[tip:x86/alternatives] jump_label: Add for_each_label_entry helper

[tip-bot for Daniel Bristot de Oliveira]

Commit-ID:  b1b944f7230f4101b5a293d5ac3b7a9627ed5e6f
Gitweb:     https://git.kernel.org/tip/b1b944f7230f4101b5a293d5ac3b7a9627ed5e6f
Author:     Daniel Bristot de Oliveira <bristot@xxxxxxxxxx>
AuthorDate: Fri, 21 Dec 2018 11:27:26 +0100
Committer:  Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Fri, 19 Apr 2019 19:37:34 +0200

jump_label: Add for_each_label_entry helper

Add a helper macro to make jump entry iteration code more readable.

Signed-off-by: Daniel Bristot de Oliveira <bristot@xxxxxxxxxx>
Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxx>
Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Brian Gerst <brgerst@xxxxxxxxx>
Cc: Chris von Recklinghausen <crecklin@xxxxxxxxxx>
Cc: Clark Williams <williams@xxxxxxxxxx>
Cc: Denys Vlasenko <dvlasenk@xxxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: H. Peter Anvin <hpa@xxxxxxxxx>
Cc: Jason Baron <jbaron@xxxxxxxxxx>
Cc: Jiri Kosina <jkosina@xxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Marcelo Tosatti <mtosatti@xxxxxxxxxx>
Cc: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Scott Wood <swood@xxxxxxxxxx>
Cc: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/206640539a01e31b6f4ef4ef74962b1394e2f930.1545228276.git.bristot@xxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
 include/linux/jump_label.h | 3 +++
 kernel/jump_label.c        | 2 +-
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/include/linux/jump_label.h b/include/linux/jump_label.h
index 3e113a1fa0f1..7e91af98bbb1 100644
--- a/include/linux/jump_label.h
+++ b/include/linux/jump_label.h
@@ -227,6 +227,9 @@ extern void static_key_disable(struct static_key *key);
 extern void static_key_enable_cpuslocked(struct static_key *key);
 extern void static_key_disable_cpuslocked(struct static_key *key);
 
+#define for_each_label_entry(key, entry, stop)				  \
+	for (; (entry < stop) && (jump_entry_key(entry) == key); entry++)
+
 /*
  * We should be using ATOMIC_INIT() for initializing .enabled, but
  * the inclusion of atomic.h is problematic for inclusion of jump_label.h
diff --git a/kernel/jump_label.c b/kernel/jump_label.c
index bad96b476eb6..288d630da22d 100644
--- a/kernel/jump_label.c
+++ b/kernel/jump_label.c
@@ -379,7 +379,7 @@ static void __jump_label_update(struct static_key *key,
 				struct jump_entry *stop,
 				bool init)
 {
-	for (; (entry < stop) && (jump_entry_key(entry) == key); entry++) {
+	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.