Don't follow null pointers if we somehow have a null devswitch entry
despite having a non-null cn_tab entry. This case now works the same as if there is no physical console, except i/o at the kernel printf level may still work. This frees drivers of physical console drivers from the responsibility of attaching the device no matter what.
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parent
be16a3aba0
commit
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Notes:
svn2git
2020-12-20 02:59:44 +00:00
svn path=/head/; revision=56582
@ -165,10 +165,12 @@ cninit_finish()
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* Hook the open and close functions.
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*/
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cdp = devsw(cn_tab->cn_dev);
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cn_phys_close = cdp->d_close;
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cdp->d_close = cnclose;
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cn_phys_open = cdp->d_open;
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cdp->d_open = cnopen;
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if (cdp != NULL) {
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cn_phys_close = cdp->d_close;
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cdp->d_close = cnclose;
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cn_phys_open = cdp->d_open;
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cdp->d_open = cnopen;
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}
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cn_dev_t = cn_tab->cn_dev;
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cn_udev_t = dev2udev(cn_dev_t);
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}
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@ -185,9 +187,11 @@ cnuninit(void)
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* Unhook the open and close functions.
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*/
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cdp = devsw(cn_tab->cn_dev);
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cdp->d_close = cn_phys_close;
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if (cdp != NULL) {
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cdp->d_close = cn_phys_close;
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cdp->d_open = cn_phys_open;
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}
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cn_phys_close = NULL;
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cdp->d_open = cn_phys_open;
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cn_phys_open = NULL;
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cn_dev_t = NODEV;
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cn_udev_t = NOUDEV;
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@ -250,7 +254,7 @@ cnopen(dev, flag, mode, p)
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dev_t cndev, physdev;
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int retval = 0;
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if (cn_tab == NULL)
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if (cn_tab == NULL || cn_phys_open == NULL)
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return (0);
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cndev = cn_tab->cn_dev;
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physdev = (major(dev) == major(cndev) ? dev : cndev);
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@ -287,7 +291,7 @@ cnclose(dev, flag, mode, p)
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dev_t cndev;
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struct tty *cn_tp;
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if (cn_tab == NULL)
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if (cn_tab == NULL || cn_phys_open == NULL)
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return (0);
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cndev = cn_tab->cn_dev;
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cn_tp = cndev->si_tty;
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@ -327,7 +331,8 @@ cnread(dev, uio, flag)
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struct uio *uio;
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int flag;
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{
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if ((cn_tab == NULL) || cn_mute)
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if (cn_tab == NULL || cn_phys_open == NULL)
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return (0);
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dev = cn_tab->cn_dev;
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return ((*devsw(dev)->d_read)(dev, uio, flag));
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@ -339,7 +344,8 @@ cnwrite(dev, uio, flag)
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struct uio *uio;
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int flag;
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{
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if ((cn_tab == NULL) || cn_mute) {
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if (cn_tab == NULL || cn_phys_open == NULL) {
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uio->uio_resid = 0; /* dump the data */
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return (0);
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}
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@ -360,7 +366,7 @@ cnioctl(dev, cmd, data, flag, p)
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{
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int error;
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if ((cn_tab == NULL) || cn_mute)
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if (cn_tab == NULL || cn_phys_open == NULL)
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return (0);
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/*
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* Superuser can always use this to wrest control of console
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