[PATCH] IB: Fix pack/unpack when size_bits == 64

Fix handling of fields with size_bits == 64.  Pointed out by Hal Rosenstock.

Signed-off-by: Roland Dreier <rolandd@cisco.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 2 insertions, 2 deletions

diff --git a/drivers/infiniband/core/packer.c b/drivers/infiniband/core/packer.c
index 5f15feffeae2..eb5ff54c10d7 100644
--- a/drivers/infiniband/core/packer.c
+++ b/drivers/infiniband/core/packer.c
@@ -96,7 +96,7 @@ void ib_pack(const struct ib_field        *desc,
                         else
                                 val = 0;
 
-                        mask = cpu_to_be64(((1ull << desc[i].size_bits) - 1) << shift);
+                        mask = cpu_to_be64((~0ull >> (64 - desc[i].size_bits)) << shift);
                         addr = (__be64 *) ((__be32 *) buf + desc[i].offset_words);
                         *addr = (*addr & ~mask) | (cpu_to_be64(val) & mask);
                 } else {
@@ -176,7 +176,7 @@ void ib_unpack(const struct ib_field        *desc,
                         __be64 *addr;
 
                         shift = 64 - desc[i].offset_bits - desc[i].size_bits;
-                        mask = ((1ull << desc[i].size_bits) - 1) << shift;
+                        mask = (~0ull >> (64 - desc[i].size_bits)) << shift;
                         addr = (__be64 *) buf + desc[i].offset_words;
                         val = (be64_to_cpup(addr) & mask) >> shift;
                         value_write(desc[i].struct_offset_bytes,