On Tue, Feb 05, 2019 at 02:50:39PM +0100, Daniel Bristot de Oliveira wrote:
>>>> +          if (jump_label_can_update_check(entry, init)) {
>>>> +                  arch_jump_label_transform(entry,
>>>> +                                            jump_label_type(entry));
>>>
>>> Yeah, let that one stick out.
>>
>> I did not get this part...
> 
> Just let the line stick outside of the 80 cols rule which is not a hard
> one:
> 
> +          if (jump_label_can_update_check(entry, init)) {
> +                  arch_jump_label_transform(entry, jump_label_type(entry));
> 
> 
> :-)
> 

How about this?

----------------- %< ----------------------------
Subject: jump_label: Add a jump_label_can_update() helper

Move the check if a jump_entry is valid to a function.

Signed-off-by: Daniel Bristot de Oliveira <bris...@redhat.com>
Cc: Thomas Gleixner <t...@linutronix.de>
Cc: Ingo Molnar <mi...@redhat.com>
Cc: Borislav Petkov <b...@alien8.de>
Cc: "H. Peter Anvin" <h...@zytor.com>
Cc: Greg Kroah-Hartman <gre...@linuxfoundation.org>
Cc: Masami Hiramatsu <mhira...@kernel.org>
Cc: "Steven Rostedt (VMware)" <rost...@goodmis.org>
Cc: Jiri Kosina <jkos...@suse.cz>
Cc: Josh Poimboeuf <jpoim...@redhat.com>
Cc: "Peter Zijlstra (Intel)" <pet...@infradead.org>
Cc: Chris von Recklinghausen <creck...@redhat.com>
Cc: Jason Baron <jba...@akamai.com>
Cc: Scott Wood <sw...@redhat.com>
Cc: Marcelo Tosatti <mtosa...@redhat.com>
Cc: Clark Williams <willi...@redhat.com>
Cc: x...@kernel.org
Cc: linux-kernel@vger.kernel.org
---
 kernel/jump_label.c | 27 +++++++++++++++++----------
 1 file changed, 17 insertions(+), 10 deletions(-)

diff --git a/kernel/jump_label.c b/kernel/jump_label.c
index 288d630da22d..1e6f4d27e28d 100644
--- a/kernel/jump_label.c
+++ b/kernel/jump_label.c
@@ -374,22 +374,29 @@ static enum jump_label_type jump_label_type(struct 
jump_entry *entry)
        return enabled ^ branch;
 }
 
+static bool jump_label_can_update(struct jump_entry *entry, bool init)
+{
+       /*
+        * Cannot update code that was in an init text area.
+        */
+       if (!init || jump_entry_is_init(entry))
+               return false;
+
+       if (WARN_ONCE(!kernel_text_address(jump_entry_code(entry)),
+                        "can't patch jump_label at %pS", (void 
*)jump_entry_code(entry)))
+               return false;
+
+       return true;
+}
+
 static void __jump_label_update(struct static_key *key,
                                struct jump_entry *entry,
                                struct jump_entry *stop,
                                bool init)
 {
        for_each_label_entry(key, entry, stop) {
-               /*
-                * An entry->code of 0 indicates an entry which has been
-                * disabled because it was in an init text area.
-                */
-               if (init || !jump_entry_is_init(entry)) {
-                       if (kernel_text_address(jump_entry_code(entry)))
-                               arch_jump_label_transform(entry, 
jump_label_type(entry));
-                       else
-                               WARN_ONCE(1, "can't patch jump_label at %pS",
-                                         (void *)jump_entry_code(entry));
+               if (jump_label_can_update(entry, init)) {
+                       arch_jump_label_transform(entry, 
jump_label_type(entry));
                }
        }
 }
---------------- >% --------------------

Thanks!

-- Daniel

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