2012-02-03 15:27:45

by Cyrill Gorcunov

Subject: [patch 3/4] c/r: procfs: add arg_start/end, env_start/end and exit_code members to /proc/$pid/stat

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 <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: Pavel Emelyanov <[email protected]>
Cc: Serge Hallyn <[email protected]>
Cc: KAMEZAWA Hiroyuki <[email protected]>
Cc: Alexey Dobriyan <[email protected]>
Cc: Tejun Heo <[email protected]>
Cc: Andrew Vagin <[email protected]>
Cc: Vasiliy Kulikov <[email protected]>
Cc: Alexey Dobriyan <[email protected]>
Cc: "Eric W. Biederman" <[email protected]>
---
Documentation/filesystems/proc.txt | 5 +++++
fs/proc/array.c | 20 +++++++++++++++++---
2 files changed, 22 insertions(+), 3 deletions(-)

Index: linux-2.6.git/Documentation/filesystems/proc.txt
===================================================================
--- linux-2.6.git.orig/Documentation/filesystems/proc.txt
+++ linux-2.6.git/Documentation/filesystems/proc.txt
@@ -311,6 +311,11 @@ Table 1-4: Contents of the stat files (a
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
Index: linux-2.6.git/fs/proc/array.c
===================================================================
--- linux-2.6.git.orig/fs/proc/array.c
+++ linux-2.6.git/fs/proc/array.c
@@ -508,9 +508,23 @@ static int do_task_stat(struct seq_file
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);

2012-02-03 16:37:42

by Kees Cook

Subject: Re: [patch 3/4] c/r: procfs: add arg_start/end, env_start/end and exit_code members to /proc/$pid/stat

On Fri, Feb 3, 2012 at 7:19 AM, Cyrill Gorcunov <[email protected]> wrote:
> 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 <[email protected]>

Acked-by: Kees Cook <[email protected]>

--
Kees Cook
ChromeOS Security