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e1000e: fix double release of mutex

PATCH In review Jeff Kirsher 2 participants 3 messages Dec 11, 2008 – Dec 12, 2008

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Jeff Kirsher

author
#0 lore raw

PATCH 1/1 e1000e: fix double release of mutex

During a reset, releasing the swflag after it failed to be acquired would cause a double unlock of the mutex. Instead, test whether acquisition of the swflag was successful and if not, do not release the swflag. The reset must still be done to bring the device to a quiescent state.

This resolves [BUG 12200] BUG: bad unlock balance detected! e1000e
http://bugzilla.kernel.org/show_bug.cgi?id=12200

Signed-off-by Jeff Kirsher <[email protected]>

---

 drivers/net/e1000e/ich8lan.c |    9 +++++++--
 1 files changed, 7 insertions(+), 2 deletions(-)
drivers/net/e1000e/ich8lan.c +7 -2
index 92f2ace..f2a5963 100644
@@ -1939,12 +1939,17 @@ static s32 e1000_reset_hw_ich8lan(struct e1000_hw *hw)
 		ctrl |= E1000_CTRL_PHY_RST;
 	}
 	ret_val = e1000_acquire_swflag_ich8lan(hw);
+	/* Whether or not the swflag was acquired, we need to reset the part */
 	hw_dbg(hw, "Issuing a global reset to ich8lan\n");
 	ew32(CTRL, (ctrl | E1000_CTRL_RST));
 	msleep(20);
 
-	/* release the swflag because it is not reset by hardware reset */
-	e1000_release_swflag_ich8lan(hw);
+	if (!ret_val) {
+		/* release the swflag because it is not reset by
+		 * hardware reset
+		 */
+		e1000_release_swflag_ich8lan(hw);
+	}
 
 	ret_val = e1000e_get_auto_rd_done(hw);
 	if (ret_val) {
maintainer
#1 lore raw

From: Jeff Kirsher <[email protected]>
Date: Thu, 11 Dec 2008 13:58:07 -0800

Quoted 9 lines

During a reset, releasing the swflag after it failed to be acquired would cause a double unlock of the mutex. Instead, test whether acquisition of the swflag was successful and if not, do not release the swflag. The reset must still be done to bring the device to a quiescent state.

This resolves [BUG 12200] BUG: bad unlock balance detected! e1000e
http://bugzilla.kernel.org/show_bug.cgi?id=12200

Signed-off-by Jeff Kirsher <[email protected]>

If we're fixing a regression like this, you should make the patch against net-2.6, and this one is against net-next-2.6

Please respin this for me, thanks Jeff.

author
#2 lore raw
Quoted 11 lines · David Miller

From: Jeff Kirsher <[email protected]>
Date: Thu, 11 Dec 2008 13:58:07 -0800

Quoted 8 lines

During a reset, releasing the swflag after it failed to be acquired would cause a double unlock of the mutex. Instead, test whether acquisition of the swflag was successful and if not, do not release the swflag. The reset must still be done to bring the device to a quiescent state.

This resolves [BUG 12200] BUG: bad unlock balance detected! e1000e
http://bugzilla.kernel.org/show_bug.cgi?id=12200

Quoted 8 lines
Quoted 1 line
Signed-off-by Jeff Kirsher <[email protected]>

If we're fixing a regression like this, you should make the patch against net-2.6, and this one is against net-next-2.6

Please respin this for me, thanks Jeff.
--

Doh! Sorry Dave. My bad, respinning now.

Signature · 8 lines
Cheers,
Jeff

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