Pull tracing updates from Steven Rostedt:
- Remove a redundant IS_ERR() check
trace_pipe_open() already checks for IS_ERR() and does it again in
the return path. Remove the return check.
- Export seq_buf_putmem_hex() to allow kunit tests against them
To add Kunit tests on seq_buf_putmem_hex(), it needs to be exported.
- Replace strcat() and strcpy() with seq_buf() logic
The code for synthetic events uses a series of strcat() and strcpy()
which can be error prone. Replace them with seq_buf() logic that does
all the necessary bound checking.
- Add a lockdep rcu_is_watching() to trace_##event##_enabled() call
The trace_##event##_enabled() is a static branch that is true if the
"event" is enabled. But this can hide bugs if this logic is in a
location where RCU is disabled and not "watching". It would only
trigger if lockdep is enabled and the event is enabled.
Add a "rcu_is_watching()" warning if lockdep is enabled in that
helper function to trigger regardless if the event is enabled or not.
- Remove the local variable in the trace_printk() macro
For name space integrity, remove the _______STR variable in the
trace_printk() macro for using the sizeof() macro directly.
- Use guard()s for the trace_recursion_record.c file
- Fix typo in a comment of eventfs_callback() kerneldoc
- Use trace_call__##event() in events within trace_##event##_enabled()
A couple of events are called within an if block guarded by
trace_##event##_enabled(). That is a static key that is only enabled
when the event is enabled. The trace_call_##event() calls the
tracepoint code directly without adding a redundant static key for
that check.
- Allow perf to read synthetic events
Currently, perf does not have the ability to enable a synthetic
event. If it does, it will either cause a kernel warning or error
with "No such device". Synthetic events are not much different than
kprobes and perf can handle fine with a few modifications.
- Replace printk(KERN_WARNING ...) with pr_warn()
- Replace krealloc() on an array with krealloc_array()
- Fix README file path name for synthetic events
- Change tracing_map tracing_map_array to use a flexible array
Instead of allocating a separate pointer to hold the pages field of
tracing_map_array, allocate the pages field as a flexible array when
allocating the structure.
- Fold trace_iterator_increment() into trace_find_next_entry_inc()
The function trace_iterator_increment() was only used by
trace_find_next_entry_inc(). It's not big enough to be a helper
function for one user. Fold it into its caller.
- Make field_var_str field a flexible array of hist_elt_data
Instead of allocating a separate pointer for the field_var_str array
of the hist_elt_data structure, allocate it as a flexible array when
allocating the structure.
- Disable KCOV for trace_irqsoff.c
Like trace_preemptirq.c, trace_irqsoff.c has code that will crash
when KCOV is enabled on ARM. The irqsoff tracing can be called on ARM
because the irqsoff tracing code can be run from early interrupt code
and produce coverage unrelated to syscall inputs.
- Fix warning in __unregister_ftrace_function() called by perf
Perf calls unregister_ftrace_function() without checking if its
ftrace_ops has already been unregistered. There's an error path where
on clean up it will unregister the ftrace_ops even if it wasn't
registered and causes a warning.
* tag 'trace-v7.2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
perf/ftrace: Fix WARNING in __unregister_ftrace_function
tracing: Disable KCOV instrumentation for trace_irqsoff.o
tracing: Turn hist_elt_data field_var_str into a flexible array
tracing: Move trace_iterator_increment() into trace_find_next_entry_inc()
tracing: Simplify pages allocation for tracing_map logic
tracing: Fix README path for synthetic_events
tracing: Use krealloc_array() for trace option array growth
tracing/branch: Use pr_warn() instead of printk(KERN_WARNING)
tracing: Allow perf to read synthetic events
HID: Use trace_call__##name() at guarded tracepoint call sites
cpufreq: amd-pstate: Use trace_call__##name() at guarded tracepoint call site
tracefs: Fix typo in a comment of eventfs_callback() kerneldoc
tracing: Switch trace_recursion_record.c code over to use guard()
tracing: Remove local variable for argument detection from trace_printk()
tracepoint: Add lockdep rcu_is_watching() check to trace_##name##_enabled()
tracing: Bound synthetic-field strings with seq_buf
seq_buf: Export seq_buf_putmem_hex() and add KUnit tests
tracing: Remove redundant IS_ERR() check in trace_pipe_open()