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Re: [PATCH] linux: spawni.c: simplify error reporting to parent
On 28/09/2016 08:22, Rich Felker wrote:
> On Wed, Sep 28, 2016 at 05:03:41PM +0200, Andreas Schwab wrote:
>> On Sep 28 2016, Rich Felker <dalias@libc.org> wrote:
>>
>>> This is a bad idea for at least one reason: running under strace seems
>>> to cause vfork _not_ to wait in the parent, leading to stack
>>> clobbering and runaway wrong code execution.
>>
>> This is not true. With modern kernels implementing ptrace events a
>> tracer can correctly handle all clone variants including vfork.
>
> The problem might very well be limited to older (but still supported,
> I think) kernels or older versions of strace; I'm not sure. That's
> what I meant by saying I don't have a formula to reproduce the issue
> at the moment.
>
> Rich
>
I am not convinced this specific issue should be a blocker for this
patch. It seems quite limited in scope (running the process in
strace) on older/not supported kernel. And the behaviour is clearly
a kernel issue.
Also I checked with CentOS 6 (2.6.32-642.el6.x86_64, strace 4.8) and
it seems to follow the expected behaviour. I would also consider
any deviation in more recent Linux releases as a kernel regression
and I see no point and trying to support it.