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2016-12-15Merge tag 'trace-v4.10' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing updates from Steven Rostedt: "This release has a few updates: - STM can hook into the function tracer - Function filtering now supports more advance glob matching - Ftrace selftests updates and added tests - Softirq tag in traces now show only softirqs - ARM nop added to non traced locations at compile time - New trace_marker_raw file that allows for binary input - Optimizations to the ring buffer - Removal of kmap in trace_marker - Wakeup and irqsoff tracers now adhere to the set_graph_notrace file - Other various fixes and clean ups" * tag 'trace-v4.10' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (42 commits) selftests: ftrace: Shift down default message verbosity kprobes/trace: Fix kprobe selftest for newer gcc tracing/kprobes: Add a helper method to return number of probe hits tracing/rb: Init the CPU mask on allocation tracing: Use SOFTIRQ_OFFSET for softirq dectection for more accurate results tracing/fgraph: Have wakeup and irqsoff tracers ignore graph functions too fgraph: Handle a case where a tracer ignores set_graph_notrace tracing: Replace kmap with copy_from_user() in trace_marker writing ftrace/x86_32: Set ftrace_stub to weak to prevent gcc from using short jumps to it tracing: Allow benchmark to be enabled at early_initcall() tracing: Have system enable return error if one of the events fail tracing: Do not start benchmark on boot up tracing: Have the reg function allow to fail ring-buffer: Force rb_end_commit() and rb_set_commit_to_write() inline ring-buffer: Froce rb_update_write_stamp() to be inlined ring-buffer: Force inline of hotpath helper functions tracing: Make __buffer_unlock_commit() always_inline tracing: Make tracepoint_printk a static_key ring-buffer: Always inline rb_event_data() ring-buffer: Make rb_reserve_next_event() always inlined ...
2016-11-22stm: Mark the functions of writing STM with notraceChunyan Zhang
If CONFIG_STM_SOURCE_FTRACE is selected, Function trace data can be writen to sink via STM, all functions that related to writing data packets to STM should be marked 'notrace' to avoid being traced by Ftrace, otherwise the program would stall into an endless loop. Link: http://lkml.kernel.org/r/1479715043-6534-7-git-send-email-zhang.chunyan@linaro.org Signed-off-by: Chunyan Zhang <zhang.chunyan@linaro.org> Acked-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-11-22stm dummy: Mark dummy_stm_packet() with notraceChunyan Zhang
If CONFIG_STM_SOURCE_FTRACE is selected, Function trace data can be writen to sink via STM, all functions that related to writing data packets to STM should be marked 'notrace' to avoid being traced by Ftrace, otherwise the program would stall into an endless loop. Link: http://lkml.kernel.org/r/1479715043-6534-6-git-send-email-zhang.chunyan@linaro.org Signed-off-by: Chunyan Zhang <zhang.chunyan@linaro.org> Acked-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-11-22stm class: ftrace: Add ftrace-export-over-stm driverChunyan Zhang
This patch adds a driver that models itself as an stm_source called stm_ftrace. Once the stm device and stm_ftrace have been linked via sysfs, the driver registers itself as a trace_export and everything passed to the interface from Ftrace subsystem will end up in the STM trace engine. Link: http://lkml.kernel.org/r/1479715043-6534-3-git-send-email-zhang.chunyan@linaro.org Signed-off-by: Chunyan Zhang <zhang.chunyan@linaro.org> Acked-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-11-18stm class: Fix device leak in open error pathJohan Hovold
Make sure to drop the reference taken by class_find_device() also on allocation errors in open(). Signed-off-by: Johan Hovold <johan@kernel.org> Fixes: 7bd1d4093c2f ("stm class: Introduce an abstraction for...") Cc: stable@vger.kernel.org # v4.6+ Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
2016-07-01stm class: Add runtime power management handlingAlexander Shishkin
Currently, there's no runtime pm in stm class devices, which makes it harder for the underlying hardware drivers to handle their power management. This patch applies the following runtime pm policy to stm class devices, which their parents can rely on for their power management tracking: * device is in use during character device writes, * delayed autosuspend is used to keep it active between adjacent writes, * device is in use while mmio regions are mapped, * device is is use while any stm_source devices are linked to it. Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org> Cc: Chunyan Zhang <zhang.chunyan@linaro.org>
2016-05-03stm class: Support devices that override software assigned mastersAlexander Shishkin
Some STM devices adjust software assigned master numbers depending on the trace source and its runtime state and whatnot. This patch adds a sysfs attribute to inform the trace-side software that master numbers assigned to software sources will not match those in the STP stream, so that, for example, master/channel allocation policy can be adjusted accordingly. Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-04-08stm class: Remove unnecessary pointer incrementAlexander Shishkin
Readability: a postfix increment is used on a pointer which is not used anywhere afterwards, which may send the reader looking through the function one extra time. Drop the unnecessary increment. Reported-by: Alan Cox <alan.cox@intel.com> Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Reviewed-by: Laurent Fert <laurent.fert@intel.com>
2016-04-08stm class: Fix stm device initialization orderAlexander Shishkin
Currently, stm_register_device() makes the device visible and then proceeds to initializing spinlocks and other properties, which leaves a window when the device can already be opened but is not yet fully operational. Fix this by reversing the initialization order. Reported-by: Alan Cox <alan.cox@intel.com> Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Reviewed-by: Laurent Fert <laurent.fert@intel.com>
2016-04-08stm class: Do not leak the chrdev in error pathAlexander Shishkin
Currently, the error path of stm_register_device() forgets to unregister the chrdev. Fix this. Reported-by: Alan Cox <alan.cox@intel.com> Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Reviewed-by: Laurent Fert <laurent.fert@intel.com>
2016-04-08stm class: Remove a pointless lineAlexander Shishkin
No point in explicitly setting something to zero right after we explicitly checked that it is zero. Fix this. Reported-by: Alan Cox <alan.cox@intel.com> Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Reviewed-by: Laurent Fert <laurent.fert@intel.com>
2016-04-08stm class: stm_heartbeat: Make nr_devs parameter read-onlyAlexander Shishkin
Changing nr_devs after the module has been loaded doesn't actually change anything, so just make it read-only. Reported-by: Alan Cox <alan.cox@intel.com> Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Reviewed-by: Laurent Fert <laurent.fert@intel.com>
2016-04-08stm class: dummy_stm: Make nr_dummies parameter read-onlyAlexander Shishkin
Changing nr_dummies after the module has been loaded doesn't actually change anything, so just make it read-only. Reported-by: Alan Cox <alan.cox@intel.com> Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Reviewed-by: Laurent Fert <laurent.fert@intel.com>
2016-04-08stm class: Fix integer boundary checks for master rangeChunyan Zhang
Master IDs are of unsigned int type, yet in the configfs policy code we're validating user's input against INT_MAX. This is both pointless and misleading as the real limits are imposed by the stm device's [sw_start..sw_end] (which are also limited by the spec to be no larger than 2^16-1). Clean this up by getting rid of the redundant comparisons. Signed-off-by: Chunyan Zhang <zhang.chunyan@linaro.org> Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Reviewed-by: Laurent Fert <laurent.fert@intel.com>
2016-02-20stm class: dummy_stm: Add link callback for fault injectionAlexander Shishkin
STM device's link callback has the power to abort master/channel assignment by returning a negative error code. Use this in dummy stm device to optionally abort assigning certain channel IDs. This is useful as fault injection into the stm class core, for testing purposes. Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-20stm class: Plug stm device's unlink callbackAlexander Shishkin
STM device's unlink callback is never actually called from anywhere in the stm class code. This patch adds calls to stm driver's unlink method after the unlinking has succeeded. Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-20stm class: Fix a race in unlinkingAlexander Shishkin
There is a window in stm_source_link_drop(), during which the source's link may change before locks are acquired. When this happens, it throws a warning, since this is not an expected scenario. This patch handles the race in such a way that if the link appears to have changed by the time we took the locks, it will release them and repeat the whole unlinking procedure from the beginning, unless the other contender beat us to it. Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-20stm class: Fix unbalanced module/device refcountingAlexander Shishkin
STM code takes references to the stm device and its module for the duration of the character device's existence or the stm_source link. Dropping these references is not well balanced everywhere, which may lead to leaks. This patch balances the acquisition and releasing of these two references and annotates each site so that it's easier to verify correctness by reading the code. Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-20stm class: Guard output assignment against concurrencyAlexander Shishkin
It is possible to concurrently assign the same output (a character device writer or an stm_source device) to different stm devices, which sets off a strategically placed warning in stm_output_assign(). To avoid this, use a spinlock to serialize (un)assignments between outputs and stm devices. Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-20stm class: Fix unlocking braino in the error pathAlexander Shishkin
If an illegal attempt is made to unlink stm source device from an stm device, the stm device's link spinlock mistakenly remains locked. While this really shouldn't happen (there's a warning in place), the locking should remain in order so that we can still recover from this situation if it indeed does happen. This patch unifies the unlocking in the exit path of __stm_source_link_drop() to fix this. Reported-by: Laurent Fert <laurent.fert@intel.com> Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-20stm class: Add heartbeat stm source deviceAlexander Shishkin
Heartbeat stm source may have multiple instances (for connecting to different stm devices). Each instance will send a periodic test message over its stm device when it is linked. This can be used for testing stm class framework, stm device drivers or as a heartbeat over the stm link. Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-20stm class: dummy_stm: Create multiple devicesAlexander Shishkin
STM framework should be able to handle multiple STM devices at a time, each one with its own master allocation policy. This patch changes dummy_stm driver to create multiple STM sinks to help testing the framework. Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-20stm class: Support devices with multiple instancesAlexander Shishkin
By convention, the name of the stm policy directory in configfs consists of the device name to which it applies and the actual policy name, separated by a dot. Now, some devices already have dots in their names that separate name of the actual device from its instance identifier. Such devices will result in two (or more, who can tell) dots in the policy directory name. Existing policy code, however, will treat the first dot as the one that separates device name from policy name, therefore failing the above case. This patch makes the last dot in the directory name be the separator, thus prohibiting dots from being used in policy names. Suggested-by: Chunyan Zhang <zhang.chunyan@linaro.org> Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-20stm class: Use driver's packet callback return valueAlexander Shishkin
STM drivers provide a callback to generate/send individual STP packets; it also tells the stm core how many bytes of payload it has consumed. However, we would also need to use the negative space of this return value to communicate errors that occur during the packet generation, in which case the stm core will have to take appropriate action. For now, we need to account for the possibility that the stm driver may not support certain combinations of packet type/flags, in which case it is expected to signal an error. Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-20stm class: Fix master deallocation in device unregisteringChunyan Zhang
The device unregister path uses wrong master index range when it tries to free the allocated masters, it should, as does the rest of the stm class code, use real master IDs. This patch fixes the device unregister path to use real master IDs to avoid memory leaks after unloading the stm driver. Signed-off-by: Chunyan Zhang <zhang.chunyan@linaro.org> [alexander.shishkin@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>
2016-02-20stm class: Use a signed return type for stm_find_master_chanLucas Tanure
The return type "unsigned int" was used by the stm_find_master_chan function despite of the aspect that it will eventually return a negative error code. Done with the help of Coccinelle. Signed-off-by: Lucas Tanure <tanure@linux.com> Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-07stm class: Prevent user-controllable allocationsAlexander Shishkin
Currently, the character device write method allocates a temporary buffer for user's data, but the user's data size is not sanitized and can cause arbitrarily large allocations via kzalloc() or an integer overflow that will then result in overwriting kernel memory. This patch trims the input buffer size to avoid these issues. Reported-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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>