Update sysdeps/mach/hurd/ioctl.c to make it more portable

Summary of the changes:
- Update msg_align to use ALIGN_UP like we have done in previous
  patches. Use it below whenever necessary to avoid repeating the same
  alignment logic.
- Define BAD_TYPECHECK to make it easier to do type checking in a few
  places below.
- Update io2mach_type to use designated initializers.
- Make RetCodeType use mach_msg_type_t. mach_msg_type_t is 8 byte for
  x86_64, so this make it portable.
- Also call msg_align for _IOT_COUNT2/_IOT_TYPE2 since it is more
  correct.
Message-Id: <ZFMvVsuFKwIy2dUS@jupiter.tail36e24.ts.net>
This commit is contained in:
Flavio Cruz 2023-05-04 00:06:46 -04:00 committed by Samuel Thibault
parent 1a62d7e5c3
commit 3f433cb895

View File

@ -16,6 +16,7 @@
<https://www.gnu.org/licenses/>. */
#include <errno.h>
#include <libc-pointer-arith.h>
#include <sys/ioctl.h>
#include <hurd.h>
#include <hurd/fd.h>
@ -31,29 +32,40 @@
#include <hurd/ioctls.defs>
#define msg_align(x) ALIGN_UP (x, __alignof__ (uintptr_t))
#define typesize(type) (1 << (type))
/* Macro used by MIG to cleanly check the type. */
#define BAD_TYPECHECK(type, check) __glibc_unlikely (({ \
union { mach_msg_type_t t; uint32_t w; } _t, _c; \
_t.t = *(type); _c.t = *(check);_t.w != _c.w; }))
/* Perform the I/O control operation specified by REQUEST on FD.
The actual type and use of ARG and the return value depend on REQUEST. */
int
__ioctl (int fd, unsigned long int request, ...)
{
#ifdef MACH_MSG_TYPE_CHAR
#ifdef MACH_MSG_TYPE_BIT
/* Map individual type fields to Mach IPC types. */
static const int mach_types[] =
{ MACH_MSG_TYPE_CHAR, MACH_MSG_TYPE_INTEGER_16, MACH_MSG_TYPE_INTEGER_32,
MACH_MSG_TYPE_INTEGER_64 };
#define io2mach_type(count, type) \
((mach_msg_type_t) { mach_types[type], typesize (type) * 8, count, 1, 0, 0 })
#define io2mach_type(count, type) \
((mach_msg_type_t) { \
.msgt_name = mach_types[type], \
.msgt_size = typesize(type) * 8, \
.msgt_number = count, \
.msgt_inline = TRUE, \
.msgt_longform = FALSE, \
.msgt_deallocate = FALSE, \
.msgt_unused = 0 \
})
#endif
/* Extract the type information encoded in the request. */
unsigned int type = _IOC_TYPE (request);
/* Message buffer. */
#define msg_align(x) \
(((x) + sizeof (mach_msg_type_t) - 1) & ~(sizeof (mach_msg_type_t) - 1))
struct
{
#ifdef MACH_MSG_TYPE_BIT
@ -63,14 +75,14 @@ __ioctl (int fd, unsigned long int request, ...)
struct
{
mach_msg_header_t Head;
int RetCodeType;
mach_msg_type_t RetCodeType;
kern_return_t RetCode;
} header_typecheck;
};
char data[3 * sizeof (mach_msg_type_t)
+ msg_align (_IOT_COUNT0 (type) * typesize (_IOT_TYPE0 (type)))
+ msg_align (_IOT_COUNT1 (type) * typesize (_IOT_TYPE1 (type)))
+ _IOT_COUNT2 (type) * typesize (_IOT_TYPE2 (type))];
+ msg_align (_IOT_COUNT2 (type) * typesize (_IOT_TYPE2 (type)))];
#else /* Untyped Mach IPC format. */
mig_reply_error_t header;
char data[_IOT_COUNT0 (type) * typesize (_IOT_TYPE0 (type))
@ -128,8 +140,7 @@ __ioctl (int fd, unsigned long int request, ...)
void *p = &t[1];
*t = io2mach_type (count, type);
p = __mempcpy (p, argptr, len);
p = (void *) (((uintptr_t) p + sizeof (*t) - 1)
& ~(sizeof (*t) - 1));
p = (void *) msg_align ((uintptr_t) p);
t = p;
#else
p = __mempcpy (p, argptr, len);
@ -150,7 +161,7 @@ __ioctl (int fd, unsigned long int request, ...)
#ifdef MACH_MSG_TYPE_BIT
*t++ = io2mach_type (1, _IOTS (integer_t));
*(integer_t *) t = (integer_t) (intptr_t) arg;
t = (void *) t + sizeof (integer_t);
t = (void *) msg_align ((uintptr_t) t + sizeof (integer_t));
#else
*(integer_t *) p = (integer_t) (intptr_t) arg;
p = (void *) p + sizeof (integer_t);
@ -205,9 +216,8 @@ __ioctl (int fd, unsigned long int request, ...)
return MIG_TYPE_ERROR;
#ifdef MACH_MSG_TYPE_BIT
if (msg.header_typecheck.RetCodeType
!= ((union { mach_msg_type_t t; int i; })
{ t: io2mach_type (1, _IOTS (msg.header.RetCode)) }).i)
mach_msg_type_t ipctype = io2mach_type(1, _IOTS (msg.header.RetCode));
if (BAD_TYPECHECK (&msg.header_typecheck.RetCodeType, &ipctype))
return MIG_TYPE_ERROR;
#endif
return msg.header.RetCode;
@ -259,8 +269,7 @@ __ioctl (int fd, unsigned long int request, ...)
/* Add the size of the type and data. */
reply_size += sizeof (mach_msg_type_t) + typesize (type) * count;
/* Align it to word size. */
reply_size += sizeof (mach_msg_type_t) - 1;
reply_size &= ~(sizeof (mach_msg_type_t) - 1);
reply_size = msg_align (reply_size);
#else
reply_size += typesize (type) * count;
#endif
@ -299,16 +308,14 @@ __ioctl (int fd, unsigned long int request, ...)
{
const size_t len = count * typesize (type);
#ifdef MACH_MSG_TYPE_BIT
union { mach_msg_type_t t; int i; } ipctype;
ipctype.t = io2mach_type (count, type);
if (*(int *) t != ipctype.i)
const mach_msg_type_t ipctype = io2mach_type(count, type);
if (BAD_TYPECHECK (t, &ipctype))
return 1;
++t;
memcpy (store, t, len);
if (update != NULL)
*update += len;
t = (void *) (((uintptr_t) t + len + sizeof (*t) - 1)
& ~(sizeof (*t) - 1));
t = (mach_msg_type_t *) msg_align ((uintptr_t) t + len);
#else
memcpy (store, p, len);
p += len;