- Remove eventfs_file descriptor
This is the biggest change, and the second part of making eventfs
create its files dynamically.
In 6.6 the first part was added, and that maintained a one to one
mapping between eventfs meta descriptors and the directories and
file inodes and dentries that were dynamically created. The
directories were represented by a eventfs_inode and the files
were represented by a eventfs_file.
In v6.7 the eventfs_file is removed. As all events have the same
directory make up (sched_switch has an "enable", "id", "format",
etc files), the handing of what files are underneath each leaf
eventfs directory is moved back to the tracing subsystem via a
callback. When a event is added to the eventfs, it registers
an array of evenfs_entry's. These hold the names of the files and
the callbacks to call when the file is referenced. The callback gets
the name so that the same callback may be used by multiple files.
The callback then supplies the filesystem_operations structure needed
to create this file.
This has brought the memory footprint of creating multiple eventfs
instances down by 2 megs each!
- User events now has persistent events that are not associated
to a single processes. These are privileged events that hang around
even if no process is attached to them.
- Clean up of seq_buf.
There's talk about using seq_buf more to replace strscpy() and friends.
But this also requires some minor modifications of seq_buf to be
able to do this.
- Expand instance ring buffers individually
Currently if boot up creates an instance, and a trace event is
enabled on that instance, the ring buffer for that instance and the
top level ring buffer are expanded (1.4 MB per CPU). This wastes
memory as this happens when nothing is using the top level instance.
- Other minor clean ups and fixes.
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Merge tag 'trace-v6.7' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull tracing updates from Steven Rostedt:
- Remove eventfs_file descriptor
This is the biggest change, and the second part of making eventfs
create its files dynamically.
In 6.6 the first part was added, and that maintained a one to one
mapping between eventfs meta descriptors and the directories and file
inodes and dentries that were dynamically created. The directories
were represented by a eventfs_inode and the files were represented by
a eventfs_file.
In v6.7 the eventfs_file is removed. As all events have the same
directory make up (sched_switch has an "enable", "id", "format", etc
files), the handing of what files are underneath each leaf eventfs
directory is moved back to the tracing subsystem via a callback.
When an event is added to the eventfs, it registers an array of
evenfs_entry's. These hold the names of the files and the callbacks
to call when the file is referenced. The callback gets the name so
that the same callback may be used by multiple files. The callback
then supplies the filesystem_operations structure needed to create
this file.
This has brought the memory footprint of creating multiple eventfs
instances down by 2 megs each!
- User events now has persistent events that are not associated to a
single processes. These are privileged events that hang around even
if no process is attached to them
- Clean up of seq_buf
There's talk about using seq_buf more to replace strscpy() and
friends. But this also requires some minor modifications of seq_buf
to be able to do this
- Expand instance ring buffers individually
Currently if boot up creates an instance, and a trace event is
enabled on that instance, the ring buffer for that instance and the
top level ring buffer are expanded (1.4 MB per CPU). This wastes
memory as this happens when nothing is using the top level instance
- Other minor clean ups and fixes
* tag 'trace-v6.7' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (34 commits)
seq_buf: Export seq_buf_puts()
seq_buf: Export seq_buf_putc()
eventfs: Use simple_recursive_removal() to clean up dentries
eventfs: Remove special processing of dput() of events directory
eventfs: Delete eventfs_inode when the last dentry is freed
eventfs: Hold eventfs_mutex when calling callback functions
eventfs: Save ownership and mode
eventfs: Test for ei->is_freed when accessing ei->dentry
eventfs: Have a free_ei() that just frees the eventfs_inode
eventfs: Remove "is_freed" union with rcu head
eventfs: Fix kerneldoc of eventfs_remove_rec()
tracing: Have the user copy of synthetic event address use correct context
eventfs: Remove extra dget() in eventfs_create_events_dir()
tracing: Have trace_event_file have ref counters
seq_buf: Introduce DECLARE_SEQ_BUF and seq_buf_str()
eventfs: Fix typo in eventfs_inode union comment
eventfs: Fix WARN_ON() in create_file_dentry()
powerpc: Remove initialisation of readpos
tracing/histograms: Simplify last_cmd_set()
seq_buf: fix a misleading comment
...
The abi_test currently uses a long sized test value for enablement
checks. On LE this works fine, however, on BE this results in inaccurate
assert checks due to a bit being used and assuming it's value is the
same on both LE and BE.
Use int type for 32-bit values and long type for 64-bit values to ensure
appropriate behavior on both LE and BE.
Fixes: 60b1af8de8 ("tracing/user_events: Add ABI self-test")
Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Now that we have exposed USER_EVENT_REG_PERSIST events can persist both
via the ABI and in the /sys/kernel/tracing/dynamic_events file.
Ensure both the ABI and DYN cases work by calling both during the parse
tests. Add new flags test that ensures only USER_EVENT_REG_PERSIST is
honored and any other flag is invalid.
Link: https://lkml.kernel.org/r/20230912180704.1284-3-beaub@linux.microsoft.com
Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Fix to unmount tracefs if the self-test mounted it to allow testing.
If tracefs was already mounted, this does nothing.
Suggested-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/all/29fce076-746c-4650-8358-b4e0fa215cf7@sirena.org.uk/
Fixes: a06023a8f7 ("selftests/user_events: Fix failures when user_events is not installed")
Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
When user_events is not installed the self tests currently fail. Now
that these self tests run by default we need to ensure they don't fail
when user_events was not enabled for the kernel being tested.
Add common methods to detect if tracefs and user_events is enabled. If
either is not enabled skip the test. If tracefs is enabled, but is not
mounted, mount tracefs and fail if there were any errors. Fail if not
run as root.
Fixes: 68b4d2d583 ("selftests/user_events: Reenable build")
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Link: https://lore.kernel.org/all/CA+G9fYuugZ0OMeS6HvpSS4nuf_A3s455ecipGBvER0LJHojKZg@mail.gmail.com/
Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
If an event is enabled and a user process unregisters user_events, the
bit is left set. Fix this by always clearing the bit in the user process
if unregister is successful.
Update abi self-test to ensure this occurs properly.
Link: https://lkml.kernel.org/r/20230425225107.8525-3-beaub@linux.microsoft.com
Suggested-by: Doug Cook <dcook@linux.microsoft.com>
Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Add ABI specific self-test to ensure enablements work in various
scenarios such as fork, VM_CLONE, and basic event enable/disable.
Ensure ABI contracts/limits are also being upheld, such as bit limits
and data size limits.
Link: https://lkml.kernel.org/r/20230328235219.203-8-beaub@linux.microsoft.com
Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
