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>
Reviewed-by: Alistair Popple <apopple@xxxxxxxxxx>
Signed-off-by: Bernard Metzler <bmt@xxxxxxxxxxxxxx>
---
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 b2b33dd3b4fa..f51ab2ccf151 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;
}
@@ -411,30 +411,27 @@ 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,
plist, NULL);
if (rv < 0)
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);
@@ -442,6 +439,10 @@ 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
