From: Sukadev Bhattiprolu <[EMAIL PROTECTED]>
Subject: [PATCH 1/5] statically initialize struct pid for swapper

Statically initialize a struct pid for the swapper process (pid_t == 0) and
attach it to init_task.  This is needed so task_pid(), task_pgrp() and
task_session() interfaces work on the swapper process also.

Signed-off-by: Sukadev Bhattiprolu <[EMAIL PROTECTED]>
Cc: Cedric Le Goater <[EMAIL PROTECTED]>
Cc: Dave Hansen <[EMAIL PROTECTED]>
Cc: Serge Hallyn <[EMAIL PROTECTED]>
Cc: Eric Biederman <[EMAIL PROTECTED]>
Cc: Herbert Poetzl <[EMAIL PROTECTED]>
Cc: <[EMAIL PROTECTED]>
Acked-by: Eric W. Biederman <[EMAIL PROTECTED]>
---

 include/linux/init_task.h |   27 +++++++++++++++++++++++++++
 include/linux/pid.h       |    2 ++
 kernel/pid.c              |    2 ++
 3 files changed, 31 insertions(+)

Index: lx26-20-mm2c/include/linux/init_task.h
===================================================================
--- lx26-20-mm2c.orig/include/linux/init_task.h 2007-02-28 15:47:44.000000000 
-0800
+++ lx26-20-mm2c/include/linux/init_task.h      2007-02-28 15:48:07.000000000 
-0800
@@ -96,6 +96,28 @@ extern struct group_info init_groups;
 #define INIT_PREEMPT_RCU
 #endif
 
+#define INIT_STRUCT_PID {                                              \
+       .count          = ATOMIC_INIT(1),                               \
+       .nr             = 0,                                            \
+       /* Don't put this struct pid in pid_hash */                     \
+       .pid_chain      = { .next = NULL, .pprev = NULL },              \
+       .tasks          = {                                             \
+               { .first = &init_task.pids[PIDTYPE_PID].node },         \
+               { .first = &init_task.pids[PIDTYPE_PGID].node },        \
+               { .first = &init_task.pids[PIDTYPE_SID].node },         \
+       },                                                              \
+       .rcu            = RCU_HEAD_INIT,                                \
+}
+
+#define INIT_PID_LINK(type)                                    \
+{                                                              \
+       .node = {                                               \
+               .next = NULL,                                   \
+               .pprev = &init_struct_pid.tasks[type].first,    \
+       },                                                      \
+       .pid = &init_struct_pid,                                \
+}
+
 /*
  *  INIT_TASK is used to set up the first task table, touch at
  * your own risk!. Base=0, limit=0x1fffff (=2MB)
@@ -145,6 +167,11 @@ extern struct group_info init_groups;
        .cpu_timers     = INIT_CPU_TIMERS(tsk.cpu_timers),              \
        .fs_excl        = ATOMIC_INIT(0),                               \
        .pi_lock        = SPIN_LOCK_UNLOCKED,                           \
+       .pids = {                                                       \
+               [PIDTYPE_PID]  = INIT_PID_LINK(PIDTYPE_PID),            \
+               [PIDTYPE_PGID] = INIT_PID_LINK(PIDTYPE_PGID),           \
+               [PIDTYPE_SID]  = INIT_PID_LINK(PIDTYPE_SID),            \
+       },                                                              \
        INIT_TRACE_IRQFLAGS                                             \
        INIT_LOCKDEP                                                    \
 }
Index: lx26-20-mm2c/include/linux/pid.h
===================================================================
--- lx26-20-mm2c.orig/include/linux/pid.h       2007-02-28 15:48:07.000000000 
-0800
+++ lx26-20-mm2c/include/linux/pid.h    2007-02-28 15:48:07.000000000 -0800
@@ -51,6 +51,8 @@ struct pid
        struct rcu_head rcu;
 };
 
+extern struct pid init_struct_pid;
+
 struct pid_link
 {
        struct hlist_node node;
Index: lx26-20-mm2c/kernel/pid.c
===================================================================
--- lx26-20-mm2c.orig/kernel/pid.c      2007-02-28 15:48:07.000000000 -0800
+++ lx26-20-mm2c/kernel/pid.c   2007-02-28 15:48:07.000000000 -0800
@@ -27,11 +27,13 @@
 #include <linux/bootmem.h>
 #include <linux/hash.h>
 #include <linux/pid_namespace.h>
+#include <linux/init_task.h>
 
 #define pid_hashfn(nr) hash_long((unsigned long)nr, pidhash_shift)
 static struct hlist_head *pid_hash;
 static int pidhash_shift;
 static struct kmem_cache *pid_cachep;
+struct pid init_struct_pid = INIT_STRUCT_PID;
 
 int pid_max = PID_MAX_DEFAULT;
 
-
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/

Reply via email to