From: "D. Jeff Dionne" <jeff@uClinux.org>
To: Rich Felker <dalias@libc.org>
Cc: "D. Jeff Dionne" <jeff@uClinux.org>,
Yoshinori Sato <ysato@users.sourceforge.jp>,
"musl@lists.openwall.com" <musl@lists.openwall.com>,
"shumpei.kawasaki@swhwc.com" <shumpei.kawasaki@swhwc.com>
Subject: Re: Moving forward with sh2/nommu
Date: Fri, 12 Jun 2015 15:46:11 +0900 [thread overview]
Message-ID: <EE05C8D2-3BE1-416B-9AC8-BCC00B2A8607@uClinux.org> (raw)
In-Reply-To: <20150612063744.GE17573@brightrain.aerifal.cx>
> On Jun 12, 2015, at 3:37 PM, Rich Felker <dalias@libc.org> wrote:
>>
>> This is not a nommu uClinux thing, it is a restriction we inherited
>> from BSD vfork(). It makes things much simpler (read: tractable at
>> all), actually.
>
> I'm not talking about returning from the function that called vfork.
> This is about returning from vfork itself, to the caller of vfork.
>>> The first return
>>> (in the child) would properly restore these registers, but subsequent
>>> execution in the child (in the function that called vfork, e.g. when
>>> it sets up the stack for a call to execl) could clobber the locations
>>> where they were saved on the stack, and when the parent resumed
>>> execution, it vfork would restore the wrong values, and very bad
>>> things could happen in the caller
Oh, I see what you were saying, sorry about that. You are correct, there
can be no C stack frame for vfork(), I agree.
Cheers,
J.
next prev parent reply other threads:[~2015-06-12 6:46 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-06-01 15:11 Rich Felker
2015-06-02 6:09 ` Rob Landley
2015-06-02 16:45 ` Rich Felker
2015-06-02 23:49 ` Rich Felker
2015-06-10 3:30 ` Rich Felker
2015-06-11 4:02 ` Rob Landley
2015-06-11 15:12 ` Rich Felker
2015-06-11 17:22 ` Rich Felker
2015-06-12 4:26 ` Yoshinori Sato
2015-06-12 4:35 ` Rich Felker
2015-06-12 4:49 ` uClinux.org
2015-06-12 6:37 ` Rich Felker
2015-06-12 6:46 ` D. Jeff Dionne [this message]
2015-06-12 4:08 ` Yoshinori Sato
2015-06-12 4:28 ` Rich Felker
2015-06-16 6:38 ` Yoshinori Sato
2015-06-16 7:02 ` Rich Felker
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