Re: [PATCH 07/10] mm: correct sign-extension issue in MMF_* flag masks

[Lorenzo Stoakes <lorenzo.stoakes@xxxxxxxxxx>]

Hi Andrew,

Quick fix-patch to use BIT() in favour of _BITUL() as requested by David,
since this is a far more sensible way of generating a bitmask.

Thanks, Lorenzo

----8<----
>From 83a10e3fe7dbbc7ab7c04312fff32b28787acf9b Mon Sep 17 00:00:00 2001
From: Lorenzo Stoakes <lorenzo.stoakes@xxxxxxxxxx>
Date: Tue, 26 Aug 2025 15:01:18 +0100
Subject: [PATCH] mm: prefer BIT() to _BITUL()

BIT() does the same thing, and is defined in actual linux headers rather
than a uapi header.

Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@xxxxxxxxxx>
---
 include/linux/mm_types.h | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
index 3affc6a9e279..c3d40fddfb60 100644
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -1755,7 +1755,7 @@ enum {
  * the modes are SUID_DUMP_* defined in linux/sched/coredump.h
  */
 #define MMF_DUMPABLE_BITS 2
-#define MMF_DUMPABLE_MASK (_BITUL(MMF_DUMPABLE_BITS) - 1)
+#define MMF_DUMPABLE_MASK (BIT(MMF_DUMPABLE_BITS) - 1)
 /* coredump filter bits */
 #define MMF_DUMP_ANON_PRIVATE	2
 #define MMF_DUMP_ANON_SHARED	3
@@ -1770,13 +1770,13 @@ enum {
 #define MMF_DUMP_FILTER_SHIFT	MMF_DUMPABLE_BITS
 #define MMF_DUMP_FILTER_BITS	9
 #define MMF_DUMP_FILTER_MASK \
-	((_BITUL(MMF_DUMP_FILTER_BITS) - 1) << MMF_DUMP_FILTER_SHIFT)
+	((BIT(MMF_DUMP_FILTER_BITS) - 1) << MMF_DUMP_FILTER_SHIFT)
 #define MMF_DUMP_FILTER_DEFAULT \
-	(_BITUL(MMF_DUMP_ANON_PRIVATE) | _BITUL(MMF_DUMP_ANON_SHARED) | \
-	 _BITUL(MMF_DUMP_HUGETLB_PRIVATE) | MMF_DUMP_MASK_DEFAULT_ELF)
+	(BIT(MMF_DUMP_ANON_PRIVATE) | BIT(MMF_DUMP_ANON_SHARED) | \
+	 BIT(MMF_DUMP_HUGETLB_PRIVATE) | MMF_DUMP_MASK_DEFAULT_ELF)

 #ifdef CONFIG_CORE_DUMP_DEFAULT_ELF_HEADERS
-# define MMF_DUMP_MASK_DEFAULT_ELF	_BITUL(MMF_DUMP_ELF_HEADERS)
+# define MMF_DUMP_MASK_DEFAULT_ELF	BIT(MMF_DUMP_ELF_HEADERS)
 #else
 # define MMF_DUMP_MASK_DEFAULT_ELF	0
 #endif
@@ -1796,7 +1796,7 @@ enum {
 #define MMF_UNSTABLE		22	/* mm is unstable for copy_from_user */
 #define MMF_HUGE_ZERO_FOLIO	23      /* mm has ever used the global huge zero folio */
 #define MMF_DISABLE_THP		24	/* disable THP for all VMAs */
-#define MMF_DISABLE_THP_MASK	_BITUL(MMF_DISABLE_THP)
+#define MMF_DISABLE_THP_MASK	BIT(MMF_DISABLE_THP)
 #define MMF_OOM_REAP_QUEUED	25	/* mm was queued for oom_reaper */
 #define MMF_MULTIPROCESS	26	/* mm is shared between processes */
 /*
@@ -1809,15 +1809,15 @@ enum {
 #define MMF_HAS_PINNED		27	/* FOLL_PIN has run, never cleared */

 #define MMF_HAS_MDWE		28
-#define MMF_HAS_MDWE_MASK	_BITUL(MMF_HAS_MDWE)
+#define MMF_HAS_MDWE_MASK	BIT(MMF_HAS_MDWE)

 #define MMF_HAS_MDWE_NO_INHERIT	29

 #define MMF_VM_MERGE_ANY	30
-#define MMF_VM_MERGE_ANY_MASK	_BITUL(MMF_VM_MERGE_ANY)
+#define MMF_VM_MERGE_ANY_MASK	BIT(MMF_VM_MERGE_ANY)

 #define MMF_TOPDOWN		31	/* mm searches top down by default */
-#define MMF_TOPDOWN_MASK	_BITUL(MMF_TOPDOWN)
+#define MMF_TOPDOWN_MASK	BIT(MMF_TOPDOWN)

 #define MMF_INIT_MASK		(MMF_DUMPABLE_MASK | MMF_DUMP_FILTER_MASK |\
 				 MMF_DISABLE_THP_MASK | MMF_HAS_MDWE_MASK |\
--
2.50.1