c/r: procfs: add arg_start/end, env_start/end and exit_code members to /proc/$pid...

We would like to have an ability to restore command line arguments and
program environment pointers but first we need to obtain them somehow.
Thus we put these values into /proc/$pid/stat.  The exit_code is needed to
restore zombie tasks.

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Serge Hallyn <serge.hallyn@canonical.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Andrew Vagin <avagin@openvz.org>
Cc: Vasiliy Kulikov <segoon@openwall.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt
index d8d3f9a..fb0a6ae 100644 (file)
--- a/Documentation/filesystems/proc.txt
+++ b/Documentation/filesystems/proc.txt
@@ -311,6 +311,11 @@ Table 1-4: Contents of the stat files (as of 2.6.30-rc7)
   start_data    address above which program data+bss is placed
   end_data      address below which program data+bss is placed
   start_brk     address above which program heap can be expanded with brk()
+  arg_start     address above which program command line is placed
+  arg_end       address below which program command line is placed
+  env_start     address above which program environment is placed
+  env_end       address below which program environment is placed
+  exit_code     the thread's exit_code in the form reported by the waitpid system call
 ..............................................................................
 
 The /proc/PID/maps file containing the currently mapped memory regions and

diff --git a/fs/proc/array.c b/fs/proc/array.c
index 62887e3..c1c207c 100644 (file)
--- a/fs/proc/array.c
+++ b/fs/proc/array.c
@@ -517,9 +517,23 @@ static int do_task_stat(struct seq_file *m, struct pid_namespace *ns,
        seq_put_decimal_ull(m, ' ', delayacct_blkio_ticks(task));
        seq_put_decimal_ull(m, ' ', cputime_to_clock_t(gtime));
        seq_put_decimal_ll(m, ' ', cputime_to_clock_t(cgtime));
-       seq_put_decimal_ull(m, ' ', (mm && permitted) ? mm->start_data : 0);
-       seq_put_decimal_ull(m, ' ', (mm && permitted) ? mm->end_data : 0);
-       seq_put_decimal_ull(m, ' ', (mm && permitted) ? mm->start_brk : 0);
+
+       if (mm && permitted) {
+               seq_put_decimal_ull(m, ' ', mm->start_data);
+               seq_put_decimal_ull(m, ' ', mm->end_data);
+               seq_put_decimal_ull(m, ' ', mm->start_brk);
+               seq_put_decimal_ull(m, ' ', mm->arg_start);
+               seq_put_decimal_ull(m, ' ', mm->arg_end);
+               seq_put_decimal_ull(m, ' ', mm->env_start);
+               seq_put_decimal_ull(m, ' ', mm->env_end);
+       } else
+               seq_printf(m, " 0 0 0 0 0 0 0");
+
+       if (permitted)
+               seq_put_decimal_ll(m, ' ', task->exit_code);
+       else
+               seq_put_decimal_ll(m, ' ', 0);
+
        seq_putc(m, '\n');
        if (mm)
                mmput(mm);