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S.Çağlar Onur 95b422fccf remove static_lock()/static_unlock() and start to use thread local storage (v2)
While testing https://github.com/lxc/lxc/pull/106, I found that concurrent starts
are hanging time to time. I then reproduced the same problem in master and got following;

 [caglar@oOo:~] sudo gdb -p 16221
 (gdb) bt
 #0  __lll_lock_wait () at ../nptl/sysdeps/unix/sysv/linux/x86_64/lowlevellock.S:135
 #1  0x00007f495526515c in _L_lock_982 () from /lib/x86_64-linux-gnu/libpthread.so.0
 #2  0x00007f4955264fab in __GI___pthread_mutex_lock (mutex=0x7f49556d4600 <static_mutex>) at pthread_mutex_lock.c:64
 #3  0x00007f49554b27a6 in lock_mutex (l=l@entry=0x7f49556d4600 <static_mutex>) at lxclock.c:78
 #4  0x00007f49554b2dac in static_lock () at lxclock.c:330
 #5  0x00007f4955498f71 in lxc_global_config_value (option_name=option_name@entry=0x7f49554c02cf "cgroup.use") at utils.c:273
 #6  0x00007f495549926c in default_cgroup_use () at utils.c:366
 #7  0x00007f49554953bd in lxc_cgroup_load_meta () at cgroup.c:94
 #8  0x00007f495548debc in lxc_spawn (handler=handler@entry=0x7f49200af300) at start.c:783
 #9  0x00007f495548e7a7 in __lxc_start (name=name@entry=0x7f49200b48a0 "lxc-test-concurrent-4", conf=conf@entry=0x7f49200b2030, ops=ops@entry=0x7f49556d3900 <start_ops>, data=data@entry=0x7f495487db90,
    lxcpath=lxcpath@entry=0x7f49200b2010 "/var/lib/lxc") at start.c:951
 #10 0x00007f495548eb9c in lxc_start (name=0x7f49200b48a0 "lxc-test-concurrent-4", argv=argv@entry=0x7f495487dbe0, conf=conf@entry=0x7f49200b2030, lxcpath=0x7f49200b2010 "/var/lib/lxc") at start.c:1048
 #11 0x00007f49554b68f1 in lxcapi_start (c=0x7f49200b1dd0, useinit=<optimized out>, argv=0x7f495487dbe0) at lxccontainer.c:648
 #12 0x0000000000401317 in do_function (arguments=0x1aa80b0) at concurrent.c:94
 #13 0x0000000000401499 in concurrent (arguments=<optimized out>) at concurrent.c:130
 #14 0x00007f4955262f6e in start_thread (arg=0x7f495487e700) at pthread_create.c:311
 #15 0x00007f4954f8d9cd in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:113

It looks like both parent and child end up with locked mutex thus deadlocks.

I ended up placing values in the thread local storage pool, instead of doing "unlock the lock in the child" dance

Signed-off-by: S.Çağlar Onur <caglar@10ur.org>
Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>
2013-12-19 13:28:28 +01:00
config ubuntu: Add comment about the mounting profile 2013-12-09 17:05:26 -05:00
doc Add Japanese man pages for lxc-user-nic 2013-12-18 12:31:03 +01:00
hooks make mountcgroups hook to lxc.include aware (v2) 2013-12-16 08:44:32 -06:00
src remove static_lock()/static_unlock() and start to use thread local storage (v2) 2013-12-19 13:28:28 +01:00
templates sshd: Don't bind-mount /sbin/init read-write 2013-12-19 12:17:39 +01:00
.gitignore Add LXC version information to version.h 2013-12-02 18:17:21 -05:00
AUTHORS Initial revision 2008-08-06 14:32:29 +00:00
autogen.sh licensing: Add missing headers and FSF address 2013-09-03 14:33:03 -04:00
configure.ac Add Japanese man pages for lxc-user-nic 2013-12-18 12:31:03 +01:00
CONTRIBUTING Update mailing-list addresses 2013-12-08 17:51:28 -05:00
COPYING Minor documentation updates 2012-12-06 00:02:36 -05:00
INSTALL Minor documentation updates 2012-12-06 00:02:36 -05:00
lxc.pc.in Update maintainers and URLs 2013-10-20 00:48:48 -04:00
lxc.spec.in Drop trailing white spaces. 2013-11-25 11:52:43 -05:00
MAINTAINERS Update mailing-list addresses 2013-12-08 17:51:28 -05:00
Makefile.am EXTRA_DIST: Fix missing files with "make dist" 2013-03-26 13:12:29 -04:00
NEWS Initial revision 2008-08-06 14:32:29 +00:00
README Update mailing-list addresses 2013-12-08 17:51:28 -05:00
runapitests.sh licensing: Add missing headers and FSF address 2013-09-03 14:33:03 -04:00
TODO Remove all trailing whitespaces. 2012-11-26 12:08:13 -05:00

Please see the COPYING file for details on copying and usage.
Please refer to the INSTALL file for instructions on how to build.

What is lxc:

  The container technology is actively being pushed into the mainstream linux
  kernel. It provides the resource management through the control groups  aka
  process containers and resource isolation through the namespaces.

  The  linux  containers, lxc, aims to use these new functionalities to pro-
  vide an userspace container object which provides full  resource  isolation
  and resource control for an applications or a system.

  The first objective of this project is to make the life easier for the ker-
  nel developers involved in the containers project and  especially  to  con-
  tinue  working  on  the  Checkpoint/Restart  new features. The lxc is small
  enough to easily manage a container with simple command lines and  complete
  enough to be used for other purposes.

Using lxc:

  Refer the lxc* man pages (generated from doc/* files)

Downloading the current source code:

  Source for the latest released version can always be downloaded from
  http://linuxcontainers.org/downloads/

  You can browse the up to the minute source code and change history online.
  http://github.com/lxc/lxc

  For detailed build instruction refer to INSTALL and man lxc man page
  but a short command line should work:
  ./autogen.sh && ./configure && make && sudo make install
  preceded by ./autogen.sh if configure do not exist yet.

Troubleshooting:

  If the ./autogen.sh script shows the following message: "aclocal: not found",
  you are likely missing the "automake" package. Make sure it's installed and
  try again.

  If the ./configure script gives you the following message:
    "configure: error: Please install the libcap development files."
  you are likely missing the "libcap-dev" package.
  The configure script will usually give you hints as to what you are missing,
  looking for those in your package manager will usually give you the package
  that you need to install.

Getting help:

  when you find you need help, you can check out one of the two
  lxc mailing list archives and register if interested:
  http://lists.linuxcontainers.org/listinfo/lxc-devel
  http://lists.linuxcontainers.org/listinfo/lxc-users

Portability:

  lxc  is  still  in  development, so the command syntax and the API can
  change. The version 1.0.0 will be the frozen version.

  lxc is developed and tested on Linux since kernel mainline version 2.6.27
  (without network) and 2.6.29 with network isolation.
  It's compiled with gcc, and should work on most architectures as long as the
  required kernel features are available. This includes (but isn't limited to):
  i686, x86_64, ppc, ppc64, S390, armel and armhf.

AUTHOR
       Daniel Lezcano <daniel.lezcano@free.fr>

Seccomp with LXC
----------------

To restrict a container with seccomp, you must specify a profile which is
basically a whitelist of system calls it may execute.  In the container
config file, add a line like

lxc.seccomp = /var/lib/lxc/q1/seccomp.full

I created a usable (but basically worthless) seccomp.full file using

cat > seccomp.full << EOF
1
whitelist
EOF
for i in `seq 0 300`; do
    echo $i >> seccomp.full
done
for i in `seq 1024 1079`; do
    echo $i >> seccomp.full
done

 -- Serge Hallyn <serge.hallyn@ubuntu.com>  Fri, 27 Jul 2012 15:47:02 +0600