[PATCH] simply fix first_tgid
Like the bug Oleg spotted in first_tid there was also a small off by one error in first_tgid, when a seek was done on the /proc directory. This fixes that and changes the code structure to make it a little more obvious what is going on. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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@ -2040,34 +2040,32 @@ out:
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* In the case of a seek we start with &init_task and walk nr
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* threads past it.
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*/
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static struct task_struct *first_tgid(int tgid, int nr)
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static struct task_struct *first_tgid(int tgid, unsigned int nr)
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{
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struct task_struct *pos = NULL;
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struct task_struct *pos;
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rcu_read_lock();
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if (tgid && nr) {
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pos = find_task_by_pid(tgid);
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if (pos && !thread_group_leader(pos))
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pos = NULL;
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if (pos)
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nr = 0;
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if (pos && thread_group_leader(pos))
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goto found;
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}
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/* If nr exceeds the number of processes get out quickly */
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pos = NULL;
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if (nr && nr >= nr_processes())
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goto done;
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/* If we haven't found our starting place yet start with
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* the init_task and walk nr tasks forward.
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*/
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if (!pos && (nr >= 0))
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pos = next_task(&init_task);
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for (; pos && pid_alive(pos); pos = next_task(pos)) {
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if (--nr > 0)
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continue;
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get_task_struct(pos);
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goto done;
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for (pos = next_task(&init_task); nr > 0; --nr) {
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pos = next_task(pos);
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if (pos == &init_task) {
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pos = NULL;
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goto done;
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}
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}
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pos = NULL;
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found:
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get_task_struct(pos);
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done:
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rcu_read_unlock();
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return pos;
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