From mboxrd@z Thu Jan  1 00:00:00 1970
From: Andrey Konovalov <andreyknvl@google.com>
Subject: [PATCH v11 08/14] net,
 arm64: untag user pointers in tcp_zerocopy_receive
Date: Fri, 15 Mar 2019 20:51:32 +0100
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To: Catalin Marinas <catalin.marinas@arm.com>, Will Deacon <will.deacon@arm.com>, Mark Rutland <mark.rutland@arm.com>, Robin Murphy <robin.murphy@arm.com>, Kees Cook <keescook@chromium.org>, Kate Stewart <kstewart@linuxfoundation.org>, Greg Kroah-Hartman <gregkh@linuxfoundation.org>, Andrew Morton <akpm@linux-foundation.org>, Ingo Molnar <mingo@kernel.org>, "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>, Shuah Khan <shuah@kernel.org>, Vincenzo Frascino <vincenzo.frascino@arm.com>, Eric Dumazet <edumazet@google.com>, "David S. Miller" <davem@davemloft.net>, Alexei Starovoitov <ast@kernel.org>, Daniel Borkmann <daniel@iogearbox.net>, Steven Rostedt <rostedt@goodmis.org>, Ingo Molnar <mingo@redhat.com>, Peter Zijlstra <peterz@infradead.org>, Arnaldo Carvalho de Melo <acme@kernel.org>, linux-arm-kernel@lists.infradead.org, linux-doc@vger.kernel.org, linux-mm@k
Cc: Kevin Brodsky <kevin.brodsky@arm.com>, Chintan Pandya <cpandya@codeaurora.org>, Jacob Bramley <Jacob.Bramley@arm.com>, Ruben Ayrapetyan <Ruben.Ayrapetyan@arm.com>, Szabolcs Nagy <Szabolcs.Nagy@arm.com>, Andrey Konovalov <andreyknvl@google.com>, Lee Smith <Lee.Smith@arm.com>, Kostya Serebryany <kcc@google.com>, Dmitry Vyukov <dvyukov@google.com>, Ramana Radhakrishnan <Ramana.Radhakrishnan@arm.com>, Luc Van Oostenryck <luc.vanoostenryck@gmail.com>, Dave Martin <Dave.Martin@arm.com>, Evgeniy Stepanov <eugenis@google.com>
List-Id: linux-arch.vger.kernel.org

This patch is a part of a series that extends arm64 kernel ABI to allow to
pass tagged user pointers (with the top byte set to something else other
than 0x00) as syscall arguments.

tcp_zerocopy_receive() uses provided user pointers for vma lookups, which
can only by done with untagged pointers.

Untag user pointers in this function.

Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
---
 net/ipv4/tcp.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 6baa6dc1b13b..89db3b4fc753 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -1758,6 +1758,8 @@ static int tcp_zerocopy_receive(struct sock *sk,
 	int inq;
 	int ret;
 
+	address = untagged_addr(address);
+
 	if (address & (PAGE_SIZE - 1) || address != zc->address)
 		return -EINVAL;
 
-- 
2.21.0.360.g471c308f928-goog