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-rw-r--r--winsup/cygwin/mmap.cc98
1 files changed, 47 insertions, 51 deletions
diff --git a/winsup/cygwin/mmap.cc b/winsup/cygwin/mmap.cc
index 38ca0073f..69b4f1168 100644
--- a/winsup/cygwin/mmap.cc
+++ b/winsup/cygwin/mmap.cc
@@ -51,6 +51,11 @@ details. */
/* Used for anonymous mappings. */
static fhandler_dev_zero fh_anonymous;
+/* Used for thread synchronization while accessing mmap bookkeeping lists. */
+static NO_COPY muto mmap_guard;
+#define LIST_LOCK() (mmap_guard.init ("mmap_guard")->acquire ())
+#define LIST_UNLOCK() (mmap_guard.release ())
+
/* Small helpers to avoid having lots of flag bit tests in the code. */
static inline bool
priv (int flags)
@@ -333,7 +338,6 @@ class mmap_list
void set (int nfd, struct __stat64 *st);
mmap_record *add_record (mmap_record r);
bool del_record (mmap_record *rec);
- mmap_record *search_record (_off64_t off, DWORD len);
caddr_t try_map (void *addr, size_t len, int flags, _off64_t off);
};
@@ -552,31 +556,6 @@ mmap_list::add_record (mmap_record r)
return rec;
}
-/* Used in mmap() */
-mmap_record *
-mmap_list::search_record (_off64_t off, DWORD len)
-{
- mmap_record *rec;
-
- if (anonymous () && !off)
- {
- len = PAGE_CNT (len);
- LIST_FOREACH (rec, &recs, mr_next)
- if (rec->find_unused_pages (len) != (DWORD)-1)
- return rec;
- }
- else
- {
- LIST_FOREACH (rec, &recs, mr_next)
- if (off >= rec->get_offset ()
- && off + len
- <= rec->get_offset ()
- + (PAGE_CNT (rec->get_len ()) * getsystempagesize ()))
- return rec;
- }
- return NULL;
-}
-
void
mmap_list::set (int nfd, struct __stat64 *st)
{
@@ -611,10 +590,13 @@ mmap_list::try_map (void *addr, size_t len, int flags, _off64_t off)
{
/* If MAP_FIXED isn't given, check if this mapping matches into the
chunk of another already performed mapping. */
- if ((rec = search_record (off, len)) != NULL
- && rec->compatible_flags (flags))
+ DWORD plen = PAGE_CNT (len);
+ LIST_FOREACH (rec, &recs, mr_next)
+ if (rec->find_unused_pages (plen) != (DWORD) -1)
+ break;
+ if (rec && rec->compatible_flags (flags))
{
- if ((off = rec->map_pages (off, len)) == (_off64_t)-1)
+ if ((off = rec->map_pages (off, len)) == (_off64_t) -1)
return (caddr_t) MAP_FAILED;
return (caddr_t) rec->get_address () + off;
}
@@ -705,6 +687,9 @@ mmap_areas::del_list (mmap_list *ml)
mmap_region_status
mmap_is_attached_or_noreserve (void *addr, size_t len)
{
+ mmap_region_status ret = MMAP_NONE;
+
+ LIST_LOCK ();
mmap_list *map_list = mmapped_areas.get_list_by_fd (-1, NULL);
size_t pagesize = getpagesize ();
@@ -713,7 +698,7 @@ mmap_is_attached_or_noreserve (void *addr, size_t len)
len = roundup2 (len, pagesize);
if (map_list == NULL)
- return MMAP_NONE;
+ goto out;
mmap_record *rec;
caddr_t u_addr;
@@ -724,9 +709,12 @@ mmap_is_attached_or_noreserve (void *addr, size_t len)
if (!rec->match (start_addr, len, u_addr, u_len))
continue;
if (rec->attached ())
- return MMAP_RAISE_SIGBUS;
+ {
+ ret = MMAP_RAISE_SIGBUS;
+ break;
+ }
if (!rec->noreserve ())
- return MMAP_NONE;
+ break;
size_t commit_len = u_len - (start_addr - u_addr);
if (commit_len > len)
@@ -734,14 +722,22 @@ mmap_is_attached_or_noreserve (void *addr, size_t len)
if (!VirtualAlloc (start_addr, commit_len, MEM_COMMIT,
rec->gen_protect ()))
- return MMAP_RAISE_SIGBUS;
+ {
+ ret = MMAP_RAISE_SIGBUS;
+ break;
+ }
start_addr += commit_len;
len -= commit_len;
if (!len)
- return MMAP_NORESERVE_COMMITED;
+ {
+ ret = MMAP_NORESERVE_COMMITED;
+ break;
+ }
}
- return MMAP_NONE;
+out:
+ LIST_UNLOCK ();
+ return ret;
}
static caddr_t
@@ -788,8 +784,6 @@ mmap64 (void *addr, size_t len, int prot, int flags, int fd, _off64_t off)
fh_anonymous.set_io_handle (INVALID_HANDLE_VALUE);
fh_anonymous.set_access (GENERIC_READ | GENERIC_WRITE | GENERIC_EXECUTE);
- SetResourceLock (LOCK_MMAP_LIST, READ_LOCK | WRITE_LOCK, "mmap");
-
/* EINVAL error conditions. */
if (off % pagesize
|| ((prot & ~(PROT_READ | PROT_WRITE | PROT_EXEC)))
@@ -939,6 +933,7 @@ go_ahead:
if (noreserve (flags) && (!anonymous (flags) || !priv (flags)))
flags &= ~MAP_NORESERVE;
+ LIST_LOCK ();
map_list = mmapped_areas.get_list_by_fd (fd, &st);
/* Test if an existing anonymous mapping can be recycled. */
@@ -946,11 +941,11 @@ go_ahead:
{
caddr_t tried = map_list->try_map (addr, len, flags, off);
/* try_map returns NULL if no map matched, otherwise it returns
- a valid address, of MAP_FAILED in case of a fatal error. */
+ a valid address, or MAP_FAILED in case of a fatal error. */
if (tried)
{
ret = tried;
- goto out;
+ goto out_with_unlock;
}
}
@@ -974,13 +969,13 @@ go_ahead:
if (!newaddr)
{
__seterrno ();
- goto out;
+ goto out_with_unlock;
}
}
if (!VirtualFree (newaddr, 0, MEM_RELEASE))
{
__seterrno ();
- goto out;
+ goto out_with_unlock;
}
addr = newaddr;
}
@@ -988,7 +983,7 @@ go_ahead:
base = mmap_worker (map_list, fh, (caddr_t) addr, len, prot, flags, fd, off,
&st);
if (!base)
- goto out;
+ goto out_with_unlock;
if (orig_len)
{
@@ -1024,7 +1019,7 @@ go_ahead:
{
fh->munmap (fh->get_handle (), base, len);
set_errno (ENOMEM);
- goto out;
+ goto out_with_unlock;
}
at_base += valid_page_len;
}
@@ -1042,9 +1037,10 @@ go_ahead:
ret = base;
-out:
+out_with_unlock:
+ LIST_UNLOCK ();
- ReleaseResourceLock (LOCK_MMAP_LIST, READ_LOCK | WRITE_LOCK, "mmap");
+out:
if (fh_disk_file)
NtClose (fh_disk_file->get_handle ());
@@ -1080,7 +1076,7 @@ munmap (void *addr, size_t len)
}
len = roundup2 (len, pagesize);
- SetResourceLock (LOCK_MMAP_LIST, WRITE_LOCK | READ_LOCK, "munmap");
+ LIST_LOCK ();
/* Iterate through the map, unmap pages between addr and addr+len
in all maps. */
@@ -1117,7 +1113,7 @@ munmap (void *addr, size_t len)
}
}
- ReleaseResourceLock (LOCK_MMAP_LIST, WRITE_LOCK | READ_LOCK, "munmap");
+ LIST_UNLOCK ();
syscall_printf ("0 = munmap(): %x", addr);
return 0;
}
@@ -1132,7 +1128,7 @@ msync (void *addr, size_t len, int flags)
syscall_printf ("msync (addr: %p, len %u, flags %x)", addr, len, flags);
- SetResourceLock (LOCK_MMAP_LIST, WRITE_LOCK | READ_LOCK, "msync");
+ LIST_LOCK ();
if (((uintptr_t) addr % getpagesize ())
|| (flags & ~(MS_ASYNC | MS_SYNC | MS_INVALIDATE))
@@ -1173,8 +1169,8 @@ msync (void *addr, size_t len, int flags)
set_errno (ENOMEM);
out:
+ LIST_UNLOCK ();
syscall_printf ("%d = msync()", ret);
- ReleaseResourceLock (LOCK_MMAP_LIST, WRITE_LOCK | READ_LOCK, "msync");
return ret;
}
@@ -1199,7 +1195,7 @@ mprotect (void *addr, size_t len, int prot)
}
len = roundup2 (len, pagesize);
- SetResourceLock (LOCK_MMAP_LIST, WRITE_LOCK | READ_LOCK, "mprotect");
+ LIST_LOCK ();
/* Iterate through the map, protect pages between addr and addr+len
in all maps. */
@@ -1235,7 +1231,7 @@ mprotect (void *addr, size_t len, int prot)
}
}
- ReleaseResourceLock (LOCK_MMAP_LIST, WRITE_LOCK | READ_LOCK, "mprotect");
+ LIST_UNLOCK ();
if (!in_mapped)
{
generated by cgit v1.2.3 (git 2.25.1) at 2025-04-30 09:10:37 +0000