Messages in this thread | | | Date | Fri, 9 Sep 2011 09:18:53 +0900 | From | Tejun Heo <> | Subject | Re: Why I want PTRACE_O_TRACESTOP option |
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Hello, Denys.
On Thu, Sep 08, 2011 at 06:50:01PM +0200, Denys Vlasenko wrote: > Consider what will happen when a next ptrace fix will require > a way to change ptrace API at runtime. A new option will likely > be introduced, say, PTRACE_O_TRACEPONY, with next available > bit position 7, and perhaps some new event will be generated, > PTRACE_EVENT_PONY, with value.... yes, it can't be 7, > PTRACE_EVENT_STOP took it. So it will probably be 8.
Then, just give it the next matching number.
If options naturally happen to match the events, that's a nice coincidence. If the real life requirement deviates from the beautiful one-to-one mapping, then, so be it. No, the magical contiguous one to one mapping isn't the most important design concern.
To me, the rationale presented here almost argues against PTRACE_O_TRACESTOP. :(
Thanks.
-- tejun
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