From 87a6aca504d65f242589583e04df5e74b5eae1fe Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Mon, 15 Mar 2010 17:14:15 -0700 Subject: Revert "tty: Add a new VT mode which is like VT_PROCESS but doesn't require a VT_RELDISP ioctl call" This reverts commit eec9fe7d1ab4a0dfac4cb43047a7657fffd0002f. Ari writes as the reason this should be reverted: The problems with this patch include: 1. There's at least one subtlety I overlooked - switching between X servers (i.e. from one X VT to another) still requires the cooperation of both X servers. I was assuming that KMS eliminated this. 2. It hasn't been tested at all (no X server patch exists which uses the new mode). As he was the original author of the patch, I'll revert it. Cc: Ari Entlich Cc: Alan Cox Signed-off-by: Greg Kroah-Hartman --- drivers/char/vt_ioctl.c | 39 +++++++++++++++++++-------------------- 1 file changed, 19 insertions(+), 20 deletions(-) (limited to 'drivers/char') diff --git a/drivers/char/vt_ioctl.c b/drivers/char/vt_ioctl.c index 87778dcf872..6aa10284104 100644 --- a/drivers/char/vt_ioctl.c +++ b/drivers/char/vt_ioctl.c @@ -888,7 +888,7 @@ int vt_ioctl(struct tty_struct *tty, struct file * file, ret = -EFAULT; goto out; } - if (tmp.mode != VT_AUTO && tmp.mode != VT_PROCESS && tmp.mode != VT_PROCESS_AUTO) { + if (tmp.mode != VT_AUTO && tmp.mode != VT_PROCESS) { ret = -EINVAL; goto out; } @@ -1622,7 +1622,7 @@ static void complete_change_console(struct vc_data *vc) * telling it that it has acquired. Also check if it has died and * clean up (similar to logic employed in change_console()) */ - if (vc->vt_mode.mode == VT_PROCESS || vc->vt_mode.mode == VT_PROCESS_AUTO) { + if (vc->vt_mode.mode == VT_PROCESS) { /* * Send the signal as privileged - kill_pid() will * tell us if the process has gone or something else @@ -1682,7 +1682,7 @@ void change_console(struct vc_data *new_vc) * vt to auto control. */ vc = vc_cons[fg_console].d; - if (vc->vt_mode.mode == VT_PROCESS || vc->vt_mode.mode == VT_PROCESS_AUTO) { + if (vc->vt_mode.mode == VT_PROCESS) { /* * Send the signal as privileged - kill_pid() will * tell us if the process has gone or something else @@ -1693,28 +1693,27 @@ void change_console(struct vc_data *new_vc) */ vc->vt_newvt = new_vc->vc_num; if (kill_pid(vc->vt_pid, vc->vt_mode.relsig, 1) == 0) { - if(vc->vt_mode.mode == VT_PROCESS) - /* - * It worked. Mark the vt to switch to and - * return. The process needs to send us a - * VT_RELDISP ioctl to complete the switch. - */ - return; - } else { /* - * The controlling process has died, so we revert back to - * normal operation. In this case, we'll also change back - * to KD_TEXT mode. I'm not sure if this is strictly correct - * but it saves the agony when the X server dies and the screen - * remains blanked due to KD_GRAPHICS! It would be nice to do - * this outside of VT_PROCESS but there is no single process - * to account for and tracking tty count may be undesirable. + * It worked. Mark the vt to switch to and + * return. The process needs to send us a + * VT_RELDISP ioctl to complete the switch. */ - reset_vc(vc); + return; } /* - * Fall through to normal (VT_AUTO and VT_PROCESS_AUTO) handling of the switch... + * The controlling process has died, so we revert back to + * normal operation. In this case, we'll also change back + * to KD_TEXT mode. I'm not sure if this is strictly correct + * but it saves the agony when the X server dies and the screen + * remains blanked due to KD_GRAPHICS! It would be nice to do + * this outside of VT_PROCESS but there is no single process + * to account for and tracking tty count may be undesirable. + */ + reset_vc(vc); + + /* + * Fall through to normal (VT_AUTO) handling of the switch... */ } -- cgit v1.2.3 From e74d098c66543d0731de62eb747ccd5b636a6f4c Mon Sep 17 00:00:00 2001 From: Amit Shah Date: Fri, 12 Mar 2010 11:53:15 +0530 Subject: hvc_console: Fix race between hvc_close and hvc_remove Alan pointed out a race in the code where hvc_remove is invoked. The recent virtio_console work is the first user of hvc_remove(). Alan describes it thus: The hvc_console assumes that a close and remove call can't occur at the same time. In addition tty_hangup(tty) is problematic as tty_hangup is asynchronous itself.... So this can happen hvc_close hvc_remove hung up ? - no lock tty = hp->tty unlock lock hp->tty = NULL unlock notify del kref_put the hvc struct close completes tty is destroyed tty_hangup dead tty tty->ops will be NULL NULL->... This patch adds some tty krefs and also converts to using tty_vhangup(). Reported-by: Alan Cox Signed-off-by: Amit Shah CC: Alan Cox CC: linuxppc-dev@ozlabs.org CC: Rusty Russell Signed-off-by: Greg Kroah-Hartman --- drivers/char/hvc_console.c | 31 +++++++++++++++++++++---------- 1 file changed, 21 insertions(+), 10 deletions(-) (limited to 'drivers/char') diff --git a/drivers/char/hvc_console.c b/drivers/char/hvc_console.c index 465185fc0f5..ba55bba151b 100644 --- a/drivers/char/hvc_console.c +++ b/drivers/char/hvc_console.c @@ -312,6 +312,7 @@ static int hvc_open(struct tty_struct *tty, struct file * filp) spin_lock_irqsave(&hp->lock, flags); /* Check and then increment for fast path open. */ if (hp->count++ > 0) { + tty_kref_get(tty); spin_unlock_irqrestore(&hp->lock, flags); hvc_kick(); return 0; @@ -319,7 +320,7 @@ static int hvc_open(struct tty_struct *tty, struct file * filp) tty->driver_data = hp; - hp->tty = tty; + hp->tty = tty_kref_get(tty); spin_unlock_irqrestore(&hp->lock, flags); @@ -336,6 +337,7 @@ static int hvc_open(struct tty_struct *tty, struct file * filp) spin_lock_irqsave(&hp->lock, flags); hp->tty = NULL; spin_unlock_irqrestore(&hp->lock, flags); + tty_kref_put(tty); tty->driver_data = NULL; kref_put(&hp->kref, destroy_hvc_struct); printk(KERN_ERR "hvc_open: request_irq failed with rc %d.\n", rc); @@ -363,13 +365,18 @@ static void hvc_close(struct tty_struct *tty, struct file * filp) return; hp = tty->driver_data; + spin_lock_irqsave(&hp->lock, flags); + tty_kref_get(tty); if (--hp->count == 0) { /* We are done with the tty pointer now. */ hp->tty = NULL; spin_unlock_irqrestore(&hp->lock, flags); + /* Put the ref obtained in hvc_open() */ + tty_kref_put(tty); + if (hp->ops->notifier_del) hp->ops->notifier_del(hp, hp->data); @@ -389,6 +396,7 @@ static void hvc_close(struct tty_struct *tty, struct file * filp) spin_unlock_irqrestore(&hp->lock, flags); } + tty_kref_put(tty); kref_put(&hp->kref, destroy_hvc_struct); } @@ -424,10 +432,11 @@ static void hvc_hangup(struct tty_struct *tty) spin_unlock_irqrestore(&hp->lock, flags); if (hp->ops->notifier_hangup) - hp->ops->notifier_hangup(hp, hp->data); + hp->ops->notifier_hangup(hp, hp->data); while(temp_open_count) { --temp_open_count; + tty_kref_put(tty); kref_put(&hp->kref, destroy_hvc_struct); } } @@ -592,7 +601,7 @@ int hvc_poll(struct hvc_struct *hp) } /* No tty attached, just skip */ - tty = hp->tty; + tty = tty_kref_get(hp->tty); if (tty == NULL) goto bail; @@ -672,6 +681,8 @@ int hvc_poll(struct hvc_struct *hp) tty_flip_buffer_push(tty); } + if (tty) + tty_kref_put(tty); return poll_mask; } @@ -807,7 +818,7 @@ int hvc_remove(struct hvc_struct *hp) struct tty_struct *tty; spin_lock_irqsave(&hp->lock, flags); - tty = hp->tty; + tty = tty_kref_get(hp->tty); if (hp->index < MAX_NR_HVC_CONSOLES) vtermnos[hp->index] = -1; @@ -819,18 +830,18 @@ int hvc_remove(struct hvc_struct *hp) /* * We 'put' the instance that was grabbed when the kref instance * was initialized using kref_init(). Let the last holder of this - * kref cause it to be removed, which will probably be the tty_hangup + * kref cause it to be removed, which will probably be the tty_vhangup * below. */ kref_put(&hp->kref, destroy_hvc_struct); /* - * This function call will auto chain call hvc_hangup. The tty should - * always be valid at this time unless a simultaneous tty close already - * cleaned up the hvc_struct. + * This function call will auto chain call hvc_hangup. */ - if (tty) - tty_hangup(tty); + if (tty) { + tty_vhangup(tty); + tty_kref_put(tty); + } return 0; } EXPORT_SYMBOL_GPL(hvc_remove); -- cgit v1.2.3 From d4bee0a677cfa5a32f964ffa420e27406c65e605 Mon Sep 17 00:00:00 2001 From: Fang Wenqi Date: Tue, 9 Mar 2010 18:54:28 +0800 Subject: tty_buffer: Fix distinct type warning MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit CC drivers/char/tty_buffer.o drivers/char/tty_buffer.c: In function ‘tty_insert_flip_string_fixed_flag’: drivers/char/tty_buffer.c:251: warning: comparison of distinct pointer types lacks a cast drivers/char/tty_buffer.c: In function ‘tty_insert_flip_string_flags’: drivers/char/tty_buffer.c:288: warning: comparison of distinct pointer types lacks a cast Fix it by replacing min() with min_t() in tty_insert_flip_string_flags and tty_insert_flip_string_fixed_flag(). Signed-off-by: Fang Wenqi Signed-off-by: Greg Kroah-Hartman --- drivers/char/tty_buffer.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'drivers/char') diff --git a/drivers/char/tty_buffer.c b/drivers/char/tty_buffer.c index af8d9771572..7ee52164d47 100644 --- a/drivers/char/tty_buffer.c +++ b/drivers/char/tty_buffer.c @@ -248,7 +248,7 @@ int tty_insert_flip_string_fixed_flag(struct tty_struct *tty, { int copied = 0; do { - int goal = min(size - copied, TTY_BUFFER_PAGE); + int goal = min_t(size_t, size - copied, TTY_BUFFER_PAGE); int space = tty_buffer_request_room(tty, goal); struct tty_buffer *tb = tty->buf.tail; /* If there is no space then tb may be NULL */ @@ -285,7 +285,7 @@ int tty_insert_flip_string_flags(struct tty_struct *tty, { int copied = 0; do { - int goal = min(size - copied, TTY_BUFFER_PAGE); + int goal = min_t(size_t, size - copied, TTY_BUFFER_PAGE); int space = tty_buffer_request_room(tty, goal); struct tty_buffer *tb = tty->buf.tail; /* If there is no space then tb may be NULL */ -- cgit v1.2.3 From 336cee42dd52824e360ab419eab4e8888eb054ec Mon Sep 17 00:00:00 2001 From: Jason Wessel Date: Mon, 8 Mar 2010 21:50:11 -0600 Subject: tty_port,usb-console: Fix usb serial console open/close regression Commit e1108a63e10d344284011cccc06328b2cd3e5da3 ("usb_serial: Use the shutdown() operation") breaks the ability to use a usb console starting in 2.6.33. This was observed when using console=ttyUSB0,115200 as a boot argument with an FTDI device. The error is: ftdi_sio ttyUSB0: ftdi_submit_read_urb - failed submitting read urb, error -22 The handling of the ASYNCB_INITIALIZED changed in 2.6.32 such that in tty_port_shutdown() it always clears the flag if it is set. The fix is to add a variable to the tty_port struct to indicate when the tty port is a console. CC: Alan Cox CC: Alan Stern CC: Oliver Neukum CC: Andrew Morton Signed-off-by: Jason Wessel Signed-off-by: Greg Kroah-Hartman --- drivers/char/tty_port.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/char') diff --git a/drivers/char/tty_port.c b/drivers/char/tty_port.c index be492dd6643..a3bd1d0b66c 100644 --- a/drivers/char/tty_port.c +++ b/drivers/char/tty_port.c @@ -119,7 +119,7 @@ EXPORT_SYMBOL(tty_port_tty_set); static void tty_port_shutdown(struct tty_port *port) { mutex_lock(&port->mutex); - if (port->ops->shutdown && + if (port->ops->shutdown && !port->console && test_and_clear_bit(ASYNCB_INITIALIZED, &port->flags)) port->ops->shutdown(port); mutex_unlock(&port->mutex); -- cgit v1.2.3