From: Davidlohr Bueso <dave@stgolabs.net>
Date: Sat, 16 Feb 2019 12:15:52 +0000 (-0800)
Subject: drivers/IB,qib: Fix pinned/locked limit check in qib_get_user_pages()
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=ec95e0fa21628ed25f12187fb1067b8b10ad7c9a;p=linux.git

drivers/IB,qib: Fix pinned/locked limit check in qib_get_user_pages()

The current check does not take into account the previous value of
pinned_vm; thus it is quite bogus as is. Fix this by checking the
new value after the (optimistic) atomic inc.

Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
---

diff --git a/drivers/infiniband/hw/qib/qib_user_pages.c b/drivers/infiniband/hw/qib/qib_user_pages.c
index ef8bcf366ddca..123ca8f64f75d 100644
--- a/drivers/infiniband/hw/qib/qib_user_pages.c
+++ b/drivers/infiniband/hw/qib/qib_user_pages.c
@@ -107,7 +107,7 @@ int qib_get_user_pages(unsigned long start_page, size_t num_pages,
 	lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
 	locked = atomic64_add_return(num_pages, &current->mm->pinned_vm);
 
-	if (num_pages > lock_limit && !capable(CAP_IPC_LOCK)) {
+	if (locked > lock_limit && !capable(CAP_IPC_LOCK)) {
 		ret = -ENOMEM;
 		goto bail;
 	}