Commit e1aacb3f authored Jun 12, 2019 by Daniel Bristot de Oliveira Committed by Ingo Molnar Jun 17, 2019

jump_label: Add a jump_label_can_update() helper

Move the check if a jump_entry is valid to a function. No functional
change.

Signed-off-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Chris von Recklinghausen <crecklin@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jason Baron <jbaron@akamai.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Scott Wood <swood@redhat.com>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/56b69bd3f8e644ed64f2dbde7c088030b8cbe76b.1560325897.git.bristot@redhat.com

Signed-off-by: Ingo Molnar <mingo@kernel.org>

parent 410df0c5

kernel/jump_label.c

+18 −11

Original line number	Diff line number	Diff line
		@@ -384,23 +384,30 @@ 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 (; (entry < stop) && (jump_entry_key(entry) == key); entry++) {
		/*
		* 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)))
		if (jump_label_can_update(entry, init))
		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));
		}
		}
		}

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