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* mmap.cc (mmap64): Pre-Reserve space for the whole mapping to get a

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useful, valid address before the actual mappings take place.
	Fix typo in comment.
This commit is contained in:
Corinna Vinschen 2007-01-10 09:30:38 +00:00
parent ac924d61de
commit 3452cdd3c5
2 changed files with 31 additions and 1 deletions
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6
winsup/cygwin/ChangeLog
View File

@ -1,3 +1,9 @@
2007-01-10 Corinna Vinschen <corinna@vinschen.de>
* mmap.cc (mmap64): Pre-Reserve space for the whole mapping to get a
useful, valid address before the actual mappings take place.
Fix typo in comment.
2007-01-10 Corinna Vinschen <corinna@vinschen.de> 2007-01-10 Corinna Vinschen <corinna@vinschen.de>
* syscalls.cc (sync): Use b_drive for B: drive (Thanks to Howard Chu). * syscalls.cc (sync): Use b_drive for B: drive (Thanks to Howard Chu).

26
winsup/cygwin/mmap.cc
View File

@ -1217,6 +1217,28 @@ go_ahead:
goto out; goto out;
} }
if (orig_len)
{
/* If the requested length is bigger than the file size, we try to
allocate an area of the full size first. This area is immediately
deallocated and the address we got is used as base address for the
subsequent real mappings. This ensures that we have enough space
for the whole thing. */
orig_len = roundup2 (orig_len, pagesize);
addr = VirtualAlloc (addr, orig_len, MEM_TOP_DOWN | MEM_RESERVE,
PAGE_READWRITE);
if (!addr)
{
__seterrno ();
goto out;
}
if (!VirtualFree (addr, 0, MEM_RELEASE))
{
__seterrno ();
goto out;
}
}
base = mmap_worker (fh, (caddr_t) addr, len, prot, flags, fd, off); base = mmap_worker (fh, (caddr_t) addr, len, prot, flags, fd, off);
if (!base) if (!base)
goto out; goto out;
@ -1225,7 +1247,7 @@ go_ahead:
{ {
/* If the requested length is bigger than the file size, the /* If the requested length is bigger than the file size, the
remainder is created as anonymous mapping. Actually two remainder is created as anonymous mapping. Actually two
mappings are created, first the reminder from the file end to mappings are created, first the remainder from the file end to
the next 64K boundary as accessible pages with the same the next 64K boundary as accessible pages with the same
protection as the file's pages, then as much pages as necessary protection as the file's pages, then as much pages as necessary
to accomodate the requested length, but as reserved pages which to accomodate the requested length, but as reserved pages which
@ -1233,7 +1255,9 @@ go_ahead:
and page protection on shared pages is only supported by 32 bit NT, and page protection on shared pages is only supported by 32 bit NT,
so don't even try on 9x and in WOW64. This is accomplished by not so don't even try on 9x and in WOW64. This is accomplished by not
setting orig_len on 9x and in WOW64 above. */ setting orig_len on 9x and in WOW64 above. */
#if 0
orig_len = roundup2 (orig_len, pagesize); orig_len = roundup2 (orig_len, pagesize);
#endif
len = roundup2 (len, getsystempagesize ()); len = roundup2 (len, getsystempagesize ());
if (orig_len - len) if (orig_len - len)
{ {