Fwd: Re: kern/51621: PT_ATTACH from a parent is unreliable

[Kamil Rytarowski <n54%gmx.com@localhost>]

The following reply was made to PR kern/51621; it has been noted by GNATS.

From: Kamil Rytarowski <n54%gmx.com@localhost>
To: gnats-bugs%NetBSD.org@localhost
Cc: 
Subject: Fwd: Re: kern/51621: PT_ATTACH from a parent is unreliable
Date: Fri, 11 Nov 2016 13:47:49 +0100

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 -------- Forwarded Message --------
 Subject: Re: kern/51621: PT_ATTACH from a parent is unreliable
 Date: Fri, 11 Nov 2016 20:45:52 +0800 (PHT)
 From: Paul Goyette <paul%whooppee.com@localhost>
 To: Kamil Rytarowski <n54%gmx.com@localhost>
 
 On Fri, 11 Nov 2016, Kamil Rytarowski wrote:
 
 > On 11.11.2016 12:36, Paul Goyette wrote:
 >> This PR got me thinking....
 >>
 >> What happens if a child process attempts to attach to its own parent? =
 Do
 >> we get all the signalling correct?  Does the parent still succeed when=
 
 >> wait(2) for the child?
 >>
 >> Sorry, just thinking about possible pathological situations.  :)
 >>
 >
 > This is currently uncovered (we are talking only PT_ATTACH, as
 > PT_TRACE_ME is already functional). I will add a test for it as well.
 >
 > There is another flaw, and I forgot to add it in the original PR; in th=
 e
 > documentation signal(7) redirects in SIGTRAP details to ptrace(2) but
 > there is no single word on SIGTRAP in the debugging interface man-page.=
 
 >
 > Signaling shall be described in details in ptrace(2) - not just that
 > something is stopped by a signal, but with a specification what exact
 > signal.
 >
 >
 > Can I CC gnats this message?
 
 Certainly!
 
 
 +------------------+--------------------------+------------------------+
 | Paul Goyette     | PGP Key fingerprint:     | E-mail addresses:      |
 | (Retired)        | FA29 0E3B 35AF E8AE 6651 | paul at whooppee.com   |
 | Kernel Developer | 0786 F758 55DE 53BA 7731 | pgoyette at netbsd.org |
 +------------------+--------------------------+------------------------+
 
 
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