Re: [PATCH 11/17] ptrace: implement PTRACE_SEIZE

From: Oleg Nesterov
Date: Wed Jun 01 2011 - 15:50:49 EST

On 05/30, Tejun Heo wrote:
> implements a new ptrace request PTRACE_SEIZE which attaches and traps
> tracee

it doesn't trap the tracee ;)

> * PTRACE_SEIZE, unlike ATTACH, doesn't force tracee to trap. After
> attaching tracee continues to run unless a trap condition occurs.


Just to remind, tracehook_report_clone() shouldn't send SIGSTOP if
the auto-attached tracee is PT_SEIZED.

> * If PTRACE_SEIZE'd, group stop uses PTRACE_EVENT_STOP trap which uses
> exit_code of (SIGTRAP | PTRACE_EVENT_STOP << 8) instead of the
> stopping signal number

Hmm. May be it would be better to report stopping_signal | PTRACE_EVENT_STOP
instead... I am not sure yet, but it seems this way we can avoid the
PTRACE_GETSIGINFO changes. I'll try to explain later, when I finsh the


To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at