Date: Fri, 20 Aug 2004 11:09:31 +0200 From: Pawel Jakub Dawidek <pjd@FreeBSD.org> To: freebsd-current@freebsd.org Subject: Re: Bogus usage of tsleep(9) in USB. Message-ID: <20040820090931.GY30151@darkness.comp.waw.pl> In-Reply-To: <20040820090006.GX30151@darkness.comp.waw.pl> References: <20040820090006.GX30151@darkness.comp.waw.pl>
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On Fri, Aug 20, 2004 at 11:00:06AM +0200, Pawel Jakub Dawidek wrote:
+> There are many calls to tsleep(9) with no timeout in our USB code.
+> As you all know, it is not permitted and we have KASSERT() for this:
+>=20
+> KASSERT(timo !=3D 0 || mtx_owned(&Giant) || mtx !=3D NULL,
+> ("sleeping without a mutex"));
+>=20
+> ehci.c:2441: tsleep(&sc->sc_softwake, PZERO, "ehciab", 0);
+> ohci.c:2288: tsleep(&sc->sc_softwake, PZERO, "ohciab", 0);
+> ubser.c:882: tsleep(&sc->sc_opening, PRIBIO, "ubser_op", 0);
+> ucom.c:275: tsleep(&sc->sc_opening, PRIBIO, "ucomop", 0);
+> ugen.c:633: error =3D tsleep(sce, PZERO | PCATCH, "u=
genri", 0);
+> ugen.c:697: error =3D tsleep(sce, PZERO | PCATCH, "u=
genri", 0);
+> uhci.c:1982: tsleep(&sc->sc_softwake, PZERO, "uhciab", 0);
+> uhid.c:496: error =3D tsleep(&sc->sc_q, PZERO | PCATCH, "uhi=
drea", 0);
+> ums.c:639: error =3D tsleep(sc, PZERO | PCATCH, "umsrea", 0=
);
+> usb.c:456: tsleep(&usb_all_tasks, PWAIT, "usbtsk", =
0);
+> usb.c:534: error =3D tsleep(&usb_events, PZERO | PCATCH, "u=
sbrea", 0);
+> usbdi.c:342: tsleep(xfer, PRIBIO, "usbsyn", 0);
+> usbdi_util.c:435: error =3D tsleep(xfer, PZERO | PCATCH, lbl, 0);
+> usbdi_util.c:477: error =3D tsleep(xfer, PZERO | PCATCH, lbl, 0);
+>=20
+> I saw only panic on tsleep(9) from usbdi.c, so I know for sure we don't
+> hold Giant there.
BTW. It looks there are more interesting places:
anger:root:~# egrep -r 'tsleep.*[^0-9]0\)' /sys/ | wc -l
123
I don't know where we hold Giant, but I'm quite sure not everywhere.
--=20
Pawel Jakub Dawidek http://www.FreeBSD.org
pjd@FreeBSD.org http://garage.freebsd.pl
FreeBSD committer Am I Evil? Yes, I Am!
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