Commit 9992554c authored by Vlastimil Babka's avatar Vlastimil Babka Committed by Andrew Morton
Browse files

mm, madvise: use standard madvise locking in madvise_set_anon_name() 

Use madvise_lock()/madvise_unlock() in madvise_set_anon_name() in the same
way as in do_madvise().  This narrows the lock scope a bit and reuses
existing functionality.  get_lock_mode() already picks the correct
MADVISE_MMAP_WRITE_LOCK mode for __MADV_SET_ANON_VMA_NAME so we can just
remove the explicit assignment.

There is a user visible change in that the prctl(PR_SET_VMA,
PR_SET_VMA_ANON_NAME...) might now return -EINTR.

Link: https://lkml.kernel.org/r/20250624-anon_name_cleanup-v2-4-600075462a11@suse.cz


Signed-off-by: default avatarVlastimil Babka <vbabka@suse.cz>
Tested-by: default avatarLorenzo Stoakes <lorenzo.stoakes@oracle.com>
Acked-by: default avatarDavid Hildenbrand <david@redhat.com>
Reviewed-by: default avatarSuren Baghdasaryan <surenb@google.com>
Reviewed-by: default avatarLorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Colin Cross <ccross@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: SeongJae Park <sj@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 986738ce

mm/madvise.c

+9 −4
Original line number Diff line number Diff line
@@ -2082,10 +2082,10 @@ static int madvise_set_anon_name(struct mm_struct *mm, unsigned long start, 
{

	unsigned long end;

	unsigned long len;

	int error;

	struct madvise_behavior madv_behavior = {

		.mm = mm,

		.behavior = __MADV_SET_ANON_VMA_NAME,

		.lock_mode = MADVISE_MMAP_WRITE_LOCK,

		.anon_name = anon_name,

	};
@@ -2106,7 +2106,14 @@ static int madvise_set_anon_name(struct mm_struct *mm, unsigned long start, 


	madv_behavior.range.start = start;

	madv_behavior.range.end = end;

	return madvise_walk_vmas(&madv_behavior);



	error = madvise_lock(&madv_behavior);

	if (error)

		return error;

	error = madvise_walk_vmas(&madv_behavior);

	madvise_unlock(&madv_behavior);



	return error;

}



int set_anon_vma_name(unsigned long addr, unsigned long size,
@@ -2136,9 +2143,7 @@ int set_anon_vma_name(unsigned long addr, unsigned long size, 
			return -ENOMEM;

	}



	mmap_write_lock(mm);

	error = madvise_set_anon_name(mm, addr, size, anon_name);

	mmap_write_unlock(mm);

	anon_vma_name_put(anon_name);



	return error;