staging: slicoss: restore IRQs correctly after slic_cmdq_reset()
Subsystems (2)
PATCH 1/1 staging: slicoss: restore IRQs correctly after slic_cmdq_reset()
We can't save two different values in "flags" so it means that IRQs are not enabled properly at the end of this function. This isn't a problem in the current code because it's always called with IRQs disabled so we don't want to enable them at the end.
This bug is old but it's thanks to David Matlack's recent cleanups that Smatch can detect it.
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The code prior to David Matlack's change was way worse because everyone shared the same IRQ flags. It's hard to imagine how it worked at all.
drivers/staging/slicoss/slicoss.c +2 -2
@@ -1392,7 +1392,7 @@ static void slic_cmdq_reset(struct adapter *adapter)unsigned long flags;spin_lock_irqsave (&adapter->cmdq_free.lock, flags); -spin_lock_irqsave (&adapter->cmdq_done.lock, flags); +spin_lock (&adapter->cmdq_done.lock); outstanding = adapter->cmdq_all.count - adapter->cmdq_done.count; outstanding -= adapter->cmdq_free.count; hcmd = adapter->cmdq_all.head;
@@ -1423,7 +1423,7 @@ static void slic_cmdq_reset(struct adapter *adapter)"free_count %d != all count %d\n" , adapter->cmdq_free.count, adapter->cmdq_all.count); } -spin_unlock_irqrestore (&adapter->cmdq_done.lock, flags); +spin_unlock (&adapter->cmdq_done.lock);spin_unlock_irqrestore (&adapter->cmdq_free.lock, flags); }
Quoted 4 lines · Dan Carpenter
We can't save two different values in "flags" so it means that IRQs are not enabled properly at the end of this function. This isn't a problem in the current code because it's always called with IRQs disabled so we don't want to enable them at the end.
Nice find. Thanks for fixing it!
Quoted 5 lines
This bug is old but it's thanks to David Matlack's recent cleanups that Smatch can detect it.
Signed-off-by Dan Carpenter <[email protected]>
Quoted 26 lines
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The code prior to David Matlack's change was way worse because everyone shared the same IRQ flags. It's hard to imagine how it worked at all.drivers/staging/slicoss/slicoss.c +2
-2@@ -1392,7 +1392,7 @@ static void slic_cmdq_reset(struct adapter *adapter)unsigned long flags;spin_lock_irqsave (&adapter->cmdq_free.lock, flags); -spin_lock_irqsave (&adapter->cmdq_done.lock, flags); +spin_lock (&adapter->cmdq_done.lock); outstanding = adapter->cmdq_all.count - adapter->cmdq_done.count; outstanding -= adapter->cmdq_free.count; hcmd = adapter->cmdq_all.head;@@ -1423,7 +1423,7 @@ static void slic_cmdq_reset(struct adapter *adapter)"free_count %d != all count %d\n" , adapter->cmdq_free.count, adapter->cmdq_all.count); } -spin_unlock_irqrestore (&adapter->cmdq_done.lock, flags); +spin_unlock (&adapter->cmdq_done.lock);spin_unlock_irqrestore (&adapter->cmdq_free.lock, flags); }