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author | Serge E. Hallyn <serue@us.ibm.com> | 2007-10-19 06:39:52 (GMT) |
---|---|---|
committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-10-19 18:53:37 (GMT) |
commit | b460cbc581a53cc088ceba80608021dd49c63c43 (patch) | |
tree | 83c28d0adbc15f4157c77b40fa60c40a71cb8673 /kernel | |
parent | 3743ca05ff464b8a9e345c08a6c9ce30485f9805 (diff) | |
download | linux-b460cbc581a53cc088ceba80608021dd49c63c43.tar.xz |
pid namespaces: define is_global_init() and is_container_init()
is_init() is an ambiguous name for the pid==1 check. Split it into
is_global_init() and is_container_init().
A cgroup init has it's tsk->pid == 1.
A global init also has it's tsk->pid == 1 and it's active pid namespace
is the init_pid_ns. But rather than check the active pid namespace,
compare the task structure with 'init_pid_ns.child_reaper', which is
initialized during boot to the /sbin/init process and never changes.
Changelog:
2.6.22-rc4-mm2-pidns1:
- Use 'init_pid_ns.child_reaper' to determine if a given task is the
global init (/sbin/init) process. This would improve performance
and remove dependence on the task_pid().
2.6.21-mm2-pidns2:
- [Sukadev Bhattiprolu] Changed is_container_init() calls in {powerpc,
ppc,avr32}/traps.c for the _exception() call to is_global_init().
This way, we kill only the cgroup if the cgroup's init has a
bug rather than force a kernel panic.
[akpm@linux-foundation.org: fix comment]
[sukadev@us.ibm.com: Use is_global_init() in arch/m32r/mm/fault.c]
[bunk@stusta.de: kernel/pid.c: remove unused exports]
[sukadev@us.ibm.com: Fix capability.c to work with threaded init]
Signed-off-by: Serge E. Hallyn <serue@us.ibm.com>
Signed-off-by: Sukadev Bhattiprolu <sukadev@us.ibm.com>
Acked-by: Pavel Emelianov <xemul@openvz.org>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Cedric Le Goater <clg@fr.ibm.com>
Cc: Dave Hansen <haveblue@us.ibm.com>
Cc: Herbert Poetzel <herbert@13thfloor.at>
Cc: Kirill Korotaev <dev@sw.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel')
-rw-r--r-- | kernel/capability.c | 3 | ||||
-rw-r--r-- | kernel/exit.c | 2 | ||||
-rw-r--r-- | kernel/kexec.c | 2 | ||||
-rw-r--r-- | kernel/pid.c | 5 | ||||
-rw-r--r-- | kernel/signal.c | 2 | ||||
-rw-r--r-- | kernel/sysctl.c | 2 |
6 files changed, 11 insertions, 5 deletions
diff --git a/kernel/capability.c b/kernel/capability.c index cbc5fd6..f02ad47 100644 --- a/kernel/capability.c +++ b/kernel/capability.c @@ -12,6 +12,7 @@ #include <linux/module.h> #include <linux/security.h> #include <linux/syscalls.h> +#include <linux/pid_namespace.h> #include <asm/uaccess.h> /* @@ -129,7 +130,7 @@ static inline int cap_set_all(kernel_cap_t *effective, int found = 0; do_each_thread(g, target) { - if (target == current || is_init(target)) + if (target == current || is_container_init(target->group_leader)) continue; found = 1; if (security_capset_check(target, effective, inheritable, diff --git a/kernel/exit.c b/kernel/exit.c index d1eddc7..d22aefa 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -221,7 +221,7 @@ static int will_become_orphaned_pgrp(struct pid *pgrp, struct task_struct *ignor do_each_pid_task(pgrp, PIDTYPE_PGID, p) { if (p == ignored_task || p->exit_state - || is_init(p->real_parent)) + || is_global_init(p->real_parent)) continue; if (task_pgrp(p->real_parent) != pgrp && task_session(p->real_parent) == task_session(p)) { diff --git a/kernel/kexec.c b/kernel/kexec.c index e9f1b4e..fbffdb4 100644 --- a/kernel/kexec.c +++ b/kernel/kexec.c @@ -51,7 +51,7 @@ struct resource crashk_res = { int kexec_should_crash(struct task_struct *p) { - if (in_interrupt() || !p->pid || is_init(p) || panic_on_oops) + if (in_interrupt() || !p->pid || is_global_init(p) || panic_on_oops) return 1; return 0; } diff --git a/kernel/pid.c b/kernel/pid.c index 78c0dbf..bb07851 100644 --- a/kernel/pid.c +++ b/kernel/pid.c @@ -70,6 +70,11 @@ struct pid_namespace init_pid_ns = { .child_reaper = &init_task }; +int is_global_init(struct task_struct *tsk) +{ + return tsk == init_pid_ns.child_reaper; +} + /* * Note: disable interrupts while the pidmap_lock is held as an * interrupt might come in and do read_lock(&tasklist_lock). diff --git a/kernel/signal.c b/kernel/signal.c index 0a6d372..8214ffa 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -256,7 +256,7 @@ flush_signal_handlers(struct task_struct *t, int force_default) int unhandled_signal(struct task_struct *tsk, int sig) { - if (is_init(tsk)) + if (is_global_init(tsk)) return 1; if (tsk->ptrace & PT_PTRACED) return 0; diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 067554b..44868e4 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -1888,7 +1888,7 @@ int proc_dointvec_bset(struct ctl_table *table, int write, struct file *filp, return -EPERM; } - op = is_init(current) ? OP_SET : OP_AND; + op = is_global_init(current) ? OP_SET : OP_AND; return do_proc_dointvec(table,write,filp,buffer,lenp,ppos, do_proc_dointvec_bset_conv,&op); } |