Merge git://git.kernel.org/pub/scm/linux/kernel/git/steve/gfs2-2.6-nmw

[pandora-kernel.git] / arch / arm / mm / alignment.c

diff --git a/arch/arm/mm/alignment.c b/arch/arm/mm/alignment.c
index d073b64..724ba3b 100644 (file)
--- a/arch/arm/mm/alignment.c
+++ b/arch/arm/mm/alignment.c
@@ -885,8 +885,23 @@ do_alignment(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
 
        if (ai_usermode & UM_SIGNAL)
                force_sig(SIGBUS, current);
-       else
-               set_cr(cr_no_alignment);
+       else {
+               /*
+                * We're about to disable the alignment trap and return to
+                * user space.  But if an interrupt occurs before actually
+                * reaching user space, then the IRQ vector entry code will
+                * notice that we were still in kernel space and therefore
+                * the alignment trap won't be re-enabled in that case as it
+                * is presumed to be always on from kernel space.
+                * Let's prevent that race by disabling interrupts here (they
+                * are disabled on the way back to user space anyway in
+                * entry-common.S) and disable the alignment trap only if
+                * there is no work pending for this thread.
+                */
+               raw_local_irq_disable();
+               if (!(current_thread_info()->flags & _TIF_WORK_MASK))
+                       set_cr(cr_no_alignment);
+       }
 
        return 0;
 }