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authorPuneet Kumar <puneetster@chromium.org>2013-11-15 11:41:29 -0800
committerBen Hutchings <ben@decadent.org.uk>2014-08-06 18:07:35 +0100
commit2934cf26e2b83e01a36fcb9ce5bfdb3209f2957e (patch)
tree354516c045bf893d4c34770b3874f16126c4648d /drivers
parentd5c85f63672263b2f8ea12ac1c1b925e793fdd0a (diff)
ACPI / EC: Ensure lock is acquired before accessing ec struct members
commit 36b15875a7819a2ec4cb5748ff7096ad7bd86cbb upstream. A bug was introduced by commit b76b51ba0cef ('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: b76b51ba0cef ('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> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/acpi/ec.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c
index 75a12f1c0ff6..692d21670670 100644
--- a/drivers/acpi/ec.c
+++ b/drivers/acpi/ec.c
@@ -178,9 +178,10 @@ 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->curr_lock, flags);
+ t = ec->curr;
if (!t)
goto unlock;
if (t->wlen > t->wi) {