To avoid racing with other user memory reservations, immediately account full amount of pages to be pinned. Fixes: 2251334dcac9 ("rdma/siw: application buffer management") Reported-by: Jason Gunthorpe <jgg@xxxxxxxxxx> Suggested-by: Alistair Popple <apopple@xxxxxxxxxx> Signed-off-by: Bernard Metzler <bmt@xxxxxxxxxxxxxx> --- drivers/infiniband/sw/siw/siw_mem.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/infiniband/sw/siw/siw_mem.c b/drivers/infiniband/sw/siw/siw_mem.c index b2b33dd3b4fa..7cf4d927bbab 100644 --- a/drivers/infiniband/sw/siw/siw_mem.c +++ b/drivers/infiniband/sw/siw/siw_mem.c @@ -398,7 +398,8 @@ struct siw_umem *siw_umem_get(u64 start, u64 len, bool writable) mlock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT; - if (num_pages + atomic64_read(&mm_s->pinned_vm) > mlock_limit) { + if (num_pages + atomic64_add_return(num_pages, &mm_s->pinned_vm) > + mlock_limit) { rv = -ENOMEM; goto out_sem_up; } @@ -429,7 +430,6 @@ struct siw_umem *siw_umem_get(u64 start, u64 len, bool writable) goto out_sem_up; umem->num_pages += rv; - atomic64_add(rv, &mm_s->pinned_vm); first_page_va += rv * PAGE_SIZE; nents -= rv; got += rv; @@ -442,6 +442,10 @@ struct siw_umem *siw_umem_get(u64 start, u64 len, bool writable) if (rv > 0) return umem; + /* Adjust accounting for pages not pinned */ + if (num_pages) + atomic64_sub(num_pages, &mm_s->pinned_vm); + siw_umem_release(umem, false); return ERR_PTR(rv); -- 2.32.0