diff options
| author | Iago López Galeiras <[email protected]> | 2015-06-25 15:00:57 -0700 | 
|---|---|---|
| committer | Linus Torvalds <[email protected]> | 2015-06-25 17:00:37 -0700 | 
| commit | 2e13ba54a2682eea24918b87ad3edf70c2cf085b (patch) | |
| tree | faa1c51d66968fada40fc971c3c17d1a242c7857 /fs/proc/array.c | |
| parent | c2c0bb44620dece7ec97e28167e32c343da22867 (diff) | |
fs, proc: introduce CONFIG_PROC_CHILDREN
Commit 818411616baf ("fs, proc: introduce /proc/<pid>/task/<tid>/children
entry") introduced the children entry for checkpoint restore and the
file is only available on kernels configured with CONFIG_EXPERT and
CONFIG_CHECKPOINT_RESTORE.
This is available in most distributions (Fedora, Debian, Ubuntu, CoreOS)
because they usually enable CONFIG_EXPERT and CONFIG_CHECKPOINT_RESTORE.
But Arch does not enable CONFIG_EXPERT or CONFIG_CHECKPOINT_RESTORE.
However, the children proc file is useful outside of checkpoint restore.
I would like to use it in rkt.  The rkt process exec() another program
it does not control, and that other program will fork()+exec() a child
process.  I would like to find the pid of the child process from an
external tool without iterating in /proc over all processes to find
which one has a parent pid equal to rkt.
This commit introduces CONFIG_PROC_CHILDREN and makes
CONFIG_CHECKPOINT_RESTORE select it.  This allows enabling
/proc/<pid>/task/<tid>/children without needing to enable
CONFIG_CHECKPOINT_RESTORE and CONFIG_EXPERT.
Alban tested that /proc/<pid>/task/<tid>/children is present when the
kernel is configured with CONFIG_PROC_CHILDREN=y but without
CONFIG_CHECKPOINT_RESTORE
Signed-off-by: Iago López Galeiras <[email protected]>
Tested-by: Alban Crequy <[email protected]>
Reviewed-by: Cyrill Gorcunov <[email protected]>
Cc: Oleg Nesterov <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: Pavel Emelyanov <[email protected]>
Cc: Serge Hallyn <[email protected]>
Cc: KAMEZAWA Hiroyuki <[email protected]>
Cc: Alexander Viro <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Djalal Harouni <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Diffstat (limited to 'fs/proc/array.c')
| -rw-r--r-- | fs/proc/array.c | 4 | 
1 files changed, 2 insertions, 2 deletions
| diff --git a/fs/proc/array.c b/fs/proc/array.c index 3f57dac31ba6..ce065cf3104f 100644 --- a/fs/proc/array.c +++ b/fs/proc/array.c @@ -577,7 +577,7 @@ int proc_pid_statm(struct seq_file *m, struct pid_namespace *ns,  	return 0;  } -#ifdef CONFIG_CHECKPOINT_RESTORE +#ifdef CONFIG_PROC_CHILDREN  static struct pid *  get_children_pid(struct inode *inode, struct pid *pid_prev, loff_t pos)  { @@ -700,4 +700,4 @@ const struct file_operations proc_tid_children_operations = {  	.llseek  = seq_lseek,  	.release = children_seq_release,  }; -#endif /* CONFIG_CHECKPOINT_RESTORE */ +#endif /* CONFIG_PROC_CHILDREN */ |