[PATCH] arch/tile: don't enable irqs unconditionally in page fault handler

From: Chris Metcalf
Date: Fri Mar 30 2012 - 18:56:31 EST


If we took a page fault while we had interrupts disabled, we
shouldn't enable them in the page fault handler.

Signed-off-by: Chris Metcalf <cmetcalf@xxxxxxxxxx>
---
arch/tile/mm/fault.c | 7 +++++--
1 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/arch/tile/mm/fault.c b/arch/tile/mm/fault.c
index bcba159..5d10a74 100644
--- a/arch/tile/mm/fault.c
+++ b/arch/tile/mm/fault.c
@@ -343,9 +343,12 @@ static int handle_page_fault(struct pt_regs *regs,
/*
* If we're trying to touch user-space addresses, we must
* be either at PL0, or else with interrupts enabled in the
- * kernel, so either way we can re-enable interrupts here.
+ * kernel, so either way we can re-enable interrupts here
+ * unless we are doing atomic access to user space with
+ * interrupts disabled.
*/
- local_irq_enable();
+ if (!(regs->flags & PT_FLAGS_DISABLE_IRQ))
+ local_irq_enable();

mm = tsk->mm;

--
1.6.5.2

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