[patch 24/24] MIPS: Fix branch emulation for floating-point exceptions.

[Greg KH <gregkh@suse.de>]

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-stable review patch.  If anyone has any objections, please let us know.

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From: Win Treese <treese@acm.org>

In the branch emulation for floating-point exceptions, __compute_return_epc
must determine for bc1f et al which condition code bit to test. This is
based on bits <4:2> of the rt field. The switch statement to distinguish
bc1f et al needs to use only the two low bits of rt, but the old code tests
on the whole rt field.  This patch masks off the proper bits.

Signed-off-by: Win Treese <treese@acm.org>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
 arch/mips/kernel/branch.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- linux-2.6.16.11.orig/arch/mips/kernel/branch.c
+++ linux-2.6.16.11/arch/mips/kernel/branch.c
@@ -184,7 +184,7 @@ int __compute_return_epc(struct pt_regs 
 		bit = (insn.i_format.rt >> 2);
 		bit += (bit != 0);
 		bit += 23;
-		switch (insn.i_format.rt) {
+		switch (insn.i_format.rt & 3) {
 		case 0:	/* bc1f */
 		case 2:	/* bc1fl */
 			if (~fcr31 & (1 << bit))

--