From: "Eric W. Biederman" <ebiederm@xmission.com>
To: linux-kernel@vger.kernel.org
Cc: David Miller <davem@davemloft.net>,
Greg Kroah-Hartman <greg@kroah.com>,
Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>,
Alexei Starovoitov <alexei.starovoitov@gmail.com>,
Kees Cook <keescook@chromium.org>,
Andrew Morton <akpm@linux-foundation.org>,
Alexei Starovoitov <ast@kernel.org>,
Al Viro <viro@zeniv.linux.org.uk>, bpf <bpf@vger.kernel.org>,
linux-fsdevel <linux-fsdevel@vger.kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Jakub Kicinski <kuba@kernel.org>,
Masahiro Yamada <yamada.masahiro@socionext.com>,
Gary Lin <GLin@suse.com>, Bruno Meneguele <bmeneg@redhat.com>,
LSM List <linux-security-module@vger.kernel.org>,
Casey Schaufler <casey@schaufler-ca.com>,
Luis Chamberlain <mcgrof@kernel.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
Christian Brauner <christian.brauner@ubuntu.com>,
"Eric W. Biederman" <ebiederm@xmission.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Subject: [PATCH v3 14/16] bpfilter: Take advantage of the facilities of struct pid
Date: Thu, 2 Jul 2020 11:41:38 -0500 [thread overview]
Message-ID: <20200702164140.4468-14-ebiederm@xmission.com> (raw)
In-Reply-To: <87y2o1swee.fsf_-_@x220.int.ebiederm.org>
Instead of relying on the exit_umh cleanup callback use the fact a
struct pid can be tested to see if a process still exists, and that
struct pid has a wait queue that notifies when the process dies.
v1: https://lkml.kernel.org/r/87h7uydlu9.fsf_-_@x220.int.ebiederm.org
v2: https://lkml.kernel.org/r/874kqt4owu.fsf_-_@x220.int.ebiederm.org
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
---
include/linux/bpfilter.h | 3 ++-
net/bpfilter/bpfilter_kern.c | 15 +++++----------
net/ipv4/bpfilter/sockopt.c | 15 ++++++++-------
3 files changed, 15 insertions(+), 18 deletions(-)
diff --git a/include/linux/bpfilter.h b/include/linux/bpfilter.h
index ec9972d822e0..9b114c718a76 100644
--- a/include/linux/bpfilter.h
+++ b/include/linux/bpfilter.h
@@ -10,6 +10,8 @@ int bpfilter_ip_set_sockopt(struct sock *sk, int optname, char __user *optval,
unsigned int optlen);
int bpfilter_ip_get_sockopt(struct sock *sk, int optname, char __user *optval,
int __user *optlen);
+void bpfilter_umh_cleanup(struct umd_info *info);
+
struct bpfilter_umh_ops {
struct umd_info info;
/* since ip_getsockopt() can run in parallel, serialize access to umh */
@@ -18,7 +20,6 @@ struct bpfilter_umh_ops {
char __user *optval,
unsigned int optlen, bool is_set);
int (*start)(void);
- bool stop;
};
extern struct bpfilter_umh_ops bpfilter_ops;
#endif
diff --git a/net/bpfilter/bpfilter_kern.c b/net/bpfilter/bpfilter_kern.c
index 08ea77c2b137..9616fb7defeb 100644
--- a/net/bpfilter/bpfilter_kern.c
+++ b/net/bpfilter/bpfilter_kern.c
@@ -18,10 +18,11 @@ static void shutdown_umh(void)
struct umd_info *info = &bpfilter_ops.info;
struct pid *tgid = info->tgid;
- if (bpfilter_ops.stop)
- return;
-
- kill_pid(tgid, SIGKILL, 1);
+ if (tgid) {
+ kill_pid(tgid, SIGKILL, 1);
+ wait_event(tgid->wait_pidfd, thread_group_exited(tgid));
+ bpfilter_umh_cleanup(info);
+ }
}
static void __stop_umh(void)
@@ -77,7 +78,6 @@ static int start_umh(void)
err = fork_usermode_driver(&bpfilter_ops.info);
if (err)
return err;
- bpfilter_ops.stop = false;
pr_info("Loaded bpfilter_umh pid %d\n", pid_nr(bpfilter_ops.info.tgid));
/* health check that usermode process started correctly */
@@ -100,16 +100,11 @@ static int __init load_umh(void)
return err;
mutex_lock(&bpfilter_ops.lock);
- if (!bpfilter_ops.stop) {
- err = -EFAULT;
- goto out;
- }
err = start_umh();
if (!err && IS_ENABLED(CONFIG_INET)) {
bpfilter_ops.sockopt = &__bpfilter_process_sockopt;
bpfilter_ops.start = &start_umh;
}
-out:
mutex_unlock(&bpfilter_ops.lock);
if (err)
umd_unload_blob(&bpfilter_ops.info);
diff --git a/net/ipv4/bpfilter/sockopt.c b/net/ipv4/bpfilter/sockopt.c
index 56cbc43145f6..9063c6767d34 100644
--- a/net/ipv4/bpfilter/sockopt.c
+++ b/net/ipv4/bpfilter/sockopt.c
@@ -12,16 +12,14 @@
struct bpfilter_umh_ops bpfilter_ops;
EXPORT_SYMBOL_GPL(bpfilter_ops);
-static void bpfilter_umh_cleanup(struct umd_info *info)
+void bpfilter_umh_cleanup(struct umd_info *info)
{
- mutex_lock(&bpfilter_ops.lock);
- bpfilter_ops.stop = true;
fput(info->pipe_to_umh);
fput(info->pipe_from_umh);
put_pid(info->tgid);
info->tgid = NULL;
- mutex_unlock(&bpfilter_ops.lock);
}
+EXPORT_SYMBOL_GPL(bpfilter_umh_cleanup);
static int bpfilter_mbox_request(struct sock *sk, int optname,
char __user *optval,
@@ -39,7 +37,11 @@ static int bpfilter_mbox_request(struct sock *sk, int optname,
goto out;
}
}
- if (bpfilter_ops.stop) {
+ if (bpfilter_ops.info.tgid &&
+ thread_group_exited(bpfilter_ops.info.tgid))
+ bpfilter_umh_cleanup(&bpfilter_ops.info);
+
+ if (!bpfilter_ops.info.tgid) {
err = bpfilter_ops.start();
if (err)
goto out;
@@ -70,9 +72,8 @@ int bpfilter_ip_get_sockopt(struct sock *sk, int optname, char __user *optval,
static int __init bpfilter_sockopt_init(void)
{
mutex_init(&bpfilter_ops.lock);
- bpfilter_ops.stop = true;
+ bpfilter_ops.info.tgid = NULL;
bpfilter_ops.info.driver_name = "bpfilter_umh";
- bpfilter_ops.info.cleanup = &bpfilter_umh_cleanup;
return 0;
}
--
2.25.0
next prev parent reply other threads:[~2020-07-02 16:48 UTC|newest]
Thread overview: 72+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20200625095725.GA3303921@kroah.com>
[not found] ` <778297d2-512a-8361-cf05-42d9379e6977@i-love.sakura.ne.jp>
[not found] ` <20200625120725.GA3493334@kroah.com>
[not found] ` <20200625.123437.2219826613137938086.davem@davemloft.net>
[not found] ` <CAHk-=whuTwGHEPjvtbBvneHHXeqJC=q5S09mbPnqb=Q+MSPMag@mail.gmail.com>
[not found] ` <87pn9mgfc2.fsf_-_@x220.int.ebiederm.org>
[not found] ` <87y2oac50p.fsf@x220.int.ebiederm.org>
2020-06-29 19:55 ` [PATCH v2 00/15] Make the user mode driver code a better citizen Eric W. Biederman
2020-06-29 19:56 ` [PATCH v2 01/15] umh: Capture the pid in umh_pipe_setup Eric W. Biederman
2020-06-29 19:57 ` [PATCH v2 02/15] umh: Move setting PF_UMH into umh_pipe_setup Eric W. Biederman
2020-06-29 19:57 ` [PATCH v2 03/15] umh: Rename the user mode driver helpers for clarity Eric W. Biederman
2020-06-29 19:59 ` [PATCH v2 04/15] umh: Remove call_usermodehelper_setup_file Eric W. Biederman
2020-06-29 20:00 ` [PATCH v2 05/15] umh: Separate the user mode driver and the user mode helper support Eric W. Biederman
2020-06-30 16:58 ` Linus Torvalds
2020-07-01 17:18 ` Eric W. Biederman
2020-07-01 17:42 ` Alexei Starovoitov
2020-06-29 20:01 ` [PATCH v2 06/15] umd: For clarity rename umh_info umd_info Eric W. Biederman
2020-06-29 20:02 ` [PATCH v2 07/15] umd: Rename umd_info.cmdline umd_info.driver_name Eric W. Biederman
2020-06-29 20:03 ` [PATCH v2 08/15] umd: Transform fork_usermode_blob into fork_usermode_driver Eric W. Biederman
2020-06-29 20:03 ` [PATCH v2 09/15] umh: Stop calling do_execve_file Eric W. Biederman
2020-06-29 20:04 ` [PATCH v2 10/15] exec: Remove do_execve_file Eric W. Biederman
2020-06-30 5:43 ` Christoph Hellwig
2020-06-30 12:14 ` Eric W. Biederman
2020-06-30 13:38 ` Christoph Hellwig
2020-06-30 14:28 ` Eric W. Biederman
2020-06-30 16:55 ` Alexei Starovoitov
2020-06-29 20:05 ` [PATCH v2 11/15] bpfilter: Move bpfilter_umh back into init data Eric W. Biederman
2020-06-29 20:06 ` [PATCH v2 12/15] umd: Track user space drivers with struct pid Eric W. Biederman
2020-06-29 20:06 ` [PATCH v2 13/15] bpfilter: Take advantage of the facilities of " Eric W. Biederman
2020-06-29 20:07 ` [PATCH v2 14/15] umd: Remove exit_umh Eric W. Biederman
2020-06-29 20:08 ` [PATCH v2 15/15] umd: Stop using split_argv Eric W. Biederman
2020-06-29 22:12 ` [PATCH v2 00/15] Make the user mode driver code a better citizen Alexei Starovoitov
2020-06-30 1:13 ` Eric W. Biederman
2020-06-30 6:16 ` Tetsuo Handa
2020-06-30 12:29 ` Eric W. Biederman
2020-06-30 13:21 ` Tetsuo Handa
2020-07-02 13:08 ` Eric W. Biederman
2020-07-02 13:40 ` Tetsuo Handa
2020-07-02 16:02 ` Eric W. Biederman
2020-07-03 13:19 ` Tetsuo Handa
2020-07-03 22:25 ` Eric W. Biederman
2020-07-04 6:57 ` Tetsuo Handa
2020-07-08 4:46 ` Eric W. Biederman
2020-06-30 16:52 ` Alexei Starovoitov
2020-07-01 17:12 ` Eric W. Biederman
2020-07-02 16:40 ` [PATCH v3 00/16] " Eric W. Biederman
2020-07-02 16:41 ` [PATCH v3 01/16] umh: Capture the pid in umh_pipe_setup Eric W. Biederman
2020-07-02 16:41 ` [PATCH v3 02/16] umh: Move setting PF_UMH into umh_pipe_setup Eric W. Biederman
2020-07-02 16:41 ` [PATCH v3 03/16] umh: Rename the user mode driver helpers for clarity Eric W. Biederman
2020-07-02 16:41 ` [PATCH v3 04/16] umh: Remove call_usermodehelper_setup_file Eric W. Biederman
2020-07-02 16:41 ` [PATCH v3 05/16] umh: Separate the user mode driver and the user mode helper support Eric W. Biederman
2020-07-02 16:41 ` [PATCH v3 06/16] umd: For clarity rename umh_info umd_info Eric W. Biederman
2020-07-02 16:41 ` [PATCH v3 07/16] umd: Rename umd_info.cmdline umd_info.driver_name Eric W. Biederman
2020-07-02 16:41 ` [PATCH v3 08/16] umd: Transform fork_usermode_blob into fork_usermode_driver Eric W. Biederman
2020-07-02 16:41 ` [PATCH v3 09/16] umh: Stop calling do_execve_file Eric W. Biederman
2020-07-02 16:41 ` [PATCH v3 10/16] exec: Remove do_execve_file Eric W. Biederman
2020-07-08 6:35 ` Luis Chamberlain
2020-07-08 12:41 ` Luis Chamberlain
2020-07-08 13:08 ` Eric W. Biederman
2020-07-08 13:32 ` Luis Chamberlain
2020-07-12 21:02 ` Pavel Machek
2020-07-02 16:41 ` [PATCH v3 11/16] bpfilter: Move bpfilter_umh back into init data Eric W. Biederman
2020-07-02 16:41 ` [PATCH v3 12/16] umd: Track user space drivers with struct pid Eric W. Biederman
2020-07-02 16:41 ` [PATCH v3 13/16] exit: Factor thread_group_exited out of pidfd_poll Eric W. Biederman
2020-07-03 20:30 ` Alexei Starovoitov
2020-07-03 21:37 ` Eric W. Biederman
2020-07-04 0:03 ` Alexei Starovoitov
2020-07-04 15:50 ` Christian Brauner
2020-07-07 17:09 ` Eric W. Biederman
2020-07-08 0:05 ` Daniel Borkmann
2020-07-08 3:50 ` Eric W. Biederman
2020-07-04 16:00 ` Christian Brauner
2020-07-02 16:41 ` Eric W. Biederman [this message]
2020-07-02 16:41 ` [PATCH v3 15/16] umd: Remove exit_umh Eric W. Biederman
2020-07-02 16:41 ` [PATCH v3 16/16] umd: Stop using split_argv Eric W. Biederman
2020-07-02 23:51 ` [PATCH v3 00/16] Make the user mode driver code a better citizen Tetsuo Handa
2020-07-09 22:05 ` [merged][PATCH " Eric W. Biederman
2020-07-14 19:42 ` Alexei Starovoitov
2020-07-08 5:20 ` [PATCH v2 00/15] " Luis Chamberlain
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=20200702164140.4468-14-ebiederm@xmission.com \
--to=ebiederm@xmission.com \
--cc=GLin@suse.com \
--cc=akpm@linux-foundation.org \
--cc=alexei.starovoitov@gmail.com \
--cc=ast@kernel.org \
--cc=bmeneg@redhat.com \
--cc=bpf@vger.kernel.org \
--cc=casey@schaufler-ca.com \
--cc=christian.brauner@ubuntu.com \
--cc=daniel@iogearbox.net \
--cc=davem@davemloft.net \
--cc=greg@kroah.com \
--cc=gregkh@linuxfoundation.org \
--cc=keescook@chromium.org \
--cc=kuba@kernel.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-security-module@vger.kernel.org \
--cc=mcgrof@kernel.org \
--cc=penguin-kernel@i-love.sakura.ne.jp \
--cc=torvalds@linux-foundation.org \
--cc=viro@zeniv.linux.org.uk \
--cc=yamada.masahiro@socionext.com \
/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
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).