[PATCH] MIPS: Fix the syscall lookup_dcookie in scall64-o32.S

[Wu Zhangjin <wuzhangjin@xxxxxxxxx>]

When the kernel is 64bit, the application in O32 ABI will pass 4
arguments to syscall lookup_dcookie, but the implementation can only
handle 3 arguments. This patch will fixes it.

Signed-off-by: Chen Jie <chenj@xxxxxxxxxx>
Signed-off-by: Hu Hongbing <huhb@xxxxxxxxxx>
Signed-off-by: Wu Zhangjin <wuzhangjin@xxxxxxxxx>
---
 arch/mips/kernel/linux32.c     |    6 ++++++
 arch/mips/kernel/scall64-o32.S |    2 +-
 2 files changed, 7 insertions(+), 1 deletions(-)

diff --git a/arch/mips/kernel/linux32.c b/arch/mips/kernel/linux32.c
index 6242bc6..9dc09be 100644
--- a/arch/mips/kernel/linux32.c
+++ b/arch/mips/kernel/linux32.c
@@ -428,3 +428,9 @@ _sys32_clone(nabi_no_regargs struct pt_regs regs)
 	return do_fork(clone_flags, newsp, &regs, 0,
 	               parent_tidptr, child_tidptr);
 }
+
+asmlinkage long sys32_lookup_dcookie(u32 dcookie_a0, u32 dcookie_a1,
+		char __user *buf, size_t len)
+{
+       return sys_lookup_dcookie(merge_64(dcookie_a0, dcookie_a1), buf, len);
+}
diff --git a/arch/mips/kernel/scall64-o32.S b/arch/mips/kernel/scall64-o32.S
index 9bbf977..ba0dde6 100644
--- a/arch/mips/kernel/scall64-o32.S
+++ b/arch/mips/kernel/scall64-o32.S
@@ -450,7 +450,7 @@ sys_call_table:
 	PTR	sys_io_submit
 	PTR	sys_io_cancel			/* 4245 */
 	PTR	sys_exit_group
-	PTR	sys_lookup_dcookie
+	PTR	sys32_lookup_dcookie
 	PTR	sys_epoll_create
 	PTR	sys_epoll_ctl
 	PTR	sys_epoll_wait			/* 4250 */
-- 
1.6.2.1