[PATCH V5 4/7] jump_label: Sort entries of the same key by the code

From: Daniel Bristot de Oliveira
Date: Mon Apr 01 2019 - 04:58:42 EST


In the batching mode, entries with the same key should also be sorted by the
code, enabling a bsearch() of a code/addr when updating a key.

Signed-off-by: Daniel Bristot de Oliveira <bristot@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
Cc: "Steven Rostedt (VMware)" <rostedt@xxxxxxxxxxx>
Cc: Jiri Kosina <jkosina@xxxxxxx>
Cc: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Cc: "Peter Zijlstra (Intel)" <peterz@xxxxxxxxxxxxx>
Cc: Chris von Recklinghausen <crecklin@xxxxxxxxxx>
Cc: Jason Baron <jbaron@xxxxxxxxxx>
Cc: Scott Wood <swood@xxxxxxxxxx>
Cc: Marcelo Tosatti <mtosatti@xxxxxxxxxx>
Cc: Clark Williams <williams@xxxxxxxxxx>
Cc: x86@xxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
---
kernel/jump_label.c | 16 ++++++++++++++++
1 file changed, 16 insertions(+)

diff --git a/kernel/jump_label.c b/kernel/jump_label.c
index e666a4d6642a..8b7bfbba4cef 100644
--- a/kernel/jump_label.c
+++ b/kernel/jump_label.c
@@ -36,12 +36,28 @@ static int jump_label_cmp(const void *a, const void *b)
const struct jump_entry *jea = a;
const struct jump_entry *jeb = b;

+ /*
+ * Entrires are sorted by key.
+ */
if (jump_entry_key(jea) < jump_entry_key(jeb))
return -1;

if (jump_entry_key(jea) > jump_entry_key(jeb))
return 1;

+#ifdef HAVE_JUMP_LABEL_BATCH
+ /*
+ * In the batching mode, entries should also be sorted by the code
+ * inside the already sorted list of entries, enabling a bsearch in
+ * the vector.
+ */
+ if (jump_entry_code(jea) < jump_entry_code(jeb))
+ return -1;
+
+ if (jump_entry_code(jea) > jump_entry_code(jeb))
+ return 1;
+#endif
+
return 0;
}

--
2.20.1