Commit 36b15875 authored Nov 15, 2013 by Puneet Kumar Committed by Rafael J. Wysocki Nov 15, 2013

ACPI / EC: Ensure lock is acquired before accessing ec struct members

A bug was introduced by commit b76b51ba ('ACPI / EC: Add more debug
info and trivial code cleanup') that erroneously caused the struct member
to be accessed before acquiring the required lock.  This change fixes
it by ensuring the lock acquisition is done first.

Found by Aaron Durbin <adurbin@chromium.org>

Fixes: b76b51ba ('ACPI / EC: Add more debug info and trivial code cleanup')
References: http://crbug.com/319019


Signed-off-by: Puneet Kumar <puneetster@chromium.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
[olof: Commit message reworded a bit]
Signed-off-by: Olof Johansson <olof@lixom.net>
Cc: 3.8+ <stable@vger.kernel.org> # 3.8+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

parent 5e01dc7b

drivers/acpi/ec.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -175,9 +175,10 @@ static void start_transaction(struct acpi_ec *ec)
		static void advance_transaction(struct acpi_ec *ec, u8 status)
		{
		unsigned long flags;
		struct transaction *t = ec->curr;
		struct transaction *t;

		spin_lock_irqsave(&ec->lock, flags);
		t = ec->curr;
		if (!t)
		goto unlock;
		if (t->wlen > t->wi) {

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