diff options
Diffstat (limited to 'include')
| -rw-r--r-- | include/mach/message.h | 52 |
1 files changed, 47 insertions, 5 deletions
diff --git a/include/mach/message.h b/include/mach/message.h index 0eab9d41..2177343a 100644 --- a/include/mach/message.h +++ b/include/mach/message.h @@ -222,6 +222,30 @@ typedef unsigned int mach_msg_type_size_t; typedef natural_t mach_msg_type_number_t; typedef struct { +#ifdef __x86_64__ + /* + * For 64 bits, this struct is 8 bytes long so we + * can pack the same amount of information as mach_msg_type_long_t. + * Note that for 64 bit userland, msgt_size only needs to be 8 bits long + * but for kernel compatibility with 32 bit userland we allow it to be + * 16 bits long. + * + * Effectively, we don't need mach_msg_type_long_t but we are keeping it + * for a while to make the code similar between 32 and 64 bits. + * + * We also keep the msgt_longform bit around simply because it makes it + * very easy to convert messages from a 32 bit userland into a 64 bit + * kernel. Otherwise, we would have to replicate some of the MiG logic + * internally in the kernel. + */ + unsigned int msgt_inline : 1, + msgt_longform : 1, + msgt_deallocate : 1, + msgt_name : 8, + msgt_size : 16, + msgt_unused : 5; + mach_msg_type_number_t msgt_number; +#else unsigned int msgt_name : 8, msgt_size : 8, msgt_number : 12, @@ -229,20 +253,38 @@ typedef struct { msgt_longform : 1, msgt_deallocate : 1, msgt_unused : 1; -#ifdef __x86_64__ - /* TODO: We want to eventually use this in favor of mach_msg_type_long_t - * as it makes the mach_msg protocol require only mach_msg_type_t. */ - mach_msg_type_number_t unused_msgtl_number; #endif } __attribute__ ((aligned (__alignof__ (uintptr_t)))) mach_msg_type_t; -typedef struct { +typedef struct { +#ifdef __x86_64__ + union { + /* On x86_64 this is equivalent to mach_msg_type_t so use + * union to overlay with the old field names. */ + mach_msg_type_t msgtl_header; + struct { + unsigned int msgtl_inline : 1, + msgtl_longform : 1, + msgtl_deallocate : 1, + msgtl_name : 8, + msgtl_size : 16, + msgtl_unused : 5; + mach_msg_type_number_t msgtl_number; + }; + }; +#else mach_msg_type_t msgtl_header; unsigned short msgtl_name; unsigned short msgtl_size; natural_t msgtl_number; +#endif } __attribute__ ((aligned (__alignof__ (uintptr_t)))) mach_msg_type_long_t; +#ifdef __x86_64__ +_Static_assert (sizeof (mach_msg_type_t) == sizeof (mach_msg_type_long_t), + "mach_msg_type_t and mach_msg_type_long_t need to have the same size."); +#endif + /* * Known values for the msgt_name field. * |