kernel/linux.git/include/linux/parport.h, branch v5.10.259

parport: Fix race between port and client registration

2026-06-19T11:21:28+00:00

commit ef15ccbb3e8640a723c42ad90eaf81d66ae02017 upstream. The parport subsystem registers port devices before they are fully initialised, resulting in a race condition where client drivers such as lp can attach to ports that are not completely initialised or even being torn down. When the port and client drivers are built as modules and loaded around the same time during boot, this occasionally results in a crash. I was able to make this happen reliably in a VM with a PC-style parallel port by patching parport_pc to fail probing: > --- a/drivers/parport/parport_pc.c > +++ b/drivers/parport/parport_pc.c > @@ -2069,7 +2069,7 @@ static struct parport *__parport_pc_probe_port(unsigned long int base, > if (!p) > goto out3; > > - base_res = request_region(base, 3, p->name); > + base_res = NULL; > if (!base_res) > goto out4; > and then running: while true; do modprobe lp & modprobe parport_pc wait rmmod lp parport_pc done for a few seconds. In the long term I think port registration should be changed to put the call to device_add() inside parport_announce_port(), but since the latter currently cannot fail this will require changing all port drivers. For now, add a flag to indicate whether a port has been "announced" and only try to attach client drivers to ports when the flag is set. Fixes: 6fa45a226897 ("parport: add device-model to parport subsystem") Closes: https://bugs.debian.org/1130365 Closes: https://lore.kernel.org/all/6ba903ad-9897-42bb-8c2d-337385cc3746@molgen.mpg.de/ Cc: stable Signed-off-by: Ben Hutchings Acked-by: Sudip Mukherjee Link: https://patch.msgid.link/afo6uBv68GDevbMD@decadent.org.uk Signed-off-by: Greg Kroah-Hartman Signed-off-by: Greg Kroah-Hartman

parport: remove unused parport_register_device()

2020-04-23T15:05:39+00:00

All the drivers that are using parallel port has been converted to use the new device model api, and parport_register_device() is no longer used. Signed-off-by: Sudip Mukherjee Link: https://lore.kernel.org/r/20200403134325.11523-10-sudipm.mukherjee@gmail.com Signed-off-by: Greg Kroah-Hartman

parport: Add comments for parport_register_dev_model()

2020-04-23T15:05:39+00:00

In preparation to remove parport_register_device(), copy the comments to parport_register_dev_model() and modify the parameters according to what parport_register_dev_model() has. Signed-off-by: Sudip Mukherjee Link: https://lore.kernel.org/r/20200403134325.11523-9-sudipm.mukherjee@gmail.com Signed-off-by: Greg Kroah-Hartman

parport: daisy: avoid hardcoded name

2019-11-13T11:09:47+00:00

The daisy device name is hardcoded, define it in the header file and use it in the code. Signed-off-by: Sudip Mukherjee Link: https://lore.kernel.org/r/20191016144540.18810-1-sudipm.mukherjee@gmail.com Signed-off-by: Greg Kroah-Hartman

Revert "parport: daisy: use new parport device model"

2019-03-25T21:49:00+00:00

This reverts commit 1aec4211204d9463d1fd209eb50453de16254599. Steven Rostedt reports that it causes a hang at bootup and bisected it to this commit. The troigger is apparently a module alias for "parport_lowlevel" that points to "parport_pc", which causes a hang with modprobe -q -- parport_lowlevel blocking forever with a backtrace like this: wait_for_completion_killable+0x1c/0x28 call_usermodehelper_exec+0xa7/0x108 __request_module+0x351/0x3d8 get_lowlevel_driver+0x28/0x41 [parport] __parport_register_driver+0x39/0x1f4 [parport] daisy_drv_init+0x31/0x4f [parport] parport_bus_init+0x5d/0x7b [parport] parport_default_proc_register+0x26/0x1000 [parport] do_one_initcall+0xc2/0x1e0 do_init_module+0x50/0x1d4 load_module+0x1c2e/0x21b3 sys_init_module+0xef/0x117 Supid says: "Due to the new device model daisy driver will now try to find the parallel ports while trying to register its driver so that it can bind with them. Now, since daisy driver is loaded while parport bus is initialising the list of parport is still empty and it tries to load the lowlevel driver, which has an alias set to parport_pc, now causes a deadlock" But I don't think the daisy driver should be loaded by the parport initialization in the first place, so let's revert the whole change. If the daisy driver can just initialize separately on its own (like a driver should), instead of hooking into the parport init sequence directly, this issue probably would go away. Reported-and-bisected-by: Steven Rostedt (VMware) Reported-by: Michal Kubecek Acked-by: Greg Kroah-Hartman Cc: Sudip Mukherjee Signed-off-by: Linus Torvalds

parport: daisy: use new parport device model

2019-02-13T18:45:56+00:00

Modify parport daisy driver to use the new parallel port device model. Signed-off-by: Sudip Mukherjee Signed-off-by: Greg Kroah-Hartman

timer: Remove init_timer_on_stack() in favor of timer_setup_on_stack()

2017-10-05T13:01:17+00:00

Remove uses of init_timer_on_stack() with open-coded function and data assignments that could be expressed using timer_setup_on_stack(). Several were removed from the stack entirely since there was a one-to-one mapping of parent structure to timer, those are switched to using timer_setup() instead. All related callbacks were adjusted to use from_timer(). Signed-off-by: Kees Cook Signed-off-by: Thomas Gleixner Cc: linux-mips@linux-mips.org Cc: Petr Mladek Cc: Benjamin Herrenschmidt Cc: Heiko Carstens Cc: Sebastian Reichel Cc: Kalle Valo Cc: Paul Mackerras Cc: Pavel Machek Cc: Wim Van Sebroeck Cc: linux1394-devel@lists.sourceforge.net Cc: Chris Metcalf Cc: linux-s390@vger.kernel.org Cc: linux-wireless@vger.kernel.org Cc: "James E.J. Bottomley" Cc: linux-scsi@vger.kernel.org Cc: Michael Ellerman Cc: Ursula Braun Cc: Geert Uytterhoeven Cc: Viresh Kumar Cc: Harish Patil Cc: Stephen Boyd Cc: Michael Reed Cc: Manish Chopra Cc: Len Brown Cc: Arnd Bergmann Cc: linux-pm@vger.kernel.org Cc: Lai Jiangshan Cc: Tejun Heo Cc: Julian Wiedmann Cc: John Stultz Cc: Mark Gross Cc: linux-watchdog@vger.kernel.org Cc: "Martin K. Petersen" Cc: Greg Kroah-Hartman Cc: "Rafael J. Wysocki" Cc: Oleg Nesterov Cc: Ralf Baechle Cc: Stefan Richter Cc: Guenter Roeck Cc: netdev@vger.kernel.org Cc: Martin Schwidefsky Cc: Andrew Morton Cc: linuxppc-dev@lists.ozlabs.org Cc: Sudip Mukherjee Link: https://lkml.kernel.org/r/1507159627-127660-4-git-send-email-keescook@chromium.org

parport: add device-model to parport subsystem

2015-05-31T22:08:18+00:00

parport subsystem starts using the device-model. Drivers using the device-model has to define devmodel as true and should register the device with parport using parport_register_dev_model(). Tested-by: Jean Delvare Tested-by: Alan Cox Signed-off-by: Sudip Mukherjee Signed-off-by: Greg Kroah-Hartman

UAPI: (Scripted) Disintegrate include/linux

2012-10-13T09:46:48+00:00

Signed-off-by: David Howells Acked-by: Arnd Bergmann Acked-by: Thomas Gleixner Acked-by: Michael Kerrisk Acked-by: Paul E. McKenney Acked-by: Dave Jones

Remove all #inclusions of asm/system.h

2012-03-28T17:30:03+00:00

Remove all #inclusions of asm/system.h preparatory to splitting and killing it. Performed with the following command: perl -p -i -e 's!^#\s*include\s*.*\n!!' `grep -Irl '^#\s*include\s*' *` Signed-off-by: David Howells