Eric Lee / linux-smarc-t335x-v3.2

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Commit 5cd204550b1a006f2b0c986b0e0f53220ebfd391

Authored by Pavel Emelyanov
Committed by Linus Torvalds
1 parent cb41d6d068
Exists in master and in 4 other branches v3.2_AM335xPSP_04.06.00.11, v3.2_NEWT335xPSP_04.06.00.11, v3.2_SBC_SMARTMEN, v3.2_SMARCT335xPSP_04.06.00.11

Deprecate find_task_by_pid() 

There are some places that are known to operate on tasks'
global pids only:

* the rest_init() call (called on boot)
* the kgdb's getthread
* the create_kthread() (since the kthread is run in init ns)

So use the find_task_by_pid_ns(..., &init_pid_ns) there
and schedule the find_task_by_pid for removal.

[sukadev@us.ibm.com: Fix warning in kernel/pid.c]
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Sukadev Bhattiprolu <sukadev@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Showing 5 changed files with 24 additions and 9 deletions Side-by-side Diff

Documentation/feature-removal-schedule.txt
Diff comments   View file @ 5cd2045
... ... @@ -138,6 +138,24 @@
138 138  
139 139 ---------------------------
140 140  
  141 +What: find_task_by_pid
  142 +When: 2.6.26
  143 +Why: With pid namespaces, calling this funciton will return the
  144 + wrong task when called from inside a namespace.
  145 +
  146 + The best way to save a task pid and find a task by this
  147 + pid later, is to find this task's struct pid pointer (or get
  148 + it directly from the task) and call pid_task() later.
  149 +
  150 + If someone really needs to get a task by its pid_t, then
  151 + he most likely needs the find_task_by_vpid() to get the
  152 + task from the same namespace as the current task is in, but
  153 + this may be not so in general.
  154 +
  155 +Who: Pavel Emelyanov <xemul@openvz.org>
  156 +
  157 +---------------------------
  158 +
141 159 What: ACPI procfs interface
142 160 When: July 2008
143 161 Why: ACPI sysfs conversion should be finished by January 2008.
include/linux/sched.h
Diff comments   View file @ 5cd2045
... ... @@ -1677,7 +1677,10 @@
1677 1677 extern struct task_struct *find_task_by_pid_type_ns(int type, int pid,
1678 1678 struct pid_namespace *ns);
1679 1679  
1680   -extern struct task_struct *find_task_by_pid(pid_t nr);
  1680 +static inline struct task_struct *__deprecated find_task_by_pid(pid_t nr)
  1681 +{
  1682 + return find_task_by_pid_type_ns(PIDTYPE_PID, nr, &init_pid_ns);
  1683 +}
1681 1684 extern struct task_struct *find_task_by_vpid(pid_t nr);
1682 1685 extern struct task_struct *find_task_by_pid_ns(pid_t nr,
1683 1686 struct pid_namespace *ns);
... ... @@ -459,7 +459,7 @@
459 459 kernel_thread(kernel_init, NULL, CLONE_FS | CLONE_SIGHAND);
460 460 numa_default_policy();
461 461 pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES);
462   - kthreadd_task = find_task_by_pid(pid);
  462 + kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns);
463 463 unlock_kernel();
464 464  
465 465 /*
... ... @@ -98,7 +98,7 @@
98 98 struct sched_param param = { .sched_priority = 0 };
99 99 wait_for_completion(&create->started);
100 100 read_lock(&tasklist_lock);
101   - create->result = find_task_by_pid(pid);
  101 + create->result = find_task_by_pid_ns(pid, &init_pid_ns);
102 102 read_unlock(&tasklist_lock);
103 103 /*
104 104 * root may have changed our (kthreadd's) priority or CPU mask.
... ... @@ -381,12 +381,6 @@
381 381  
382 382 EXPORT_SYMBOL(find_task_by_pid_type_ns);
383 383  
384   -struct task_struct *find_task_by_pid(pid_t nr)
385   -{
386   - return find_task_by_pid_type_ns(PIDTYPE_PID, nr, &init_pid_ns);
387   -}
388   -EXPORT_SYMBOL(find_task_by_pid);
389   -
390 384 struct task_struct *find_task_by_vpid(pid_t vnr)
391 385 {
392 386 return find_task_by_pid_type_ns(PIDTYPE_PID, vnr,