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path: root/drivers/hwtracing/stm/core.c
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2019-04-25stm class: Fix channel bitmap on 32-bit systemsAlexander Shishkin
Commit 7bd1d4093c2f ("stm class: Introduce an abstraction for System Trace Module devices") naively calculates the channel bitmap size in 64-bit chunks regardless of the size of underlying unsigned long, making the bitmap half as big on a 32-bit system. This leads to an out of bounds access with the upper half of the bitmap. Fix this by using BITS_TO_LONGS. While at it, convert to using struct_size() for the total size calculation of the master struct. Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Fixes: 7bd1d4093c2f ("stm class: Introduce an abstraction for System Trace Module devices") Reported-by: Mulu He <muluhe@codeaurora.org> Cc: stable@vger.kernel.org # v4.4+ Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-25stm class: Fix channel free in stm output free pathTingwei Zhang
Number of free masters is not set correctly in stm free path. Fix this by properly adding the number of output channels before setting them to 0 in stm_output_disclaim(). Currently it is equivalent to doing nothing since master->nr_free is incremented by 0. Fixes: 7bd1d4093c2f ("stm class: Introduce an abstraction for System Trace Module devices") Signed-off-by: Tingwei Zhang <tingwei@codeaurora.org> Signed-off-by: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org> Cc: stable@vger.kernel.org # v4.4 Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-21stm class: Prevent division by zeroAlexander Shishkin
Using STP_POLICY_ID_SET ioctl command with dummy_stm device, or any STM device that supplies zero mmio channel size, will trigger a division by zero bug in the kernel. Prevent this by disallowing channel widths other than 1 for such devices. Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Fixes: 7bd1d4093c2f ("stm class: Introduce an abstraction for System Trace Module devices") CC: stable@vger.kernel.org # v4.4+
2019-02-21stm class: Fix an endless loop in channel allocationZhi Jin
There is a bug in the channel allocation logic that leads to an endless loop when looking for a contiguous range of channels in a range with a mixture of free and occupied channels. For example, opening three consequtive channels, closing the first two and requesting 4 channels in a row will trigger this soft lockup. The bug is that the search loop forgets to skip over the range once it detects that one channel in that range is occupied. Restore the original intent to the logic by fixing the omission. Signed-off-by: Zhi Jin <zhi.jin@intel.com> Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Fixes: 7bd1d4093c2f ("stm class: Introduce an abstraction for System Trace Module devices") CC: stable@vger.kernel.org # v4.4+
2018-10-11stm class: Switch over to the protocol driverAlexander Shishkin
Now that the default framing protocol is factored out into its own driver, switch over to using the driver for writing data. To that end, make the policy code require a valid protocol name (or absence thereof, which is equivalent to "p_basic"). Also, to make transition easier, make stm class request "p_basic" module at initialization time. Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Tested-by: Mathieu Poirier <mathieu.poirier@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-11stm class: Add a helper for writing data packetsAlexander Shishkin
Add a helper to write a sequence of bytes as STP data packets. This is used by protocol drivers to output their metadata, as well as the actual data payload. Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Tested-by: Mathieu Poirier <mathieu.poirier@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-11stm class: Introduce framing protocol driversAlexander Shishkin
At the moment, the stm class applies a certain STP framing pattern to the data as it is written to the underlying STM device. In order to allow different framing patterns (aka protocols), this patch introduces the concept of STP protocol drivers, defines data structures and APIs for the protocol drivers to use. Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Tested-by: Mathieu Poirier <mathieu.poirier@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-11stm class: Rework policy node fallbackAlexander Shishkin
Currently, if no matching policy node can be found for a trace source, we'll try to use "default" policy node, then, if that doesn't exist, we'll pick the first node, in order of creation. If that also fails, we'll allocate M/C range from the beginning of the device's M/C range. This makes it difficult to know which node (if any) was used in any particular case. In order to make things more deterministic, the new order is as follows: * if they supply ID string, use that and nothing else, * if they are a task, use their task name (comm), * use "default", if it exists, * return failure, to let them know there is no suitable rule. This should provide enough convenience with the "default" catch-all node, while not leaving *everything* to chance. As a side effect, this relaxes the requirement of using ioctl() for identification with the possibility of using task names as policy nodes. Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Tested-by: Mathieu Poirier <mathieu.poirier@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-26hwtracing: stm: fix build error on some archesGreg Kroah-Hartman
Commit b5e2ced9bf81 ("stm class: Use vmalloc for the master map") caused a build error on some arches as vmalloc.h was not explicitly included. Fix that by adding it to the list of includes. Fixes: b5e2ced9bf81 ("stm class: Use vmalloc for the master map") Reported-by: kbuild test robot <lkp@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-25stm class: Use vmalloc for the master mapAlexander Shishkin
Fengguang is running into a warning from the buddy allocator: > swapper/0: page allocation failure: order:9, mode:0x14040c0(GFP_KERNEL|__GFP_COMP), nodemask=(null) > CPU: 1 PID: 1 Comm: swapper/0 Not tainted 4.17.0-rc1 #262 > Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014 > Call Trace: ... > __kmalloc+0x14b/0x180: ____cache_alloc at mm/slab.c:3127 > stm_register_device+0xf3/0x5c0: stm_register_device at drivers/hwtracing/stm/core.c:695 ... Which is basically a result of the stm class trying to allocate ~512kB for the dummy_stm with its default parameters. There's no reason, however, for it not to be vmalloc()ed instead, which is what this patch does. Reported-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> CC: stable@vger.kernel.org # v4.4+ Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-28stm class: Add SPDX GPL-2.0 header to replace GPLv2 boilerplateAlexander Shishkin
This adds SPDX GPL-2.0 header to to stm core files and removes the GPLv2 boilerplate text. Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
2017-09-22stm class: Fix a use-after-freeAlexander Shishkin
For reasons unknown, the stm_source removal path uses device_destroy() to kill the underlying device object. Because device_destroy() uses devt to look for the device to destroy and the fact that stm_source devices don't have one (or all have the same one), it just picks the first device in the class, which may well be the wrong one. That is, loading stm_console and stm_heartbeat and then removing both will die in dereferencing a freed object. Since this should have been device_unregister() in the first place, use it instead of device_destroy(). Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Fixes: 7bd1d4093c2 ("stm class: Introduce an abstraction for System Trace Module devices") Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-25stm: Potential read overflow in stm_char_policy_set_ioctl()Dan Carpenter
The "size" variable comes from the user so we need to verify that it's large enough to hold an stp_policy_id struct. Fixes: 7bd1d4093c2f ("stm class: Introduce an abstraction for System Trace Module devices") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
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>
2016-11-18stm 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: 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>
2016-02-20stm 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: 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>
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: 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>