Messages in this thread | | | From | Denys Vlasenko <> | Subject | Re: Why I want PTRACE_O_TRACESTOP option | Date | Sat, 10 Sep 2011 03:17:03 +0200 |
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On Saturday 10 September 2011 01:09, Indan Zupancic wrote: > On Fri, September 9, 2011 18:26, Oleg Nesterov wrote: > > On 09/09, Indan Zupancic wrote: > >> > >> It is very useful to set options atomically at SEIZE time. > > > > Nobody argues with this. > > > >> Another important reason to make PTRACE_O_TRACESTOP an option is > >> because not everyone uses SEIZE: Users using PTRACE_TRACEME can't > >> set this option at all. > > > > Yes. This was already discussed, PTRACE_TRACEME obviously doesn't > > work if you need the new features. So far it was decided TRACEME > > should be avoided, > > How do you want to attach/seize a just forked child without races > in a less ugly way than with TRACEME?
I needed to do it when I was adding usage of SEIZE to strace. It goes like this:
- fork - child: raise(SIGSTOP) - parent: waits until it sees child stopping - parent: seizes the child - parent: kill(child, SIGCONT)
-- vda
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