newlib-cygwin/winsup/cygwin/fhandler_mem.cc

258 lines
5.4 KiB
C++

/* fhandler_mem.cc. See fhandler.h for a description of the fhandler classes.
Copyright 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2008, 2009,
2010, 2011, 2012 Red Hat, Inc.
This file is part of Cygwin.
This software is a copyrighted work licensed under the terms of the
Cygwin license. Please consult the file "CYGWIN_LICENSE" for
details. */
#include "winsup.h"
#include <unistd.h>
#include "cygerrno.h"
#include "path.h"
#include "fhandler.h"
#include "ntdll.h"
/**********************************************************************/
/* fhandler_dev_mem */
fhandler_dev_mem::fhandler_dev_mem ()
: fhandler_base ()
{
}
fhandler_dev_mem::~fhandler_dev_mem ()
{
}
int
fhandler_dev_mem::open (int flags, mode_t)
{
NTSTATUS status;
if (!wincap.has_physical_mem_access ())
{
set_errno (EACCES);
debug_printf ("%s is accessible under NT4/W2K/XP only", dev ().name);
return 0;
}
if (dev () == FH_MEM) /* /dev/mem */
{
SYSTEM_BASIC_INFORMATION sbi;
status = NtQuerySystemInformation (SystemBasicInformation, (PVOID) &sbi,
sizeof sbi, NULL);
if (NT_SUCCESS (status))
{
__seterrno_from_nt_status (status);
debug_printf("NtQuerySystemInformation: status %p, %E", status);
mem_size = 0;
}
else
mem_size = sbi.PhysicalPageSize * sbi.NumberOfPhysicalPages;
debug_printf ("MemSize: %d MB", mem_size >> 20);
}
else if (dev () == FH_KMEM) /* /dev/kmem - Not yet supported */
{
mem_size = 0;
debug_printf ("KMemSize: %d MB", mem_size >> 20);
}
else if (dev () == FH_PORT) /* /dev/port == First 64K of /dev/mem */
{
mem_size = 65536;
debug_printf ("PortSize: 64 KB");
}
else
{
mem_size = 0;
debug_printf ("Illegal minor number");
}
/* Check for illegal flags. */
if (flags & (O_APPEND | O_TRUNC | O_EXCL))
{
set_errno (EINVAL);
return 0;
}
OBJECT_ATTRIBUTES attr;
InitializeObjectAttributes (&attr, &ro_u_pmem,
OBJ_CASE_INSENSITIVE
| (flags & O_CLOEXEC ? 0 : OBJ_INHERIT),
NULL, NULL);
ACCESS_MASK section_access;
if ((flags & O_ACCMODE) == O_RDONLY)
{
set_access (GENERIC_READ);
section_access = SECTION_MAP_READ;
}
else if ((flags & O_ACCMODE) == O_WRONLY)
{
set_access (GENERIC_WRITE);
section_access = SECTION_MAP_READ | SECTION_MAP_WRITE;
}
else
{
set_access (GENERIC_READ | GENERIC_WRITE);
section_access = SECTION_MAP_READ | SECTION_MAP_WRITE;
}
HANDLE mem;
status = NtOpenSection (&mem, section_access, &attr);
if (!NT_SUCCESS (status))
{
__seterrno_from_nt_status (status);
set_io_handle (NULL);
return 0;
}
set_io_handle (mem);
set_open_status ();
return 1;
}
ssize_t __stdcall
fhandler_dev_mem::write (const void *ptr, size_t ulen)
{
if (!ulen || pos >= mem_size)
return 0;
if (!(get_access () & GENERIC_WRITE))
{
set_errno (EINVAL);
return -1;
}
if (pos + ulen > mem_size)
ulen = mem_size - pos;
PHYSICAL_ADDRESS phys;
NTSTATUS status;
void *viewmem = NULL;
DWORD len = ulen + wincap.page_size () - 1;
phys.QuadPart = (ULONGLONG) pos;
status = NtMapViewOfSection (get_handle (), INVALID_HANDLE_VALUE, &viewmem,
0L, len, &phys, &len, ViewShare, 0,
PAGE_READONLY);
if (!NT_SUCCESS (status))
{
__seterrno_from_nt_status (status);
return -1;
}
memcpy ((char *) viewmem + (pos - phys.QuadPart), ptr, ulen);
status = NtUnmapViewOfSection (INVALID_HANDLE_VALUE, viewmem);
if (!NT_SUCCESS (status))
{
__seterrno_from_nt_status (status);
return -1;
}
pos += ulen;
return ulen;
}
void __stdcall
fhandler_dev_mem::read (void *ptr, size_t& ulen)
{
if (!ulen || pos >= mem_size)
{
ulen = 0;
return;
}
if (!(get_access () & GENERIC_READ))
{
set_errno (EINVAL);
ulen = (size_t) -1;
return;
}
if (pos + ulen > mem_size)
ulen = mem_size - pos;
PHYSICAL_ADDRESS phys;
NTSTATUS status;
void *viewmem = NULL;
DWORD len = ulen + wincap.page_size () - 1;
phys.QuadPart = (ULONGLONG) pos;
status = NtMapViewOfSection (get_handle (), INVALID_HANDLE_VALUE, &viewmem,
0L, len, &phys, &len, ViewShare, 0,
PAGE_READONLY);
if (!NT_SUCCESS (status))
{
__seterrno_from_nt_status (status);
ulen = (size_t) -1;
return;
}
memcpy (ptr, (char *) viewmem + (pos - phys.QuadPart), ulen);
status = NtUnmapViewOfSection (INVALID_HANDLE_VALUE, viewmem);
if (!NT_SUCCESS (status))
{
__seterrno_from_nt_status (status);
ulen = (size_t) -1;
return;
}
pos += ulen;
}
_off64_t
fhandler_dev_mem::lseek (_off64_t offset, int whence)
{
switch (whence)
{
case SEEK_SET:
pos = offset;
break;
case SEEK_CUR:
pos += offset;
break;
case SEEK_END:
pos = mem_size;
pos += offset;
break;
default:
set_errno (EINVAL);
return ILLEGAL_SEEK;
}
if (pos > mem_size)
{
set_errno (EINVAL);
return ILLEGAL_SEEK;
}
return pos;
}
int
fhandler_dev_mem::fstat (struct __stat64 *buf)
{
fhandler_base::fstat (buf);
buf->st_blksize = wincap.page_size ();
if (is_auto_device ())
{
buf->st_mode = S_IFCHR;
if (wincap.has_physical_mem_access ())
buf->st_mode |= S_IRUSR | S_IWUSR |
S_IRGRP | S_IWGRP |
S_IROTH | S_IWOTH;
}
return 0;
}