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Subject[PATCH 10/14] net: teach the mm about range locking
Date
Conversion is straightforward, mmap_sem is used within the
the same function context most of the time. No change in
semantics.

Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
---
net/ipv4/tcp.c | 5 +++--
net/xdp/xdp_umem.c | 5 +++--
2 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 53d61ca3ac4b..2be929dcafa8 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -1731,6 +1731,7 @@ static int tcp_zerocopy_receive(struct sock *sk,
struct tcp_sock *tp;
int inq;
int ret;
+ DEFINE_RANGE_LOCK_FULL(mmrange);

if (address & (PAGE_SIZE - 1) || address != zc->address)
return -EINVAL;
@@ -1740,7 +1741,7 @@ static int tcp_zerocopy_receive(struct sock *sk,

sock_rps_record_flow(sk);

- down_read(&current->mm->mmap_sem);
+ mm_read_lock(current->mm, &mmrange);

ret = -EINVAL;
vma = find_vma(current->mm, address);
@@ -1802,7 +1803,7 @@ static int tcp_zerocopy_receive(struct sock *sk,
frags++;
}
out:
- up_read(&current->mm->mmap_sem);
+ mm_read_unlock(current->mm, &mmrange);
if (length) {
tp->copied_seq = seq;
tcp_rcv_space_adjust(sk);
diff --git a/net/xdp/xdp_umem.c b/net/xdp/xdp_umem.c
index 2b18223e7eb8..2bf444fb998d 100644
--- a/net/xdp/xdp_umem.c
+++ b/net/xdp/xdp_umem.c
@@ -246,16 +246,17 @@ static int xdp_umem_pin_pages(struct xdp_umem *umem)
unsigned int gup_flags = FOLL_WRITE;
long npgs;
int err;
+ DEFINE_RANGE_LOCK_FULL(mmrange);

umem->pgs = kcalloc(umem->npgs, sizeof(*umem->pgs),
GFP_KERNEL | __GFP_NOWARN);
if (!umem->pgs)
return -ENOMEM;

- down_read(&current->mm->mmap_sem);
+ mm_read_lock(current->mm, &mmrange);
npgs = get_user_pages(umem->address, umem->npgs,
gup_flags | FOLL_LONGTERM, &umem->pgs[0], NULL);
- up_read(&current->mm->mmap_sem);
+ mm_read_unlock(current->mm, &mmrange);

if (npgs != umem->npgs) {
if (npgs >= 0) {
--
2.16.4
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