From: Dmitry Safonov <dima@xxxxxxxxxx> Subject: mm/mremap: account memory on do_munmap() failure Patch series "mremap: move_vma() fixes". This patch (of 6): move_vma() copies VMA without adding it to account, then unmaps old part of VMA. On failure it unmaps the new VMA. With hacks accounting in munmap is disabled as it's a copy of existing VMA. Account the memory on munmap() failure which was previously copied into a new VMA. Link: https://lkml.kernel.org/r/20201013013416.390574-1-dima@xxxxxxxxxx Link: https://lkml.kernel.org/r/20201013013416.390574-2-dima@xxxxxxxxxx Fixes: commit e2ea83742133 ("[PATCH] mremap: move_vma fixes and cleanup") Signed-off-by: Dmitry Safonov <dima@xxxxxxxxxx> Cc: Alexander Viro <viro@xxxxxxxxxxxxxxxxxx> Cc: Andy Lutomirski <luto@xxxxxxxxxx> Cc: Brian Geffon <bgeffon@xxxxxxxxxx> Cc: Catalin Marinas <catalin.marinas@xxxxxxx> Cc: Dan Williams <dan.j.williams@xxxxxxxxx> Cc: Dave Jiang <dave.jiang@xxxxxxxxx> Cc: Hugh Dickins <hughd@xxxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxxxxx> Cc: "Kirill A. Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx> Cc: Mike Kravetz <mike.kravetz@xxxxxxxxxx> Cc: Minchan Kim <minchan@xxxxxxxxxx> Cc: Russell King <linux@xxxxxxxxxxxxxxx> Cc: Thomas Bogendoerfer <tsbogend@xxxxxxxxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: Vishal Verma <vishal.l.verma@xxxxxxxxx> Cc: Vlastimil Babka <vbabka@xxxxxxx> Cc: Will Deacon <will@xxxxxxxxxx> Cc: Dan Carpenter <dan.carpenter@xxxxxxxxxx> Cc: John Hubbard <jhubbard@xxxxxxxxxx> Cc: Jason Gunthorpe <jgg@xxxxxxxx> Cc: Ralph Campbell <rcampbell@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/mremap.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/mm/mremap.c~mm-mremap-account-memory-on-do_munmap-failure +++ a/mm/mremap.c @@ -600,7 +600,8 @@ static unsigned long move_vma(struct vm_ if (do_munmap(mm, old_addr, old_len, uf_unmap) < 0) { /* OOM: unable to split vma, just get accounts right */ - vm_unacct_memory(excess >> PAGE_SHIFT); + if (vm_flags & VM_ACCOUNT) + vm_acct_memory(new_len >> PAGE_SHIFT); excess = 0; } _
