Linux-Bluetooth Archive on lore.kernel.org
 help / color / Atom feed
From: Christoph Hellwig <hch@lst.de>
To: "David S. Miller" <davem@davemloft.net>,
	Jakub Kicinski <kuba@kernel.org>,
	Alexei Starovoitov <ast@kernel.org>,
	Daniel Borkmann <daniel@iogearbox.net>,
	Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>,
	Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>,
	Eric Dumazet <edumazet@google.com>
Cc: linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org,
	netdev@vger.kernel.org, bpf@vger.kernel.org,
	netfilter-devel@vger.kernel.org, coreteam@netfilter.org,
	linux-sctp@vger.kernel.org, linux-hams@vger.kernel.org,
	linux-bluetooth@vger.kernel.org,
	bridge@lists.linux-foundation.org, linux-can@vger.kernel.org,
	dccp@vger.kernel.org, linux-decnet-user@lists.sourceforge.net,
	linux-wpan@vger.kernel.org, linux-s390@vger.kernel.org,
	mptcp@lists.01.org, lvs-devel@vger.kernel.org,
	rds-devel@oss.oracle.com, linux-afs@lists.infradead.org,
	tipc-discussion@lists.sourceforge.net, linux-x25@vger.kernel.org
Subject: [PATCH 26/26] net: optimize the sockptr_t for unified kernel/user address spaces
Date: Thu, 23 Jul 2020 08:09:08 +0200
Message-ID: <20200723060908.50081-27-hch@lst.de> (raw)
In-Reply-To: <20200723060908.50081-1-hch@lst.de>

For architectures like x86 and arm64 we don't need the separate bit to
indicate that a pointer is a kernel pointer as the address spaces are
unified.  That way the sockptr_t can be reduced to a union of two
pointers, which leads to nicer calling conventions.

The only caveat is that we need to check that users don't pass in kernel
address and thus gain access to kernel memory.  Thus the USER_SOCKPTR
helper is replaced with a init_user_sockptr function that does this check
and returns an error if it fails.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 include/linux/sockptr.h     | 32 ++++++++++++++++++++++++++++++--
 net/ipv4/bpfilter/sockopt.c | 14 ++++++++------
 net/socket.c                |  6 +++++-
 3 files changed, 43 insertions(+), 9 deletions(-)

diff --git a/include/linux/sockptr.h b/include/linux/sockptr.h
index 700856e13ea0c4..7d5cdb2b30b5f0 100644
--- a/include/linux/sockptr.h
+++ b/include/linux/sockptr.h
@@ -8,9 +8,34 @@
 #ifndef _LINUX_SOCKPTR_H
 #define _LINUX_SOCKPTR_H
 
+#include <linux/compiler.h>
 #include <linux/slab.h>
 #include <linux/uaccess.h>
 
+#ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
+typedef union {
+	void		*kernel;
+	void __user	*user;
+} sockptr_t;
+
+static inline bool sockptr_is_kernel(sockptr_t sockptr)
+{
+	return (unsigned long)sockptr.kernel >= TASK_SIZE;
+}
+
+static inline sockptr_t KERNEL_SOCKPTR(void *p)
+{
+	return (sockptr_t) { .kernel = p };
+}
+
+static inline int __must_check init_user_sockptr(sockptr_t *sp, void __user *p)
+{
+	if ((unsigned long)p >= TASK_SIZE)
+		return -EFAULT;
+	sp->user = p;
+	return 0;
+}
+#else /* CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE */
 typedef struct {
 	union {
 		void		*kernel;
@@ -29,10 +54,13 @@ static inline sockptr_t KERNEL_SOCKPTR(void *p)
 	return (sockptr_t) { .kernel = p, .is_kernel = true };
 }
 
-static inline sockptr_t USER_SOCKPTR(void __user *p)
+static inline int __must_check init_user_sockptr(sockptr_t *sp, void __user *p)
 {
-	return (sockptr_t) { .user = p };
+	sp->user = p;
+	sp->is_kernel = false;
+	return 0;
 }
+#endif /* CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE */
 
 static inline bool sockptr_is_null(sockptr_t sockptr)
 {
diff --git a/net/ipv4/bpfilter/sockopt.c b/net/ipv4/bpfilter/sockopt.c
index 1b34cb9a7708ec..94f18d2352d007 100644
--- a/net/ipv4/bpfilter/sockopt.c
+++ b/net/ipv4/bpfilter/sockopt.c
@@ -57,16 +57,18 @@ int bpfilter_ip_set_sockopt(struct sock *sk, int optname, sockptr_t optval,
 	return bpfilter_mbox_request(sk, optname, optval, optlen, true);
 }
 
-int bpfilter_ip_get_sockopt(struct sock *sk, int optname, char __user *optval,
-			    int __user *optlen)
+int bpfilter_ip_get_sockopt(struct sock *sk, int optname,
+			    char __user *user_optval, int __user *optlen)
 {
-	int len;
+	sockptr_t optval;
+	int err, len;
 
 	if (get_user(len, optlen))
 		return -EFAULT;
-
-	return bpfilter_mbox_request(sk, optname, USER_SOCKPTR(optval), len,
-				     false);
+	err = init_user_sockptr(&optval, user_optval);
+	if (err)
+		return err;
+	return bpfilter_mbox_request(sk, optname, optval, len, false);
 }
 
 static int __init bpfilter_sockopt_init(void)
diff --git a/net/socket.c b/net/socket.c
index e44b8ac47f6f46..94ca4547cd7c53 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -2097,7 +2097,7 @@ static bool sock_use_custom_sol_socket(const struct socket *sock)
 int __sys_setsockopt(int fd, int level, int optname, char __user *user_optval,
 		int optlen)
 {
-	sockptr_t optval = USER_SOCKPTR(user_optval);
+	sockptr_t optval;
 	char *kernel_optval = NULL;
 	int err, fput_needed;
 	struct socket *sock;
@@ -2105,6 +2105,10 @@ int __sys_setsockopt(int fd, int level, int optname, char __user *user_optval,
 	if (optlen < 0)
 		return -EINVAL;
 
+	err = init_user_sockptr(&optval, user_optval);
+	if (err)
+		return err;
+
 	sock = sockfd_lookup_light(fd, &err, &fput_needed);
 	if (!sock)
 		return err;
-- 
2.27.0


  parent reply index

Thread overview: 64+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-23  6:08 get rid of the address_space override in setsockopt v2 Christoph Hellwig
2020-07-23  6:08 ` [PATCH 01/26] bpfilter: fix up a sparse annotation Christoph Hellwig
2020-07-23 11:14   ` Luc Van Oostenryck
2020-07-23  6:08 ` [PATCH 02/26] net/bpfilter: split __bpfilter_process_sockopt Christoph Hellwig
2020-07-23  6:08 ` [PATCH 03/26] bpfilter: reject kernel addresses Christoph Hellwig
2020-07-23 14:42   ` David Laight
2020-07-23 14:44     ` 'Christoph Hellwig'
2020-07-23 14:56       ` David Laight
2020-07-23  6:08 ` [PATCH 04/26] net: add a new sockptr_t type Christoph Hellwig
2020-07-23 15:40   ` Jan Engelhardt
2020-07-23 16:40   ` Eric Dumazet
2020-07-23 16:44     ` Christoph Hellwig
2020-07-23  6:08 ` [PATCH 05/26] net: switch copy_bpf_fprog_from_user to sockptr_t Christoph Hellwig
2020-07-23  6:08 ` [PATCH 06/26] net: switch sock_setbindtodevice " Christoph Hellwig
2020-07-23  6:08 ` [PATCH 07/26] net: switch sock_set_timeout " Christoph Hellwig
2020-07-23  6:08 ` [PATCH 08/26] " Christoph Hellwig
2020-07-23  8:39   ` [MPTCP] " Matthieu Baerts
2020-07-23  6:08 ` [PATCH 09/26] net/xfrm: switch xfrm_user_policy " Christoph Hellwig
2020-07-23  6:08 ` [PATCH 10/26] netfilter: remove the unused user argument to do_update_counters Christoph Hellwig
2020-07-23  6:08 ` [PATCH 11/26] netfilter: switch xt_copy_counters to sockptr_t Christoph Hellwig
2020-07-23  6:08 ` [PATCH 12/26] netfilter: switch nf_setsockopt " Christoph Hellwig
2020-07-27 15:03   ` Jason A. Donenfeld
2020-07-27 15:06     ` Christoph Hellwig
2020-07-27 16:16       ` Jason A. Donenfeld
2020-07-27 16:23         ` Christoph Hellwig
2020-07-28  8:07           ` David Laight
2020-07-28  8:17             ` Jason A. Donenfeld
2020-07-27 16:16     ` Christoph Hellwig
2020-07-27 16:21       ` Jason A. Donenfeld
2020-07-23  6:08 ` [PATCH 13/26] bpfilter: switch bpfilter_ip_set_sockopt " Christoph Hellwig
2020-07-23 11:16   ` David Laight
2020-07-23 11:44     ` 'Christoph Hellwig'
2020-07-23  6:08 ` [PATCH 14/26] net/ipv4: switch ip_mroute_setsockopt " Christoph Hellwig
2020-07-23  6:08 ` [PATCH 15/26] net/ipv4: merge ip_options_get and ip_options_get_from_user Christoph Hellwig
2020-07-23  6:08 ` [PATCH 16/26] net/ipv4: switch do_ip_setsockopt to sockptr_t Christoph Hellwig
2020-07-23  6:08 ` [PATCH 17/26] net/ipv6: switch ip6_mroute_setsockopt " Christoph Hellwig
2020-07-23  6:09 ` [PATCH 18/26] net/ipv6: split up ipv6_flowlabel_opt Christoph Hellwig
2020-07-23  6:09 ` [PATCH 19/26] net/ipv6: switch ipv6_flowlabel_opt to sockptr_t Christoph Hellwig
2020-07-27 12:15   ` Ido Schimmel
2020-07-27 13:00     ` Christoph Hellwig
2020-07-27 13:33       ` Ido Schimmel
2020-07-27 16:15         ` Christoph Hellwig
2020-07-27 18:22           ` Ido Schimmel
2020-07-27 13:24     ` David Laight
2020-07-23  6:09 ` [PATCH 20/26] net/ipv6: factor out a ipv6_set_opt_hdr helper Christoph Hellwig
2020-07-23  6:09 ` [PATCH 21/26] net/ipv6: switch do_ipv6_setsockopt to sockptr_t Christoph Hellwig
2020-07-23  6:09 ` [PATCH 22/26] net/udp: switch udp_lib_setsockopt " Christoph Hellwig
2020-07-23  6:09 ` [PATCH 23/26] net/tcp: switch ->md5_parse " Christoph Hellwig
2020-07-23  6:09 ` [PATCH 24/26] net/tcp: switch do_tcp_setsockopt " Christoph Hellwig
2020-07-23  6:09 ` [PATCH 25/26] net: pass a sockptr_t into ->setsockopt Christoph Hellwig
2020-07-23  8:39   ` [MPTCP] " Matthieu Baerts
2020-08-06 22:21   ` Eric Dumazet
2020-08-07  7:21     ` Christoph Hellwig
2020-08-07  9:18     ` David Laight
2020-08-07 18:29       ` Eric Dumazet
2020-08-08 13:54         ` David Laight
2020-07-23  6:09 ` Christoph Hellwig [this message]
2020-07-24 22:43 ` get rid of the address_space override in setsockopt v2 David Miller
2020-07-26  7:03   ` Christoph Hellwig
2020-07-26  7:08     ` Andreas Schwab
2020-07-26  7:46     ` David Miller
2020-07-27  9:51   ` David Laight
2020-07-27 13:48     ` Al Viro
2020-07-27 14:09       ` David Laight

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20200723060908.50081-27-hch@lst.de \
    --to=hch@lst.de \
    --cc=ast@kernel.org \
    --cc=bpf@vger.kernel.org \
    --cc=bridge@lists.linux-foundation.org \
    --cc=coreteam@netfilter.org \
    --cc=daniel@iogearbox.net \
    --cc=davem@davemloft.net \
    --cc=dccp@vger.kernel.org \
    --cc=edumazet@google.com \
    --cc=kuba@kernel.org \
    --cc=kuznet@ms2.inr.ac.ru \
    --cc=linux-afs@lists.infradead.org \
    --cc=linux-bluetooth@vger.kernel.org \
    --cc=linux-can@vger.kernel.org \
    --cc=linux-crypto@vger.kernel.org \
    --cc=linux-decnet-user@lists.sourceforge.net \
    --cc=linux-hams@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-s390@vger.kernel.org \
    --cc=linux-sctp@vger.kernel.org \
    --cc=linux-wpan@vger.kernel.org \
    --cc=linux-x25@vger.kernel.org \
    --cc=lvs-devel@vger.kernel.org \
    --cc=mptcp@lists.01.org \
    --cc=netdev@vger.kernel.org \
    --cc=netfilter-devel@vger.kernel.org \
    --cc=rds-devel@oss.oracle.com \
    --cc=tipc-discussion@lists.sourceforge.net \
    --cc=yoshfuji@linux-ipv6.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Linux-Bluetooth Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-bluetooth/0 linux-bluetooth/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-bluetooth linux-bluetooth/ https://lore.kernel.org/linux-bluetooth \
		linux-bluetooth@vger.kernel.org
	public-inbox-index linux-bluetooth

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-bluetooth


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git