[PATCH] include:linux: task_struct personality comment

[PATCH] include:linux: task_struct personality comment

[Andrei Epure]

Signed-off-by: Andrei Epure <epure.andrei@gmail.com>
---
 include/linux/sched.h |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/include/linux/sched.h b/include/linux/sched.h
index d35d2b6..8621bb0 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1274,8 +1274,10 @@ struct task_struct {
 	int exit_code, exit_signal;
 	int pdeath_signal;  /*  The signal sent when the parent dies  */
 	unsigned int jobctl;	/* JOBCTL_*, siglock protected */
-	/* ??? */
+
+	/* used with exec_domain for compatibility with other UNIX-like OSs */
 	unsigned int personality;
+
 	unsigned did_exec:1;
 	unsigned in_execve:1;	/* Tell the LSMs that the process is doing an
 				 * execve */
-- 
1.7.9.5

Re: [PATCH] include:linux: task_struct personality comment

[Ingo Molnar]

* Andrei Epure <epure.andrei@gmail.com> wrote:

> Signed-off-by: Andrei Epure <epure.andrei@gmail.com>
> ---
>  include/linux/sched.h |    4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/include/linux/sched.h b/include/linux/sched.h
> index d35d2b6..8621bb0 100644
> --- a/include/linux/sched.h
> +++ b/include/linux/sched.h
> @@ -1274,8 +1274,10 @@ struct task_struct {
>  	int exit_code, exit_signal;
>  	int pdeath_signal;  /*  The signal sent when the parent dies  */
>  	unsigned int jobctl;	/* JOBCTL_*, siglock protected */
> -	/* ??? */
> +
> +	/* used with exec_domain for compatibility with other UNIX-like OSs */
>  	unsigned int personality;

I don't mind documenting the p->personality flag, but in practice it's not used 
for emulation of other OSs really, but for emulating ABI behavior with previous 
_Linux_ versions, see include/uapi/linux/personality.h:

 * Flags for bug emulation.
 *
 * These occupy the top three bytes.
 */
enum {
        UNAME26 =               0x0020000,
        ADDR_NO_RANDOMIZE =     0x0040000,      /* disable randomization of VA space */
        FDPIC_FUNCPTRS =        0x0080000,      /* userspace function ptrs point to descriptors
                                                 * (signal handling)
                                                 */
        MMAP_PAGE_ZERO =        0x0100000,
        ADDR_COMPAT_LAYOUT =    0x0200000,
        READ_IMPLIES_EXEC =     0x0400000,
        ADDR_LIMIT_32BIT =      0x0800000,
        SHORT_INODE =           0x1000000,
        WHOLE_SECONDS =         0x2000000,
        STICKY_TIMEOUTS =       0x4000000,
        ADDR_LIMIT_3GB =        0x8000000,

So the updated comment should say that.

Thanks,

	Ingo

Re: [PATCH] include:linux: task_struct personality comment

[Andrei Epure]

On 10 April 2013 12:30, Ingo Molnar <mingo@kernel.org> wrote:
>
> I don't mind documenting the p->personality flag, but in practice it's not used
> for emulation of other OSs really, but for emulating ABI behavior with previous
> _Linux_ versions, see include/uapi/linux/personality.h:
>
>
> So the updated comment should say that.
>

Ok, thanks, I will send a v2.

Andrei



--
Andrei Epure