kernel/git/stable/linux.git/drivers/s390/char, branch linux-3.18.y

s390/3270: fix lockdep false positive on view->lock

2019-05-16T07:17:22+00:00

[ Upstream commit 5712f3301a12c0c3de9cc423484496b0464f2faf ] The spinlock in the raw3270_view structure is used by con3270, tty3270 and fs3270 in different ways. For con3270 the lock can be acquired in irq context, for tty3270 and fs3270 the highest context is bh. Lockdep sees the view->lock as a single class and if the 3270 driver is used for the console the following message is generated: WARNING: inconsistent lock state 5.1.0-rc3-05157-g5c168033979d #12 Not tainted -------------------------------- inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage. swapper/0/1 [HC0[0]:SC1[1]:HE1:SE0] takes: (____ptrval____) (&(&view->lock)->rlock){?.-.}, at: tty3270_update+0x7c/0x330 Introduce a lockdep subclass for the view lock to distinguish bh from irq locks. Signed-off-by: Martin Schwidefsky Signed-off-by: Sasha Levin

s390/smp: fix CPU hotplug deadlock with CPU rescan

2019-02-06T16:34:51+00:00

commit b7cb707c373094ce4008d4a6ac9b6b366ec52da5 upstream. smp_rescan_cpus() is called without the device_hotplug_lock, which can lead to a dedlock when a new CPU is found and immediately set online by a udev rule. This was observed on an older kernel version, where the cpu_hotplug_begin() loop was still present, and it resulted in hanging chcpu and systemd-udev processes. This specific deadlock will not show on current kernels. However, there may be other possible deadlocks, and since smp_rescan_cpus() can still trigger a CPU hotplug operation, the device_hotplug_lock should be held. For reference, this was the deadlock with the old cpu_hotplug_begin() loop: chcpu (rescan) systemd-udevd echo 1 > /sys/../rescan -> smp_rescan_cpus() -> (*) get_online_cpus() (increases refcount) -> smp_add_present_cpu() (new CPU found) -> register_cpu() -> device_add() -> udev "add" event triggered -----------> udev rule sets CPU online -> echo 1 > /sys/.../online -> lock_device_hotplug_sysfs() (this is missing in rescan path) -> device_online() -> (**) device_lock(new CPU dev) -> cpu_up() -> cpu_hotplug_begin() (loops until refcount == 0) -> deadlock with (*) -> bus_probe_device() -> device_attach() -> device_lock(new CPU dev) -> deadlock with (**) Fix this by taking the device_hotplug_lock in the CPU rescan path. Cc: Signed-off-by: Gerald Schaefer Signed-off-by: Martin Schwidefsky Signed-off-by: Greg Kroah-Hartman

s390/vmlogrdr: fix IUCV buffer allocation

2017-01-15T14:49:52+00:00

[ Upstream commit 5457e03de918f7a3e294eb9d26a608ab8a579976 ] The buffer for iucv_message_receive() needs to be below 2 GB. In __iucv_message_receive(), the buffer address is casted to an u32, which would result in either memory corruption or an addressing exception when using addresses >= 2 GB. Fix this by using GFP_DMA for the buffer allocation. Cc: stable@vger.kernel.org Signed-off-by: Gerald Schaefer Signed-off-by: Martin Schwidefsky Signed-off-by: Sasha Levin

s390/3270: redraw screen on unsolicited device end

2015-12-03T03:59:03+00:00

[ Upstream commit 05bfd70bcdd3cd12c061cb77b73a11ba6f87379d ] If a 3270 terminal is disconnected and later reconnected again, it gets an unsolicited device end. This is currently ignored and you have to hit the clear key to get the screen redrawn. Add an automatic full redraw of the screen for this case. Signed-off-by: Martin Schwidefsky Signed-off-by: Sasha Levin

s390/sclp: fix compile error

2015-10-28T02:14:33+00:00

[ Upstream commit a313bdc5310dd807655d3ca3eb2219cd65dfe45a ] Fix this error when compiling with CONFIG_SMP=n and CONFIG_DYNAMIC_DEBUG=y: drivers/s390/char/sclp_early.c: In function 'sclp_read_info_early': drivers/s390/char/sclp_early.c:87:19: error: 'EBUSY' undeclared (first use in this function) } while (rc == -EBUSY); ^ Signed-off-by: Sebastian Ott Signed-off-by: Martin Schwidefsky Signed-off-by: Sasha Levin

s390/hmcdrv: Restrict s390 HMC driver to S390 arch

2014-10-15T14:56:26+00:00

This driver is only usable on 64-bit s390 machines. Mark the Kconfig dependencies to that users on other architectures are not prompted for it. Fixes: 8f933b1043e1e5 ("s390/hmcdrv: HMC drive CD/DVD access") Signed-off-by: Josh Boyer Signed-off-by: Martin Schwidefsky

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

2014-10-14T01:47:00+00:00

Pull s390 updates from Martin Schwidefsky: "This patch set contains the main portion of the changes for 3.18 in regard to the s390 architecture. It is a bit bigger than usual, mainly because of a new driver and the vector extension patches. The interesting bits are: - Quite a bit of work on the tracing front. Uprobes is enabled and the ftrace code is reworked to get some of the lost performance back if CONFIG_FTRACE is enabled. - To improve boot time with CONFIG_DEBIG_PAGEALLOC, support for the IPTE range facility is added. - The rwlock code is re-factored to improve writer fairness and to be able to use the interlocked-access instructions. - The kernel part for the support of the vector extension is added. - The device driver to access the CD/DVD on the HMC is added, this will hopefully come in handy to improve the installation process. - Add support for control-unit initiated reconfiguration. - The crypto device driver is enhanced to enable the additional AP domains and to allow the new crypto hardware to be used. - Bug fixes" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (39 commits) s390/ftrace: simplify enabling/disabling of ftrace_graph_caller s390/ftrace: remove 31 bit ftrace support s390/kdump: add support for vector extension s390/disassembler: add vector instructions s390: add support for vector extension s390/zcrypt: Toleration of new crypto hardware s390/idle: consolidate idle functions and definitions s390/nohz: use a per-cpu flag for arch_needs_cpu s390/vtime: do not reset idle data on CPU hotplug s390/dasd: add support for control unit initiated reconfiguration s390/dasd: fix infinite loop during format s390/mm: make use of ipte range facility s390/setup: correct 4-level kernel page table detection s390/topology: call set_sched_topology early s390/uprobes: architecture backend for uprobes s390/uprobes: common library for kprobes and uprobes s390/rwlock: use the interlocked-access facility 1 instructions s390/rwlock: improve writer fairness s390/rwlock: remove interrupt-enabling rwlock variant. s390/mm: remove change bit override support ...

s390/kdump: add support for vector extension

2014-10-09T07:14:16+00:00

With this patch for kdump the s390 vector registers are stored into the prepared save areas in the old kernel and into the REGSET_VX_LOW and REGSET_VX_HIGH ELF notes for /proc/vmcore in the new kernel. The NT_S390_VXRS_LOW note contains the lower halves of the first 16 vector registers 0-15. The higher halves are stored in the floating point register ELF note. The NT_S390_VXRS_HIGH contains the full vector registers 16-31. The kernel provides a save area for storing vector register in case of machine checks. A pointer to this save are is stored in the CPU lowcore at offset 0x11b0. This save area is also used to save the registers for kdump. In case of a dumped crashed kdump those areas are used to extract the registers of the production system. The vector registers for remote CPUs are stored using the "store additional status at address" SIGP. For the dump CPU the vector registers are stored with the VSTM instruction. With this patch also zfcpdump stores the vector registers. Reviewed-by: Heiko Carstens Signed-off-by: Michael Holzheu Signed-off-by: Martin Schwidefsky

[s390] remove pointless assignment of ->f_op in vmlogrdr ->open()

2014-10-09T06:39:13+00:00

The only way we can get to that function is from misc_open(), after the latter has set file->f_op to exactly the same value we are (re)assigning there. Signed-off-by: Al Viro

s390/tape: fix MTIOCGET ioctl to report blocksize

2014-09-25T08:52:03+00:00

Remove tape_state from status register and report the drive's current setting for block size instead as known from other tapes. Density is not supported so nothing to report here. Signed-off-by: Stefan Haberland Signed-off-by: Martin Schwidefsky