[PATCH 3.13 020/187] sparc64: Handle 32-bit tasks properly in compute_effective_address().

Kamal Mostafa
2014-09-15T22:10:35Z

From: "David S. Miller" <davem@davemloft.net>

[ Upstream commit d037d16372bbe4d580342bebbb8826821ad9edf0 ]

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>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
---
arch/sparc/kernel/unaligned_64.c | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/arch/sparc/kernel/unaligned_64.c b/arch/sparc/kernel/unaligned_64.c
index 3c1a7cb..35ab8b6 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... */
--
1.9.1