Make VM_* flag constant definitions consistent - unify all to use BIT()
macro.
This is a separete follow-up fix after we changed VM_MERGEABLE
separately to isolate bugfix for easier backporting. As suggested by
David in [1].
[1]: https://lore.kernel.org/all/85f852f9-8577-4230-adc7-c52e7f479454@redhat.com/
Signed-off-by: Jakub Acs <acsjakub@amazon.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Xu Xin <xu.xin16@zte.com.cn>
Cc: Chengming Zhou <chengming.zhou@linux.dev>
Cc: Peter Xu <peterx@redhat.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: linux-mm@kvack.org
Cc: linux-kernel@vger.kernel.org
---
include/linux/mm.h | 66 +++++++++++++++++++++++-----------------------
1 file changed, 33 insertions(+), 33 deletions(-)
diff --git a/include/linux/mm.h b/include/linux/mm.h
index c6794d0e24eb..88cab3d7eea2 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -246,56 +246,56 @@ extern unsigned int kobjsize(const void *objp);
* vm_flags in vm_area_struct, see mm_types.h.
* When changing, update also include/trace/events/mmflags.h
*/
-#define VM_NONE 0x00000000
+#define VM_NONE 0
-#define VM_READ 0x00000001 /* currently active flags */
-#define VM_WRITE 0x00000002
-#define VM_EXEC 0x00000004
-#define VM_SHARED 0x00000008
+#define VM_READ BIT(0) /* currently active flags */
+#define VM_WRITE BIT(1)
+#define VM_EXEC BIT(2)
+#define VM_SHARED BIT(3)
/* mprotect() hardcodes VM_MAYREAD >> 4 == VM_READ, and so for r/w/x bits. */
-#define VM_MAYREAD 0x00000010 /* limits for mprotect() etc */
-#define VM_MAYWRITE 0x00000020
-#define VM_MAYEXEC 0x00000040
-#define VM_MAYSHARE 0x00000080
+#define VM_MAYREAD BIT(4) /* limits for mprotect() etc */
+#define VM_MAYWRITE BIT(5)
+#define VM_MAYEXEC BIT(6)
+#define VM_MAYSHARE BIT(7)
-#define VM_GROWSDOWN 0x00000100 /* general info on the segment */
+#define VM_GROWSDOWN BIT(8) /* general info on the segment */
#ifdef CONFIG_MMU
-#define VM_UFFD_MISSING 0x00000200 /* missing pages tracking */
+#define VM_UFFD_MISSING BIT(9) /* missing pages tracking */
#else /* CONFIG_MMU */
-#define VM_MAYOVERLAY 0x00000200 /* nommu: R/O MAP_PRIVATE mapping that might overlay a file mapping */
+#define VM_MAYOVERLAY BIT(10) /* nommu: R/O MAP_PRIVATE mapping that might overlay a file mapping */
#define VM_UFFD_MISSING 0
#endif /* CONFIG_MMU */
-#define VM_PFNMAP 0x00000400 /* Page-ranges managed without "struct page", just pure PFN */
-#define VM_UFFD_WP 0x00001000 /* wrprotect pages tracking */
+#define VM_PFNMAP BIT(11) /* Page-ranges managed without "struct page", just pure PFN */
+#define VM_UFFD_WP BIT(12) /* wrprotect pages tracking */
-#define VM_LOCKED 0x00002000
-#define VM_IO 0x00004000 /* Memory mapped I/O or similar */
+#define VM_LOCKED BIT(13)
+#define VM_IO BIT(14) /* Memory mapped I/O or similar */
/* Used by sys_madvise() */
-#define VM_SEQ_READ 0x00008000 /* App will access data sequentially */
-#define VM_RAND_READ 0x00010000 /* App will not benefit from clustered reads */
-
-#define VM_DONTCOPY 0x00020000 /* Do not copy this vma on fork */
-#define VM_DONTEXPAND 0x00040000 /* Cannot expand with mremap() */
-#define VM_LOCKONFAULT 0x00080000 /* Lock the pages covered when they are faulted in */
-#define VM_ACCOUNT 0x00100000 /* Is a VM accounted object */
-#define VM_NORESERVE 0x00200000 /* should the VM suppress accounting */
-#define VM_HUGETLB 0x00400000 /* Huge TLB Page VM */
-#define VM_SYNC 0x00800000 /* Synchronous page faults */
-#define VM_ARCH_1 0x01000000 /* Architecture-specific flag */
-#define VM_WIPEONFORK 0x02000000 /* Wipe VMA contents in child. */
-#define VM_DONTDUMP 0x04000000 /* Do not include in the core dump */
+#define VM_SEQ_READ BIT(15) /* App will access data sequentially */
+#define VM_RAND_READ BIT(16) /* App will not benefit from clustered reads */
+
+#define VM_DONTCOPY BIT(17) /* Do not copy this vma on fork */
+#define VM_DONTEXPAND BIT(18) /* Cannot expand with mremap() */
+#define VM_LOCKONFAULT BIT(19) /* Lock the pages covered when they are faulted in */
+#define VM_ACCOUNT BIT(20) /* Is a VM accounted object */
+#define VM_NORESERVE BIT(21) /* should the VM suppress accounting */
+#define VM_HUGETLB BIT(22) /* Huge TLB Page VM */
+#define VM_SYNC BIT(23) /* Synchronous page faults */
+#define VM_ARCH_1 BIT(24) /* Architecture-specific flag */
+#define VM_WIPEONFORK BIT(25) /* Wipe VMA contents in child. */
+#define VM_DONTDUMP BIT(26) /* Do not include in the core dump */
#ifdef CONFIG_MEM_SOFT_DIRTY
-# define VM_SOFTDIRTY 0x08000000 /* Not soft dirty clean area */
+# define VM_SOFTDIRTY BIT(27) /* Not soft dirty clean area */
#else
# define VM_SOFTDIRTY 0
#endif
-#define VM_MIXEDMAP 0x10000000 /* Can contain "struct page" and pure PFN pages */
-#define VM_HUGEPAGE 0x20000000 /* MADV_HUGEPAGE marked this vma */
-#define VM_NOHUGEPAGE 0x40000000 /* MADV_NOHUGEPAGE marked this vma */
+#define VM_MIXEDMAP BIT(28) /* Can contain "struct page" and pure PFN pages */
+#define VM_HUGEPAGE BIT(29) /* MADV_HUGEPAGE marked this vma */
+#define VM_NOHUGEPAGE BIT(30) /* MADV_NOHUGEPAGE marked this vma */
#define VM_MERGEABLE BIT(31) /* KSM may merge identical pages */
#ifdef CONFIG_ARCH_USES_HIGH_VMA_FLAGS
--
2.47.3
Amazon Web Services Development Center Germany GmbH
Tamara-Danz-Str. 13
10243 Berlin
Geschaeftsfuehrung: Christian Schlaeger
Eingetragen am Amtsgericht Charlottenburg unter HRB 257764 B
Sitz: Berlin
Ust-ID: DE 365 538 597On Wed, 1 Oct 2025 09:03:53 +0000 Jakub Acs <acsjakub@amazon.de> wrote: > Make VM_* flag constant definitions consistent - unify all to use BIT() > macro. > > This is a separete follow-up fix after we changed VM_MERGEABLE > separately to isolate bugfix for easier backporting. As suggested by > David in [1]. > > [1]: https://lore.kernel.org/all/85f852f9-8577-4230-adc7-c52e7f479454@redhat.com/ > > Signed-off-by: Jakub Acs <acsjakub@amazon.de> > Cc: Andrew Morton <akpm@linux-foundation.org> > Cc: David Hildenbrand <david@redhat.com> > Cc: Xu Xin <xu.xin16@zte.com.cn> > Cc: Chengming Zhou <chengming.zhou@linux.dev> > Cc: Peter Xu <peterx@redhat.com> > Cc: Axel Rasmussen <axelrasmussen@google.com> > Cc: linux-mm@kvack.org > Cc: linux-kernel@vger.kernel.org > --- > include/linux/mm.h | 66 +++++++++++++++++++++++----------------------- > 1 file changed, 33 insertions(+), 33 deletions(-) > > diff --git a/include/linux/mm.h b/include/linux/mm.h > index c6794d0e24eb..88cab3d7eea2 100644 > --- a/include/linux/mm.h > +++ b/include/linux/mm.h > @@ -246,56 +246,56 @@ extern unsigned int kobjsize(const void *objp); > * vm_flags in vm_area_struct, see mm_types.h. > * When changing, update also include/trace/events/mmflags.h > */ > -#define VM_NONE 0x00000000 > +#define VM_NONE 0 I'm wondering if it could be more consistent to use 0UL instead. > > -#define VM_READ 0x00000001 /* currently active flags */ > -#define VM_WRITE 0x00000002 > -#define VM_EXEC 0x00000004 > -#define VM_SHARED 0x00000008 > +#define VM_READ BIT(0) /* currently active flags */ > +#define VM_WRITE BIT(1) > +#define VM_EXEC BIT(2) > +#define VM_SHARED BIT(3) > > /* mprotect() hardcodes VM_MAYREAD >> 4 == VM_READ, and so for r/w/x bits. */ > -#define VM_MAYREAD 0x00000010 /* limits for mprotect() etc */ > -#define VM_MAYWRITE 0x00000020 > -#define VM_MAYEXEC 0x00000040 > -#define VM_MAYSHARE 0x00000080 > +#define VM_MAYREAD BIT(4) /* limits for mprotect() etc */ > +#define VM_MAYWRITE BIT(5) > +#define VM_MAYEXEC BIT(6) > +#define VM_MAYSHARE BIT(7) > > -#define VM_GROWSDOWN 0x00000100 /* general info on the segment */ > +#define VM_GROWSDOWN BIT(8) /* general info on the segment */ > #ifdef CONFIG_MMU > -#define VM_UFFD_MISSING 0x00000200 /* missing pages tracking */ > +#define VM_UFFD_MISSING BIT(9) /* missing pages tracking */ > #else /* CONFIG_MMU */ > -#define VM_MAYOVERLAY 0x00000200 /* nommu: R/O MAP_PRIVATE mapping that might overlay a file mapping */ > +#define VM_MAYOVERLAY BIT(10) /* nommu: R/O MAP_PRIVATE mapping that might overlay a file mapping */ s/10/9/ ? > #define VM_UFFD_MISSING 0 > #endif /* CONFIG_MMU */ > -#define VM_PFNMAP 0x00000400 /* Page-ranges managed without "struct page", just pure PFN */ > -#define VM_UFFD_WP 0x00001000 /* wrprotect pages tracking */ > +#define VM_PFNMAP BIT(11) /* Page-ranges managed without "struct page", just pure PFN */ s/11/10/ ? > +#define VM_UFFD_WP BIT(12) /* wrprotect pages tracking */ > > -#define VM_LOCKED 0x00002000 > -#define VM_IO 0x00004000 /* Memory mapped I/O or similar */ > +#define VM_LOCKED BIT(13) > +#define VM_IO BIT(14) /* Memory mapped I/O or similar */ > > /* Used by sys_madvise() */ > -#define VM_SEQ_READ 0x00008000 /* App will access data sequentially */ > -#define VM_RAND_READ 0x00010000 /* App will not benefit from clustered reads */ > - > -#define VM_DONTCOPY 0x00020000 /* Do not copy this vma on fork */ > -#define VM_DONTEXPAND 0x00040000 /* Cannot expand with mremap() */ > -#define VM_LOCKONFAULT 0x00080000 /* Lock the pages covered when they are faulted in */ > -#define VM_ACCOUNT 0x00100000 /* Is a VM accounted object */ > -#define VM_NORESERVE 0x00200000 /* should the VM suppress accounting */ > -#define VM_HUGETLB 0x00400000 /* Huge TLB Page VM */ > -#define VM_SYNC 0x00800000 /* Synchronous page faults */ > -#define VM_ARCH_1 0x01000000 /* Architecture-specific flag */ > -#define VM_WIPEONFORK 0x02000000 /* Wipe VMA contents in child. */ > -#define VM_DONTDUMP 0x04000000 /* Do not include in the core dump */ > +#define VM_SEQ_READ BIT(15) /* App will access data sequentially */ > +#define VM_RAND_READ BIT(16) /* App will not benefit from clustered reads */ > + > +#define VM_DONTCOPY BIT(17) /* Do not copy this vma on fork */ > +#define VM_DONTEXPAND BIT(18) /* Cannot expand with mremap() */ > +#define VM_LOCKONFAULT BIT(19) /* Lock the pages covered when they are faulted in */ > +#define VM_ACCOUNT BIT(20) /* Is a VM accounted object */ > +#define VM_NORESERVE BIT(21) /* should the VM suppress accounting */ > +#define VM_HUGETLB BIT(22) /* Huge TLB Page VM */ > +#define VM_SYNC BIT(23) /* Synchronous page faults */ > +#define VM_ARCH_1 BIT(24) /* Architecture-specific flag */ > +#define VM_WIPEONFORK BIT(25) /* Wipe VMA contents in child. */ > +#define VM_DONTDUMP BIT(26) /* Do not include in the core dump */ > > #ifdef CONFIG_MEM_SOFT_DIRTY > -# define VM_SOFTDIRTY 0x08000000 /* Not soft dirty clean area */ > +# define VM_SOFTDIRTY BIT(27) /* Not soft dirty clean area */ > #else > # define VM_SOFTDIRTY 0 > #endif > > -#define VM_MIXEDMAP 0x10000000 /* Can contain "struct page" and pure PFN pages */ > -#define VM_HUGEPAGE 0x20000000 /* MADV_HUGEPAGE marked this vma */ > -#define VM_NOHUGEPAGE 0x40000000 /* MADV_NOHUGEPAGE marked this vma */ > +#define VM_MIXEDMAP BIT(28) /* Can contain "struct page" and pure PFN pages */ > +#define VM_HUGEPAGE BIT(29) /* MADV_HUGEPAGE marked this vma */ > +#define VM_NOHUGEPAGE BIT(30) /* MADV_NOHUGEPAGE marked this vma */ > #define VM_MERGEABLE BIT(31) /* KSM may merge identical pages */ > > #ifdef CONFIG_ARCH_USES_HIGH_VMA_FLAGS > -- > 2.47.3 Thanks, SJ [...]
On 01.10.25 18:51, SeongJae Park wrote: > On Wed, 1 Oct 2025 09:03:53 +0000 Jakub Acs <acsjakub@amazon.de> wrote: > >> Make VM_* flag constant definitions consistent - unify all to use BIT() >> macro. >> >> This is a separete follow-up fix after we changed VM_MERGEABLE >> separately to isolate bugfix for easier backporting. As suggested by >> David in [1]. >> >> [1]: https://lore.kernel.org/all/85f852f9-8577-4230-adc7-c52e7f479454@redhat.com/ >> >> Signed-off-by: Jakub Acs <acsjakub@amazon.de> >> Cc: Andrew Morton <akpm@linux-foundation.org> >> Cc: David Hildenbrand <david@redhat.com> >> Cc: Xu Xin <xu.xin16@zte.com.cn> >> Cc: Chengming Zhou <chengming.zhou@linux.dev> >> Cc: Peter Xu <peterx@redhat.com> >> Cc: Axel Rasmussen <axelrasmussen@google.com> >> Cc: linux-mm@kvack.org >> Cc: linux-kernel@vger.kernel.org >> --- >> include/linux/mm.h | 66 +++++++++++++++++++++++----------------------- >> 1 file changed, 33 insertions(+), 33 deletions(-) >> >> diff --git a/include/linux/mm.h b/include/linux/mm.h >> index c6794d0e24eb..88cab3d7eea2 100644 >> --- a/include/linux/mm.h >> +++ b/include/linux/mm.h >> @@ -246,56 +246,56 @@ extern unsigned int kobjsize(const void *objp); >> * vm_flags in vm_area_struct, see mm_types.h. >> * When changing, update also include/trace/events/mmflags.h >> */ >> -#define VM_NONE 0x00000000 >> +#define VM_NONE 0 > > I'm wondering if it could be more consistent to use 0UL instead. Not really required, and if we're switching to BIT already there is not a lot of consistency to be had. Would be different if we were avoid BIT() is in patch v2. -- Cheers David / dhildenb
On Thu, 2 Oct 2025 09:29:37 +0200 David Hildenbrand <david@redhat.com> wrote: > On 01.10.25 18:51, SeongJae Park wrote: > > On Wed, 1 Oct 2025 09:03:53 +0000 Jakub Acs <acsjakub@amazon.de> wrote: > > > >> Make VM_* flag constant definitions consistent - unify all to use BIT() > >> macro. > >> > >> This is a separete follow-up fix after we changed VM_MERGEABLE > >> separately to isolate bugfix for easier backporting. As suggested by > >> David in [1]. > >> > >> [1]: https://lore.kernel.org/all/85f852f9-8577-4230-adc7-c52e7f479454@redhat.com/ > >> > >> Signed-off-by: Jakub Acs <acsjakub@amazon.de> > >> Cc: Andrew Morton <akpm@linux-foundation.org> > >> Cc: David Hildenbrand <david@redhat.com> > >> Cc: Xu Xin <xu.xin16@zte.com.cn> > >> Cc: Chengming Zhou <chengming.zhou@linux.dev> > >> Cc: Peter Xu <peterx@redhat.com> > >> Cc: Axel Rasmussen <axelrasmussen@google.com> > >> Cc: linux-mm@kvack.org > >> Cc: linux-kernel@vger.kernel.org > >> --- > >> include/linux/mm.h | 66 +++++++++++++++++++++++----------------------- > >> 1 file changed, 33 insertions(+), 33 deletions(-) > >> > >> diff --git a/include/linux/mm.h b/include/linux/mm.h > >> index c6794d0e24eb..88cab3d7eea2 100644 > >> --- a/include/linux/mm.h > >> +++ b/include/linux/mm.h > >> @@ -246,56 +246,56 @@ extern unsigned int kobjsize(const void *objp); > >> * vm_flags in vm_area_struct, see mm_types.h. > >> * When changing, update also include/trace/events/mmflags.h > >> */ > >> -#define VM_NONE 0x00000000 > >> +#define VM_NONE 0 > > > > I'm wondering if it could be more consistent to use 0UL instead. > > Not really required, and if we're switching to BIT already there is not > a lot of consistency to be had. Would be different if we were avoid > BIT() is in patch v2. Agreed. :) Thanks, SJ [...]
> > -#define VM_GROWSDOWN 0x00000100 /* general info on the segment */ > +#define VM_GROWSDOWN BIT(8) /* general info on the segment */ > #ifdef CONFIG_MMU > -#define VM_UFFD_MISSING 0x00000200 /* missing pages tracking */ > +#define VM_UFFD_MISSING BIT(9) /* missing pages tracking */ > #else /* CONFIG_MMU */ > -#define VM_MAYOVERLAY 0x00000200 /* nommu: R/O MAP_PRIVATE mapping that might overlay a file mapping */ > +#define VM_MAYOVERLAY BIT(10) /* nommu: R/O MAP_PRIVATE mapping that might overlay a file mapping */ Careful: VM_UFFD_MISSING and VM_MAYOVERLAY share the same bit, depending on CONFIG_MMU (9). > #define VM_UFFD_MISSING 0 > #endif /* CONFIG_MMU */ > -#define VM_PFNMAP 0x00000400 /* Page-ranges managed without "struct page", just pure PFN */ > -#define VM_UFFD_WP 0x00001000 /* wrprotect pages tracking */ > +#define VM_PFNMAP BIT(11) /* Page-ranges managed without "struct page", just pure PFN */ -> 10 11 is actually unused IIUC. > +#define VM_UFFD_WP BIT(12) /* wrprotect pages tracking */ > This seems to be correct again. IIRC, Andrew prefers not mixing fixes and cleanups in the same series if possible. So you might just want to send out patch #1 separately and, send out patch #2 separately with a note under the --- that it depends on patch #1. -- Cheers David / dhildenb
On Wed, Oct 01, 2025 at 04:04:51PM +0200, David Hildenbrand wrote: > >-#define VM_GROWSDOWN 0x00000100 /* general info on the segment */ > >+#define VM_GROWSDOWN BIT(8) /* general info on the segment */ > > #ifdef CONFIG_MMU > >-#define VM_UFFD_MISSING 0x00000200 /* missing pages tracking */ > >+#define VM_UFFD_MISSING BIT(9) /* missing pages tracking */ > > #else /* CONFIG_MMU */ > >-#define VM_MAYOVERLAY 0x00000200 /* nommu: R/O MAP_PRIVATE mapping that might overlay a file mapping */ > >+#define VM_MAYOVERLAY BIT(10) /* nommu: R/O MAP_PRIVATE mapping that might overlay a file mapping */ > > Careful: VM_UFFD_MISSING and VM_MAYOVERLAY share the same bit, > depending on CONFIG_MMU (9). > > > #define VM_UFFD_MISSING 0 > > #endif /* CONFIG_MMU */ > >-#define VM_PFNMAP 0x00000400 /* Page-ranges managed without "struct page", just pure PFN */ > >-#define VM_UFFD_WP 0x00001000 /* wrprotect pages tracking */ > >+#define VM_PFNMAP BIT(11) /* Page-ranges managed without "struct page", just pure PFN */ > > -> 10 Ugh, thanks for catching these! > > 11 is actually unused IIUC. > > >+#define VM_UFFD_WP BIT(12) /* wrprotect pages tracking */ > > This seems to be correct again. > > > IIRC, Andrew prefers not mixing fixes and cleanups in the same > series if possible. So you might just want to send out patch #1 > separately and, send out patch #2 separately with a note under the > --- that it depends on patch #1. > I saw that patch #1 was applied so will leave that alone now, but took a note for future. For completeness adding the link to v4: https://lore.kernel.org/all/20251002075202.11306-1-acsjakub@amazon.de/ Many Thanks, Jakub Amazon Web Services Development Center Germany GmbH Tamara-Danz-Str. 13 10243 Berlin Geschaeftsfuehrung: Christian Schlaeger Eingetragen am Amtsgericht Charlottenburg unter HRB 257764 B Sitz: Berlin Ust-ID: DE 365 538 597
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