sparc64: Handle 32-bit tasks properly in compute_effective_address().

If we have a 32-bit task we must chop off the top 32-bits of the
64-bit value just as the cpu would.

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 9 insertions, 3 deletions

diff --git a/arch/sparc/kernel/unaligned_64.c b/arch/sparc/kernel/unaligned_64.c
index 3c1a7cb31579..35ab8b60d256 100644
--- a/arch/sparc/kernel/unaligned_64.c
+++ b/arch/sparc/kernel/unaligned_64.c
@@ -166,17 +166,23 @@ static unsigned long *fetch_reg_addr(unsigned int reg, struct pt_regs *regs)
 unsigned long compute_effective_address(struct pt_regs *regs,
                                         unsigned int insn, unsigned int rd)
 {
+        int from_kernel = (regs->tstate & TSTATE_PRIV) != 0;
         unsigned int rs1 = (insn >> 14) & 0x1f;
         unsigned int rs2 = insn & 0x1f;
-        int from_kernel = (regs->tstate & TSTATE_PRIV) != 0;
+        unsigned long addr;
 
         if (insn & 0x2000) {
                 maybe_flush_windows(rs1, 0, rd, from_kernel);
-                return (fetch_reg(rs1, regs) + sign_extend_imm13(insn));
+                addr = (fetch_reg(rs1, regs) + sign_extend_imm13(insn));
         } else {
                 maybe_flush_windows(rs1, rs2, rd, from_kernel);
-                return (fetch_reg(rs1, regs) + fetch_reg(rs2, regs));
+                addr = (fetch_reg(rs1, regs) + fetch_reg(rs2, regs));
         }
+
+        if (!from_kernel && test_thread_flag(TIF_32BIT))
+                addr &= 0xffffffff;
+
+        return addr;
 }
 
 /* This is just to make gcc think die_if_kernel does return... */