On 04/29, Eric W. Biederman wrote: > > Call send_sig_info in PTRACE_KILL instead of ptrace_resume. Calling > ptrace_resume is not safe to call if the task has not been stopped > with ptrace_freeze_traced. Oh, I was never, never able to understand why do we have PTRACE_KILL and what should it actually do. I suggested many times to simply remove it but OK, we probably can't do this. > --- a/kernel/ptrace.c > +++ b/kernel/ptrace.c > @@ -1238,7 +1238,7 @@ int ptrace_request(struct task_struct *child, long request, > case PTRACE_KILL: > if (child->exit_state) /* already dead */ > return 0; > - return ptrace_resume(child, request, SIGKILL); > + return send_sig_info(SIGKILL, SEND_SIG_NOINFO, child); Note that currently ptrace(PTRACE_KILL) can never fail (yes, yes, it is unsafe), but send_sig_info() can. If we do not remove PTRACE_KILL, then I'd suggest case PTRACE_KILL: if (!child->exit_state) send_sig_info(SIGKILL); return 0; to make this change a bit more compatible. Also, please remove the note about PTRACE_KILL in set_task_blockstep(). Oleg.
