The patch titled
start the global /sbin/init with 0,0 special pids
has been added to the -mm tree. Its filename is
start-the-global-sbin-init-with-00-special-pids.patch
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: start the global /sbin/init with 0,0 special pids
From: Oleg Nesterov <oleg@xxxxxxxxxx>
As Eric pointed out, there is no problem with init starting with sid == pgid
== 0, and this was historical linux behavior changed in 2.6.18.
Remove kernel_init()->__set_special_pids(), this is unneeded and complicates
the rules for sys_setsid().
This change and the previous change in daemonize() mean that /sbin/init does
not need the special "session != 1" hack in sys_setsid() any longer. We can't
remove this check yet, we should cleanup copy_process(CLONE_NEWPID) first, so
update the comment only.
Signed-off-by: Oleg Nesterov <oleg@xxxxxxxxxx>
Acked-by: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
Cc: Pavel Emelyanov <xemul@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
init/main.c | 1 -
kernel/sys.c | 9 ++++-----
2 files changed, 4 insertions(+), 6 deletions(-)
diff -puN init/main.c~start-the-global-sbin-init-with-00-special-pids init/main.c
--- a/init/main.c~start-the-global-sbin-init-with-00-special-pids
+++ a/init/main.c
@@ -830,7 +830,6 @@ static int __init kernel_init(void * unu
*/
init_pid_ns.child_reaper = current;
- __set_special_pids(task_pid(current));
cad_pid = task_pid(current);
smp_prepare_cpus(max_cpus);
diff -puN kernel/sys.c~start-the-global-sbin-init-with-00-special-pids kernel/sys.c
--- a/kernel/sys.c~start-the-global-sbin-init-with-00-special-pids
+++ a/kernel/sys.c
@@ -1054,12 +1054,11 @@ asmlinkage long sys_setsid(void)
if (group_leader->signal->leader)
goto out;
- /* Fail if a process group id already exists that equals the proposed
- * session id.
+ /* Fail if a process group id already exists that equals the
+ * proposed session id.
*
- * Don't check if session == 1 because kernel threads and CLONE_NEWPID
- * tasks use this session id and so the check will always fail and make
- * it so init cannot successfully call setsid.
+ * Don't check if session == 1, clone(CLONE_NEWPID) creates
+ * this group/session beforehand.
*/
if (session != 1 && pid_task(sid, PIDTYPE_PGID))
goto out;
_
Patches currently in -mm which might be from oleg@xxxxxxxxxx are
wait_task_stopped-dont-use-task_pid_nr_ns-lockless.patch
proc-remove-races-from-proc_id_readdir.patch
wait_task_stopped-pass-correct-exit_code-to.patch
use-__set_task_state-for-traced-stopped-tasks.patch
add-task_wakekill.patch
do_wait-remove-one-else-if-branch.patch
proc-implement-proc_single_file_operations.patch
proc-rewrite-do_task_stat-to-correctly-handle-pid-namespaces.patch
proc-seqfile-convert-proc_pid_statm.patch
proc-proper-pidns-handling-for-proc-self.patch
proc-fix-the-threaded-proc-self.patch
kill-pt_attached.patch
kill-my_ptrace_child.patch
ptrace_check_attach-remove-unneeded-signal-=-null-check.patch
ptrace_stop-fix-the-race-with-ptrace-detachattach.patch
wait_task_stopped-simplify-and-fix-races-with-sigcont-sigkill-untrace.patch
do_wait-factor-out-retval-=-0-checks.patch
ptrace_stop-fix-racy-nonstop_code-setting.patch
wait_task_stopped-remove-unneeded-delay_group_leader-check.patch
do_wait-cleanup-delay_group_leader-usage.patch
do_wait-fix-security-checks.patch
do_wait-fix-security-checks-fix.patch
wait_task_continued-zombie-dont-use-task_pid_nr_ns-lockless.patch
wait_task_zombie-remove-exit_state-exit_signal-checks-for-wnowait.patch
sys_setpgid-simplify-pid-ns-interaction.patch
fix-setsid-for-sub-namespace-sbin-init.patch
teach-set_special_pids-to-use-struct-pid.patch
move-daemonized-kernel-threads-into-the-swappers-session.patch
start-the-global-sbin-init-with-00-special-pids.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
