Re: [PATCH] fs/proc/task_mmu: Add display flag for VM_MAYOVERLAY

[Andrew Morton]

On Thu, 8 Feb 2024 17:48:26 +0100 David Hildenbrand <david@xxxxxxxxxx> wrote:

> On 08.02.24 09:48, Anshuman Khandual wrote:
> > VM_UFFD_MISSING flag is mutually exclussive with VM_MAYOVERLAY flag as they
> > both use the same bit position i.e 0x00000200 in the vm_flags. Let's update
> > show_smap_vma_flags() to display the correct flags depending on CONFIG_MMU.
> > 
> > Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> > Cc: David Hildenbrand <david@xxxxxxxxxx>
> > Cc: linux-kernel@xxxxxxxxxxxxxxx
> > Cc: linux-fsdevel@xxxxxxxxxxxxxxx
> > Signed-off-by: Anshuman Khandual <anshuman.khandual@xxxxxxx>
> > ---
> > This applies on v6.8-rc3
> > 
> >   fs/proc/task_mmu.c | 4 ++++
> >   1 file changed, 4 insertions(+)
> > 
> > diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
> > index 3f78ebbb795f..1c4eb25cfc17 100644
> > --- a/fs/proc/task_mmu.c
> > +++ b/fs/proc/task_mmu.c
> > @@ -681,7 +681,11 @@ static void show_smap_vma_flags(struct seq_file *m, struct vm_area_struct *vma)
> >   		[ilog2(VM_HUGEPAGE)]	= "hg",
> >   		[ilog2(VM_NOHUGEPAGE)]	= "nh",
> >   		[ilog2(VM_MERGEABLE)]	= "mg",
> > +#ifdef CONFIG_MMU
> >   		[ilog2(VM_UFFD_MISSING)]= "um",
> > +#else
> > +		[ilog2(VM_MAYOVERLAY)]	= "ov",
> > +#endif /* CONFIG_MMU */
> >   		[ilog2(VM_UFFD_WP)]	= "uw",
> >   #ifdef CONFIG_ARM64_MTE
> >   		[ilog2(VM_MTE)]		= "mt",
> 
> Reviewed-by: David Hildenbrand <david@xxxxxxxxxx>

I'm thinking

Fixes: b6b7a8faf05c ("mm/nommu: don't use VM_MAYSHARE for MAP_PRIVATE mappings")
Cc: <stable@xxxxxxxxxxxxxxx>