Currently many console drivers for s390 rely on panic/reboot notifiers
to invoke callbacks on these events. The panic() function disables local
IRQs, secondary CPUs and preemption, so callbacks invoked on panic are
effectively running in atomic context.
Happens that most of these console callbacks from s390 doesn't take the
proper care with regards to atomic context, like taking spinlocks that
might be taken in other function/CPU and hence will cause a lockup
situation.
The goal for this patch is to improve the notifiers reliability, acting
on 4 console drivers, as detailed below:
(1) con3215: changed a regular spinlock to the trylock alternative.
(2) con3270: also changed a regular spinlock to its trylock counterpart,
but here we also have another problem: raw3270_activate_view() takes a
different spinlock. So, we worked a helper to validate if this other lock
is safe to acquire, and if so, raw3270_activate_view() should be safe.
Notice though that there is a functional change here: it's now possible
to continue the notifier code [reaching con3270_wait_write() and
con3270_rebuild_update()] without executing raw3270_activate_view().
(3) sclp: a global lock is used heavily in the functions called from
the notifier, so we added a check here - if the lock is taken already,
we just bail-out, preventing the lockup.
(4) sclp_vt220: same as (3), a lock validation was added to prevent the
potential lockup problem.
Besides (1)-(4), we also removed useless void functions, adding the
code called from the notifier inside its own body, and changed the
priority of such notifiers to execute late, since they are "heavyweight"
for the panic environment, so we aim to reduce risks here.
Changed return values to NOTIFY_DONE as well, the standard one.
Signed-off-by: Guilherme G. Piccoli <gpiccoli@igalia.com>
Link: https://lore.kernel.org/r/20220427224924.592546-14-gpiccoli@igalia.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
cleanup the s390's use of the timer API
- del_timer() contains timer_pending() condition
- mod_timer(timer, expires) is equivalent to:
del_timer(timer);
timer->expires = expires;
add_timer(timer);
If the timer is inactive it will be activated, using add_timer() on
condition !timer_pending(&private->timer) is redundant.
Just cleanup, no logic change.
Signed-off-by: Yu Liao <liaoyu15@huawei.com>
Link: https://lore.kernel.org/r/20220322030057.1243196-1-liaoyu15@huawei.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
When CONFIG_SCLP_VT220_TTY=y and CONFIG_SCLP_VT220_CONSOLE is not set:
../drivers/s390/char/sclp_vt220.c:771:13: warning: '__sclp_vt220_flush_buffer' defined but not used [-Wunused-function]
771 | static void __sclp_vt220_flush_buffer(void)
so move this function inside the #ifdef block where it is used.
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Link: https://lore.kernel.org/r/20210927215647.11506-1-rdunlap@infradead.org
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
put_tty_driver() is an alias for tty_driver_kref_put(). There is no need
for two exported identical functions, therefore switch all users of
old put_tty_driver() to new tty_driver_kref_put() and remove the former
for good.
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Samuel Iglesias Gonsalvez <siglesias@igalia.com>
Cc: Jens Taprogge <jens.taprogge@taprogge.org>
Cc: Karsten Keil <isdn@linux-pingi.de>
Cc: Scott Branden <scott.branden@broadcom.com>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: David Lin <dtwlin@gmail.com>
Cc: Johan Hovold <johan@kernel.org>
Cc: Alex Elder <elder@kernel.org>
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: Laurentiu Tudor <laurentiu.tudor@nxp.com>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: David Sterba <dsterba@suse.com>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Pengutronix Kernel Team <kernel@pengutronix.de>
Cc: Fabio Estevam <festevam@gmail.com>
Cc: NXP Linux Team <linux-imx@nxp.com>
Cc: Oliver Neukum <oneukum@suse.com>
Cc: Felipe Balbi <balbi@kernel.org>
Cc: Mathias Nyman <mathias.nyman@intel.com>
Cc: Marcel Holtmann <marcel@holtmann.org>
Cc: Johan Hedberg <johan.hedberg@gmail.com>
Cc: Luiz Augusto von Dentz <luiz.dentz@gmail.com>
Acked-by: Alex Elder <elder@linaro.org>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Max Filippov <jcmvbkbc@gmail.com>
Acked-by: David Sterba <dsterba@suse.com>
Acked-by: Samuel Iglesias Gonsálvez <siglesias@igalia.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210723074317.32690-8-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
alloc_tty_driver was deprecated by tty_alloc_driver in commit
7f0bc6a68e (TTY: pass flags to alloc_tty_driver) in 2012.
I never got into eliminating alloc_tty_driver until now. So we still
have two functions for allocating drivers which might be confusing. So
get rid of alloc_tty_driver uses to eliminate it for good in the next
patch.
Note we need to switch return value checking as tty_alloc_driver uses
ERR_PTR. And flags are now a parameter of tty_alloc_driver.
Cc: Richard Henderson <rth@twiddle.net>(odd fixer:ALPHA PORT)
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Samuel Iglesias Gonsalvez <siglesias@igalia.com>
Cc: Jens Taprogge <jens.taprogge@taprogge.org>
Cc: Karsten Keil <isdn@linux-pingi.de>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Laurentiu Tudor <laurentiu.tudor@nxp.com>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: David Sterba <dsterba@suse.com>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Oliver Neukum <oneukum@suse.com>
Cc: Felipe Balbi <balbi@kernel.org>
Cc: Johan Hovold <johan@kernel.org>
Cc: Marcel Holtmann <marcel@holtmann.org>
Cc: Johan Hedberg <johan.hedberg@gmail.com>
Cc: Luiz Augusto von Dentz <luiz.dentz@gmail.com>
Acked-by: Samuel Iglesias Gonsálvez <siglesias@igalia.com>
Acked-by: Max Filippov <jcmvbkbc@gmail.com>
Acked-by: David Sterba <dsterba@suse.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210723074317.32690-5-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Here is the big set of tty and serial driver patches for 5.14-rc1.
A bit more than normal, but nothing major, lots of cleanups. Highlights
are:
- lots of tty api cleanups and mxser driver cleanups from Jiri
- build warning fixes
- various serial driver updates
- coding style cleanups
- various tty driver minor fixes and updates
- removal of broken and disable r3964 line discipline (finally!)
All of these have been in linux-next for a while with no reported
issues.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'tty-5.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty
Pull tty / serial updates from Greg KH:
"Here is the big set of tty and serial driver patches for 5.14-rc1.
A bit more than normal, but nothing major, lots of cleanups.
Highlights are:
- lots of tty api cleanups and mxser driver cleanups from Jiri
- build warning fixes
- various serial driver updates
- coding style cleanups
- various tty driver minor fixes and updates
- removal of broken and disable r3964 line discipline (finally!)
All of these have been in linux-next for a while with no reported
issues"
* tag 'tty-5.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (227 commits)
serial: mvebu-uart: remove unused member nb from struct mvebu_uart
arm64: dts: marvell: armada-37xx: Fix reg for standard variant of UART
dt-bindings: mvebu-uart: fix documentation
serial: mvebu-uart: correctly calculate minimal possible baudrate
serial: mvebu-uart: do not allow changing baudrate when uartclk is not available
serial: mvebu-uart: fix calculation of clock divisor
tty: make linux/tty_flip.h self-contained
serial: Prefer unsigned int to bare use of unsigned
serial: 8250: 8250_omap: Fix possible interrupt storm on K3 SoCs
serial: qcom_geni_serial: use DT aliases according to DT bindings
Revert "tty: serial: Add UART driver for Cortina-Access platform"
tty: serial: Add UART driver for Cortina-Access platform
MAINTAINERS: add me back as mxser maintainer
mxser: Documentation, fix typos
mxser: Documentation, make the docs up-to-date
mxser: Documentation, remove traces of callout device
mxser: introduce mxser_16550A_or_MUST helper
mxser: rename flags to old_speed in mxser_set_serial_info
mxser: use port variable in mxser_set_serial_info
mxser: access info->MCR under info->slock
...
- Rework inline asm to get rid of error prone "register asm" constructs,
which are problematic especially when code instrumentation is enabled. In
particular introduce and use register pair union to allocate even/odd
register pairs. Unfortunately this breaks compatibility with older
clang compilers and minimum clang version for s390 has been raised to 13.
https://lore.kernel.org/linux-next/CAK7LNARuSmPCEy-ak0erPrPTgZdGVypBROFhtw+=3spoGoYsyw@mail.gmail.com/
- Fix gcc 11 warnings, which triggered various minor reworks all over
the code.
- Add zstd kernel image compression support.
- Rework boot CPU lowcore handling.
- De-duplicate and move kernel memory layout setup logic earlier.
- Few fixes in preparation for FORTIFY_SOURCE performing compile-time
and run-time field bounds checking for mem functions.
- Remove broken and unused power management support leftovers in s390
drivers.
- Disable stack-protector for decompressor and purgatory to fix buildroot
build.
- Fix vt220 sclp console name to match the char device name.
- Enable HAVE_IOREMAP_PROT and add zpci_set_irq()/zpci_clear_irq() in
zPCI code.
- Remove some implausible WARN_ON_ONCEs and remove arch specific counter
transaction call backs in favour of default transaction handling in
perf code.
- Extend/add new uevents for online/config/mode state changes of
AP card / queue device in zcrypt.
- Minor entry and ccwgroup code improvements.
- Other small various fixes and improvements all over the code.
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Merge tag 's390-5.14-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Pull s390 updates from Vasily Gorbik:
- Rework inline asm to get rid of error prone "register asm"
constructs, which are problematic especially when code
instrumentation is enabled.
In particular introduce and use register pair union to allocate
even/odd register pairs. Unfortunately this breaks compatibility with
older clang compilers and minimum clang version for s390 has been
raised to 13.
https://lore.kernel.org/linux-next/CAK7LNARuSmPCEy-ak0erPrPTgZdGVypBROFhtw+=3spoGoYsyw@mail.gmail.com/
- Fix gcc 11 warnings, which triggered various minor reworks all over
the code.
- Add zstd kernel image compression support.
- Rework boot CPU lowcore handling.
- De-duplicate and move kernel memory layout setup logic earlier.
- Few fixes in preparation for FORTIFY_SOURCE performing compile-time
and run-time field bounds checking for mem functions.
- Remove broken and unused power management support leftovers in s390
drivers.
- Disable stack-protector for decompressor and purgatory to fix
buildroot build.
- Fix vt220 sclp console name to match the char device name.
- Enable HAVE_IOREMAP_PROT and add zpci_set_irq()/zpci_clear_irq() in
zPCI code.
- Remove some implausible WARN_ON_ONCEs and remove arch specific
counter transaction call backs in favour of default transaction
handling in perf code.
- Extend/add new uevents for online/config/mode state changes of AP
card / queue device in zcrypt.
- Minor entry and ccwgroup code improvements.
- Other small various fixes and improvements all over the code.
* tag 's390-5.14-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (91 commits)
s390/dasd: use register pair instead of register asm
s390/qdio: get rid of register asm
s390/ioasm: use symbolic names for asm operands
s390/ioasm: get rid of register asm
s390/cmf: get rid of register asm
s390/lib,string: get rid of register asm
s390/lib,uaccess: get rid of register asm
s390/string: get rid of register asm
s390/cmpxchg: use register pair instead of register asm
s390/mm,pages-states: get rid of register asm
s390/lib,xor: get rid of register asm
s390/timex: get rid of register asm
s390/hypfs: use register pair instead of register asm
s390/zcrypt: Switch to flexible array member
s390/speculation: Use statically initialized const for instructions
virtio/s390: get rid of open-coded kvm hypercall
s390/pci: add zpci_set_irq()/zpci_clear_irq()
scripts/min-tool-version.sh: Raise minimum clang version to 13.0.0 for s390
s390/ipl: use register pair instead of register asm
s390/mem_detect: fix tprot() program check new psw handling
...
kernel.h is being used as a dump for all kinds of stuff for a long time.
Here is the attempt to start cleaning it up by splitting out panic and
oops helpers.
There are several purposes of doing this:
- dropping dependency in bug.h
- dropping a loop by moving out panic_notifier.h
- unload kernel.h from something which has its own domain
At the same time convert users tree-wide to use new headers, although for
the time being include new header back to kernel.h to avoid twisted
indirected includes for existing users.
[akpm@linux-foundation.org: thread_info.h needs limits.h]
[andriy.shevchenko@linux.intel.com: ia64 fix]
Link: https://lkml.kernel.org/r/20210520130557.55277-1-andriy.shevchenko@linux.intel.com
Link: https://lkml.kernel.org/r/20210511074137.33666-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Co-developed-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: Corey Minyard <cminyard@mvista.com>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Wei Liu <wei.liu@kernel.org>
Acked-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Sebastian Reichel <sre@kernel.org>
Acked-by: Luis Chamberlain <mcgrof@kernel.org>
Acked-by: Stephen Boyd <sboyd@kernel.org>
Acked-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Acked-by: Helge Deller <deller@gmx.de> # parisc
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Power management support was removed for s390 with
commit 394216275c ("s390: remove broken hibernate / power management
support").
Remove leftover sclp vt220-related power management code.
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Console name reported in /proc/consoles:
ttyS1 -W- (EC p ) 4:65
does not match the char device name:
crw--w---- 1 root root 4, 65 May 17 12:18 /dev/ttysclp0
so debian-installer inside a QEMU s390x instance gets confused and fails
to start with the following error:
steal-ctty: No such file or directory
Signed-off-by: Valentin Vidic <vvidic@valentin-vidic.from.hr>
Link: https://lore.kernel.org/r/20210427194010.9330-1-vvidic@valentin-vidic.from.hr
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
tty_operations::chars_in_buffer is another hook which is expected to
return values >= 0. So make it explicit by the return type too -- use
unsigned int.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Acked-By: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Acked-by: David Sterba <dsterba@suse.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Samuel Iglesias Gonsalvez <siglesias@igalia.com>
Cc: Jens Taprogge <jens.taprogge@taprogge.org>
Cc: Karsten Keil <isdn@linux-pingi.de>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: David Lin <dtwlin@gmail.com>
Cc: Johan Hovold <johan@kernel.org>
Cc: Alex Elder <elder@kernel.org>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Oliver Neukum <oneukum@suse.com>
Cc: Felipe Balbi <balbi@kernel.org>
Cc: Mathias Nyman <mathias.nyman@intel.com>
Cc: Marcel Holtmann <marcel@holtmann.org>
Cc: Johan Hedberg <johan.hedberg@gmail.com>
Cc: Luiz Augusto von Dentz <luiz.dentz@gmail.com>
Link: https://lore.kernel.org/r/20210505091928.22010-27-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Line disciplines expect a positive value or zero returned from
tty->ops->write_room (invoked by tty_write_room). So make this
assumption explicit by using unsigned int as a return value. Both of
tty->ops->write_room and tty_write_room.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Acked-by: Laurentiu Tudor <laurentiu.tudor@nxp.com>
Acked-by: Alex Elder <elder@linaro.org>
Acked-by: Max Filippov <jcmvbkbc@gmail.com> # xtensa
Acked-by: David Sterba <dsterba@suse.com>
Acked-By: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Chris Zankel <chris@zankel.net>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Samuel Iglesias Gonsalvez <siglesias@igalia.com>
Cc: Jens Taprogge <jens.taprogge@taprogge.org>
Cc: Karsten Keil <isdn@linux-pingi.de>
Cc: Scott Branden <scott.branden@broadcom.com>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: David Lin <dtwlin@gmail.com>
Cc: Johan Hovold <johan@kernel.org>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Oliver Neukum <oneukum@suse.com>
Cc: Felipe Balbi <balbi@kernel.org>
Cc: Mathias Nyman <mathias.nyman@intel.com>
Cc: Marcel Holtmann <marcel@holtmann.org>
Cc: Johan Hedberg <johan.hedberg@gmail.com>
Cc: Luiz Augusto von Dentz <luiz.dentz@gmail.com>
Link: https://lore.kernel.org/r/20210505091928.22010-23-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The main purpose of tty_port::low_latency was removed in commit
a9c3f68f3c (tty: Fix low_latency BUG) back in 2014. It was left in
place for drivers as an optional tune knob. But only one driver has been
using it until the previous commit. So remove this misconcept
completely, given there are no users.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210105120239.28031-11-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In preparation for unconditionally passing the struct timer_list pointer to
all timer callbacks, switch to using the new timer_setup() and from_timer()
to pass the timer pointer explicitly. Instead of creating an external static
data variable, just define a separate callback which encodes the "force
restart" desire.
Cc: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
[heiko.carstens@de.ibm.com: get rid of compile warning]
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.
By default all files without license information are under the default
license of the kernel, which is GPL version 2.
Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.
This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.
How this work was done:
Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,
Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.
The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.
The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.
Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).
All documentation files were explicitly excluded.
The following heuristics were used to determine which SPDX license
identifiers to apply.
- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.
For non */uapi/* files that summary was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139
and resulted in the first patch in this series.
If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930
and resulted in the second patch in this series.
- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:
SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1
and that resulted in the third patch in this series.
- when the two scanners agreed on the detected license(s), that became
the concluded license(s).
- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.
- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).
- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.
- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.
In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.
Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.
Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.
In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.
Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct
This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.
These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This was entirely automated, using the script by Al:
PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*<asm/uaccess.h>'
sed -i -e "s!$PATT!#include <linux/uaccess.h>!" \
$(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h)
to do the replacement at the end of the merge window.
Requested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Implement magic sysrequest handling for the VT220 terminal (also known as
the Integrated ASCII console on the HMC/SE).
To invoke a "magic sysrequest" function, press "Ctrl+o" followed by a
second character that designates the debugging function.
The handling of the sysrq is scheduled away from the SCLP IRQ context;
because large amounts of sysrq output might fill up the console buffers.
The console might deadlock because it cannot empty the buffers while still
in the receiving IRQ context. This behavior is the same as for the SCLP
console.
Reported-by: Horst Weber <hweber@de.ibm.com>
Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Reviewed-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The event type masks can change asynchronously. These changes are reported
by SCLP to the OS by state-change events which are retrieved with the read
event data command. The SCLP driver has a request queue, there is a window
where the read event data request has not completed yet but the SCLP console
drivers are trying to queue output requests. As the masks are not updated
yet the requests are discarded.
The simplest fix is to queue the console requests independent of the
event type masks and rely on SCLP to return with an error code if a
specific event type is not available.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
When you want to use the HMC's ASCII console as console device for
a z/VM guest you have to specify console=ttyS1 on the kernel command
line. But it won't work until you specify conmode=sclp as well.
This behavior is inconsistent with the use of the ASCII console as
TTY device which works on z/VM without the need to specify a conmode.
Fix this inconsistency by removing the check for conmode=sclp in the
ASCII console registration function.
Signed-off-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
A kernel panic might occur when there is terminal input available via
the SCLP VT220 interface at an early time during the boot process.
The processing of terminal input requires prior initialization which is
done via an early_initcall function (init_workqueues) while the SCLP
VT220 driver registers for terminal input during a console_initcall
function (sclp_vt220_con_init). When there is terminal input available
via the SCLP interface between console_initcall and early_initcall, a
null pointer dereference occurs (system_wq is null).
Fix this problem by moving the registration for terminal input to a
device_initcall function (sclp_vt220_tty_init).
Reported-by: Christian Borntraeger <borntraeger@de.ibm.com>
Tested-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Add a kernel parameter to be able to specify the number of pages to be
used as output buffer by the line-mode sclp driver and the vt220 sclp
driver. The current number of output pages is 6, if the service element
is unavailable the boot messages alone can fill up the output buffer.
If this happens the system blocks until the service element is working
again. For a large LPAR with many devices it is sensible to have the
ability to increase the output buffer size. To help to debug this
situation add a counter for the page-pool-empty situation and make it
available as a sclp driver attribute.
To avoid the system to stall until the service element works again
add another kernel parameter to allow to drop output buffers.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
It allows for cleaning up on a considerable amount of places. They did
port_get, wakeup, kref_put. Now the only thing needed is to call
tty_port_tty_wakeup which does exactly that.
One exception is ifx6x60 where tty_wakeup was open-coded. We now call
tty_wakeup properly there.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Now, we start converting tty buffer functions to actually use
tty_port. This will allow us to get rid of the need of tty in many
call sites. Only tty_port will needed and hence no more
tty_port_tty_get in those paths.
Now, the one where most of tty_port_tty_get gets removed:
tty_flip_buffer_push.
IOW we also closed all the races in drivers not using tty_port_tty_get
at all yet.
Also we move tty_flip_buffer_push declaration from include/linux/tty.h
to include/linux/tty_flip.h to all others while we are changing it
anyway.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
One point is to have less places where we actually need tty pointer.
The other is that low_latency is bound to buffer processing and
buffers are now in tty_port. So it makes sense to move low_latency to
tty_port too.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Now, we start converting tty buffer functions to actually use
tty_port. This will allow us to get rid of the need of tty in many
call sites. Only tty_port will needed and hence no more
tty_port_tty_get in those paths.
tty_insert_flip_string this time.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
After commit "TTY: move tty buffers to tty_port", the tty buffers are
not freed in some drivers. This is because tty_port_destructor is not
called whenever a tty_port is freed. This was an assumption I counted
with but was unfortunately untrue. So fix the drivers to fulfil this
assumption.
To be sure, the TTY buffers (and later some stuff) are gone along with
the tty_port, we have to call tty_port_destroy at tear-down places.
This is mostly where the structure containing a tty_port is freed.
This patch does exactly that -- put tty_port_destroy at those places.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
So now for those drivers that can use neither tty_port_install nor
tty_port_register_driver but still have tty_port available before
tty_register_driver we use newly added tty_port_link_device.
The rest of the drivers that still do not provide tty_struct <->
tty_port link will have to be converted to implement
tty->ops->install.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
80 bytes which are allocated in tty->ops->open and assigned to
tty->driver_data are never used. Remove that.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: linux390@de.ibm.com
Cc: linux-s390@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tty_port will hold tty buffers in the future. So we need to have it
even here. The only needed member here is tty, so let us store it in
the structure now.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: linux390@de.ibm.com
Cc: linux-s390@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
All num, magic and owner are set by alloc_tty_driver. No need to
re-set them on each allocation site.
pti driver sets something different to what it passes to
alloc_tty_driver. It is not a bug, since we don't use the lines
parameter in any way. Anyway this is fixed, and now we do the right
thing.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Acked-by: Tilman Schmidt <tilman@imap.cc>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.
percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.
http://userweb.kernel.org/~tj/misc/slabh-sweep.py
The script does the followings.
* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.
* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.
* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.
The conversion was done in the following steps.
1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.
2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.
3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.
4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.
5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.
6. percpu.h was updated not to include slab.h.
7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).
* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig
8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.
Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
When opening a SCLP VT220 terminal, the terminal window size is not
initialized (defaults to zero).
Since the SCLP VT220 terminal supports only 80x24, explicitly set
the window size to prevent (n)curses applications from guessing
the default setting.
Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Fix this build error:
next-20091013 randconfig build on s390x build breaks with
drivers/s390/built-in.o:(.data+0x3354): undefined reference to `sclp_vt220_pm_event_fn'
Reported-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Signed-off-by: Michael Holzheu <michael.holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The slab allocator is earlier available so convert the
bootmem allocations to slab/gfp allocations.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The SCLP base driver defines a new notifier call back for all upper level SCLP
drivers, like the SCLP console, etc. This guarantees that in suspend first the
upper level drivers are suspended and afterwards the SCLP base driver. For
resume it is the other way round. The SCLP base driver itself registers a
new platform device at the platform bus and gets PM notifications via
the dev_pm_ops.
In suspend, the SCLP base driver switches off the receiver and sender mask
This is done in sclp_deactivate(). After suspend all new requests will be
rejected with -EIO and no more interrupts will be received, because the masks
are switched off. For resume the sender and receiver masks are reset in
the sclp_reactivate() function.
When the SCLP console is suspended, all new messages are cached in the
sclp console buffers. In resume, all the cached messages are written to the
console. In addition to that we have an early resume function that removes
the cached messages from the suspend image.
Signed-off-by: Michael Holzheu <holzheu@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
get rid of this one:
CC drivers/s390/char/sclp_vt220.o
drivers/s390/char/sclp_vt220.c:588: warning: '__sclp_vt220_flush_buffer' defined but not used
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The s390 console drivers use the unblank callback of the console
structure to flush the console buffer. In case of a panic or a
reboot the CPU doing the callback can block on the console i/o.
The other CPUs in the system continue to work. For panic this is
not a good idea.
Replace the unblank callback with proper panic/reboot notifier.
These get called after all but one CPU have been stopped.
Signed-off-by: Holger Smolinski <Holger.Smolinski@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Fix a number of sclp_vt220 cleanup problems:
* fix list_empty check after list_del()
* mark init-only flag as __initdata
* remove implicit dependency between slab_available() and num_pages
* straighten multiple init handling (use init count)
Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
The driver incorrectly assumed that putchar will only be called from
schedulable process context and therefore blocked and waited if no
free output buffers where available.
Since putchar may also be called from BH context this may lead to
deadlocks.
To fix this just return the number of characters accepted and let the
upper layer handle the rest.
The console write function will busy wait (sclp_sync_wait) until a
buffer is available again.
Cc: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Put the changes into the drivers first. This will still compile/work but
produce a warning if bisected so can still be debugged
Signed-off-by: Alan Cox <alan@redhat.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Reintroduces in_interrupt() check in sclp_tty code. Add may_schedule
parameter to vt220 write function, so we can let the write function
know if it may schedule or not. So we disallow scheduling for all
console calls and may allow them for tty calls.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Currently an output buffer can wait up to HZ/2 until the buffer is
flushed. The wait time is noticeable in interactive tools like mc.
Change the value to HZ/20, which seems enough for interactive work.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Make state change events adjust the correct mask by cleaning up
naming inconsistencies. Also remove chance for lockup by removing
unnecessary mask related check before reading events.
Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
There are two problems in the vt220 intialization:
o Currently the vt220 console looses early printk events until the
the vt220 tty is registered.
o console should work if tty_register fails
sclp_vt220_con_init calls __sclp_vt220_init and register_console.
It does not register the driver with the sclp core code via
sclp_register. That results in an sclp_send_mask=0. Therefore,
__sclp_vt220_emit will reject buffers with EIO. Unfortunately
register_console will cause the printk buffer to be sent to the
console and, therefore, every early message gets dropped. The
sclp_send_mask is set later during boot, when sclp_vt220_tty_init
calls sclp_register.
The solution is to move the sclp_register call from sclp_vt220_tty_init
to __sclp_vt220_init. This makes sure that the console is properly
registered with the sclp subsystem before the first log buffer messages
are passed to the vt220 console.
We also adopt the cleanup on error to keep the console alive if
tty_register fails.
Thanks to Peter Oberparleiter and Heiko Carstens for review and ideas
for improvement.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Under load the following bug message appeared while using sysrq-t:
BUG: scheduling while atomic: bash/3662/0x00000004
0000000000105b74 000000003ba17740 0000000000000002 0000000000000000
000000003ba177e0 000000003ba17758 000000003ba17758 0000000000105bfe
0000000000817ba8 000000003f2a5350 0000000000000000 0000000000000000
000000003ba17740 000000000000000c 000000003ba17740 000000003ba177b0
0000000000568630 0000000000105bfe 000000003ba17740 000000003ba17790
Call Trace:
([<0000000000105b74>] show_trace+0x13c/0x158)
[<0000000000105c58>] show_stack+0xc8/0xfc
[<0000000000105cbc>] dump_stack+0x30/0x40
[<000000000012a0c8>] __schedule_bug+0x84/0x94
[<000000000056234e>] schedule+0x5ea/0x970
[<0000000000477cd2>] __sclp_vt220_write+0x1f6/0x3ec
[<0000000000477f00>] sclp_vt220_con_write+0x38/0x48
[<0000000000130b4a>] __call_console_drivers+0xbe/0xd8
[<0000000000130bf0>] _call_console_drivers+0x8c/0xd0
[<0000000000130eea>] release_console_sem+0x1a6/0x2fc
[<0000000000131786>] vprintk+0x262/0x480
[<00000000001319fa>] printk+0x56/0x68
[<0000000000125aaa>] print_cfs_rq+0x45e/0x4a4
[<000000000012614e>] sched_debug_show+0x65e/0xee8
[<000000000012a8fc>] show_state_filter+0x1cc/0x1f0
[<000000000044d39c>] sysrq_handle_showstate+0x2c/0x3c
[<000000000044d1fe>] __handle_sysrq+0xae/0x18c
[<00000000002001f2>] write_sysrq_trigger+0x8a/0x90
[<00000000001f7862>] proc_reg_write+0x9a/0xc4
[<00000000001a83d4>] vfs_write+0xb8/0x174
[<00000000001a8b88>] sys_write+0x58/0x8c
[<0000000000112e7c>] sysc_noemu+0x10/0x16
[<0000020000116f68>] 0x20000116f68
The problem seems to be, that with a full console buffer, release_console_sem
disables interrupts with spin_lock_irqsave and then calls the console function
without enabling interrupts. __sclp_vt220_write checks for in_interrupt, to
decide if it can schedule. It should check for in_atomic instead.
The same is true for sclp_tty.c.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Also convert to slab_is_available() as an indicator if
get_zeroed_page() will work or not.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Guilherme G. Piccoli