Commit Graph

44 Commits

Author SHA1 Message Date
Felipe Balbi a773d41927 tracing: Pass export pointer as argument to ->write()
By passing an export descriptor to the write function, users don't need to
keep a global static pointer and can rely on container_of() to fetch their
own structure.

Link: http://lkml.kernel.org/r/20170602102025.5140-1-felipe.balbi@linux.intel.com

Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Reviewed-by: Chunyan Zhang <zhang.chunyan@linaro.org>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-12-04 07:14:30 -05:00
Linus Torvalds abc36be236 A couple of configfs cleanups:
- proper use of the bool type (Thomas Meyer)
   - constification of struct config_item_type (Bhumika Goyal)
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Merge tag 'configfs-for-4.15' of git://git.infradead.org/users/hch/configfs

Pull configfs updates from Christoph Hellwig:
 "A couple of configfs cleanups:

   - proper use of the bool type (Thomas Meyer)

   - constification of struct config_item_type (Bhumika Goyal)"

* tag 'configfs-for-4.15' of git://git.infradead.org/users/hch/configfs:
  RDMA/cma: make config_item_type const
  stm class: make config_item_type const
  ACPI: configfs: make config_item_type const
  nvmet: make config_item_type const
  usb: gadget: configfs: make config_item_type const
  PCI: endpoint: make config_item_type const
  iio: make function argument and some structures const
  usb: gadget: make config_item_type structures const
  dlm: make config_item_type const
  netconsole: make config_item_type const
  nullb: make config_item_type const
  ocfs2/cluster: make config_item_type const
  target: make config_item_type const
  configfs: make ci_type field, some pointers and function arguments const
  configfs: make config_item_type const
  configfs: Fix bool initialization/comparison
2017-11-14 14:44:04 -08:00
Greg Kroah-Hartman b24413180f License cleanup: add SPDX GPL-2.0 license identifier to files with no license
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>
2017-11-02 11:10:55 +01:00
Bhumika Goyal 085006e834 stm class: make config_item_type const
Make config_item_type structures const as they are either passed to a
function having the argument as const or used inside a if statement or
stored in the const "ci_type" field of a config_item structure.

Done using Coccinelle.

Signed-off-by: Bhumika Goyal <bhumirks@gmail.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2017-10-19 16:15:30 +02:00
Alexander Shishkin fd085bb176 stm class: Fix a use-after-free
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: 7bd1d4093c ("stm class: Introduce an abstraction for System Trace Module devices")
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-09-22 10:28:00 +02:00
Dan Carpenter 71c488f32b stm: Potential read overflow in stm_char_policy_set_ioctl()
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: 7bd1d4093c ("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>
2017-08-25 17:58:33 +03:00
Linus Torvalds 179a7ba680 This release has a few updates:
o STM can hook into the function tracer
  o Function filtering now supports more advance glob matching
  o Ftrace selftests updates and added tests
  o Softirq tag in traces now show only softirqs
  o ARM nop added to non traced locations at compile time
  o New trace_marker_raw file that allows for binary input
  o Optimizations to the ring buffer
  o Removal of kmap in trace_marker
  o Wakeup and irqsoff tracers now adhere to the set_graph_notrace file
  o Other various fixes and clean ups
 
 Note, there are two patches marked for stable. These were discovered
 near the end of the 4.9 rc release cycle. By the time I had them tested
 it was just a matter of days before 4.9 would be released, and I
 figured I would just submit them in the merge window. They are old
 bugs and not critical. Nothing non-root could abuse.
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Merge tag 'trace-v4.10' of 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
  ...
2016-12-15 13:49:34 -08:00
Chunyan Zhang 9dfed80d87 stm: Mark the functions of writing STM with notrace
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>
2016-11-22 17:48:04 -05:00
Chunyan Zhang 9b5e3ff6b9 stm dummy: Mark dummy_stm_packet() with notrace
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>
2016-11-22 17:48:00 -05:00
Chunyan Zhang 262e1f6e39 stm class: ftrace: Add ftrace-export-over-stm driver
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>
2016-11-22 17:47:48 -05:00
Johan Hovold a0ebf519b8 stm class: Fix device leak in open error path
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: 7bd1d4093c ("stm class: Introduce an abstraction for...")
Cc: stable@vger.kernel.org # v4.6+
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
2016-11-18 16:54:39 +02:00
Alexander Shishkin 8e0469a4f3 stm class: Add runtime power management handling
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>
2016-07-01 11:00:14 +03:00
Alexander Shishkin 8e996a2874 stm class: Support devices that override software assigned masters
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>
2016-05-03 14:59:30 -07:00
Alexander Shishkin fb0801904b stm class: Remove unnecessary pointer increment
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>
2016-04-08 16:11:54 +03:00
Alexander Shishkin 389b6699a2 stm class: Fix stm device initialization order
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>
2016-04-08 16:11:53 +03:00
Alexander Shishkin cbe4a61d1d stm class: Do not leak the chrdev in error path
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>
2016-04-08 16:11:52 +03:00
Alexander Shishkin 8fa11d1c13 stm class: Remove a pointless line
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>
2016-04-08 16:11:52 +03:00
Alexander Shishkin c8be489944 stm class: stm_heartbeat: Make nr_devs parameter read-only
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>
2016-04-08 16:11:51 +03:00
Alexander Shishkin 118b4515aa stm class: dummy_stm: Make nr_dummies parameter read-only
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>
2016-04-08 16:11:50 +03:00
Chunyan Zhang f57af6df6a stm class: Fix integer boundary checks for master range
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>
2016-04-08 16:08:00 +03:00
Alexander Shishkin adcde635f5 stm class: dummy_stm: Add link callback for fault injection
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>
2016-02-20 14:09:14 -08:00
Alexander Shishkin cc8424074e stm class: Plug stm device's unlink callback
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>
2016-02-20 14:09:14 -08:00
Alexander Shishkin b4ca34aaf7 stm class: Fix a race in unlinking
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>
2016-02-20 14:09:14 -08:00
Alexander Shishkin f7c81c7176 stm class: Fix unbalanced module/device refcounting
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>
2016-02-20 14:09:14 -08:00
Alexander Shishkin cde4ad8368 stm class: Guard output assignment against concurrency
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>
2016-02-20 14:09:14 -08:00
Alexander Shishkin 1810f2c448 stm class: Fix unlocking braino in the error path
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>
2016-02-20 14:09:14 -08:00
Alexander Shishkin 1192918530 stm class: Add heartbeat stm source device
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>
2016-02-20 14:09:14 -08:00
Alexander Shishkin bcfdf8afde stm class: dummy_stm: Create multiple devices
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>
2016-02-20 14:09:14 -08:00
Alexander Shishkin 59be422e4c stm class: Support devices with multiple instances
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>
2016-02-20 14:09:14 -08:00
Alexander Shishkin f8560a9bc7 stm class: Use driver's packet callback return value
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>
2016-02-20 14:09:14 -08:00
Chunyan Zhang 73a3ed1903 stm class: Fix master deallocation in device unregistering
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>
2016-02-20 14:09:14 -08:00
Lucas Tanure f45f40ad65 stm class: Use a signed return type for stm_find_master_chan
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>
2016-02-20 14:09:14 -08:00
Alexander Shishkin f08b18266c stm class: Prevent user-controllable allocations
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>
2016-02-07 22:43:17 -08:00
Chunyan Zhang 7b3bb0e753 stm class: Fix an off-by-one in master array allocation
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>
2016-02-07 22:43:17 -08:00
Alexander Shishkin c74f7e8281 stm class: Fix link list locking
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>
2016-02-07 22:43:17 -08:00
Alexander Shishkin 4c127fd16e stm class: Fix locking in unbinding policy path
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>
2016-02-07 22:43:17 -08:00
Arnd Bergmann 042d4460b5 stm class: Select CONFIG_SRCU
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: 7bd1d4093c ("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>
2016-02-07 22:43:17 -08:00
Geert Uytterhoeven 4a2e2b19f9 stm class: Hide STM-specific options if STM is disabled
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>
2016-02-07 22:43:17 -08:00
Linus Torvalds 9aa3d651a9 Merge branch 'for-next' of 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 7bd1d4093c ("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 517982229f
("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
  ...
2015-11-13 20:04:17 -08:00
Alexander Shishkin 1c090575b0 stm class: Select configfs
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>
2015-10-16 23:25:48 -07:00
Alexander Shishkin 0df771dedf stm class: Mark src::link __rcu
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>
2015-10-10 12:24:47 -07:00
Alexander Shishkin e3e5a3d3da stm class: stm_console: Add kernel-console-over-stm driver
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>
2015-10-04 20:28:58 +01:00
Alexander Shishkin 2c41538191 stm class: dummy_stm: Add dummy driver for testing stm class
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>
2015-10-04 20:28:58 +01:00
Alexander Shishkin 7bd1d4093c stm class: Introduce an abstraction for System Trace Module devices
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>
2015-10-04 20:28:58 +01:00