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From: Daniel Bristot de Oliveira <bristot@redhat.com>
To: linux-kernel@vger.kernel.org
Cc: Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
	"H. Peter Anvin" <hpa@zytor.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Masami Hiramatsu <mhiramat@kernel.org>,
	"Steven Rostedt (VMware)" <rostedt@goodmis.org>,
	Jiri Kosina <jkosina@suse.cz>,
	Josh Poimboeuf <jpoimboe@redhat.com>,
	"Peter Zijlstra (Intel)" <peterz@infradead.org>,
	Chris von Recklinghausen <crecklin@redhat.com>,
	Jason Baron <jbaron@akamai.com>, Scott Wood <swood@redhat.com>,
	Marcelo Tosatti <mtosatti@redhat.com>,
	Clark Williams <williams@redhat.com>,
	x86@kernel.org
Subject: [PATCH V5 2/7] jump_label: Add a jump_label_can_update() helper
Date: Mon,  1 Apr 2019 10:58:14 +0200	[thread overview]
Message-ID: <18e435c1a23d49638ed0d0eac8ecbe9ef274c04f.1554106794.git.bristot@redhat.com> (raw)
In-Reply-To: <cover.1554106794.git.bristot@redhat.com>

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

Signed-off-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org>
Cc: Chris von Recklinghausen <crecklin@redhat.com>
Cc: Jason Baron <jbaron@akamai.com>
Cc: Scott Wood <swood@redhat.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: x86@kernel.org
Cc: linux-kernel@vger.kernel.org
---
 kernel/jump_label.c | 28 ++++++++++++++++++----------
 1 file changed, 18 insertions(+), 10 deletions(-)

diff --git a/kernel/jump_label.c b/kernel/jump_label.c
index 288d630da22d..e666a4d6642a 100644
--- a/kernel/jump_label.c
+++ b/kernel/jump_label.c
@@ -374,22 +374,30 @@ 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 (!kernel_text_address(jump_entry_code(entry))) {
+		WARN_ONCE(1, "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));
 		}
 	}
 }
-- 
2.20.1


  parent reply	other threads:[~2019-04-01  8:59 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-04-01  8:58 [PATCH V5 0/7] x86/jump_label: Bound IPIs sent when updating a static key Daniel Bristot de Oliveira
2019-04-01  8:58 ` [PATCH V5 1/7] jump_label: Add for_each_label_entry helper Daniel Bristot de Oliveira
2019-04-15 10:51   ` Peter Zijlstra
2019-04-15 11:29     ` Daniel Bristot de Oliveira
2019-04-01  8:58 ` Daniel Bristot de Oliveira [this message]
2019-04-01  8:58 ` [PATCH V5 3/7] x86/jump_label: Add a __jump_label_set_jump_code() helper Daniel Bristot de Oliveira
2019-04-01  8:58 ` [PATCH V5 4/7] jump_label: Sort entries of the same key by the code Daniel Bristot de Oliveira
2019-04-15 10:55   ` Peter Zijlstra
2019-04-15 11:33     ` Daniel Bristot de Oliveira
2019-04-01  8:58 ` [PATCH V5 5/7] x86/alternative: Batch of patch operations Daniel Bristot de Oliveira
2019-04-15 11:35   ` Peter Zijlstra
2019-04-01  8:58 ` [PATCH V5 6/7] jump_label: Batch updates if arch supports it Daniel Bristot de Oliveira
2019-04-15 11:50   ` Peter Zijlstra
2019-04-01  8:58 ` [PATCH V5 7/7] x86/jump_label: Batch jump label updates Daniel Bristot de Oliveira
2019-04-15 11:54   ` Peter Zijlstra
2019-04-15 12:15     ` Daniel Bristot de Oliveira
2019-05-02 20:18     ` Daniel Bristot de Oliveira
2019-04-15  9:52 ` [PATCH V5 0/7] x86/jump_label: Bound IPIs sent when updating a static key Daniel Bristot de Oliveira

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