[ros-diffs] [reactos] 01/01: [NTOS:MM] Do not use PAGE_ROUND_DOWN for LONGLONG values (#7603)

[Vincent Franchomme]

https://git.reactos.org/?p=reactos.git;a=commitdiff;h=6ada5978d023504e591bc…

commit 6ada5978d023504e591bce2fd91d48ed7c262fd6
Author:     Vincent Franchomme <franchomme.vincent(a)gmail.com>
AuthorDate: Thu Jan 16 04:30:38 2025 +0100
Commit:     GitHub <noreply(a)github.com>
CommitDate: Thu Jan 16 10:30:38 2025 +0700

    [NTOS:MM] Do not use PAGE_ROUND_DOWN for LONGLONG values (#7603)
    
    PAGE_ROUND_DOWN macro seems to not work correctly with LONGLONG values. It creates
some random freezes in the 1st-stage setup after commit
69bf14050686f81db153c70df4f874b5dfa4a5ff.
    It's fixed by creating PAGE_ROUND_UP_64 and PAGE_ROUND_DOWN_64 macros for 64-bit
only data types.
    
    ---------
    
    Co-authored-by: Thamatip Chitpong <thamatip.chitpong(a)reactos.org>
---
 ntoskrnl/include/internal/mm.h | 7 +++++++
 ntoskrnl/mm/section.c          | 8 ++++----
 2 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/ntoskrnl/include/internal/mm.h b/ntoskrnl/include/internal/mm.h
index 91bf7599df2..1c3870d6370 100644
--- a/ntoskrnl/include/internal/mm.h
+++ b/ntoskrnl/include/internal/mm.h
@@ -131,6 +131,13 @@ typedef ULONG_PTR SWAPENTRY;
 #define MM_ROUND_DOWN(x,s)                  \
     ((PVOID)(((ULONG_PTR)(x)) & ~((ULONG_PTR)(s)-1)))
 
+/* PAGE_ROUND_UP and PAGE_ROUND_DOWN equivalent, with support for 64-bit-only data types
*/
+#define PAGE_ROUND_UP_64(x) \
+    (((x) + PAGE_SIZE - 1) & ~(PAGE_SIZE - 1))
+
+#define PAGE_ROUND_DOWN_64(x) \
+    ((x) & ~(PAGE_SIZE - 1))
+
 #define PAGE_FLAGS_VALID_FOR_SECTION \
     (PAGE_READONLY | \
      PAGE_READWRITE | \
diff --git a/ntoskrnl/mm/section.c b/ntoskrnl/mm/section.c
index 73b414315fe..d570dbc3cec 100644
--- a/ntoskrnl/mm/section.c
+++ b/ntoskrnl/mm/section.c
@@ -4876,7 +4876,7 @@ MmPurgeSegment(
     }
 
     /* Find byte offset of the page to start */
-    PurgeStart.QuadPart = PAGE_ROUND_DOWN(PurgeStart.QuadPart);
+    PurgeStart.QuadPart = PAGE_ROUND_DOWN_64(PurgeStart.QuadPart);
 
     while (PurgeStart.QuadPart < PurgeEnd.QuadPart)
     {
@@ -4947,7 +4947,7 @@ MmIsDataSectionResident(
         return FALSE;
 
     /* Find byte offset of the page to start */
-    RangeStart.QuadPart = PAGE_ROUND_DOWN(RangeStart.QuadPart);
+    RangeStart.QuadPart = PAGE_ROUND_DOWN_64(RangeStart.QuadPart);
 
     MmLockSectionSegment(Segment);
 
@@ -5010,7 +5010,7 @@ MmMakeSegmentDirty(
         return STATUS_NOT_MAPPED_VIEW;
 
     /* Find byte offset of the page to start */
-    RangeStart.QuadPart = PAGE_ROUND_DOWN(RangeStart.QuadPart);
+    RangeStart.QuadPart = PAGE_ROUND_DOWN_64(RangeStart.QuadPart);
 
     MmLockSectionSegment(Segment);
 
@@ -5098,7 +5098,7 @@ MmFlushSegment(
     }
 
     /* Find byte offset of the page to start */
-    FlushStart.QuadPart = PAGE_ROUND_DOWN(FlushStart.QuadPart);
+    FlushStart.QuadPart = PAGE_ROUND_DOWN_64(FlushStart.QuadPart);
 
     while (FlushStart.QuadPart < FlushEnd.QuadPart)
     {