Re: [PATCH 4/5] [V2] Define is_global_init() and is_container_init()

2007-07-20 Thread sukadev 
Andrew Morton [EMAIL PROTECTED] wrote:
| On Thu, 19 Jul 2007 00:21:58 -0700
| [EMAIL PROTECTED] wrote:
| 
| > --- lx26-22-rc6-mm1a.orig/kernel/pid.c  2007-07-16 12:55:15.0 
-0700
| > +++ lx26-22-rc6-mm1a/kernel/pid.c   2007-07-16 13:10:48.0 -0700
| > @@ -69,6 +69,13 @@ struct pid_namespace init_pid_ns = {
| > .last_pid = 0,
| > .child_reaper = _task
| >  };
| > +EXPORT_SYMBOL(init_pid_ns);
| > +
| > +int is_global_init(struct task_struct *tsk)
| > +{
| > +   return tsk == init_pid_ns.child_reaper;
| > +}
| > +EXPORT_SYMBOL(is_global_init);
| 
| I don't immediately see why init_pid_ns was exported to modules.

| 
| It would need to be exported if is_global_init() was made static inline in a
| header (which seems like a sensible thing to do), but it wasn't.

It did not need to be exported in this patch.

I have a couple of follow-on patches that cleaned up some header-file
dependencies and made is_global_init() inline. Those patches are
changing a bit as I merge them with Pavel Emelianov's pid ns changes.

I will send a separate patch to inline is_global_init().

Suka
-
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Re: [PATCH 4/5] [V2] Define is_global_init() and is_container_init()

2007-07-20 Thread Andrew Morton 
On Thu, 19 Jul 2007 00:21:58 -0700
[EMAIL PROTECTED] wrote:

> --- lx26-22-rc6-mm1a.orig/kernel/pid.c2007-07-16 12:55:15.0 
> -0700
> +++ lx26-22-rc6-mm1a/kernel/pid.c 2007-07-16 13:10:48.0 -0700
> @@ -69,6 +69,13 @@ struct pid_namespace init_pid_ns = {
>   .last_pid = 0,
>   .child_reaper = _task
>  };
> +EXPORT_SYMBOL(init_pid_ns);
> +
> +int is_global_init(struct task_struct *tsk)
> +{
> + return tsk == init_pid_ns.child_reaper;
> +}
> +EXPORT_SYMBOL(is_global_init);

I don't immediately see why init_pid_ns was exported to modules.

It would need to be exported if is_global_init() was made static inline in a
header (which seems like a sensible thing to do), but it wasn't.

-
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the body of a message to [EMAIL PROTECTED]
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Re: [PATCH 4/5] [V2] Define is_global_init() and is_container_init()

2007-07-20 Thread Andrew Morton 
On Thu, 19 Jul 2007 00:21:58 -0700
[EMAIL PROTECTED] wrote:

 --- lx26-22-rc6-mm1a.orig/kernel/pid.c2007-07-16 12:55:15.0 
 -0700
 +++ lx26-22-rc6-mm1a/kernel/pid.c 2007-07-16 13:10:48.0 -0700
 @@ -69,6 +69,13 @@ struct pid_namespace init_pid_ns = {
   .last_pid = 0,
   .child_reaper = init_task
  };
 +EXPORT_SYMBOL(init_pid_ns);
 +
 +int is_global_init(struct task_struct *tsk)
 +{
 + return tsk == init_pid_ns.child_reaper;
 +}
 +EXPORT_SYMBOL(is_global_init);

I don't immediately see why init_pid_ns was exported to modules.

It would need to be exported if is_global_init() was made static inline in a
header (which seems like a sensible thing to do), but it wasn't.

-
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Re: [PATCH 4/5] [V2] Define is_global_init() and is_container_init()

2007-07-20 Thread sukadev 
Andrew Morton [EMAIL PROTECTED] wrote:
| On Thu, 19 Jul 2007 00:21:58 -0700
| [EMAIL PROTECTED] wrote:
| 
|  --- lx26-22-rc6-mm1a.orig/kernel/pid.c  2007-07-16 12:55:15.0 
-0700
|  +++ lx26-22-rc6-mm1a/kernel/pid.c   2007-07-16 13:10:48.0 -0700
|  @@ -69,6 +69,13 @@ struct pid_namespace init_pid_ns = {
|  .last_pid = 0,
|  .child_reaper = init_task
|   };
|  +EXPORT_SYMBOL(init_pid_ns);
|  +
|  +int is_global_init(struct task_struct *tsk)
|  +{
|  +   return tsk == init_pid_ns.child_reaper;
|  +}
|  +EXPORT_SYMBOL(is_global_init);
| 
| I don't immediately see why init_pid_ns was exported to modules.

| 
| It would need to be exported if is_global_init() was made static inline in a
| header (which seems like a sensible thing to do), but it wasn't.

It did not need to be exported in this patch.

I have a couple of follow-on patches that cleaned up some header-file
dependencies and made is_global_init() inline. Those patches are
changing a bit as I merge them with Pavel Emelianov's pid ns changes.

I will send a separate patch to inline is_global_init().

Suka
-
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

[PATCH 4/5] [V2] Define is_global_init() and is_container_init()

2007-07-19 Thread sukadev 
Subject: [PATCH 4/5] Define is_global_init() and is_container_init().

From: Serge E. Hallyn <[EMAIL PROTECTED]>


is_init() is an ambiguous name for the pid==1 check.  Split it into
is_global_init() and is_container_init().

A container 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 container if the container's init has a
  bug rather than force a kernel panic.

Signed-off-by: Serge E. Hallyn <[EMAIL PROTECTED]>
Signed-off-by: Sukadev Bhattiprolu <[EMAIL PROTECTED]>
Acked-by: Pavel Emelianov <[EMAIL PROTECTED]>

Cc: Eric W. Biederman <[EMAIL PROTECTED]>
Cc: Cedric Le Goater <[EMAIL PROTECTED]>
Cc: Dave Hansen <[EMAIL PROTECTED]>
Cc: Herbert Poetzel <[EMAIL PROTECTED]>
---
 arch/alpha/mm/fault.c|2 +-
 arch/arm/mm/fault.c  |2 +-
 arch/arm26/mm/fault.c|2 +-
 arch/avr32/kernel/traps.c|2 +-
 arch/avr32/mm/fault.c|6 +++---
 arch/i386/lib/usercopy.c |2 +-
 arch/i386/mm/fault.c |2 +-
 arch/ia64/mm/fault.c |2 +-
 arch/m68k/mm/fault.c |2 +-
 arch/mips/mm/fault.c |2 +-
 arch/powerpc/kernel/traps.c  |2 +-
 arch/powerpc/mm/fault.c  |2 +-
 arch/powerpc/platforms/pseries/ras.c |2 +-
 arch/ppc/kernel/traps.c  |2 +-
 arch/ppc/mm/fault.c  |2 +-
 arch/s390/lib/uaccess_pt.c   |2 +-
 arch/s390/mm/fault.c |2 +-
 arch/sh/mm/fault.c   |2 +-
 arch/sh64/mm/fault.c |6 +++---
 arch/um/kernel/trap.c|2 +-
 arch/x86_64/mm/fault.c   |2 +-
 arch/xtensa/mm/fault.c   |2 +-
 drivers/char/sysrq.c |2 +-
 include/linux/sched.h|   12 ++--
 kernel/capability.c  |3 ++-
 kernel/exit.c|2 +-
 kernel/kexec.c   |2 +-
 kernel/pid.c |7 +++
 kernel/signal.c  |2 +-
 kernel/sysctl.c  |2 +-
 mm/oom_kill.c|4 ++--
 security/commoncap.c |3 ++-
 32 files changed, 54 insertions(+), 37 deletions(-)

Index: lx26-22-rc6-mm1a/include/linux/sched.h
===
--- lx26-22-rc6-mm1a.orig/include/linux/sched.h 2007-07-16 12:55:15.0 
-0700
+++ lx26-22-rc6-mm1a/include/linux/sched.h  2007-07-16 13:10:48.0 
-0700
@@ -1219,12 +1219,20 @@ static inline int pid_alive(struct task_
 }
 
 /**
- * is_init - check if a task structure is init
+ * is_global_init - check if a task structure is init
  * @tsk: Task structure to be checked.
  *
  * Check if a task structure is the first user space task the kernel created.
+ *
+ * TODO: We should inline this function after some cleanups in pid_namespace.h
+ */
+extern int is_global_init(struct task_struct *tsk);
+
+/*
+ * is_container_init:
+ * check whether in the task is init in it's own pid namespace.
  */
-static inline int is_init(struct task_struct *tsk)
+static inline int is_container_init(struct task_struct *tsk)
 {
return tsk->pid == 1;
 }
Index: lx26-22-rc6-mm1a/kernel/pid.c
===
--- lx26-22-rc6-mm1a.orig/kernel/pid.c  2007-07-16 12:55:15.0 -0700
+++ lx26-22-rc6-mm1a/kernel/pid.c   2007-07-16 13:10:48.0 -0700
@@ -69,6 +69,13 @@ struct pid_namespace init_pid_ns = {
.last_pid = 0,
.child_reaper = _task
 };
+EXPORT_SYMBOL(init_pid_ns);
+
+int is_global_init(struct task_struct *tsk)
+{
+   return tsk == init_pid_ns.child_reaper;
+}
+EXPORT_SYMBOL(is_global_init);
 
 /*
  * Note: disable interrupts while the pidmap_lock is held as an
Index: lx26-22-rc6-mm1a/arch/alpha/mm/fault.c
===
--- lx26-22-rc6-mm1a.orig/arch/alpha/mm/fault.c 2007-07-16 12:55:15.0 
-0700
+++ lx26-22-rc6-mm1a/arch/alpha/mm/fault.c  2007-07-16 13:10:48.0 
-0700
@@ -192,7 +192,7 @@ do_page_fault(unsigned long address, uns
/* We ran out of memory, or

[PATCH 4/5] [V2] Define is_global_init() and is_container_init()

2007-07-19 Thread sukadev 
Subject: [PATCH 4/5] Define is_global_init() and is_container_init().

From: Serge E. Hallyn [EMAIL PROTECTED]


is_init() is an ambiguous name for the pid==1 check.  Split it into
is_global_init() and is_container_init().

A container 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 container if the container's init has a
  bug rather than force a kernel panic.

Signed-off-by: Serge E. Hallyn [EMAIL PROTECTED]
Signed-off-by: Sukadev Bhattiprolu [EMAIL PROTECTED]
Acked-by: Pavel Emelianov [EMAIL PROTECTED]

Cc: Eric W. Biederman [EMAIL PROTECTED]
Cc: Cedric Le Goater [EMAIL PROTECTED]
Cc: Dave Hansen [EMAIL PROTECTED]
Cc: Herbert Poetzel [EMAIL PROTECTED]
---
 arch/alpha/mm/fault.c|2 +-
 arch/arm/mm/fault.c  |2 +-
 arch/arm26/mm/fault.c|2 +-
 arch/avr32/kernel/traps.c|2 +-
 arch/avr32/mm/fault.c|6 +++---
 arch/i386/lib/usercopy.c |2 +-
 arch/i386/mm/fault.c |2 +-
 arch/ia64/mm/fault.c |2 +-
 arch/m68k/mm/fault.c |2 +-
 arch/mips/mm/fault.c |2 +-
 arch/powerpc/kernel/traps.c  |2 +-
 arch/powerpc/mm/fault.c  |2 +-
 arch/powerpc/platforms/pseries/ras.c |2 +-
 arch/ppc/kernel/traps.c  |2 +-
 arch/ppc/mm/fault.c  |2 +-
 arch/s390/lib/uaccess_pt.c   |2 +-
 arch/s390/mm/fault.c |2 +-
 arch/sh/mm/fault.c   |2 +-
 arch/sh64/mm/fault.c |6 +++---
 arch/um/kernel/trap.c|2 +-
 arch/x86_64/mm/fault.c   |2 +-
 arch/xtensa/mm/fault.c   |2 +-
 drivers/char/sysrq.c |2 +-
 include/linux/sched.h|   12 ++--
 kernel/capability.c  |3 ++-
 kernel/exit.c|2 +-
 kernel/kexec.c   |2 +-
 kernel/pid.c |7 +++
 kernel/signal.c  |2 +-
 kernel/sysctl.c  |2 +-
 mm/oom_kill.c|4 ++--
 security/commoncap.c |3 ++-
 32 files changed, 54 insertions(+), 37 deletions(-)

Index: lx26-22-rc6-mm1a/include/linux/sched.h
===
--- lx26-22-rc6-mm1a.orig/include/linux/sched.h 2007-07-16 12:55:15.0 
-0700
+++ lx26-22-rc6-mm1a/include/linux/sched.h  2007-07-16 13:10:48.0 
-0700
@@ -1219,12 +1219,20 @@ static inline int pid_alive(struct task_
 }
 
 /**
- * is_init - check if a task structure is init
+ * is_global_init - check if a task structure is init
  * @tsk: Task structure to be checked.
  *
  * Check if a task structure is the first user space task the kernel created.
+ *
+ * TODO: We should inline this function after some cleanups in pid_namespace.h
+ */
+extern int is_global_init(struct task_struct *tsk);
+
+/*
+ * is_container_init:
+ * check whether in the task is init in it's own pid namespace.
  */
-static inline int is_init(struct task_struct *tsk)
+static inline int is_container_init(struct task_struct *tsk)
 {
return tsk-pid == 1;
 }
Index: lx26-22-rc6-mm1a/kernel/pid.c
===
--- lx26-22-rc6-mm1a.orig/kernel/pid.c  2007-07-16 12:55:15.0 -0700
+++ lx26-22-rc6-mm1a/kernel/pid.c   2007-07-16 13:10:48.0 -0700
@@ -69,6 +69,13 @@ struct pid_namespace init_pid_ns = {
.last_pid = 0,
.child_reaper = init_task
 };
+EXPORT_SYMBOL(init_pid_ns);
+
+int is_global_init(struct task_struct *tsk)
+{
+   return tsk == init_pid_ns.child_reaper;
+}
+EXPORT_SYMBOL(is_global_init);
 
 /*
  * Note: disable interrupts while the pidmap_lock is held as an
Index: lx26-22-rc6-mm1a/arch/alpha/mm/fault.c
===
--- lx26-22-rc6-mm1a.orig/arch/alpha/mm/fault.c 2007-07-16 12:55:15.0 
-0700
+++ lx26-22-rc6-mm1a/arch/alpha/mm/fault.c  2007-07-16 13:10:48.0 
-0700
@@ -192,7 +192,7 @@ do_page_fault(unsigned long address, uns
/* We ran out of memory, or some other thing