Patch attached.
From 87e07edb7c53f425c86579d013d29efd3f905203 Mon Sep 17 00:00:00 2001
From: Ken Brown <kbr...@cornell.edu>
Date: Fri, 20 Dec 2024 13:11:22 -0500
Subject: [PATCH 3/5] Cygwin: mmap: remove __PROT_FILLER and the associated
methods
This is left over from 32 bit Cygwin and is no longer used.
Signed-off-by: Ken Brown <kbr...@cornell.edu>
---
winsup/cygwin/mm/mmap.cc | 31 +++++++------------------------
1 file changed, 7 insertions(+), 24 deletions(-)
diff --git a/winsup/cygwin/mm/mmap.cc b/winsup/cygwin/mm/mmap.cc
index 13e64c23256c..9e6415de9951 100644
--- a/winsup/cygwin/mm/mmap.cc
+++ b/winsup/cygwin/mm/mmap.cc
@@ -27,14 +27,8 @@ details. */
is to support mappings longer than the file, without the file growing
to mapping length (POSIX semantics). */
#define __PROT_ATTACH 0x8000000
-/* Filler pages are the pages from the last file backed page to the next
- 64K boundary. These pages are created as anonymous pages, but with
- the same page protection as the file's pages, since POSIX applications
- expect to be able to access this part the same way as the file pages. */
-#define __PROT_FILLER 0x4000000
-
-/* Stick with 4K pages for bookkeeping, otherwise we just get confused
- when trying to do file mappings with trailing filler pages correctly. */
+
+/* Stick with 4K pages for bookkeeping. */
#define PAGE_CNT(bytes) howmany((bytes), wincap.page_size())
#define PGBITS (sizeof (DWORD)*8)
@@ -91,12 +85,6 @@ attached (int prot)
return (prot & __PROT_ATTACH) == __PROT_ATTACH;
}
-static inline bool
-filler (int prot)
-{
- return (prot & __PROT_FILLER) == __PROT_FILLER;
-}
-
static inline DWORD
gen_create_protect (DWORD openflags, int flags)
{
@@ -125,7 +113,7 @@ gen_protect (int prot, int flags)
return PAGE_EXECUTE_READWRITE;
if (prot & PROT_WRITE)
- ret = (priv (flags) && (!anonymous (flags) || filler (prot)))
+ ret = (priv (flags) && !anonymous (flags))
? PAGE_WRITECOPY : PAGE_READWRITE;
else if (prot & PROT_READ)
ret = PAGE_READONLY;
@@ -330,7 +318,6 @@ class mmap_record
bool noreserve () const { return ::noreserve (flags); }
bool autogrow () const { return ::autogrow (flags); }
bool attached () const { return ::attached (prot); }
- bool filler () const { return ::filler (prot); }
off_t get_offset () const { return offset; }
SIZE_T get_len () const { return len; }
caddr_t get_address () const { return base_address; }
@@ -430,13 +417,9 @@ mmap_record::match (caddr_t addr, SIZE_T len, caddr_t
&m_addr, SIZE_T &m_len,
bool &contains)
{
contains = false;
+ SIZE_T rec_len = PAGE_CNT (get_len ()) * wincap.page_size ();
caddr_t low = MAX (addr, get_address ());
- caddr_t high = get_address ();
- if (filler ())
- high += get_len ();
- else
- high += (PAGE_CNT (get_len ()) * wincap.page_size ());
- high = MIN (addr + len, high);
+ caddr_t high = MIN (addr + len, get_address () + rec_len);
if (low < high)
{
m_addr = low;
@@ -1569,7 +1552,7 @@ fhandler_dev_zero::mmap (caddr_t *addr, size_t len, int
prot,
HANDLE h;
void *base;
- if (priv (flags) && !filler (prot))
+ if (priv (flags))
{
/* Private anonymous maps are now implemented using VirtualAlloc.
This has two advantages:
@@ -1678,7 +1661,7 @@ fhandler_dev_zero::fixup_mmap_after_fork (HANDLE h, int
prot, int flags,
{
/* Re-create the map */
void *base;
- if (priv (flags) && !filler (prot))
+ if (priv (flags))
{
DWORD alloc_type = MEM_RESERVE | (noreserve (flags) ? 0 : MEM_COMMIT);
/* Always allocate R/W so that ReadProcessMemory doesn't fail
--
2.45.1
