From: Bernard Metzler bmt@zurich.ibm.com
[ Upstream commit 65a8fc30fb6722fc25adec6d7dd5b53b0bb85820 ]
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@nvidia.com Suggested-by: Alistair Popple apopple@nvidia.com Reviewed-by: Alistair Popple apopple@nvidia.com Signed-off-by: Bernard Metzler bmt@zurich.ibm.com Link: https://lore.kernel.org/r/20230202101000.402990-1-bmt@zurich.ibm.com Signed-off-by: Leon Romanovsky leon@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/infiniband/sw/siw/siw_mem.c | 23 ++++++++++++----------- 1 file changed, 12 insertions(+), 11 deletions(-)
diff --git a/drivers/infiniband/sw/siw/siw_mem.c b/drivers/infiniband/sw/siw/siw_mem.c index 61c17db70d658..bf69566e2eb63 100644 --- a/drivers/infiniband/sw/siw/siw_mem.c +++ b/drivers/infiniband/sw/siw/siw_mem.c @@ -398,7 +398,7 @@ 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 (atomic64_add_return(num_pages, &mm_s->pinned_vm) > mlock_limit) { rv = -ENOMEM; goto out_sem_up; } @@ -411,18 +411,16 @@ struct siw_umem *siw_umem_get(u64 start, u64 len, bool writable) goto out_sem_up; } for (i = 0; num_pages; i++) { - int got, nents = min_t(int, num_pages, PAGES_PER_CHUNK); - - umem->page_chunk[i].plist = + int nents = min_t(int, num_pages, PAGES_PER_CHUNK); + struct page **plist = kcalloc(nents, sizeof(struct page *), GFP_KERNEL); - if (!umem->page_chunk[i].plist) { + + if (!plist) { rv = -ENOMEM; goto out_sem_up; } - got = 0; + umem->page_chunk[i].plist = plist; while (nents) { - struct page **plist = &umem->page_chunk[i].plist[got]; - rv = pin_user_pages(first_page_va, nents, foll_flags | FOLL_LONGTERM, plist, NULL); @@ -430,12 +428,11 @@ 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; + plist += rv; nents -= rv; - got += rv; + num_pages -= rv; } - num_pages -= got; } out_sem_up: mmap_read_unlock(mm_s); @@ -443,6 +440,10 @@ 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);