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charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Rspamd-Server: rspam10 X-Rspamd-Queue-Id: EEEB520005 X-Stat-Signature: ykr1pykieugf5ygu6pjh6tbtktdy5zux X-Rspam-User: X-HE-Tag: 1785707715-788169 X-HE-Meta: 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 4rBBAZ9W 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 lADJ/DPr 2P+1T62+9ZJwDBhZBCmtcpYzirLaTtYIik85lKtQqIWUXPMURLdMc0xV4rONaMtxYu1CVO23dYg= Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: From: Dave Hansen Previously, the per-VMA locking could fail in the face of writers which necessitates a fallback to mmap_lock. The new lock_vma_under_rcu_wait() will wait for writers instead of failing. Use the new helper. Wait for writers. Remove the fallback to mmap_lock. This really is a nice cleanup. It removes the need to pass the lock state back and forth to find_tcp_vma(). Signed-off-by: Dave Hansen Signed-off-by: Suren Baghdasaryan Acked-by: Lorenzo Stoakes Acked-by: Vlastimil Babka (SUSE) Tested-by: syzbot@syzkaller.appspotmail.com Cc: Andrew Morton Cc: Liam R. Howlett Cc: Vlastimil Babka Cc: Shakeel Butt Cc: linux-mm@kvack.org Cc: Greg Kroah-Hartman Cc: Arve Hj=C3=B8nnev=C3=A5g Cc: Todd Kjos Cc: Christian Brauner Cc: Carlos Llamas Cc: Alice Ryhl Cc: David S. Miller Cc: David Ahern Cc: netdev@vger.kernel.org --- net/ipv4/tcp.c | 31 +++++++++---------------------- 1 file changed, 9 insertions(+), 22 deletions(-) diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 455441f1b694..62defe70f3ce 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -2167,27 +2167,18 @@ static void tcp_zc_finalize_rx_tstamp(struct sock *= sk, } =20 static struct vm_area_struct *find_tcp_vma(struct mm_struct *mm, - unsigned long address, - bool *mmap_locked) + unsigned long address) { - struct vm_area_struct *vma =3D lock_vma_under_rcu(mm, address); + struct vm_area_struct *vma =3D vma_start_read_unlocked(mm, address); =20 - if (vma) { - if (vma->vm_ops !=3D &tcp_vm_ops) { - vma_end_read(vma); - return NULL; - } - *mmap_locked =3D false; - return vma; - } + if (!vma) + return NULL; =20 - mmap_read_lock(mm); - vma =3D vma_lookup(mm, address); - if (!vma || vma->vm_ops !=3D &tcp_vm_ops) { - mmap_read_unlock(mm); + if (vma->vm_ops !=3D &tcp_vm_ops) { + vma_end_read(vma); return NULL; } - *mmap_locked =3D true; + return vma; } =20 @@ -2208,7 +2199,6 @@ static int tcp_zerocopy_receive(struct sock *sk, u32 seq =3D tp->copied_seq; u32 total_bytes_to_map; int inq =3D tcp_inq(sk); - bool mmap_locked; int ret; =20 zc->copybuf_len =3D 0; @@ -2233,7 +2223,7 @@ static int tcp_zerocopy_receive(struct sock *sk, return 0; } =20 - vma =3D find_tcp_vma(current->mm, address, &mmap_locked); + vma =3D find_tcp_vma(current->mm, address); if (!vma) return -EINVAL; =20 @@ -2315,10 +2305,7 @@ static int tcp_zerocopy_receive(struct sock *sk, zc, total_bytes_to_map); } out: - if (mmap_locked) - mmap_read_unlock(current->mm); - else - vma_end_read(vma); + vma_end_read(vma); /* Try to copy straggler data. */ if (!ret) copylen =3D tcp_zc_handle_leftover(zc, sk, skb, &seq, copybuf_len, tss); --=20 2.55.0.508.g3f0d502094-goog