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Re: [PATCH gnumach] Support alignment requirements for a 64 bit kernel.
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From: |
Samuel Thibault |
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Subject: |
Re: [PATCH gnumach] Support alignment requirements for a 64 bit kernel. |
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Date: |
Mon, 27 Feb 2023 23:20:40 +0100 |
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User-agent: |
NeoMutt/20170609 (1.8.3) |
Applied, thanks!
Flavio Cruz, le dim. 19 févr. 2023 18:06:51 -0500, a ecrit:
> We introduce both a user alignment and a kernel alignment. These are
> separate requirements since for 64 bit with a 32 bit kernel we need to
> ensure the kernel can consume messages that are 8-byte aligned. This
> change removes any possibility of undefined behavior and also allows the
> kernel to support 64 bit RPCs for the userland.
>
> A lot of the code that performs alignment was simplified under the
> assumption that the message headers are well aligned. To enforce that
> going forward, a few static assertions were added.
> ---
> include/mach/message.h | 34 +++++++---
> ipc/ipc_kmsg.c | 144 ++++++++++++++++-------------------------
> x86_64/copy_user.c | 36 +++++++----
> 3 files changed, 101 insertions(+), 113 deletions(-)
>
> diff --git a/include/mach/message.h b/include/mach/message.h
> index eb3b34c0..22a17b03 100644
> --- a/include/mach/message.h
> +++ b/include/mach/message.h
> @@ -334,19 +334,33 @@ typedef integer_t mach_msg_option_t;
>
> #define MACH_SEND_ALWAYS 0x00010000 /* internal use only */
>
> -/* This is the alignment of msg descriptors and the actual data.
> +#ifdef KERNEL
> +/* This is the alignment of msg descriptors and the actual data
> + * for both in kernel messages and user land messages.
> *
> - * On x86 it is made equal to the default structure alignment on
> - * 32-bit, so we can easily maintain compatibility with 32-bit user
> - * space on a 64-bit kernel. Other architectures might have different
> - * needs, so this value might change in the future for differents
> - * architectures.
> + * 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_ALIGNMENT 4
> +#define MACH_MSG_KERNEL_ALIGNMENT sizeof(uintptr_t)
> +#ifdef __x86_64__
> +#ifdef USER32
> +#define MACH_MSG_USER_ALIGNMENT 4
> +#else
> +#define MACH_MSG_USER_ALIGNMENT 8
> +#endif
> +#else
> +#define MACH_MSG_USER_ALIGNMENT 4
> +#endif
>
> -#define mach_msg_is_misaligned(x) ( ((vm_offset_t)(x)) &
> (MACH_MSG_ALIGNMENT-1) )
> -#define mach_msg_align(x) \
> - ( ( ((vm_offset_t)(x)) + (MACH_MSG_ALIGNMENT-1) ) &
> ~(MACH_MSG_ALIGNMENT-1) )
> +#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.
> diff --git a/ipc/ipc_kmsg.c b/ipc/ipc_kmsg.c
> index dac4f5dc..1988da45 100644
> --- a/ipc/ipc_kmsg.c
> +++ b/ipc/ipc_kmsg.c
> @@ -229,28 +229,23 @@ ipc_kmsg_clean_body(
> type = (mach_msg_type_long_t *) saddr;
> is_inline = ((mach_msg_type_t*)type)->msgt_inline;
> if (((mach_msg_type_t*)type)->msgt_longform) {
> - /* This must be aligned */
> - if ((sizeof(natural_t) > sizeof(mach_msg_type_t)) &&
> - (mach_msg_is_misaligned(type))) {
> - saddr = mach_msg_align(saddr);
> - continue;
> - }
> name = type->msgtl_name;
> size = type->msgtl_size;
> number = type->msgtl_number;
> saddr += sizeof(mach_msg_type_long_t);
> + if
> (mach_msg_kernel_is_misaligned(sizeof(mach_msg_type_long_t))) {
> + saddr = mach_msg_kernel_align(saddr);
> + }
> } else {
> name = ((mach_msg_type_t*)type)->msgt_name;
> size = ((mach_msg_type_t*)type)->msgt_size;
> number = ((mach_msg_type_t*)type)->msgt_number;
> saddr += sizeof(mach_msg_type_t);
> + if
> (mach_msg_kernel_is_misaligned(sizeof(mach_msg_type_t))) {
> + saddr = mach_msg_kernel_align(saddr);
> + }
> }
>
> - /* padding (ptrs and ports) ? */
> - if ((sizeof(natural_t) > sizeof(mach_msg_type_t)) &&
> - ((size >> 3) == sizeof(natural_t)))
> - saddr = mach_msg_align(saddr);
> -
> /* calculate length of data in bytes, rounding up */
>
> length = ((number * size) + 7) >> 3;
> @@ -283,9 +278,7 @@ ipc_kmsg_clean_body(
> }
>
> if (is_inline) {
> - /* inline data sizes round up to int boundaries */
> -
> - saddr += (length + 3) &~ 3;
> + saddr += length;
> } else {
> vm_offset_t data = * (vm_offset_t *) saddr;
>
> @@ -300,6 +293,7 @@ ipc_kmsg_clean_body(
>
> saddr += sizeof(vm_offset_t);
> }
> + saddr = mach_msg_kernel_align(saddr);
> }
> }
>
> @@ -387,31 +381,26 @@ ipc_kmsg_clean_partial(
> boolean_t is_inline, is_port;
> vm_size_t length;
>
> -xxx: type = (mach_msg_type_long_t *) eaddr;
> + type = (mach_msg_type_long_t *) eaddr;
> is_inline = ((mach_msg_type_t*)type)->msgt_inline;
> if (((mach_msg_type_t*)type)->msgt_longform) {
> - /* This must be aligned */
> - if ((sizeof(natural_t) > sizeof(mach_msg_type_t)) &&
> - (mach_msg_is_misaligned(type))) {
> - eaddr = mach_msg_align(eaddr);
> - goto xxx;
> - }
> name = type->msgtl_name;
> size = type->msgtl_size;
> rnumber = type->msgtl_number;
> eaddr += sizeof(mach_msg_type_long_t);
> + if
> (mach_msg_kernel_is_misaligned(sizeof(mach_msg_type_long_t))) {
> + eaddr = mach_msg_kernel_align(eaddr);
> + }
> } else {
> name = ((mach_msg_type_t*)type)->msgt_name;
> size = ((mach_msg_type_t*)type)->msgt_size;
> rnumber = ((mach_msg_type_t*)type)->msgt_number;
> eaddr += sizeof(mach_msg_type_t);
> + if
> (mach_msg_kernel_is_misaligned(sizeof(mach_msg_type_t))) {
> + eaddr = mach_msg_kernel_align(eaddr);
> + }
> }
>
> - /* padding (ptrs and ports) ? */
> - if ((sizeof(natural_t) > sizeof(mach_msg_type_t)) &&
> - ((size >> 3) == sizeof(natural_t)))
> - eaddr = mach_msg_align(eaddr);
> -
> /* calculate length of data in bytes, rounding up */
>
> length = ((rnumber * size) + 7) >> 3;
> @@ -501,7 +490,7 @@ ipc_kmsg_get(
> {
> ipc_kmsg_t kmsg;
>
> - if ((size < sizeof(mach_msg_user_header_t)) || (size & 3))
> + if ((size < sizeof(mach_msg_user_header_t)) ||
> mach_msg_user_is_misaligned(size))
> return MACH_SEND_MSG_TOO_SMALL;
>
> if (size <= IKM_SAVED_MSG_SIZE) {
> @@ -553,7 +542,7 @@ ipc_kmsg_get_from_kernel(
> ipc_kmsg_t kmsg;
>
> assert(size >= sizeof(mach_msg_header_t));
> - assert((size & 3) == 0);
> + assert(!mach_msg_kernel_is_misaligned(size));
>
> kmsg = ikm_alloc(size);
> if (kmsg == IKM_NULL)
> @@ -1307,6 +1296,10 @@ ipc_kmsg_copyin_body(
> saddr = (vm_offset_t) (&kmsg->ikm_header + 1);
> eaddr = (vm_offset_t) &kmsg->ikm_header + kmsg->ikm_header.msgh_size;
>
> + // We make assumptions about the alignment of the header.
> +
> _Static_assert(!mach_msg_kernel_is_misaligned(sizeof(mach_msg_header_t)),
> + "mach_msg_header_t needs to be
> MACH_MSG_KERNEL_ALIGNMENT aligned.");
> +
> while (saddr < eaddr) {
> vm_offset_t taddr = saddr;
> mach_msg_type_long_t *type;
> @@ -1330,21 +1323,21 @@ ipc_kmsg_copyin_body(
> is_inline = ((mach_msg_type_t*)type)->msgt_inline;
> dealloc = ((mach_msg_type_t*)type)->msgt_deallocate;
> if (longform) {
> - /* This must be aligned */
> - if ((sizeof(natural_t) > sizeof(mach_msg_type_t)) &&
> - (mach_msg_is_misaligned(type))) {
> - saddr = mach_msg_align(saddr);
> - continue;
> - }
> name = type->msgtl_name;
> size = type->msgtl_size;
> number = type->msgtl_number;
> saddr += sizeof(mach_msg_type_long_t);
> + if
> (mach_msg_kernel_is_misaligned(sizeof(mach_msg_type_long_t))) {
> + saddr = mach_msg_kernel_align(saddr);
> + }
> } else {
> name = ((mach_msg_type_t*)type)->msgt_name;
> size = ((mach_msg_type_t*)type)->msgt_size;
> number = ((mach_msg_type_t*)type)->msgt_number;
> saddr += sizeof(mach_msg_type_t);
> + if
> (mach_msg_kernel_is_misaligned(sizeof(mach_msg_type_t))) {
> + saddr = mach_msg_kernel_align(saddr);
> + }
> }
>
> is_port = MACH_MSG_TYPE_PORT_ANY(name);
> @@ -1359,21 +1352,13 @@ ipc_kmsg_copyin_body(
> return MACH_SEND_INVALID_TYPE;
> }
>
> - /* padding (ptrs and ports) ? */
> - if ((sizeof(natural_t) > sizeof(mach_msg_type_t)) &&
> - ((size >> 3) == sizeof(natural_t)))
> - saddr = mach_msg_align(saddr);
> -
> /* calculate length of data in bytes, rounding up */
>
> length = (((uint64_t) number * size) + 7) >> 3;
>
> if (is_inline) {
> - vm_size_t amount;
> -
> - /* inline data sizes round up to int boundaries */
> + vm_size_t amount = length;
>
> - amount = (length + 3) &~ 3;
> if ((eaddr - saddr) < amount) {
> ipc_kmsg_clean_partial(kmsg, taddr, FALSE, 0);
> return MACH_SEND_MSG_TOO_SMALL;
> @@ -1384,9 +1369,6 @@ ipc_kmsg_copyin_body(
> } else {
> vm_offset_t addr;
>
> - if (MACH_MSG_ALIGNMENT > sizeof(mach_msg_type_t))
> - saddr = mach_msg_align(saddr);
> -
> if ((eaddr - saddr) < sizeof(vm_offset_t)) {
> ipc_kmsg_clean_partial(kmsg, taddr, FALSE, 0);
> return MACH_SEND_MSG_TOO_SMALL;
> @@ -1491,6 +1473,7 @@ ipc_kmsg_copyin_body(
>
> complex = TRUE;
> }
> + saddr = mach_msg_kernel_align(saddr);
> }
>
> if (!complex)
> @@ -1613,28 +1596,23 @@ ipc_kmsg_copyin_from_kernel(ipc_kmsg_t kmsg)
> longform = ((mach_msg_type_t*)type)->msgt_longform;
> /* type->msgtl_header.msgt_deallocate not used */
> if (longform) {
> - /* This must be aligned */
> - if ((sizeof(natural_t) > sizeof(mach_msg_type_t)) &&
> - (mach_msg_is_misaligned(type))) {
> - saddr = mach_msg_align(saddr);
> - continue;
> - }
> name = type->msgtl_name;
> size = type->msgtl_size;
> number = type->msgtl_number;
> saddr += sizeof(mach_msg_type_long_t);
> + if
> (mach_msg_kernel_is_misaligned(sizeof(mach_msg_type_long_t))) {
> + saddr = mach_msg_kernel_align(saddr);
> + }
> } else {
> name = ((mach_msg_type_t*)type)->msgt_name;
> size = ((mach_msg_type_t*)type)->msgt_size;
> number = ((mach_msg_type_t*)type)->msgt_number;
> saddr += sizeof(mach_msg_type_t);
> + if
> (mach_msg_kernel_is_misaligned(sizeof(mach_msg_type_t))) {
> + saddr = mach_msg_kernel_align(saddr);
> + }
> }
>
> - /* padding (ptrs and ports) ? */
> - if ((sizeof(natural_t) > sizeof(mach_msg_type_t)) &&
> - ((size >> 3) == sizeof(natural_t)))
> - saddr = mach_msg_align(saddr);
> -
> /* calculate length of data in bytes, rounding up */
>
> length = ((number * size) + 7) >> 3;
> @@ -1642,10 +1620,8 @@ ipc_kmsg_copyin_from_kernel(ipc_kmsg_t kmsg)
> is_port = MACH_MSG_TYPE_PORT_ANY(name);
>
> if (is_inline) {
> - /* inline data sizes round up to int boundaries */
> -
> data = saddr;
> - saddr += (length + 3) &~ 3;
> + saddr += length;
> } else {
> /*
> * The sender should supply ready-made memory
> @@ -1682,6 +1658,7 @@ ipc_kmsg_copyin_from_kernel(ipc_kmsg_t kmsg)
> MACH_MSGH_BITS_CIRCULAR;
> }
> }
> + saddr = mach_msg_kernel_align(saddr);
> }
> }
>
> @@ -2386,28 +2363,23 @@ ipc_kmsg_copyout_body(
> is_inline = ((mach_msg_type_t*)type)->msgt_inline;
> longform = ((mach_msg_type_t*)type)->msgt_longform;
> if (longform) {
> - /* This must be aligned */
> - if ((sizeof(natural_t) > sizeof(mach_msg_type_t)) &&
> - (mach_msg_is_misaligned(type))) {
> - saddr = mach_msg_align(saddr);
> - continue;
> - }
> name = type->msgtl_name;
> size = type->msgtl_size;
> number = type->msgtl_number;
> saddr += sizeof(mach_msg_type_long_t);
> + if
> (mach_msg_kernel_is_misaligned(sizeof(mach_msg_type_long_t))) {
> + saddr = mach_msg_kernel_align(saddr);
> + }
> } else {
> name = ((mach_msg_type_t*)type)->msgt_name;
> size = ((mach_msg_type_t*)type)->msgt_size;
> number = ((mach_msg_type_t*)type)->msgt_number;
> saddr += sizeof(mach_msg_type_t);
> + if
> (mach_msg_kernel_is_misaligned(sizeof(mach_msg_type_t))) {
> + saddr = mach_msg_kernel_align(saddr);
> + }
> }
>
> - /* padding (ptrs and ports) ? */
> - if ((sizeof(natural_t) > sizeof(mach_msg_type_t)) &&
> - ((size >> 3) == sizeof(natural_t)))
> - saddr = mach_msg_align(saddr);
> -
> /* calculate length of data in bytes, rounding up */
>
> length = (((uint64_t) number * size) + 7) >> 3;
> @@ -2442,16 +2414,11 @@ ipc_kmsg_copyout_body(
> }
>
> if (is_inline) {
> - /* inline data sizes round up to int boundaries */
> -
> ((mach_msg_type_t*)type)->msgt_deallocate = FALSE;
> - saddr += (length + 3) &~ 3;
> + saddr += length;
> } else {
> vm_offset_t data;
>
> - if (MACH_MSG_ALIGNMENT > sizeof(mach_msg_type_t))
> - saddr = mach_msg_align(saddr);
> -
> data = * (vm_offset_t *) saddr;
>
> /* copyout memory carried in the message */
> @@ -2502,6 +2469,9 @@ ipc_kmsg_copyout_body(
> * (vm_offset_t *) saddr = addr;
> saddr += sizeof(vm_offset_t);
> }
> +
> + /* Next element is always correctly aligned */
> + saddr = mach_msg_kernel_align(saddr);
> }
>
> return mr;
> @@ -2827,21 +2797,21 @@ ipc_msg_print(mach_msg_header_t *msgh)
> is_inline = ((mach_msg_type_t*)type)->msgt_inline;
> dealloc = ((mach_msg_type_t*)type)->msgt_deallocate;
> if (longform) {
> - /* This must be aligned */
> - if ((sizeof(natural_t) > sizeof(mach_msg_type_t)) &&
> - (mach_msg_is_misaligned(type))) {
> - saddr = mach_msg_align(saddr);
> - continue;
> - }
> name = type->msgtl_name;
> size = type->msgtl_size;
> number = type->msgtl_number;
> saddr += sizeof(mach_msg_type_long_t);
> + if
> (mach_msg_kernel_is_misaligned(sizeof(mach_msg_type_long_t))) {
> + saddr = mach_msg_kernel_align(saddr);
> + }
> } else {
> name = ((mach_msg_type_t*)type)->msgt_name;
> size = ((mach_msg_type_t*)type)->msgt_size;
> number = ((mach_msg_type_t*)type)->msgt_number;
> saddr += sizeof(mach_msg_type_t);
> + if
> (mach_msg_kernel_is_misaligned(sizeof(mach_msg_type_t))) {
> + saddr = mach_msg_kernel_align(saddr);
> + }
> }
>
> db_printf("-- type=");
> @@ -2872,11 +2842,6 @@ ipc_msg_print(mach_msg_header_t *msgh)
> return;
> }
>
> - /* padding (ptrs and ports) ? */
> - if ((sizeof(natural_t) > sizeof(mach_msg_type_t)) &&
> - ((size >> 3) == sizeof(natural_t)))
> - saddr = mach_msg_align(saddr);
> -
> /* calculate length of data in bytes, rounding up */
>
> length = ((number * size) + 7) >> 3;
> @@ -2885,7 +2850,7 @@ ipc_msg_print(mach_msg_header_t *msgh)
> vm_size_t amount;
> unsigned i, numwords;
>
> - /* inline data sizes round up to int boundaries */
> + /* round up to int boundaries for printing */
> amount = (length + 3) &~ 3;
> if ((eaddr - saddr) < amount) {
> db_printf("*** too small\n");
> @@ -2910,6 +2875,7 @@ ipc_msg_print(mach_msg_header_t *msgh)
> db_printf("0x%x\n", * (vm_offset_t *) saddr);
> saddr += sizeof(vm_offset_t);
> }
> + saddr = mach_msg_kernel_align(saddr);
> }
> }
> #endif /* MACH_KDB */
> diff --git a/x86_64/copy_user.c b/x86_64/copy_user.c
> index dd9fe2d7..089cb1d1 100644
> --- a/x86_64/copy_user.c
> +++ b/x86_64/copy_user.c
> @@ -136,7 +136,9 @@ size_t msg_usize(const mach_msg_header_t *kmsg)
> boolean_t is_inline;
> amount = unpack_msg_type(saddr, &name, &size, &number, &is_inline);
> saddr += amount;
> + saddr = mach_msg_kernel_align(saddr);
> usize += amount;
> + usize = mach_msg_user_align(usize);
>
> if (is_inline)
> {
> @@ -150,8 +152,6 @@ size_t msg_usize(const mach_msg_header_t *kmsg)
> size_t n = descsize_to_bytes(size);
> saddr += n*number;
> usize += n*number;
> - saddr = mach_msg_align(saddr);
> - usize = mach_msg_align(usize);
> }
> }
> else
> @@ -160,6 +160,8 @@ size_t msg_usize(const mach_msg_header_t *kmsg)
> saddr += sizeof(vm_offset_t);
> usize += sizeof(rpc_vm_offset_t);
> }
> + saddr = mach_msg_kernel_align(saddr);
> + usize = mach_msg_user_align(usize);
> }
> }
> return usize;
> @@ -168,7 +170,7 @@ size_t msg_usize(const mach_msg_header_t *kmsg)
> /*
> * Expand the msg header and, if required, the msg body (ports, pointers)
> *
> - * To not make the code too compicated, we use the fact that some fields of
> + * To not make the code too complicated, we use the fact that some fields of
> * mach_msg_header have the same size in the kernel and user variant
> (basically
> * all fields except ports and addresses)
> */
> @@ -200,6 +202,10 @@ int copyinmsg (const void *userbuf, void *kernelbuf,
> const size_t usize)
> ksaddr = (vm_offset_t)(kmsg + 1);
> usaddr = (vm_offset_t)(umsg + 1);
> ueaddr = (vm_offset_t)umsg + usize;
> +
> +
> _Static_assert(!mach_msg_user_is_misaligned(sizeof(mach_msg_user_header_t)),
> + "mach_msg_user_header_t needs to be MACH_MSG_USER_ALIGNMENT
> aligned.");
> +
> if (usize > sizeof(mach_msg_user_header_t))
> {
> /* check we have at least space for an empty descryptor */
> @@ -210,8 +216,6 @@ int copyinmsg (const void *userbuf, void *kernelbuf,
> const size_t usize)
> mach_msg_type_size_t size;
> mach_msg_type_number_t number;
> boolean_t is_inline;
> - usaddr = mach_msg_align(usaddr);
> - ksaddr = mach_msg_align(ksaddr);
> if (copyin_unpack_msg_type(usaddr, ksaddr, &name, &size, &number,
> &is_inline, &amount))
> return 1;
> @@ -220,7 +224,9 @@ int copyinmsg (const void *userbuf, void *kernelbuf,
> const size_t usize)
> // might need to adjust it later depending on the type
> vm_offset_t ktaddr = ksaddr;
> usaddr += amount;
> + usaddr = mach_msg_user_align(usaddr);
> ksaddr += amount;
> + ksaddr = mach_msg_kernel_align(ksaddr);
>
> if (is_inline)
> {
> @@ -247,8 +253,6 @@ int copyinmsg (const void *userbuf, void *kernelbuf,
> const size_t usize)
> return 1;
> usaddr += n*number;
> ksaddr += n*number;
> - usaddr = mach_msg_align(usaddr);
> - ksaddr = mach_msg_align(ksaddr);
> }
> }
> else
> @@ -262,15 +266,19 @@ int copyinmsg (const void *userbuf, void *kernelbuf,
> const size_t usize)
>
> if (copyin_address((rpc_vm_offset_t*)usaddr,
> (vm_offset_t*)ksaddr))
> return 1;
> - // advance one pointer
> + // Advance one pointer.
> ksaddr += sizeof(vm_offset_t);
> usaddr += sizeof(rpc_vm_offset_t);
> }
> + // Note that we have to align because mach_port_name_t might not
> align
> + // with the required user alignment.
> + usaddr = mach_msg_user_align(usaddr);
> + ksaddr = mach_msg_kernel_align(ksaddr);
> }
> }
>
> kmsg->msgh_size = sizeof(mach_msg_header_t) + ksaddr - (vm_offset_t)(kmsg
> + 1);
> - kmsg->msgh_size = mach_msg_align(kmsg->msgh_size);
> + kmsg->msgh_size = kmsg->msgh_size;
> return 0;
> }
>
> @@ -308,15 +316,15 @@ int copyoutmsg (const void *kernelbuf, void *userbuf,
> const size_t ksize)
> mach_msg_type_size_t size;
> mach_msg_type_number_t number;
> boolean_t is_inline;
> - usaddr = mach_msg_align(usaddr);
> - ksaddr = mach_msg_align(ksaddr);
> amount = unpack_msg_type(ksaddr, &name, &size, &number,
> &is_inline);
> // TODO: optimize and bring here type adjustment??
> vm_offset_t utaddr=usaddr, ktaddr=ksaddr;
> if (copyout((void*)ksaddr, (void*)usaddr, amount))
> return 1;
> usaddr += amount;
> + usaddr = mach_msg_user_align(usaddr);
> ksaddr += amount;
> + ksaddr = mach_msg_kernel_align(ksaddr);
>
> if (is_inline)
> {
> @@ -341,8 +349,6 @@ int copyoutmsg (const void *kernelbuf, void *userbuf,
> const size_t ksize)
> return 1;
> usaddr += n*number;
> ksaddr += n*number;
> - usaddr = mach_msg_align(usaddr);
> - ksaddr = mach_msg_align(ksaddr);
> }
> }
> else
> @@ -361,12 +367,14 @@ int copyoutmsg (const void *kernelbuf, void *userbuf,
> const size_t ksize)
> ksaddr += sizeof(vm_offset_t);
> usaddr += sizeof(rpc_vm_offset_t);
> }
> + usaddr = mach_msg_user_align(usaddr);
> + ksaddr = mach_msg_kernel_align(ksaddr);
> }
> }
>
> mach_msg_size_t usize;
> usize = sizeof(mach_msg_user_header_t) + usaddr - (vm_offset_t)(umsg + 1);
> - usize = mach_msg_align(usize);
> + usize = usize;
> if (copyout(&usize, &umsg->msgh_size, sizeof(kmsg->msgh_size)))
> return 1;
>
> --
> 2.39.1
>
>
--
Samuel
---
Pour une évaluation indépendante, transparente et rigoureuse !
Je soutiens la Commission d'Évaluation de l'Inria.