diff options
Diffstat (limited to 'include/mach/message.h')
| -rw-r--r-- | include/mach/message.h | 151 |
1 files changed, 139 insertions, 12 deletions
diff --git a/include/mach/message.h b/include/mach/message.h index 0a7297e1..9790ef98 100644 --- a/include/mach/message.h +++ b/include/mach/message.h @@ -132,18 +132,47 @@ typedef unsigned int mach_msg_size_t; typedef natural_t mach_msg_seqno_t; typedef integer_t mach_msg_id_t; -typedef struct { +/* full header structure, may have different size in user/kernel spaces */ +typedef struct mach_msg_header { mach_msg_bits_t msgh_bits; mach_msg_size_t msgh_size; - mach_port_t msgh_remote_port; + union { + mach_port_t msgh_remote_port; + /* + * Ensure msgh_remote_port is wide enough to hold a kernel pointer + * to avoid message resizing for the 64 bits case. This field should + * not be used since it is here just for padding purposes. + */ + rpc_uintptr_t msgh_remote_port_do_not_use; + }; union { mach_port_t msgh_local_port; - unsigned long msgh_protected_payload; + rpc_uintptr_t msgh_protected_payload; }; mach_port_seqno_t msgh_seqno; mach_msg_id_t msgh_id; } mach_msg_header_t; +#ifdef KERNEL +/* user-side header format, needed in the kernel */ +typedef struct { + mach_msg_bits_t msgh_bits; + mach_msg_size_t msgh_size; + union { + mach_port_name_t msgh_remote_port; + rpc_uintptr_t msgh_remote_port_do_not_use; + }; + union { + mach_port_name_t msgh_local_port; + rpc_uintptr_t msgh_protected_payload; + }; + mach_port_seqno_t msgh_seqno; + mach_msg_id_t msgh_id; +} mach_msg_user_header_t; +#else +typedef mach_msg_header_t mach_msg_user_header_t; +#endif + /* * There is no fixed upper bound to the size of Mach messages. */ @@ -192,7 +221,49 @@ typedef unsigned int mach_msg_type_name_t; typedef unsigned int mach_msg_type_size_t; typedef natural_t mach_msg_type_number_t; +/** + * Structure used for inlined port rights in messages. + * + * We use this to avoid having to perform message resizing in the kernel + * since userspace port rights might be smaller than kernel ports in 64 bit + * architectures. + */ +typedef struct { + union { + mach_port_name_t name; +#ifdef KERNEL + mach_port_t kernel_port; +#else + uintptr_t kernel_port_do_not_use; +#endif /* KERNEL */ + }; +} mach_port_name_inlined_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_name : 8, + msgt_size : 16, + msgt_unused : 5, + msgt_inline : 1, + msgt_longform : 1, + msgt_deallocate : 1; + mach_msg_type_number_t msgt_number; +#else unsigned int msgt_name : 8, msgt_size : 8, msgt_number : 12, @@ -200,15 +271,44 @@ typedef struct { msgt_longform : 1, msgt_deallocate : 1, msgt_unused : 1; -} mach_msg_type_t; +#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_name : 8, + msgtl_size : 16, + msgtl_unused : 5, + msgtl_inline : 1, + msgtl_longform : 1, + msgtl_deallocate : 1; + 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; -} mach_msg_type_long_t; +#endif +} __attribute__ ((aligned (__alignof__ (uintptr_t)))) mach_msg_type_long_t; +#ifdef __x86_64__ +#ifdef __cplusplus +#if __cplusplus >= 201103L +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 +#else +_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 +#endif /* * Known values for the msgt_name field. @@ -301,6 +401,34 @@ typedef integer_t mach_msg_option_t; #define MACH_SEND_ALWAYS 0x00010000 /* internal use only */ +#ifdef __x86_64__ +#if defined(KERNEL) && defined(USER32) +#define MACH_MSG_USER_ALIGNMENT 4 +#else +#define MACH_MSG_USER_ALIGNMENT 8 +#endif +#else +#define MACH_MSG_USER_ALIGNMENT 4 +#endif + +#ifdef KERNEL +/* This is the alignment of msg descriptors and the actual data + * for both in kernel messages and user land messages. + * + * We have two types of alignment because for specific configurations + * (in particular a 64 bit kernel with 32 bit userland) we transform + * 4-byte aligned user messages into 8-byte aligned messages (and vice-versa) + * so that kernel messages are correctly aligned. + */ +#define MACH_MSG_KERNEL_ALIGNMENT sizeof(uintptr_t) + +#define mach_msg_align(x, alignment) \ + ( ( ((vm_offset_t)(x)) + ((alignment)-1) ) & ~((alignment)-1) ) +#define mach_msg_user_align(x) mach_msg_align(x, MACH_MSG_USER_ALIGNMENT) +#define mach_msg_kernel_align(x) mach_msg_align(x, MACH_MSG_KERNEL_ALIGNMENT) +#define mach_msg_user_is_misaligned(x) ((x) & ((MACH_MSG_USER_ALIGNMENT)-1)) +#define mach_msg_kernel_is_misaligned(x) ((x) & ((MACH_MSG_KERNEL_ALIGNMENT)-1)) +#endif /* KERNEL */ /* * Much code assumes that mach_msg_return_t == kern_return_t. @@ -386,16 +514,15 @@ typedef kern_return_t mach_msg_return_t; #define MACH_RCV_BODY_ERROR 0x1000400c /* Error receiving message body. See special bits. */ - extern mach_msg_return_t mach_msg_trap - (mach_msg_header_t *msg, + (mach_msg_user_header_t *msg, mach_msg_option_t option, mach_msg_size_t send_size, mach_msg_size_t rcv_size, - mach_port_t rcv_name, + mach_port_name_t rcv_name, mach_msg_timeout_t timeout, - mach_port_t notify); + mach_port_name_t notify); extern mach_msg_return_t mach_msg @@ -403,9 +530,9 @@ mach_msg mach_msg_option_t option, mach_msg_size_t send_size, mach_msg_size_t rcv_size, - mach_port_t rcv_name, + mach_port_name_t rcv_name, mach_msg_timeout_t timeout, - mach_port_t notify); + mach_port_name_t notify); extern __typeof (mach_msg) __mach_msg; extern __typeof (mach_msg_trap) __mach_msg_trap; |