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2016-02-07stm class: Fix an off-by-one in master array allocationChunyan Zhang
Since both sw_start and sw_end are master indices, the size of array that holds them is sw_end - sw_start + 1, which the current code gets wrong, allocating one item less than required. This patch corrects the allocation size, avoiding potential slab corruption. Signed-off-by: Chunyan Zhang <zhang.chunyan@linaro.org> [alexander.shishkin@linux.intel.com: re-wrote the commit message] Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-07stm class: Fix link list lockingAlexander Shishkin
Currently, the list of stm_sources linked to an stm device is protected by a spinlock, which also means that sources' .unlink() method is called under this spinlock. However, this method may (and does) sleep, which means trouble. This patch slightly reworks locking around stm::link_list so that bits that might_sleep() are called with a mutex held instead. Modification of this list requires both mutex and spinlock to be held, while looking at the list can be done under either mutex or spinlock. Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-07stm class: Fix locking in unbinding policy pathAlexander Shishkin
Right now, if stm device removal has to unbind from a policy (that is, an stm device that has STP policy, gets removed), it will trigger a nested lock on the stm device's policy mutex. This patch fixes the problem by moving the locking from the policy unbinding to policy removal (configfs path), where it's actually needed; the other caller of the policy unbinding function already takes the mutex around the call. Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-07stm class: Select CONFIG_SRCUArnd Bergmann
The newly added STM code uses SRCU, but does not ensure that this code is part of the kernel: drivers/built-in.o: In function `stm_source_link_show': include/linux/srcu.h:221: undefined reference to `__srcu_read_lock' include/linux/srcu.h:238: undefined reference to `__srcu_read_unlock' drivers/built-in.o: In function `stm_source_link_drop': include/linux/srcu.h:221: undefined reference to `__srcu_read_lock' include/linux/srcu.h:238: undefined reference to `__srcu_read_unlock' This adds a Kconfig 'select' statement like all the other SRCU using drivers have. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Fixes: 7bd1d4093c2f ("stm class: Introduce an abstraction for System Trace Module devices") Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-07stm class: Hide STM-specific options if STM is disabledGeert Uytterhoeven
If STM=n, it doesn't make sense to ask about STM_DUMMY and STM_SOURCE_CONSOLE support, which are not even built when enabled anyway. Hence hide these options if STM=n. Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-11-13Merge branch 'for-next' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending Pull SCSI target updates from Nicholas Bellinger: "This series contains HCH's changes to absorb configfs attribute ->show() + ->store() function pointer usage from it's original tree-wide consumers, into common configfs code. It includes usb-gadget, target w/ drivers, netconsole and ocfs2 changes to realize the improved simplicity, that now renders the original include/target/configfs_macros.h CPP magic for fabric drivers and others, unnecessary and obsolete. And with common code in place, new configfs attributes can be added easier than ever before. Note, there are further improvements in-flight from other folks for v4.5 code in configfs land, plus number of target fixes for post -rc1 code" In the meantime, a new user of the now-removed old configfs API came in through the char/misc tree in commit 7bd1d4093c2f ("stm class: Introduce an abstraction for System Trace Module devices"). This merge resolution comes from Alexander Shishkin, who updated his stm class tracing abstraction to account for the removal of the old show_attribute and store_attribute methods in commit 517982229f78 ("configfs: remove old API") from this pull. As Alexander says about that patch: "There's no need to keep an extra wrapper structure per item and the awkward show_attribute/store_attribute item ops are no longer needed. This patch converts policy code to the new api, all the while making the code quite a bit smaller and easier on the eyes. Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>" That patch was folded into the merge so that the tree should be fully bisectable. * 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending: (23 commits) configfs: remove old API ocfs2/cluster: use per-attribute show and store methods ocfs2/cluster: move locking into attribute store methods netconsole: use per-attribute show and store methods target: use per-attribute show and store methods spear13xx_pcie_gadget: use per-attribute show and store methods dlm: use per-attribute show and store methods usb-gadget/f_serial: use per-attribute show and store methods usb-gadget/f_phonet: use per-attribute show and store methods usb-gadget/f_obex: use per-attribute show and store methods usb-gadget/f_uac2: use per-attribute show and store methods usb-gadget/f_uac1: use per-attribute show and store methods usb-gadget/f_mass_storage: use per-attribute show and store methods usb-gadget/f_sourcesink: use per-attribute show and store methods usb-gadget/f_printer: use per-attribute show and store methods usb-gadget/f_midi: use per-attribute show and store methods usb-gadget/f_loopback: use per-attribute show and store methods usb-gadget/ether: use per-attribute show and store methods usb-gadget/f_acm: use per-attribute show and store methods usb-gadget/f_hid: use per-attribute show and store methods ...
2015-10-16stm class: Select configfsAlexander Shishkin
STM policy handling is basically configfs, I honestly don't know how we ended up without a Kconfig dependency, but thanks to randconfig testing, it's now caught. Reported-by: Jim Davis <jim.epost@gmail.com> Reported-by: kbuild test robot <fengguang.wu@intel.com> Reported-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-10stm class: Mark src::link __rcuAlexander Shishkin
Source device's link is protected with srcu, mark it as such to have proper build-time validation of accesses to this field. The update side that's dereferencing it under an update lock also needs an accessor to dereference this field to keep sparse happy. Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04stm class: stm_console: Add kernel-console-over-stm driverAlexander Shishkin
This is a simple stm_source class device driver (kernelspace stm trace source) that registers a console and sends kernel messages over STM devices. Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org> Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04stm class: dummy_stm: Add dummy driver for testing stm classAlexander Shishkin
This is a simple module that pretends to be an stm device and discards all the data that comes in. Useful for testing stm class and its users. Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org> Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04stm class: Introduce an abstraction for System Trace Module devicesAlexander Shishkin
A System Trace Module (STM) is a device exporting data in System Trace Protocol (STP) format as defined by MIPI STP standards. Examples of such devices are Intel(R) Trace Hub and Coresight STM. This abstraction provides a unified interface for software trace sources to send their data over an STM device to a debug host. In order to do that, such a trace source needs to be assigned a pair of master/channel identifiers that all the data from this source will be tagged with. The STP decoder on the debug host side will use these master/channel tags to distinguish different trace streams from one another inside one STP stream. This abstraction provides a configfs-based policy management mechanism for dynamic allocation of these master/channel pairs based on trace source-supplied string identifier. It has the flexibility of being defined at runtime and at the same time (provided that the policy definition is aligned with the decoding end) consistency. For userspace trace sources, this abstraction provides write()-based and mmap()-based (if the underlying stm device allows this) output mechanism. For kernel-side trace sources, we provide "stm_source" device class that can be connected to an stm device at run time. Cc: linux-api@vger.kernel.org Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org> Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>