[PATCH 1/3] fix message fields alignment for 64 bit

[Luca Dariz]

On x86_64 alignment of structures is different, as the pointer size is 
different.
For simplicity we keep the same 4-byte alignment as used on
32-bit. This simplifies the support for 32-bit rpc on 64-bit kernels,
and also it seems not worth as an optimization, as we would need to
add more code in the ipc_kmsg* routines.

* routine.c: align both short and long descriptors
* utils.c: use a fixed alignment for data fields in structures
  representing messages.

Signed-off-by: Luca Dariz <luca@orpolo.org>
---
 routine.c | 3 +--
 utils.c   | 2 ++
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/routine.c b/routine.c
index 0edc6b9..e6e18c3 100644
--- a/routine.c
+++ b/routine.c
@@ -321,9 +321,8 @@ rtFindSize(const argument_t *args, u_int mask)
        {
            ipc_type_t *it = arg->argType;
 
+           size = (size + word_size-1) & ~(word_size-1);
            if (arg->argLongForm) {
-               /* might need proper alignment on 64bit archies */
-               size = (size + word_size-1) & ~(word_size-1);
                size += sizeof_mach_msg_type_long_t;
            } else {
                size += sizeof_mach_msg_type_t;
diff --git a/utils.c b/utils.c
index bdc39b7..a8ebc6b 100644
--- a/utils.c
+++ b/utils.c
@@ -338,10 +338,12 @@ void
 WriteStructDecl(FILE *file, const argument_t *args, write_list_fn_t *func,
                u_int mask, const char *name)
 {
+    fprintf(file, "#pragma pack(push,%d)\n", word_size);
     fprintf(file, "\ttypedef struct {\n");
     fprintf(file, "\t\tmach_msg_header_t Head;\n");
     WriteList(file, args, func, mask, "\n", "\n");
     fprintf(file, "\t} %s;\n", name);
+    fprintf(file, "#pragma pack(pop)\n");
     fprintf(file, "\n");
 }
 
-- 
2.30.2