newlib/winsup/cygwin/miscfuncs.cc

/* miscfuncs.cc: misc funcs that don't belong anywhere else

   Copyright 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004,
   2005, 2006, 2007, 2008, 2009, 2010, 2011 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 "miscfuncs.h"
#include <sys/uio.h>
#include <assert.h>
#include <alloca.h>
#include <limits.h>
#include <sys/param.h>
#include <wchar.h>
#include <wingdi.h>
#include <winuser.h>
#include <winnls.h>
#include "cygtls.h"
#include "ntdll.h"
#include "path.h"
#include "fhandler.h"
#include "dtable.h"
#include "cygheap.h"

long tls_ix = -1;

const char case_folded_lower[] NO_COPY = {
   0,   1,   2,   3,   4,   5,   6,   7,   8,   9,  10,  11,  12,  13,  14,  15,
  16,  17,  18,  19,  20,  21,  22,  23,  24,  25,  26,  27,  28,  29,  30,  31,
  32, '!', '"', '#', '$', '%', '&',  39, '(', ')', '*', '+', ',', '-', '.', '/',
 '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', ':', ';', '<', '=', '>', '?',
 '@', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o',
 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', '[',  92, ']', '^', '_',
 '`', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o',
 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', '{', '|', '}', '~', 127,
 128, 129, 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143,
 144, 145, 146, 147, 148, 149, 150, 151, 152, 153, 154, 155, 156, 157, 158, 159,
 160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 172, 173, 174, 175,
 176, 177, 178, 179, 180, 181, 182, 183, 184, 185, 186, 187, 188, 189, 190, 191,
 192, 193, 194, 195, 196, 197, 198, 199, 200, 201, 202, 203, 204, 205, 206, 207,
 208, 209, 210, 211, 212, 213, 214, 215, 216, 217, 218, 219, 220, 221, 222, 223,
 224, 225, 226, 227, 228, 229, 230, 231, 232, 233, 234, 235, 236, 237, 238, 239,
 240, 241, 242, 243, 244, 245, 246, 247, 248, 249, 250, 251, 252, 253, 254, 255
};

const char case_folded_upper[] NO_COPY = {
   0,   1,   2,   3,   4,   5,   6,   7,   8,   9,  10,  11,  12,  13,  14,  15,
  16,  17,  18,  19,  20,  21,  22,  23,  24,  25,  26,  27,  28,  29,  30,  31,
  32, '!', '"', '#', '$', '%', '&',  39, '(', ')', '*', '+', ',', '-', '.', '/',
 '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', ':', ';', '<', '=', '>', '?',
 '@', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O',
 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', '[',  92, ']', '^', '_',
 '`', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O',
 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', '{', '|', '}', '~', 127,
 128, 129, 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143,
 144, 145, 146, 147, 148, 149, 150, 151, 152, 153, 154, 155, 156, 157, 158, 159,
 160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 172, 173, 174, 175,
 176, 177, 178, 179, 180, 181, 182, 183, 184, 185, 186, 187, 188, 189, 190, 191,
 192, 193, 194, 195, 196, 197, 198, 199, 200, 201, 202, 203, 204, 205, 206, 207,
 208, 209, 210, 211, 212, 213, 214, 215, 216, 217, 218, 219, 220, 221, 222, 223,
 224, 225, 226, 227, 228, 229, 230, 231, 232, 233, 234, 235, 236, 237, 238, 239,
 240, 241, 242, 243, 244, 245, 246, 247, 248, 249, 250, 251, 252, 253, 254, 255
};

const char isalpha_array[] NO_COPY = {
   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
   0,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,
0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,   0,   0,   0,   0,   0,
   0,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,
0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,   0,   0,   0,   0,   0,
   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0
};

extern "C" int __stdcall
cygwin_wcscasecmp (const wchar_t *ws, const wchar_t *wt)
{
  UNICODE_STRING us, ut;

  RtlInitUnicodeString (&us, ws);
  RtlInitUnicodeString (&ut, wt);
  return RtlCompareUnicodeString (&us, &ut, TRUE);
}

extern "C" int __stdcall
cygwin_wcsncasecmp (const wchar_t  *ws, const wchar_t *wt, size_t n)
{
  UNICODE_STRING us, ut;
  size_t ls = 0, lt = 0;

  while (ws[ls] && ls < n)
    ++ls;
  RtlInitCountedUnicodeString (&us, ws, ls * sizeof (WCHAR));
  while (wt[lt] && lt < n)
    ++lt;
  RtlInitCountedUnicodeString (&ut, wt, lt * sizeof (WCHAR));
  return RtlCompareUnicodeString (&us, &ut, TRUE);
}

extern "C" int __stdcall
cygwin_strcasecmp (const char *cs, const char *ct)
{
  UNICODE_STRING us, ut;
  ULONG len;

  len = (strlen (cs) + 1) * sizeof (WCHAR);
  RtlInitEmptyUnicodeString (&us, (PWCHAR) alloca (len), len);
  us.Length = sys_mbstowcs (us.Buffer, us.MaximumLength, cs) * sizeof (WCHAR);
  len = (strlen (ct) + 1) * sizeof (WCHAR);
  RtlInitEmptyUnicodeString (&ut, (PWCHAR) alloca (len), len);
  ut.Length = sys_mbstowcs (ut.Buffer, ut.MaximumLength, ct) * sizeof (WCHAR);
  return RtlCompareUnicodeString (&us, &ut, TRUE);
}

extern "C" int __stdcall
cygwin_strncasecmp (const char *cs, const char *ct, size_t n)
{
  UNICODE_STRING us, ut;
  ULONG len;
  size_t ls = 0, lt = 0;

  while (cs[ls] && ls < n)
    ++ls;
  len = (ls + 1) * sizeof (WCHAR);
  RtlInitEmptyUnicodeString (&us, (PWCHAR) alloca (len), len);
  us.Length = sys_mbstowcs (us.Buffer, ls + 1, cs, ls) * sizeof (WCHAR);
  while (ct[lt] && lt < n)
    ++lt;
  len = (lt + 1) * sizeof (WCHAR);
  RtlInitEmptyUnicodeString (&ut, (PWCHAR) alloca (len), len);
  ut.Length = sys_mbstowcs (ut.Buffer, lt + 1, ct, lt)  * sizeof (WCHAR);
  return RtlCompareUnicodeString (&us, &ut, TRUE);
}

extern "C" char * __stdcall
cygwin_strlwr (char *string)
{
  UNICODE_STRING us;
  size_t len = (strlen (string) + 1) * sizeof (WCHAR);

  us.MaximumLength = len; us.Buffer = (PWCHAR) alloca (len);
  us.Length = sys_mbstowcs (us.Buffer, len, string) * sizeof (WCHAR)
	      - sizeof (WCHAR);
  RtlDowncaseUnicodeString (&us, &us, FALSE);
  sys_wcstombs (string, len / sizeof (WCHAR), us.Buffer);
  return string;
}

extern "C" char * __stdcall
cygwin_strupr (char *string)
{
  UNICODE_STRING us;
  size_t len = (strlen (string) + 1) * sizeof (WCHAR);

  us.MaximumLength = len; us.Buffer = (PWCHAR) alloca (len);
  us.Length = sys_mbstowcs (us.Buffer, len, string) * sizeof (WCHAR)
	      - sizeof (WCHAR);
  RtlUpcaseUnicodeString (&us, &us, FALSE);
  sys_wcstombs (string, len / sizeof (WCHAR), us.Buffer);
  return string;
}

int __stdcall
check_invalid_virtual_addr (const void *s, unsigned sz)
{
  MEMORY_BASIC_INFORMATION mbuf;
  const void *end;

  for (end = (char *) s + sz; s < end;
       s = (char *) mbuf.BaseAddress + mbuf.RegionSize)
    if (!VirtualQuery (s, &mbuf, sizeof mbuf))
      return EINVAL;
  return 0;
}

static char __attribute__ ((noinline))
dummytest (volatile char *p)
{
  return *p;
}

ssize_t
check_iovec (const struct iovec *iov, int iovcnt, bool forwrite)
{
  if (iovcnt <= 0 || iovcnt > IOV_MAX)
    {
      set_errno (EINVAL);
      return -1;
    }

  myfault efault;
  if (efault.faulted (EFAULT))
    return -1;

  size_t tot = 0;

  while (iovcnt != 0)
    {
      if (iov->iov_len > SSIZE_MAX || (tot += iov->iov_len) > SSIZE_MAX)
	{
	  set_errno (EINVAL);
	  return -1;
	}

      volatile char *p = ((char *) iov->iov_base) + iov->iov_len - 1;
      if (!iov->iov_len)
	/* nothing to do */;
      else if (!forwrite)
	*p  = dummytest (p);
      else
	dummytest (p);

      iov++;
      iovcnt--;
    }

  assert (tot <= SSIZE_MAX);

  return (ssize_t) tot;
}

void
yield ()
{
  for (int i = 0; i < 3; i++)
    SwitchToThread ();
}

/* Get a default value for the nice factor.  When changing these values,
   have a look into the below function nice_to_winprio.  The values must
   match the layout of the static "priority" array. */
int
winprio_to_nice (DWORD prio)
{
  switch (prio)
    {
      case REALTIME_PRIORITY_CLASS:
	return -20;
      case HIGH_PRIORITY_CLASS:
	return -16;
      case ABOVE_NORMAL_PRIORITY_CLASS:
	return -8;
      case NORMAL_PRIORITY_CLASS:
	return 0;
      case BELOW_NORMAL_PRIORITY_CLASS:
	return 8;
      case IDLE_PRIORITY_CLASS:
	return 16;
    }
  return 0;
}

/* Get a Win32 priority matching the incoming nice factor.  The incoming
   nice is limited to the interval [-NZERO,NZERO-1]. */
DWORD
nice_to_winprio (int &nice)
{
  static const DWORD priority[] NO_COPY =
    {
      REALTIME_PRIORITY_CLASS,		/*  0 */
      HIGH_PRIORITY_CLASS,		/*  1 */
      HIGH_PRIORITY_CLASS,
      HIGH_PRIORITY_CLASS,
      HIGH_PRIORITY_CLASS,
      HIGH_PRIORITY_CLASS,
      HIGH_PRIORITY_CLASS,
      HIGH_PRIORITY_CLASS,		/*  7 */
      ABOVE_NORMAL_PRIORITY_CLASS,	/*  8 */
      ABOVE_NORMAL_PRIORITY_CLASS,
      ABOVE_NORMAL_PRIORITY_CLASS,
      ABOVE_NORMAL_PRIORITY_CLASS,
      ABOVE_NORMAL_PRIORITY_CLASS,
      ABOVE_NORMAL_PRIORITY_CLASS,
      ABOVE_NORMAL_PRIORITY_CLASS,
      ABOVE_NORMAL_PRIORITY_CLASS,	/* 15 */
      NORMAL_PRIORITY_CLASS,		/* 16 */
      NORMAL_PRIORITY_CLASS,
      NORMAL_PRIORITY_CLASS,
      NORMAL_PRIORITY_CLASS,
      NORMAL_PRIORITY_CLASS,
      NORMAL_PRIORITY_CLASS,
      NORMAL_PRIORITY_CLASS,
      NORMAL_PRIORITY_CLASS,		/* 23 */
      BELOW_NORMAL_PRIORITY_CLASS,	/* 24 */
      BELOW_NORMAL_PRIORITY_CLASS,
      BELOW_NORMAL_PRIORITY_CLASS,
      BELOW_NORMAL_PRIORITY_CLASS,
      BELOW_NORMAL_PRIORITY_CLASS,
      BELOW_NORMAL_PRIORITY_CLASS,
      BELOW_NORMAL_PRIORITY_CLASS,
      BELOW_NORMAL_PRIORITY_CLASS,	/* 31 */
      IDLE_PRIORITY_CLASS,		/* 32 */
      IDLE_PRIORITY_CLASS,
      IDLE_PRIORITY_CLASS,
      IDLE_PRIORITY_CLASS,
      IDLE_PRIORITY_CLASS,
      IDLE_PRIORITY_CLASS,
      IDLE_PRIORITY_CLASS,
      IDLE_PRIORITY_CLASS		/* 39 */
    };
  if (nice < -NZERO)
    nice = -NZERO;
  else if (nice > NZERO - 1)
    nice = NZERO - 1;
  DWORD prio = priority[nice + NZERO];
  return prio;
}

#undef CreatePipe
bool
create_pipe (PHANDLE hr,PHANDLE hw, LPSECURITY_ATTRIBUTES sa, DWORD n)
{
  for (int i = 0; i < 10; i++)
    if (CreatePipe (hr, hw, sa, n))
      return true;
    else if (GetLastError () == ERROR_PIPE_BUSY && i < 9)
      Sleep (10);
    else
      break;
  return false;
}

/* backslashify: Convert all forward slashes in src path to back slashes
   in dst path.  Add a trailing slash to dst when trailing_slash_p arg
   is set to 1. */

void
backslashify (const char *src, char *dst, bool trailing_slash_p)
{
  const char *start = src;

  while (*src)
    {
      if (*src == '/')
	*dst++ = '\\';
      else
	*dst++ = *src;
      ++src;
    }
  if (trailing_slash_p
      && src > start
      && !isdirsep (src[-1]))
    *dst++ = '\\';
  *dst++ = 0;
}

/* slashify: Convert all back slashes in src path to forward slashes
   in dst path.  Add a trailing slash to dst when trailing_slash_p arg
   is set to 1. */

void
slashify (const char *src, char *dst, bool trailing_slash_p)
{
  const char *start = src;

  while (*src)
    {
      if (*src == '\\')
	*dst++ = '/';
      else
	*dst++ = *src;
      ++src;
    }
  if (trailing_slash_p
      && src > start
      && !isdirsep (src[-1]))
    *dst++ = '/';
  *dst++ = 0;
}

/* CygwinCreateThread.

   Replacement function for CreateThread.  What we do here is to remove
   parameters we don't use and instead to add parameters we need to make
   the function pthreads compatible. */

struct thread_wrapper_arg
{
  LPTHREAD_START_ROUTINE func;
  PVOID arg;
  PVOID stackaddr;
  ULONG stacksize;
  ULONG guardsize;
};

DWORD WINAPI
thread_wrapper (VOID *arg)
{
  if (!arg)
    return ERROR_INVALID_PARAMETER;

  thread_wrapper_arg wrapper_arg = *(thread_wrapper_arg *) arg;
  cfree (arg);

  if (wrapper_arg.stackaddr)
    {
      /* If the application provided the stack, we must make sure that
	 it's actually used by the thread function.  So what we do here is
	 to compute the stackbase of the application-provided stack and
	 change the stack pointer accordingly.

	 NOTE: _my_tls is on the stack created by CreateThread!  It's
	       unlikely the tls structure will ever exceed 64K, but if
	       so, we have to raise the size of the stack in the call
	       to CreateThread, too. */
      wrapper_arg.stackaddr = (PVOID) ((PBYTE) wrapper_arg.stackaddr
					       + wrapper_arg.stacksize
					       - sizeof (PVOID));
      __asm__ ("\n\
	       movl %[WRAPPER_ARG], %%ebx \n\
	       movl (%%ebx), %%eax \n\
	       movl 4(%%ebx), %%ecx \n\
	       movl 8(%%ebx), %%edx \n\
	       xorl %%ebp, %%ebp \n\
	       movl %%edx, %%esp \n\
	       pushl %%ecx \n\
	       pushl %%eax \n\
	       jmp  *%%eax \n" : : [WRAPPER_ARG] "r" (&wrapper_arg));

    }
  if (wrapper_arg.guardsize)
    {
      /* Set up POSIX guard pages.  Note that this is not the same as the
	 PAGE_GUARD protection.  Rather, the POSIX guard pages are a
	 PAGE_NOACCESS protected area which is supposed to guard against
	 stack overflow and to trigger a SIGSEGV if that happens. */
      PNT_TIB tib = &NtCurrentTeb ()->Tib;
      wrapper_arg.stackaddr = (PVOID) ((PBYTE) tib->StackBase
				       - wrapper_arg.stacksize);
      if (!VirtualAlloc (wrapper_arg.stackaddr, wrapper_arg.guardsize,
			 MEM_COMMIT, PAGE_NOACCESS))
	system_printf ("VirtualAlloc, %E");
    }
  __asm__ ("\n\
	   movl %[WRAPPER_ARG], %%ebx \n\
	   movl (%%ebx), %%eax \n\
	   movl 4(%%ebx), %%ecx \n\
	   pushl %%ecx \n\
	   pushl %%eax \n\
	   jmp  *%%eax \n" : : [WRAPPER_ARG] "r" (&wrapper_arg));
  /* Never reached. */
  return ERROR_INVALID_FUNCTION;
}

/* FIXME: This should be settable via setrlimit (RLIMIT_STACK). */
#define DEFAULT_STACKSIZE (512 * 1024)

HANDLE WINAPI
CygwinCreateThread (LPTHREAD_START_ROUTINE thread_func, PVOID thread_arg,
		    PVOID stackaddr, ULONG stacksize, ULONG guardsize,
		    DWORD creation_flags, LPDWORD thread_id)
{
  ULONG real_stacksize = 0;
  ULONG real_guardsize = 0;
  thread_wrapper_arg *wrapper_arg;
  
  wrapper_arg = (thread_wrapper_arg *) ccalloc (HEAP_STR, 1,
						sizeof *wrapper_arg);
  if (!wrapper_arg)
    {
      SetLastError (ERROR_OUTOFMEMORY);
      return NULL;
    }
  wrapper_arg->func = thread_func;
  wrapper_arg->arg = thread_arg;

  /* Set stacksize. */
  real_stacksize = stacksize ?: DEFAULT_STACKSIZE;
  if (real_stacksize < PTHREAD_STACK_MIN)
    real_stacksize = PTHREAD_STACK_MIN;
  if (stackaddr)
    {
      wrapper_arg->stackaddr = stackaddr;
      wrapper_arg->stacksize = real_stacksize;
      real_stacksize = PTHREAD_STACK_MIN;
    }
  else
    {
      /* If not, we have to create the stack here. */
      real_stacksize = roundup2 (real_stacksize, wincap.page_size ());
      /* If no guardsize has been specified by the application, use the
	 system pagesize as default. */
      real_guardsize = (guardsize != 0xffffffff)
		       ? guardsize : wincap.page_size ();
      if (real_guardsize)
	real_guardsize = roundup2 (real_guardsize, wincap.page_size ());
      /* If the default stacksize is used and guardsize has not been specified,
	 don't add a guard page to the size. */
      if (stacksize && guardsize != 0xffffffff)
	real_stacksize += real_guardsize;
      /* Now roundup the result to the next allocation boundary. */
      real_stacksize = roundup2 (real_stacksize,
				 wincap.allocation_granularity ());

      wrapper_arg->stacksize = real_stacksize;
      wrapper_arg->guardsize = real_guardsize;
    }
  /* Use the STACK_SIZE_PARAM_IS_A_RESERVATION parameter to make sure the
     stack size is exactly the size we want. */
  return CreateThread (&sec_none_nih, real_stacksize, thread_wrapper,
		       wrapper_arg,
		       creation_flags | STACK_SIZE_PARAM_IS_A_RESERVATION,
		       thread_id);
}