Paul Gofman : ntdll: Factor out get_vprot_range_size() function.

[Alexandre Julliard]

Module: wine
Branch: master
Commit: b7fafabc77b58fb33a5a543d423232f18f9d5f05
URL:    https://source.winehq.org/git/wine.git/?a=commit;h=b7fafabc77b58fb33a5a543d423232f18f9d5f05

Author: Paul Gofman <pgofman at codeweavers.com>
Date:   Thu Sep 23 18:20:04 2021 +0300

ntdll: Factor out get_vprot_range_size() function.

Signed-off-by: Paul Gofman <pgofman at codeweavers.com>
Signed-off-by: Alexandre Julliard <julliard at winehq.org>

---

 dlls/ntdll/unix/virtual.c | 40 +++++++++++++++++++++++++++++-----------
 1 file changed, 29 insertions(+), 11 deletions(-)

diff --git a/dlls/ntdll/unix/virtual.c b/dlls/ntdll/unix/virtual.c
index 984af2d4a21..41d878546bb 100644
--- a/dlls/ntdll/unix/virtual.c
+++ b/dlls/ntdll/unix/virtual.c
@@ -943,6 +943,24 @@ static BYTE get_page_vprot( const void *addr )
 }
 
 
+/***********************************************************************
+ *           get_vprot_range_size
+ *
+ * Return the size of the region with equal masked vprot byte.
+ * Also return the protections for the first page.
+ * The function assumes that base and size are page aligned and
+ * base + size does not wrap around. */
+static SIZE_T get_vprot_range_size( char *base, SIZE_T size, BYTE mask, BYTE *vprot )
+{
+    char *addr;
+
+    *vprot = get_page_vprot( base );
+    for (addr = base + page_size; addr != base + size; addr += page_size)
+        if ((*vprot ^ get_page_vprot( addr )) & mask) break;
+
+    return addr - base;
+}
+
 /***********************************************************************
  *           set_page_vprot
  *
@@ -2047,18 +2065,21 @@ done:
  */
 static SIZE_T get_committed_size( struct file_view *view, void *base, BYTE *vprot )
 {
-    SIZE_T i, start;
+    SIZE_T offset;
 
-    start = ((char *)base - (char *)view->base) >> page_shift;
-    *vprot = get_page_vprot( base );
+    base = ROUND_ADDR( base, page_mask );
+    offset = (char *)base - (char *)view->base;
 
     if (view->protect & SEC_RESERVE)
     {
         SIZE_T ret = 0;
+
+        *vprot = get_page_vprot( base );
+
         SERVER_START_REQ( get_mapping_committed_range )
         {
             req->base   = wine_server_client_ptr( view->base );
-            req->offset = start << page_shift;
+            req->offset = offset;
             if (!wine_server_call( req ))
             {
                 ret = reply->size;
@@ -2072,9 +2093,8 @@ static SIZE_T get_committed_size( struct file_view *view, void *base, BYTE *vpro
         SERVER_END_REQ;
         return ret;
     }
-    for (i = start + 1; i < view->size >> page_shift; i++)
-        if ((*vprot ^ get_page_vprot( (char *)view->base + (i << page_shift) )) & VPROT_COMMITTED) break;
-    return (i - start) << page_shift;
+
+    return get_vprot_range_size( base, view->size - offset, VPROT_COMMITTED, vprot );
 }
 
 
@@ -4196,7 +4216,6 @@ static NTSTATUS get_basic_memory_info( HANDLE process, LPCVOID addr,
     else
     {
         BYTE vprot;
-        char *ptr;
         SIZE_T range_size = get_committed_size( view, base, &vprot );
 
         info->State = (vprot & VPROT_COMMITTED) ? MEM_COMMIT : MEM_RESERVE;
@@ -4205,9 +4224,8 @@ static NTSTATUS get_basic_memory_info( HANDLE process, LPCVOID addr,
         if (view->protect & SEC_IMAGE) info->Type = MEM_IMAGE;
         else if (view->protect & (SEC_FILE | SEC_RESERVE | SEC_COMMIT)) info->Type = MEM_MAPPED;
         else info->Type = MEM_PRIVATE;
-        for (ptr = base; ptr < base + range_size; ptr += page_size)
-            if ((get_page_vprot( ptr ) ^ vprot) & ~VPROT_WRITEWATCH) break;
-        info->RegionSize = ptr - base;
+
+        info->RegionSize = get_vprot_range_size( base, range_size, ~VPROT_WRITEWATCH, &vprot );
     }
     server_leave_uninterrupted_section( &virtual_mutex, &sigset );