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author | Scott James Remnant <scott@ubuntu.com> | 2009-09-22 16:43:44 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-09-23 07:39:29 -0700 |
commit | 02b51df1b07b4e9ca823c89284e704cadb323cd1 (patch) | |
tree | c68de4809f261d742f597c686826cdc9d047fb4a /drivers/connector | |
parent | 88e9d34c727883d7d6f02cf1475b3ec98b8480c7 (diff) | |
download | blackbird-obmc-linux-02b51df1b07b4e9ca823c89284e704cadb323cd1.tar.gz blackbird-obmc-linux-02b51df1b07b4e9ca823c89284e704cadb323cd1.zip |
proc connector: add event for process becoming session leader
The act of a process becoming a session leader is a useful signal to a
supervising init daemon such as Upstart.
While a daemon will normally do this as part of the process of becoming a
daemon, it is rare for its children to do so. When the children do, it is
nearly always a sign that the child should be considered detached from the
parent and not supervised along with it.
The poster-child example is OpenSSH; the per-login children call setsid()
so that they may control the pty connected to them. If the primary daemon
dies or is restarted, we do not want to consider the per-login children
and want to respawn the primary daemon without killing the children.
This patch adds a new PROC_SID_EVENT and associated structure to the
proc_event event_data union, it arranges for this to be emitted when the
special PIDTYPE_SID pid is set.
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Scott James Remnant <scott@ubuntu.com>
Acked-by: Matt Helsley <matthltc@us.ibm.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru>
Acked-by: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/connector')
-rw-r--r-- | drivers/connector/cn_proc.c | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/drivers/connector/cn_proc.c b/drivers/connector/cn_proc.c index 85e5dc0431fe..abf4a2529f80 100644 --- a/drivers/connector/cn_proc.c +++ b/drivers/connector/cn_proc.c @@ -139,6 +139,31 @@ void proc_id_connector(struct task_struct *task, int which_id) cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL); } +void proc_sid_connector(struct task_struct *task) +{ + struct cn_msg *msg; + struct proc_event *ev; + struct timespec ts; + __u8 buffer[CN_PROC_MSG_SIZE]; + + if (atomic_read(&proc_event_num_listeners) < 1) + return; + + msg = (struct cn_msg *)buffer; + ev = (struct proc_event *)msg->data; + get_seq(&msg->seq, &ev->cpu); + ktime_get_ts(&ts); /* get high res monotonic timestamp */ + put_unaligned(timespec_to_ns(&ts), (__u64 *)&ev->timestamp_ns); + ev->what = PROC_EVENT_SID; + ev->event_data.sid.process_pid = task->pid; + ev->event_data.sid.process_tgid = task->tgid; + + memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id)); + msg->ack = 0; /* not used */ + msg->len = sizeof(*ev); + cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL); +} + void proc_exit_connector(struct task_struct *task) { struct cn_msg *msg; |