Date: Mon, 1 Jun 2009 12:31:41 GMT From: Hans Petter Selasky <hselasky@FreeBSD.org> To: Perforce Change Reviews <perforce@FreeBSD.org> Subject: PERFORCE change 163254 for review Message-ID: <200906011231.n51CVf7C066020@repoman.freebsd.org>
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http://perforce.freebsd.org/chv.cgi?CH=163254 Change 163254 by hselasky@hselasky_laptop001 on 2009/06/01 12:30:53 USB CORE: Fix multithread issue where the is_uref variable was not set and cleared properly in the CDEV private data. Affected files ... .. //depot/projects/usb/src/sys/dev/usb/usb_dev.c#25 edit Differences ... ==== //depot/projects/usb/src/sys/dev/usb/usb_dev.c#25 (text+ko) ==== @@ -169,21 +169,23 @@ cpd->bus = devclass_get_softc(usb2_devclass_ptr, cpd->bus_index); if (cpd->bus == NULL) { DPRINTFN(2, "no bus at %u\n", cpd->bus_index); + need_uref = 0; goto error; } cpd->udev = cpd->bus->devices[cpd->dev_index]; if (cpd->udev == NULL) { DPRINTFN(2, "no device at %u\n", cpd->dev_index); + need_uref = 0; goto error; } if (cpd->udev->refcount == USB_DEV_REF_MAX) { DPRINTFN(2, "no dev ref\n"); + need_uref = 0; goto error; } if (need_uref) { DPRINTFN(2, "ref udev - needed\n"); cpd->udev->refcount++; - cpd->is_uref = 1; mtx_unlock(&usb2_ref_lock); @@ -194,6 +196,11 @@ sx_xlock(cpd->udev->default_sx + 1); mtx_lock(&usb2_ref_lock); + + /* + * Set "is_uref" after grabbing the default SX lock + */ + cpd->is_uref = 1; } /* check if we are doing an open */ @@ -258,18 +265,18 @@ } mtx_unlock(&usb2_ref_lock); - if (cpd->is_uref) { + if (need_uref) { mtx_lock(&Giant); /* XXX */ } return (0); error: - if (cpd->is_uref) { + if (need_uref) { + cpd->is_uref = 0; sx_unlock(cpd->udev->default_sx + 1); if (--(cpd->udev->refcount) == 0) { usb2_cv_signal(cpd->udev->default_cv + 1); } - cpd->is_uref = 0; } mtx_unlock(&usb2_ref_lock); DPRINTFN(2, "fail\n"); @@ -289,10 +296,14 @@ static usb_error_t usb2_usb_ref_device(struct usb_cdev_privdata *cpd) { + uint8_t is_uref; + + is_uref = cpd->is_uref && sx_xlocked(cpd->udev->default_sx + 1); + /* * Check if we already got an USB reference on this location: */ - if (cpd->is_uref) + if (is_uref) return (0); /* success */ /* @@ -313,7 +324,12 @@ void usb2_unref_device(struct usb_cdev_privdata *cpd) { - if (cpd->is_uref) { + uint8_t is_uref; + + is_uref = cpd->is_uref && sx_xlocked(cpd->udev->default_sx + 1); + + if (is_uref) { + cpd->is_uref = 0; mtx_unlock(&Giant); /* XXX */ sx_unlock(cpd->udev->default_sx + 1); } @@ -330,11 +346,10 @@ } cpd->is_write = 0; } - if (cpd->is_uref) { + if (is_uref) { if (--(cpd->udev->refcount) == 0) { usb2_cv_signal(cpd->udev->default_cv + 1); } - cpd->is_uref = 0; } mtx_unlock(&usb2_ref_lock); }
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