[PATCH v3] getrandom system call wrapper [BZ #17252]

[Zack Weinberg]

On Fri, Sep 9, 2016 at 10:28 AM, Florian Weimer <fweimer@redhat.com> wrote:
> On 09/09/2016 04:21 PM, Torvald Riegel wrote:
>> On Thu, 2016-09-08 at 13:44 +0200, Florian Weimer wrote:
>>>
>>> I have made the system call wrapper a cancellation point.  (If we
>>> implement the simpler getentropy interface, it would not be a
>>> cancellation point.)
>>
>>
>> Why did you do that?
>
> I have to, because it can block indefinitely.

Is it practical to make it a cancellation point if and only if called
in blocking mode?  I suspect that is the behavior basically everyone
wants.  Unlike with file descriptors, blocking/nonblocking is visible
in the flags passed to the function, so it might not be hard.

(What does Solaris' implementation do?  OpenBSD's?)

zw