metag/usercopy: Set flags before ADDZ

BugLink: http://bugs.launchpad.net/bugs/1682140
commit fd40eee1290ad7add7aa665e3ce6b0f9fe9734b4 upstream.

The fixup code for the copy_to_user rapf loops reads TXStatus.LSM_STEP
to decide how far to rewind the source pointer. There is a special case
for the last execution of an MGETL/MGETD, since it leaves LSM_STEP=0
even though the number of MGETLs/MGETDs attempted was 4. This uses ADDZ
which is conditional upon the Z condition flag, but the AND instruction
which masked the TXStatus.LSM_STEP field didn't set the condition flags
based on the result.

Fix that now by using ANDS which does set the flags, and also marking
the condition codes as clobbered by the inline assembly.

Fixes: 373cd784d0fc ("metag: Memory handling")
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: linux-metag@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>

diff --git a/arch/metag/lib/usercopy.c b/arch/metag/lib/usercopy.c
index e1d553872fd78676ae71f230b4a1edd718872541..4422928a174623d835e7ae28e5070a2fbe6e65c0 100644 (file)
--- a/arch/metag/lib/usercopy.c
+++ b/arch/metag/lib/usercopy.c
@@ -315,7 +315,7 @@
                "       .previous\n"                                    \
                : "=r" (to), "=r" (from), "=r" (ret), "=d" (n)          \
                : "0" (to), "1" (from), "2" (ret), "3" (n)              \
-               : "D1Ar1", "D0Ar2", "memory")
+               : "D1Ar1", "D0Ar2", "cc", "memory")
 
 /*     rewind 'to' and 'from'  pointers when a fault occurs
  *
@@ -341,7 +341,7 @@
 #define __asm_copy_to_user_64bit_rapf_loop(to, from, ret, n, id)\
        __asm_copy_user_64bit_rapf_loop(to, from, ret, n, id,           \
                "LSR    D0Ar2, D0Ar2, #8\n"                             \
-               "AND    D0Ar2, D0Ar2, #0x7\n"                           \
+               "ANDS   D0Ar2, D0Ar2, #0x7\n"                           \
                "ADDZ   D0Ar2, D0Ar2, #4\n"                             \
                "SUB    D0Ar2, D0Ar2, #1\n"                             \
                "MOV    D1Ar1, #4\n"                                    \
@@ -486,7 +486,7 @@
                "       .previous\n"                                    \
                : "=r" (to), "=r" (from), "=r" (ret), "=d" (n)          \
                : "0" (to), "1" (from), "2" (ret), "3" (n)              \
-               : "D1Ar1", "D0Ar2", "memory")
+               : "D1Ar1", "D0Ar2", "cc", "memory")
 
 /*     rewind 'to' and 'from'  pointers when a fault occurs
  *
@@ -512,7 +512,7 @@
 #define __asm_copy_to_user_32bit_rapf_loop(to, from, ret, n, id)\
        __asm_copy_user_32bit_rapf_loop(to, from, ret, n, id,           \
                "LSR    D0Ar2, D0Ar2, #8\n"                             \
-               "AND    D0Ar2, D0Ar2, #0x7\n"                           \
+               "ANDS   D0Ar2, D0Ar2, #0x7\n"                           \
                "ADDZ   D0Ar2, D0Ar2, #4\n"                             \
                "SUB    D0Ar2, D0Ar2, #1\n"                             \
                "MOV    D1Ar1, #4\n"                                    \