The patch titled
connector: fix regression introduced by sid connector
has been added to the -mm tree. Its filename is
connector-fix-regression-introduced-by-sid-connector.patch
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://userweb.kernel.org/~akpm/stuff/added-to-mm.txt to find
out what to do about this
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: connector: fix regression introduced by sid connector
From: Christian Borntraeger <borntraeger@xxxxxxxxxx>
Since commit 02b51df1b07b4e9ca823c89284e704cadb323cd1 (proc connector: add
event for process becoming session leader) we have the following warning:
Badness at kernel/softirq.c:143
[...]
Krnl PSW : 0404c00180000000 00000000001481d4 (local_bh_enable+0xb0/0xe0)
[...]
Call Trace:
([<000000013fe04100>] 0x13fe04100)
[<000000000048a946>] sk_filter+0x9a/0xd0
[<000000000049d938>] netlink_broadcast+0x2c0/0x53c
[<00000000003ba9ae>] cn_netlink_send+0x272/0x2b0
[<00000000003baef0>] proc_sid_connector+0xc4/0xd4
[<0000000000142604>] __set_special_pids+0x58/0x90
[<0000000000159938>] sys_setsid+0xb4/0xd8
[<00000000001187fe>] sysc_noemu+0x10/0x16
[<00000041616cb266>] 0x41616cb266
The warning is
---> WARN_ON_ONCE(in_irq() || irqs_disabled());
The network code must not be called with disabled interrupts but
sys_setsid holds the tasklist_lock with spinlock_irq while calling the
connector.
After a discussion we agreed that we can move proc_sid_connector from
__set_special_pids to sys_setsid.
We also agreed that it is sufficient to change the check from
task_session(curr) != pid into err > 0, since if we don't change the
session, this means we were already the leader and return -EPERM.
One last thing:
There is also daemonize(), and some people might want to get a
notification in that case. Since daemonize() is only needed if a user
space does kernel_thread this does not look important (and there seems
to be no consensus if this connector should be called in daemonize). If
we really want this, we can add proc_sid_connector to daemonize() in an
additional patch (Scott?)
Signed-off-by: Christian Borntraeger <borntraeger@xxxxxxxxxx>
Cc: Scott James Remnant <scott@xxxxxxxxxx>
Cc: Matt Helsley <matthltc@xxxxxxxxxx>
Cc: David S. Miller <davem@xxxxxxxxxxxxx>
Acked-by: Oleg Nesterov <oleg@xxxxxxxxxx>
Acked-by: Evgeniy Polyakov <zbr@xxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
diff -puN kernel/exit.c~connector-fix-regression-introduced-by-sid-connector kernel/exit.c
--- a/kernel/exit.c~connector-fix-regression-introduced-by-sid-connector
+++ a/kernel/exit.c
@@ -359,10 +359,8 @@ void __set_special_pids(struct pid *pid)
{
struct task_struct *curr = current->group_leader;
- if (task_session(curr) != pid) {
+ if (task_session(curr) != pid)
change_pid(curr, PIDTYPE_SID, pid);
- proc_sid_connector(curr);
- }
if (task_pgrp(curr) != pid)
change_pid(curr, PIDTYPE_PGID, pid);
diff -puN kernel/sys.c~connector-fix-regression-introduced-by-sid-connector kernel/sys.c
--- a/kernel/sys.c~connector-fix-regression-introduced-by-sid-connector
+++ a/kernel/sys.c
@@ -1110,6 +1110,8 @@ SYSCALL_DEFINE0(setsid)
err = session;
out:
write_unlock_irq(&tasklist_lock);
+ if (err > 0)
+ proc_sid_connector(group_leader);
return err;
}
_
Patches currently in -mm which might be from borntraeger@xxxxxxxxxx are
origin.patch
linux-next.patch
connector-fix-regression-introduced-by-sid-connector.patch
--
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
