Re: [PATCH] UML: Use PTRACE_KILL instead of SIGKILL to kill host-OS processes

Anton Altaparmakov
2004-11-03T11:48:38Z

On Wed, 2004-11-03 at 11:37, Chris Wedgwood wrote:
> kill(..., SIGKILL) doesn't work to kill host-OS processes created in
> the exec path in TT mode --- for this we need PTRACE_KILL (it did work
> in previous kernels, but not by design). Without this process will
> accumulate on the host-OS (although the won't be visible inside UML).
>
> Signed-off-by: Chris Wedgwood <cw@f00f.org>
> ---
>
> Yes, there are other fixes along these lines which are needed but one
> at a time as we test these...
>
> Index: cw-current/arch/um/kernel/tt/exec_user.c
> ===================================================================
> --- cw-current.orig/arch/um/kernel/tt/exec_user.c 2004-11-03 02:10:18.064830204 -0800
> +++ cw-current/arch/um/kernel/tt/exec_user.c 2004-11-03 02:12:10.447716745 -0800
> @@ -35,7 +35,8 @@
> tracer_panic("do_exec failed to get registers - errno = %d",
> errno);
>
> - kill(old_pid, SIGKILL);
> + if (ptrace(PTRACE_KILL, old_pid, NULL, NULL))
> + printk("Warning: ptrace(PTRACE_KILL, %d, ...) saw %d\n", errno);

You have two %d but only one argument. You seem to have forgotten an
"old_pid, " in there.

>
> if(ptrace_setregs(new_pid, regs) < 0)
> tracer_panic("do_exec failed to start new proc - errno = %d",

Best regards,

Anton
--
Anton Altaparmakov <aia21 at cam.ac.uk> (replace at with @)
Unix Support, Computing Service, University of Cambridge, CB2 3QH, UK
Linux NTFS maintainer / IRC: #ntfs on irc.freenode.net
WWW: http://linux-ntfs.sf.net/, http://www-stu.christs.cam.ac.uk/~aia21/