Re: git: fd9e09cb2ab0 - main - kern: replace several EBADF with EINVAL

On Sat, Sep 13, 2025 at 10:27 PM Konstantin Belousov
<kostikbel@gmail.com> wrote:
>
> On Sat, Sep 13, 2025 at 09:55:52PM +0300, Gleb Popov wrote:
> > This change affects following code inside the Qt library:
> > https://github.com/qt/qtbase/blob/d6cc7562689d8a07bc933178ea367706ca38e4ac/src/3rdparty/forkfd/forkfd.c#L902
> >
> > The code in question expects to receive EBADF when being fed a wrong
> > type of the descriptor. Returning EINVAL makes sense to me, so maybe
> > we should patch Qt rather than revert this change?
>
> It is really weird code, calling pdgetpid(2) on random fds.  Anyway, please
> confirm that the following revert makes the problem go away.

It does!

> BTW, would it be useful to implement something like waitid(P_PROCDESC)
> to eliminate the ugly code you pointed to?

From what I gather, yes. The pdgetpid() call there is only used to
obtain a PID to pass to wait4. Having  waitid(P_PROCDESC) would save
us from calling pdgetpid()

> commit 4b47521ce2bc4ede52611c268d00ceb1608d959e
> Author: Konstantin Belousov <kib@FreeBSD.org>
> Date:   Sat Sep 13 22:23:27 2025 +0300
>
>     pdgetpid(2): switch back returning EBADF for non-procdesc fd
>
>     This partially reverts fd9e09cb2ab0, since apparently QT depends on this
>     specific error code.  It seems that it applies pdgetpid() to random fds
>     and filters non-procdescs by checking errno for EBADF.
>
>     Reported by:    gleb

That's a different Gleb, my freefall handle is arrowd. But anyways,
the original report came from "Kenneth Raplee
<kenrap@kennethraplee.com>".